does legionella pneumophila cause pneumonia

Legionnaires' disease is a type of pneumonia. It is caused by bacteria called Legionella pneumophila. The bacteria got its name in 1976, when a group of people attending an American Legion convention became infected.

Legionnaires' Disease and Pontiac Fever - Topic Overview

Legionnaires' Disease and Pontiac Fever - Topic Overview Articles On Legionnaires' Disease and Pontiac Fever Topic Overview Related Information References Credits What are Legionnaires' disease and Pontiac fever?

Although it was present before 1976, Legionnaires' disease is being diagnosed more often now as doctors look for Legionella bacteria in people who have pneumonia. You can get Legionnaire's disease at any time of the year, but more cases are usually found in the summer and early fall.

While Legionnaires' disease can be very serious, most cases can be treated successfully. The Legionella pneumophila bacteria can also cause a less severe, flu -like condition known as Pontiac fever.

How do you get these conditions? People usually get Legionnaires' disease or Pontiac fever when they breathe in a mist or vapor (small droplets of water in the air) that contains the bacteria. One example might be from breathing in the steam from a whirlpool spa that has not been properly cleaned and disinfected.

Other sources include fountains and water sources in hotels, cruise ships, nursing homes, and hospitals. These diseases aren't contagious. The bacteria are not spread from one person to another person. You can get the diseases again if you are exposed to the bacteria again. Legionnaires' disease typically affects people older than 45, especially if they smoke or have a long-term lung disease such as asthma.

1 People with a weak immune system are also more likely to get the condition. Despite its being named after infecting a large group of people, Legionnaires' disease usually occurs in single cases, not in large groups at one time (an outbreak). Continue Reading Belowyou might like Pontiac fever usually occurs in otherwise healthy people. What are the symptoms? The most common symptoms of Legionnaires' disease include: Cough. High fever. Chills. Less common symptoms range from muscle aches and headaches to abdominal (belly) pain, shortness of breath, and chest pain.

Legionnaire's disease symptoms usually appear 2 days to 2 weeks after a person is exposed to the bacteria. Symptoms can range from mild to severe. Pontiac fever symptoms include fever and muscle aches. Symptoms usually appear 1 to 2 days after a person is exposed to the bacteria. They usually go away without treatment in a few days.1 2 View All Next In Legionnaires' Disease and Pontiac Fever Related Information

Most of the cases have been in Vila Franca de Xira, a town about 25km (16 miles) north-east of Lisbon. The World Health Organisation (WHO) says the outbreak constitutes a ""major public health emergency"". Legionnaires' disease is a pneumonia-like lung infection caused by the legionella bacteria. The source of the outbreak is yet to be found. Local media report that the bacteria has been discovered in a cooling tower in Vila Franca de Xira, but it is thought there may be other sources.

Portugal Legionnaires' disease outbreak kills five

"Portugal Legionnaires' disease outbreak kills five11 November 2014Share Science Photo Library Symptoms of Legionnaires' disease include high fever, muscle pain and persistent cough An outbreak of Legionnaires' disease has killed five people and infected more than 230 others in Portugal, the authorities there say.

'Unusual and unexpected'Thirty-eight people are being treated in intensive care, officials say. Facilities in many of the capital's hospitals were stretched because of the outbreak, Portuguese media reported.

""This is the biggest Legionnaire's disease (outbreak) in Portugal and is considered a major public health emergency,"" WHO spokesman Christian Lindmeier said. The outbreak was ""unusual and unexpected"", Mr Lindmeier added. Portuguese President Anibal Cavaco Silva has expressed his condolences to the victims.

He said the public should trust the health authorities to deal with the outbreak. Legionnaires' disease is caught by inhaling infected water. The bacteria can grow in cooling towers, air conditioning and other artificial water supply systems.

It mostly affects people aged over 50, with those already in poor health most at risk. It was first identified in the US in the 1970s following an outbreak at a hotel hosting a veteran organisation known as the American Legion. "

ia. Atypical pneumonia is caused by bacteria such as Legionella pneumophila, Mycoplasma pneumoniae, and Chlamydophila pneumoniae. Other bacteria that can cause pneumonia include Staphylococcus aureus, Moraxella catarrhalis, Streptococcus pyogenes, Neisseria meningitidis, Klebsiellapneumoniae, and Haemophilus influenzae.

What Causes Pneumonia?

What Causes Pneumonia? Many different germs and other things can cause pneumonia. There are five main causes of pneumonia: Bacteria Viruses Mycoplasma Other infectious agents, such as fungi—including pneumocystis Various chemicals If you have viral pneumonia, you also are at risk of getting bacterial pneumonia. Types of Pneumonia Bacterial Pneumonia Bacterial pneumonia can attack anyone, at any age. It can occur on its own or develop after you've had a cold or the flu.

People at greatest risk for bacterial pneumonia include people recovering from surgery, people with respiratory diseases or viral infections and people who have weakened immune systems. If your body's defenses are weakened—by illness, old age, malnutrition, or impaired immunity—the pneumonia bacteria, which can live in healthy throats, can multiply and work their way into the lungs.

The infection can quickly spread through the bloodstream and invade the entire body. Dozens of different types of bacteria can cause pneumonia: The most common type of bacterial pneumonia is pneumococcal pneumonia, affecting over 900,000 Americans every year. Children under the age of 5 and adults over 65 have a recommendation to receive a pneumococcal vaccination to help protect them against the Streptococcus (pneumococcus) bacter

Viral Pneumonia Most respiratory viruses attack the upper respiratory tract, but some cause pneumonia, especially in children. Most of these pneumonias are not serious and last a short time but others can be severe. Viral pneumonia caused by the influenza virus may be severe and sometimes fatal.

The virus invades the lungs and multiplies; however, there are almost no physical signs of lung tissue becoming filled with fluid. This pneumonia is most serious in people who have pre-existing heart or lung disease and pregnant women.

In extreme cases, the patient has a desperate need for air and extreme breathlessness. Viral pneumonias may be complicated by an invasion of bacteria, with all the typical symptoms of bacterial pneumonia. Mycoplasma Pneumonia Mycoplasma are the smallest free-living agents of disease. They are not classified as to whether they are bacteria or viruses, but they have traits of both. Mycoplasma usually cause a mild form of pneumonia but may be severe with certain symptoms lasting a long time.

They affect all age groups but occur most often in older children and young adults. Other Types of Pneumonia Tuberculosis (TB) rarely can cause pneumonia (tuberculosis pneumonia).

It is a very serious lung infection and extremely dangerous unless treated early. Pneumocystis jiroveci pneumonia, which is caused by a fungus, is sometimes seen in people whose immune system is impaired (due to HIV infection or certain medications that suppress the immune system).

Various special pneumonias are caused by the inhalation of food, liquid, gases or dust. Learn more about diagnosing and treating pneumonia »News & Events News: Individual Mandate Repeal Will Deprive More Americans of Affordable Health Care, say 15 Patient and Consumer Groups News: This Holiday, Protect Health of Loved Ones and Yourself with Flu Vaccination, says American Lung Association Blog: I Hope One Person Quits Smoking Because of This Blog Blog: Protecting My Child from Nicotine Addiction Approved by Scientific and Medical Editorial Review Panel. Last reviewed March 30, 2018.

Watch out: attempts to avoid scalding burn hazards by lowering the maintenance temperature of the water heater itself convey a new hazard: at lower temperatures in water heaters there is a risk of formation of Legionella sp. bacteria.

Hot Water Temperature Laws: Anti-Scald Regulations

"Hot Water Temperature Laws: Anti-Scald Regulations HOT WATER ANTI-SCALD REGULATIONS - CONTENTS: Tables of laws regulating hot water temperatures to avoid scalding burns & to prevent Legionnaires bacteria formation in water heater tanks POST a QUESTION or READ FAQs about the required limits of hot water temperatures in buildings REFERENCESInspect APedia tolerates no conflicts of interest.

We have no relationship with advertisers, products, or services discussed at this website. Hot water temperature code, laws & regulations listed by authority, country, state or province. This article gives the allowable limits set on hot water temperatures for hot water used in buildings and compares regulations in various countries.

For the U. S. we also include code citations and temperature limits by individual U. S. state. What is the maximum hot water temperature that shall be delivered at the point of use? What hot water temperatures shall be maintained inside the water heater itself? Comparison of water temperature laws by country and by U. S. state.

BODY OVERHEATING HAZARDS are discussed here. Most other countries provide a single hot water temperature limit for water provided at plumbing fixtures and a separate hot water maintenance level for temperatures within the water heater itself.

We also provide a MASTER INDEX to this topic, or you can try the page top or bottom SEARCH BOX as a quick way to find information you need.

Green links show where you are. © Copyright 2017 Inspect Apedia.com, All Rights Reserved. Hot Water Anti-Scald Limits: Laws & Regulations Article Contents HOT WATER ANTI-SCALD REGULATIONSANTI-SCALD TEMPERATURES & REGULATIONSCOUNTRIES with ANTI-SCALD REGULATIONSAUSTRALIA Plumbing & Anti-Scald Codes CANADA Plumbing & Anti-Scald Codes FRANCE Plumbing & Anti-Scald Codes GERMANY Plumbing & Anti-Scald Codes HONG KONG Plumbing & Hot Water Anti Scald Laws INDONESIA Plumbing & Hot Water Anti-Scald Codes JAPAN Plumbing & Hot Water Scald Protection Regulations MEXICO Plumbing & Hot Water Anti Scald Regulations NETHERLANDS Plumbing & Anti-Scald Codes NEW ZEALAND Plumbing & Anti-Scald Codes UNITED KINGDOM Plumbing & Anti-Scald Codes UNITED STATESAK - AL - AR - AZ - CA - CO - CT - DC - DE - FL - GA - HI - IA - ID - IL - IN - KS - KY - LA - MA - MD - ME - MI - MN - MO - MS - MT - NC - ND - NE - NH - NM - NV - NJ - NY - OH - OK - OR - PA - RI - SC - SD - TN - TX - UT - VA - VT - WA - WI - WV - WYBODY OVERHEATING HAZARDSLegionella BACTERIA in WATER HEATERSAnti-Scald Hot Water Regulations & Temperatures Maximum Temperature Authority96-102 deg F Typical comfortable temperature for washing and bathing [15]105 deg FUFAS (Uniform Federal Accessibility Standard), 105°F max by automatically controlled tempered water flow, 1988 edition, and ADA (American with Disabilities Act).

Arizona Prison Construction 401T-PPS provided below110 deg F U. S. Dept. Health & Human Services, Guidelines for Construction & Equipment of Hospital & Medical Facilities, HRP - 0905974, JUL84, avail.

from NTIS, p48: “Hot water for showers and bathing facilities shall be at an appropriate temperature for comfortable use but shall not exceed 49°C (120°F) (see Table 4).” Table 4 gives temp in °F as 100 clinical (include shower), 120 dietary, 160 laundry.100-120 deg F ACA (American Correctional Association), 100 to 120°F max automatically controlled for prison showers, “Adult Correctional Institutions, 3rd Ed, 1990.”120 deg F 1993 International Plumbing Code 97/00 - adopted by 18 U. S. states120 deg F 1994 Uniform Plumbing Code (IAPMO/ICBO) 97/00 - 13 U. S. states120 deg F 1996 International Plumbing Code SBCCI 97/00 - 10 U. S. states120 deg F 1996 National Standard Plumbing Code PHCC 96/98 - 5 U. S. states No state code committed in 1998 - 3 U. S. states Reference A40 1993 Safety Standard for Plumbing (ANSI/MCA/PHCC/IAPMO) 93/Notes: U. S. Federal Regulations on Hot Water Scald Protection According to Domestic Hot Water Scald Burn Lawsuits ... D. Bynum et als., there are three different federal standards for limits on safe hot water temperatures1.

110 deg F Max: U. S. Dept. Health & Human Services, Guidelines for Construction & Equipment of Hospital & Medical Facilities, HRP - 0905974, JUL84, avail.

from NTIS, p48: “Hot water for showers and bathing facilities shall be at an appropriate temperature for comfortable use but shall not exceed 49°C (120°F) (see Table 4).” Table 4 gives temp in °F as 100 clinical (include shower), 120 dietary, 160 laundry.2.

105°F Max UFAS (Uniform Federal Accessibility Standard), 105°F max by automatically controlled tempered water flow, 1988 edition, and ADA (American with Disabilities Act).3. 100–120°F ACA (American Correctional Association), 100 to 120°F max automatically controlled for prison showers, ""Adult Correctional Institutrions, 3rd Ed. 1990""Additional anti-scald protection regulation details: See TABLE of ANTI-SCALD REGULATIONS for country by country and within the U. S. state by state codes, regulations or laws regulating hot water temperatures at the water heater tank, cylinder or geyser and at the point of use bath, shower, sink, etc.

Table of Countries, States or Provinces Adopting Specific Anti-Scald Laws & Regulations Also use your browser's on-page search function [ Ctrl-F ] to search for a country or U. S. state in the data below.

AUSTRALIA Plumbing & Anti-Scald Codes CANADA Plumbing & Anti-Scald Codes FRANCE Plumbing & Anti-Scald Codes GERMANY Plumbing & Anti-Scald Codes HONG KONG Plumbing & Hot Water Anti Scald Laws INDONESIA Plumbing & Hot Water Anti-Scald Codes JAPAN Plumbing & Hot Water Scald Protection Regulations MEXICO Plumbing & Hot Water Anti Scald Regulations NETHERLANDS Plumbing & Anti-Scald Codes NEW ZEALAND Plumbing & Anti-Scald Codes UNITED KINGDOM Plumbing & Anti-Scald Codes UNITED STATES - AK AL AR AZ CA CO CT DC DE FL GA HI IA ID IL IN KS KY LA MA MD ME MI MN MO MS MT NCND NE NH NM NV NJ NY OH OK OR PA RI SC SD TN TX UT VA VT WA WI WV WYTable of States or Provinces Adopting Anti-Scald Plumbing Codes Hot Sater Scald Protection Code Citations for Australia, Britain, Canada, France, New Zealand, U. K., United States, Other Areas United States Anti-Scald Codes & Regulations States or Provinces Adopted Plumbing Code Adopted Date or Edition18 States including Delaware Illinois Indiana Kansas Maine Massachussetts Michigan Missouri New Hampshire New York Ohio Oklahoma Pennsylvania Utah Vermont Virginia West Virginia International Plumbing Code 1993, Max 120°F.

New York City: Multiple Dwelling Law § 75; Multiple Residence Law§ 170; NYC Admin. Code § 27-2031Hot Water Landlords must provide all tenants of multiple dwellings with both hot and cold water. Hot water must register at or above a constant temperature of 120 degrees at the tap. If a tub or shower is equipped with an anti-scald valve that prevents the hot water temperature from exceeding 120 degrees, the minimum hot water temperature for that tub or shower is 110 degrees.

New York City Housing Maintenance Code and NY State Multiple Dwelling Law require building owners to provide heat nd hot water to all tenants, providing hot water 365 days a year at a constant minimum [sic] temperature of 120°F1997 & 200013 States Alaska Arizona California Colorado Hawaii Idaho Iowa Montana Nevada New Mexico Oregon Washington Wyoming Uniform Plumbing Code (IAPMO / ICBO) 1994, Max 120°F.

Arizona: DEPARTMENT ORDER 401-PRISON CONSTRUCTION CHAPTER: 401T-PPS ADC Administrative Services, Physical Plant Standards Rev. 02/23/12 [PDF], 105°F adjustable from 100°F to 120°F for sinks, lavatories and showers. Arizona: Maricopa County, Hot Water Supply Code [PDF] Temperatures above 120°F are considered a scald hazard. California: anti-scald devices are required by the CA 2007 Plumbing Code, Chapter 4, section 418.0 Shower and Tub Combination Control Valves1997 / 200010 States Alabama Arkansas Florida Georgia Louisiana North Carolina Mississippi South Carolina Tennessee Texas SBCCI or International Plumbing Code (1996), Max 120°F.

1997 / 20005 States Connecticut Maryland New Jersey North Dakota South Dakota National Standard Plumbing Code (PHCC) (1996), Max 120°F.

1996/19983 States Kentucky Minnesota Wisconsin State Code Not Yet Committed Nebraska A40 1993 Safety Standard for Plumbing (ANSI/MCA/PHCC/IAPMO) 1993States or districts for which hot water temperature limits have not been identified in the U. S. District of Columbia Rhode Island Vermont [research pending]Notes: Australia hot water anti-scald Codes & Regulations Australia's National Plumbing Code AS3500 requires that hot water is stored at a temperature above 60C (140F) and that hot water delivery temperature (at the plumbing fixture) shall not be above 50°C (122°F). The higher storage considers the effort to reduce the risk of Legionella bacteria formation in the system. Canadian Anti-Scald Codes & Regulations Ontario, Canada Effective Sept. 1, 2004, all water heaters replaced or installed are required to have an “anti-scald” device installed.

A change was made to the Ontario Building Code making anti-scald devices mandatory. [14] 2004Notes: proposed change to Canadian plumbing code will specify that water temperature shall not excee 120°F (49°C) and that water heater temperatures shall not be set so low as to permit growth of Legionella bacteria. France: hot water and anti-scald Codes & Regulations Proposed regulation: hot water stored at at least 60C (140F) and delivered at or below 50C (120F).

See the French National Standards Organization AFNOR (website www.afnor.fr) and see the French National Testing Authority (CSTB) (www.cstb.fr). Netherlands hot water laws References: www.kiwa.ni provides information on steps to prevent growth of Legionella bacteria in hot water systems. GERMANY Plumbing & Anti-Scald Codes [pending]References:""Federal German Laws and Regulations"", http://www.berlin-klimaschutz.de/en/climate-protection-berlin/federal-german-laws-and-regulations""German Landlord-Tenant Law"", Kaiserslautern Legal Services Center Legal Assistance Information, retrieved 3/21/2014, original source: http://www.ramstein.af.mil/shared/media/document/AFD-130109-017.pdf HONG KONG Plumbing & Hot Water Anti Scald Laws [pending]INDONESIA Plumbing & Hot Water Anti-Scald Codes [pending]JAPAN Plumbing & Hot Water Scald Protection Regulations [pending]MEXICO Plumbing & Hot Water Anti Scald Regulations [pending]New Zealand Anti-Scald & Hot Water Cylinder Storage Codes & Regulations Hot water tempeature at the tap (bath sink, tub, shower) must be 55°C or less.

New Zealand building code requires that the maximum hot water temperature at the tap shall be 45°C or less for childcare centres, schools, homes for the elderly and similar facilities. Typical sources give the ideal hot water temperature setting for hot water cylinders in New Zealand as 60°C in order to keep water hot enough to kill bacteria inside the heater.

Higher temperature settings in the cylinder are not necessary and increase water heating costs. Watch out: 60°C is not the temperature of water that should be delivered at the tap or plumbing fixture - that temperature will cause scalding burns. See NZS 4617:1989 Tempering (3-port mixing) valves, Date modified: 28/11/1989 regarding Tempering (3-port mixing) valves Requirements for tempering valves for storage hot water systems particularly in domestic situations where hot water poses a hazard.

These valves are intended to prevent scalding in locations such as homes, schools, motels and residential premises, where ideally all hot water outlets should be sourced from a tempering valve. Provides for valves suitable for water inlet temperatures of up to 100 degrees C. Notes:""Hot water cylinder temprature"", Econation, website: econation.com.nz, retrieved 3/21/2014, original source: http://www.econation.co.nz/hot-water-temperature.html#.

Uyx6SV6MFpg The site author does not provide direct contact information. United Kingdom UK hot water anti-scald Codes & Regulations England and Wales, from 1 April 2010, revisions to Part G of the Building Regulations (Hot water supply and systems) include the requirement that baths, subject to building regulations, are fitted with a protective device (i.e. a thermostatic mixing valve) to limit the temperature of hot water. Similar regulations have been in force in Scotland since 2006.

[2]As of 1st May 2006 a new Scottish Building Regulation will require that all bath water in a domestic property must be controlled to a maximum of 48°C. Hot Water Temperature from Sanitary Fittings Where hot water is provided from storage, building regulations require a storage temperature of 60°C and a circulating temperature of no less than 55°C to prevent the development of Legionella or similar pathogens.

Where water is supplied at high temperature from any source, there is a danger of scalding to building users. Risk of severe injury increases proportionally with the increase in temperature and with the extent of contact.

Fittings Used for Personal Hygiene To prevent scalding, the temperature of hot water discharged from, or to, any bath or bidet should not exceed 48o C. Where hot and cold water are supplied to a fitting, this may be achieved by use of a thermostatic mixing valve (TMV) or fitting.

Such valves or fittings should comply with BS EN 1111 or BS EN 1287. Guidance on the installation, use and maintenance of thermostatic mixing valves and fittings can be found in BRE information Paper IP 14/03 or from the Thermostatic Mixing Valve Association (TMVA) - www.tmva.org.uk Additional reglations may yet be pending, under study by the Building Research Establishment (BRE, www.bre.co.uk) for the Department of Transport, Local Government and REgions (DTLR).

Proposed hot water storage temperature is 6°C (140°F)Reference: ""Recommended Code of Practice for Safe Water Temperatures"", Thermostatic Mixing Valve Manufacturers Association (TMVA), TMVA, Westminster Tower, 3 Albert Embankment, London SE1 7SL Tel: 020 7793 3008 Fax: 020 7793 9730 e-mail: tmva@beama.org.uk www.tmva.org.uk, retrieved 3/21/2014, original source: www.beama.org.uk Burn, Thermal Shock or Body Overheating Hazards in Hot Tubs, Plunge Pools & Spas The World Health Organization (WHO) has pointed out a different set of hot water or thermal shock water temperature hazards as well as cold water thermal shock hazards.

Quoting: Body overheating can occur in natural spas and hot tubs, where water temperatures may be above 40 °C.

High temperatures can cause drowsiness, which may lead to unconsciousness (especially when associated with alcohol consumption), resulting in drowning (Press, 1991; see Section 2.1). In addition, high temperatures can lead to heat stroke and death (CPSC, undated). The CPSC has received reports of several deaths from extremely hot water (approximately 43 °C) in hot tubs (CPSC, undated).

It is recommended that water temperatures in hot tubs be kept below 40 °C. Plunge pools present similar problems, but at the other temperature extreme. These small, deep pools generally contain water at a temperature of 8–10 °C and in conjunction with saunas or steam baths.

Adverse health outcomes that may result from the intense and sudden changes in temperature associated with the use of these pools include immediate impaired coordination, loss of control of breathing and, after some time when the core body temperature has fallen, slowed heart beat, hypothermia, muscle cramps and loss of consciousness.

In general, exposure to temperature extremes should be avoided by pregnant women, users with medical problems and young children, and prolonged immersion in hot tubs or other pools with high or low temperatures should be avoided or approached with caution. - WHO (2014)References:""Guidelines for Safe Recreational Water Environments, Vol. 2, Swimming Pools & Similar Environments"", World Health Organization, WHO, retrieved 3/21/2014.

Original source: http://www.who.int/water_sanitation_health/bathing/srwe2full.pdf Reader Question: is it legal to have showers with no hot water temperature adjustment? I want to know if it is legal to have showers with no way to adjust the temperature of the water. I hope you are unbiased.

[At our facilities] our showers only have hot water coming out. I have RSD and my legs are extremely sensitive to hot and cold, and I can't even stand the mist if I stand back from the shower spray.

Is there any law that says you have to be able to lower temps of hot water? I would think by now that there could be built in temp adjustments so there would be no handles to break.

Thank you for any help you can provide. Reply: Thank you for the question , it helps us realize where we need to work on making our text more clear or more complete.

We must emphasize that an onsite inspection by a competent investigator will certainly find conditions and clues that may not yet have been observed nor reported, so any advice by remote email is of necessity incomplete and a bit theoretical. For example, if the water coming out of showers is hotter than recommended by various safety standards that would be improper. I'm not sure I can say what's legal since rules that pertain to various types of public shower facilities management may be different, but it seems reasonable to me that you could expect basic safety and health standards to apply.

That apology made, here are some comments: There are several types of automatic mixing valves that are designed to be installed on hot water supplies or right at bath fixtures (like a shower) that can be set to a particular temperature - as a safety device to avoid scalding.

See the article above for a table of temperatures that suggest what hot water temperature is considered ""too hot"" or at risk of scalding someone.

In my OPINION, where manual adjustments to shower temperature are not provided, an automatic anti-scalding device should be in place and should be set to a safe temperature. The highest temperature permissible that will reliably avoid scalding is 100 deg F. So start by making some actual temperature measurements, documenting the temp range and the temp variation (if it does) at different times of the day.

Regarding your question of ""is it legal"" to have no shower temperature control, see the various codes and laws summarized in our table above - Hot Water Anti-Scald Limits: Laws & Regulations Plumbing & Safety Standards for Hot Water There are plumbing and safety standards that may apply to shower hot water temperature regulation, such as ADA (Americans with Disabilities Act) that might require provision of lower temperature for people with special needs.

If you'll excuse a personal remark, I imagine that the judge sentencing you to time did not include scalding or hot water burning as part of his/her decision. However from what I've read, ADA addresses controls that can be operated by people with disabilities, not temperature directly.

ANSI/ASME A112.1016-2011/ASSE 1016-2011/CSA B125.16-11 Performance Requirements for Automatic Compensating Valves for Individual Showers and Tub/Shower Combinations addresses temperature control requirements [12]Arizona: DEPARTMENT ORDER 401-PRISON CONSTRUCTION CHAPTER: 401T-PPS ADC Administrative Services, Physical Plant Standards Rev.

02/23/12 [PDF], 105°F adjustable from 100°F to 120°F for sinks, lavatories and showers. Arizona: Maricopa County, Hot Water Supply Code [PDF] Temperatures above 120°F are considered a scald hazard. California: anti-scald devices are required by the CA 2007 Plumbing Code, Chapter 4, section 418.0 Shower and Tub Combination Control Valves In the U. S. & Canada several companies, including Bradly Corporation, provide bath temperature controls that comply with standards and are ""tamper resistant"" that might meet the needs of your institution where there is a reason to not provide individual shower temperature controls. [11]Jason Renner in Hospitality Construction magazine described current ADA requirements that allows a temperature of 120F. [3]Uniform Plumbing Code (IAPMO / ICBO) 1994, Max 120°F. For details begin at HOT WATER ANTI-SCALD REGULATIONSPlease keep me posted on how things progress, What we both learn may help me help someone else. As for your hope that our reply would be unbiased, Inspect APedia is an independent publisher of building, environmental, and forensic inspection, diagnosis, and repair information for the public - we have no business nor financial connection with any manufacturer or service provider discussed at our website. We are dedicated to making our information as accurate, complete, useful, and unbiased as possible: we very much welcome critique, questions, or content suggestions for our web articles. Legionella Bacteria & Legionnaires' disease hazards in hot water cylinders, geyers, water heater tanks

Watch out: attempts to avoid scalding burn hazards by lowering the maintenance temperature of the water heater itself convey a new hazard: at lower temperatures in water heaters there is a risk of formation of Legionella sp. bacteria.

Regarding prevention of Legionella, cf Veterans Administration source in citations at the end of this article. Water temperatures exceeding 124 degrees Fahrenheit (°F) (51 degrees Celsius (°C)) are necessary to prevent the rapid growth of Legionella , the causative agent of Legionella pneumonia (traditionally known as Legionnaires’ disease) in hot water systems.

Details are at Legionella BACTERIA in WATER HEATERS.... Continue reading at TABLE OF SCALDING TEMPERATURES & TIMES or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.

Or see HOT WATER ANTI-SCALD REGULATION FAQs questions & answers posted originally at this page Or see these Anti-Scald & Hot Water Safety Articles ANTI SCALD VALVES / MIXING VALVES - home ANTI_SCALD VALVES & HOT WATER QUANTITYANTI-SCALD VALVE INSPECTIONANTI SCALD VALVE PROTECTION, Best Practices ANTI SCALD VALVE at TANKLESS COILHOT WATER ANTI-SCALD REGULATIONSHOT WATER ANTI-SCALD REGULATION FAQs MANUAL ANTI-SCALD TEMPERING VALVESPOINT of USE BUILT-IN FIXTURE ANTI-SCALD VALVESTABLE OF SCALDING TEMPERATURES & TIMESWATER HEATER SAFETYLegionella BACTERIA in WATER HEATERSSuggested citation for this web page HOT WATER ANTI-SCALD REGULATIONS at Inspect A pedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

INDEX to RELATED ARTICLES: ARTICLE INDEX to ARTICLE INDEX to WATER HEATERSOr use the SEARCH BOX found below to Ask a Question or Search Inspect Apedia Share this article...

Frequently Asked Questions (FAQs)Click to Show or Hide FAQs Ask a Question or Search Inspect Apedia Use the ""Click to Show or Hide FAQs"" link just above to see recently-posted questions, comments, replies, try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly. Search the Inspect Apedia website Comment Box is loading comments... Technical Reviewers & References Click to Show or Hide Citations & References Publisher's Google+ Page by Daniel Friedman "

s A form of pneumonia that is caused by the bacterium Legionella pneumophilia is called Legionnaires' disease oradenocarcinoma of the lung also known as lung cancer, it arises from the soft tissues of the lung. The two major forms are small-cell lung cancer and non-small-cell lung cancer.

Medical Terminology Ch. 9

"173 terms warrel66Medical Terminology Ch. 9Learn Flashcards Write Spell Test Match Gravity Advertisement Upgrade to remove ads Sortrespiratory system brings oxygen into the bloodstream, through which it is transported to all body cells.

In addition to bringing oxygen into the bloodstream, it also removes the waste products, carbon dioxide, from the blood and channels it outside.pulmonologist physician with specialized training in lung disease; also called a pulmonary specialist.otolaryngologist (ENT) physician who specializes in disease of the ears, nose, and throat.oncologist physician who specializes in cancer.respiratory therapist assistant to a physician who has received special training in the operation of equipment used to diagnose or treat breathing problems.acapnia The absence of carbon dioxide.anoxia The absence of oxygen.

an/oxiaaphonia The absence of voice. a/phoniaapnea The inability to breathe or inhale. a/pneabradypnea Abnormal slowing of the breathing rhythm. brady/pneabronchospasm Narrowing of the airway caused by the contraction of smooth muscles in the walls of the tiny tubes known as bronchioles within the lung.

A common sign of asthma. bronch/o/spasm Cheyne-Stokes respiration -chain stohks * ress pih RAY shun- A repeated pattern of distressed breathing marked by a gradual increase in deep breathing, followed by shallow breathing, and apnea. A sign of CHF or nervous dysfunction.dysphonia -diss FOH nee ah- The symptom of a hoarse voice. dys/phonia.dyspnea -DISP nee ah- The symptom of difficult breathing.

dys/pneaepistaxsis -ep ih STAK siss- Clinical term for a nosebleed. It is also called a rhinorrhagia epi/staxis- dripping upon rhin/o/rrhagia- condition of profusely bleeding nose.hemoptysis -hee MOP tih siss- The symptom of coughing up or spitting out blood.

hem/o/ptysis- to cough up bloodhemothorax The pooling of blood within the pleural cavity surrounding the lungs. hem/o/thorax- chesst bloodeupnea A normal breathing pattern. eu/pnea- good breathhypercapnia Excessive levels of carbon dioxide in the blood.hypocapnia Deficient levels of carbon dioxide in the blood.hyperpnea The sign of abnormal deep breathing or a high rate of breathing. hyper/pneahyperventilation The sign of abnormally rapid breathing. hyper/ventilationhypopnea The sign of abnormally shallow breathing.

hypo/pneahypoventilation A reduced breathing rhythm that fails to meet the body's gas exchange demands.hypoxemia -high pahk SEE mee ah- Abnormally low levels of oxygen in the blood.

hyp/ox/emiahypoxia Abnormally low levels of oxygen throughout the body.laryngospasm The closure of the glottis, the opening into the larynx, due to muscular contractions of the throat. laryng/o/spasmorthopnea Is the inability to breathe when lying down, which becomes relieved when sitting upright.

orth/o/pneaparoxysm -PAIR ahk sizm- A sudden, sharp reocurrence of syptoms or a convulsion. Greek meaning ""to sharpen or to irrritate""sputum An expectorated (coughed out from the lungs) matter.tachypnea rapid breathing tachy/pneathoracalgia -thor ah KAL jee ah- The symptom of pain in the chest region. An alternate term of the same meaning is thoracodynia. thorac/algiaasphyxia -ass FIK see ah- The absence of respiratory ventilation, or suffocation.

a/sphyx/ia- condition of without a pulseasthma A condition of the lung that is characterized by widespread narrowing of the bronchioles and formation of mucous plugs.

It produces the symptoms of wheezing, SOB, and chest pain. When asthma is complicated with bronchitis, it is reffered to as asthmatic bronchitis.atelectasis -at eh LEK tah siss- A condition in which trauma or disease causes the alveoli to collapse and prevents air from entering, commonly called a collapsed lung. atel/ectasis- incomplete expansion or dilationbronchiectasis -BRONG kee EK tah siss- Abnormal dilation of the bronchi, most commonly seen in infants and young children and relatively rare among adults.

bronchi/ectasisbronchitis Inflammation of the bronchi. bronch/itisbronchogenic carcinoma An aggressive form of cancer arising from cells within the bronchi. bronch/o/genic carcin/omabronchopneumonia -BRONG koh noo MOH nee ah- An acute inflammartory disease involving the bronchioles and the alveoli.

Usually caused by bacterial infection that involves the bronchi and the soft tissue of the lungs, causing the alveoli to fill with fluid that leads to loss of air space.

It is also reffered to as lobar pneumonia. bronch/o/pneumon/iachronic obstructive pulmonary disease (COPD) general term for several different forms of pulmonary obstruction, including chronic bronchitis, bronchospasm, cystic fibrosis, and emphysema.coccidioidomycosis -kok SIDD ee oy doh mye KOH siss- A fungal infection of the upper respiratory tract, which often spreads to the lungs and other organs. Also called valley fever due to its place of origin in California. coccidioid/o/myc/osiscoryza -koh RYE zah- An infection of the upper respiratory tract that causes local inflammation and a runny nose; also called rhinitis.

rhin/itis- nose inflammationcroup Viral infectious disease that produces a characteristic barklike, hoarse cough due to acute obstruction of the larynx, also known by the clinical term laryngotracheobronchitis or, LTB.

laryng/o/trache/obronch/itiscystic fibrosis (CF) -SISS tik * fye BROH siss- A hereditary disease characterized by excess mucus production in the respiratory tract, digestive tract, and elsewhere. cyst/ic fibr/osis- condition of fibrous cysts (bladders)emphysema A chronic lung disease characterized by dyspnea, chronic cough, barrel chest, and chronic hypoxemia and hypercapnia. Symptoms arise when the alveolar walls deteriorate, resulting in a loss of elasticity that causes an inability to breathe.epiglottitis -ep ih glah TYE tiss- Inflammation of the epiglottis. Usually a bacterial infection that spreads from the throat to the epiglottis. epi/glott/itislaryngitis -LAIR in JYE tiss- Inflammation of the larynx. laryng/itislegionellosi

s A form of pneumonia that is caused by the bacterium Legionella pneumophilia is called Legionnaires' disease oradenocarcinoma of the lung also known as lung cancer, it arises from the soft tissues of the lung. The two major forms are small-cell lung cancer and non-small-cell lung cancer.

nasopharyngitis -nay zoh FAIR in JYE tiss- Inflammation of the nose and pharynx. nas/o/pharyng/itispertussis -per TUSS siss- An acute infectious disease characterized by inflammation of the larnyx, trachea, and bronchi that produces spasmodic coughing. Commonly known as whooping cough, it can become fatal due to the exhaustive coughing and obstructed airflow.pharyngitis Inflammation of the pharynx.

Commonly called ""sore throat."" pharyng/itispleural effusion Effusion refers to leakage of fluid. When fluid leaks into the pleural cavity. pleur/alpleuitis -ploo RYE tiss- Inflammation of the pleural membrane. It is also called pleurisy. Inflammation of the pleural membranes and the lungs is called pleuropneumonia.pneumoconiosis -noo moh KOH nee OH siss- Inflammation of the lung, when caused by the chronic inhalation of fine particles.

Asbestosis, and silicosis are the most common forms. pneum/o/coni/osis-- condition of dusty lungpneumonia Inflammation of soft lung tissue that results in the formation of an exudate (fluid) within alveoli. pneumon/iapneumonitis -NOO moh NYE tiss- An inflammatory condition of the lungs that is independent of a particular cause.

It is usually associated with pulmonary edema. pneumon/itispneumothorax -NOO moh THOH raks- The abnormal presence of air or gas within the pleural cavity.

It is caused by a penetrating injury to the chest or severe coughing and leads to atelectasis. pneum/o/thoraxpulmonary edema The accumulation of fluid within the tiny air sacs within the lungs (the alveoli) is a response to infection or injury.pulmonary embolism (PE) A blood clot that moves along with the bloodstream is called an embolus. A blockage in the pulmonary circulation by a blood clot. pulmon/ary embol/ismpyothorax -pye oh THOH raks- The presence of pus in the plural cavity.

It is also known as empyema. py/o/thoraxrespiratory distress syndrome (RDS) A respiratory disease that is characterized by atelectasis. It occurs in two forms, one is neonatal respiratory distress syndrome (NRDS), or hyaline membrane disease (HMD).

It is caused by insufficient surfactant. The second is adult (or acute) respiratory distress syndrome (ARDS), caused by severe lung infectionss or injury.rhinitis -rye NYE tiss- Inflammation of the mucous membrane lining the nasal cavity. rhin/itissevere acute respiratory syndrome (SARS) A severe, rapid-onset viral infection resulting in respiratory distress that includes acute lung inflammation, alveolar damage and atelectasis.

Usually caused by the influenza virus and become fatal.sinusitis An inflammation of the mucous membranes affecting the nasal cavity and also the paranasal sinuses in the skull. sinus/itistonsillitis Inflammation of one or more tonsils. tonsill/itistracheitis -tray kee EYE tiss- Inflammation of the trachea. trache/itistracheostenosis -TRAY kee oh steh NOH siss- Inflammation that leads to a narrowing of the trachea.

trache/o/sten/osistuberculosis (TB) Infection of the lungs by the bacterium Mycobacterium tuberculosis. The little swelling, or tubercle, is a colony of bacteria within the soft tissue of the lung that forms a hardened barrier, preventing white blood cells from entering and destroying the bacteria.

In time, the bacteria colonies multiply throughout the lung until necrosis and inflammation overwhelm the function of gas exchange. tubercul/osis- condition of a little swelling.upper respiratory infection (URI) A generalized infection of the upper respiratory tract (nasal cavity, pharynx, and larynx.

)acid-fast bacilli smear (AFB) A clinical test performed on sputum to identify the presence of bacteria that react to acidadenoid A pharyngeal tonsil. aden/oid- resembling a gland.adenoidectomy The surgical removal of a chronically inflammed adenoid to avoid complications.antihistamine A therapeutic drug that inhibits the effects of histamines.arterial blood gases (ABGs) A clinical test on arterial blood to identify the levels of oxygen and carbon dioxide.aspiration The removal of fluid, air, or foreign bodies with suction.

Latin word meaning ""to breathe on. ""auscultation -aw skull TAY shun- A procedure that involves listening to sounds within the body as part of a physical examination., often with the aid of a stethoscope.

Latin word meaning ""to listen to. ""bronchodilation A procedure that uses a bronchdilating agent in an inhaler to reduce bronchial constriction in an effort to open the airway and improve breathing.

bronch/o/dilat/ion-process of widening the airwaysbronchography The x-ray imaging of the bronchi. This procedure produces an X-ray image of the bronchi called a bronchogram.chest CT scan Diagnostic imaging of the chest by a computed tomography by providing a 3-D image of the thoracic cavity.chest X-ray (CXR) An X-ray image of the thoracic cavity that is used to diagnose lung conditions.

Also called chest radiograph.ears, nose, and throat specialist (ENT) A physician specializing in the treatment of upper respiratory tract disease. Alternate terms include otolaryngologist, otonasolaryngologist, and otorhinolaryngologist.endotracheal Insertion of a noncollapsible breathing tube into the trachea through the nose or mouth. Performed to open the airway or, if the patient is comatose, to keep the airway open. endo/trache/alexpectorant A drug that breaks up the mucus and promotes the coughing reflex to expel the mucus.

A latin word meaning ""spit out of the chest. ""incentive spirometry A postoperative breathing therapy that reduces pulmonary complications and helps to correct atelectasis. It involves the use of a portable spirometer to promote deeper breathing to improve lung expansion after operation.laryngectomy Surgical removal of the larnyx.

Laryngectomy patients have a permanent tracheostomy. laryng/ectomylaryngoscopy A diagnostic procedure that uses a modified endoscope, called a laryngoscope to visually examine the larnyx.laryngotracheotomy -lair ring goh TRAY kee OTT oh mee- Surgical incision into the larynx and trachea.

laryng/o/trache/o/tomylobectomy Surgical removal of a single lobe of a lung. lob/ectomymechanical ventilation A medical treatment to provide supplemental oxygen to patients in respiratory distress. It provides assisted breathing using a ventilator, which pushes air into the patients airway.nebulizer A device used to convert a liquid medication to a mist and deliver it to the lung with the aid of deep inhalation.

Latin word meaning ""fog""oximetry The procedure that measures oxygen levels in the blood using an instrument called an oximeter. ox/i/metrypleurocentesis -ploor oh sehn TEE siss- The surgical puncture and aspiration of fluid from the pleural cavity. It is also called thoracentesis or thoracocentesis. pleur/o/centesispneumonectomy -NOO moh NEK toh mee- The surgical removal of a lung, also called pneumectomy. pneumon/ectomypulmonary angiography A diagnostic procedure that evaluates the blood circulation of the lungs.

X-ray images are taken of the lungs following the injection of a contrast medium into the pulmonary circulation. pulmon/ary angi/o/graphy- recording of blood vessels pertaining to lung.pulmonary function test (PFT) A series of diagnostic tests performed to determine the cause of lung disease by evaluating lung capacity through the use of spirometry.

A spirometer measures the amount of air inhaled/exhaled after a normal breathing cycle, called tidal volume (TV) and the amount of air inhaled/exhaled during a forced expiration, calledvital capacity (VC).pulmonologist A physician specializing in the treatment of diseases affecting the lower respiratory tract, particularly the lungs.resuscitation Artificial respiration that is used to restore breathing.

The most common form is cardiopulmonary resuscitation or CPR, which combines artificial breathing with chest compressions.rhinoplasty The surgical repair of the nose.

Septoplasty is the repair of a deviation of the nasal septum and helps improve breathing. rhin/o/plasty TB skin test A simple skin test to determine the presence of a tuberculosis infection. Also known as a PPD skin test and Mantoux skin test.thoracentesis -THOR ah sehn TEE siss- Surgical puncture using a needle and syringe into the thoracic cavity to aspire pleural fluid for diagnosis or treatment.

Also known as tharacentesis or pleurocentesis. thora/centesisthoracostomy Surgical puncture into the chest cavity, usually for the insertion of a drainage or air tube. thorac/o/stomy- placing a chest tubethoracotomy -THOR ah KOTT oh mee- A surgical incision into the chest wall.

The procedure is often used to treat pleural effusion by draining the excess fluid from the pleural cavity. thorac/o/tomytracheoplasty The surgical repair of the trachea. trache/o/plastytracheostomy Surgical creation of an opening into the trachea, usually for the insertion of a breathing tube. trache/o/stomytracheotomy Surgical incision into the trachea. trache/o/tomyventilation-perfusion scanning (VPS) A diagnostic tool that uses nuclear medicine, or the use of radioactive material, to evaluate pulmonary function.

It is also called lung scan and V/Q scan.a- without or absence ofbrady- slowdys- bad, abnormal, painful, or difficultepi- upon, over, above, on topeu- normal or goodhyper- excessive, abnormally high, abovehypo- deficient, abnormally low, belowtachy- rapid or fastan- without or absence ofanti- against or opposite ofendo- withinaden/o- glandalveol/o- air sac, alveolusangi/o blood vesselatel/o incompletebronch/o airway, bronchusbronchi/o airwaycarcin/o cancercoccidioid/o Coccidioides immitis organismconi/o dustcyst/o bladderdilat/o to widenembol/o a plugfibr/o fiberglott/o opening into the windpipehem/o, hemat/o bloodlaryng/o voice box, larynxlob/o a rounded part, lobemuc/o mucusmyc/o fungusnas/o noseorth/o straightox/i oxygenox/o oxygenpharyng/o throat, pharynxphragm/o partitionphragmat/o partitionpleur/o pleura, ribpneum/o air, lungpneumon/o air, lungpneumat/o air, lungpulmon/o lungpy/o pusrhin/o nosesept/o wall, partition; putrefyingsinus/o cavitysphyx/o pulsespir/o breathesten/o narrowthorac/o chest, thoraxtonsill/o almond, tonsiltrache/o windpipe, tracheatubercul/o little swelling-al pertaining to-algia condition of pain-capnia condition of carbon dioxide-centesis surgical puncture-dynia pain-ectasis expansion or dilation-ectomy surgical removal or excision-emia condition of blood-genic pertain to, producing, formation, or causing-gram a record or image-graphy recording process-ia condition of-ic expansion or dilation "

a. The most common cause of bacterial pneumonia is a type of bacteria known as Streptococcus pneumoniae. Haemophilus influenzae, Chlamydia pneumoniae, Mycoplasma pneumoniae, and Legionella pneumophila are some other major bacteria that cause pneumonia.

Bacterial Pneumonia

"Bacterial Pneumonia Quick Overview What Causes Bacterial Pneumonia? What Are Bacterial Pneumonia Symptomsand Signs? Is Bacterial Pneumonia Contagious? When Should Someone Seek Medical Care for Bacterial Pneumonia?

What Tests Do Doctors Use to Diagnose Bacterial Pneumonia? What Is the Treatmentfor Bacterial Pneumonia? Are There Home Remedies for Bacterial Pneumonia? What Is the Medical Treatment for Bacterial Pneumonia? Are Antibiotics Necessary? Bacterial Pneumonia Follow-up Is It Possible to Prevent Bacterial Pneumonia? What Is the Prognosis of Bacterial Pneumonia? Bacterial Pneumonia Quick Overview Readers Comments 40 Share Your Story

Pneumonia is an infection of the lungs. People with pneumonia usually complain of coughing, mucus production, fever, shortness of breath, and/or chest pain. The body's immune system usually keeps bacteria from infecting the lungs. In bacterial pneumonia, bacteria reproduce in the lungs, while the body tries to fight off the infection.

This response to bacterial invaders is called inflammation. When the inflammation occurs in the alveoli (microscopic air sacs in the lungs) they fill with fluid. The lungs become less elastic and cannot take oxygen into the blood or remove carbon dioxide from the blood as efficiently as usual.

When the alveoli don't work efficiently, the lungs are less able to extract oxygen from the air. This causes the feeling of being short of breath (dyspnea), which is one of the most common symptoms of pneumonia. Inflammation is the body's attempt to destroy infection, and causes many of the other symptoms of bacterial pneumonia, including fever and chest pain.

The lungs themselves do not have any pain fibers but are surrounded by a membrane called the pleura. The pleura does contain many nerve fibers, and if it becomes inflamed by an adjacent infection in the lungs, significant pain can result.

This is called pleurisy and often can accompany pneumonia. It is not infrequent, however, for inflammation not to involve the surface of the lung and therefore, little if any pain may be present.

Pneumonia can be very serious, because it directly interferes with the body's ability to exchange carbon dioxide and oxygen. Pneumonia is different from acute bronchitis (another disease that can cause fever, cough, chest pain, and shortness of breath) because acute bronchitis is caused by inflammation in the air passages (called bronchi) leading to the alveoli, not the alveoli themselves.

Sometimes it is very difficult, even for a doctor, to tell pneumonia and bronchitis apart. The symptoms and physical examination can be identical. Sometimes a chest X-ray is the only way to distinguish pneumonia from bronchitis. There is also an entity in which both the airways and air sacs are involved with infection, and this is referred to as bronchopneumonia.

As noted above, if the surface of the lung is inflamed, pleurisy may result. ""Itis"" is added to the end of the anatomical location to describe where the inflammation is.

The symptoms often follow the location (for example, tracheitis [trachea, the main airway in the lung], laryngitis [larynx or voice box], pharyngitis [throat], bronchitis [bronchi, smaller lung airways], or pneumonitis [pneumonia]). Take the Pneumonia Quiz Common Cold Prevention Slideshow Bronchitis Slideshow Pictures What Causes Bacterial Pneumonia? Most pneumonia is caused by bacteria or a virus. Pneumonia from any cause can occur at any age, but people in certain age groups are at higher risk for certain types of pneumoni

Other commonly seen pathogens include S pneumoniae, P aeruginosa, Legionella pneumophila, L monocytogenes, Nocardia species, Mycobacterium species, fungi, VZV, HSV, CMV, Epstein-Barr virus (EBV), respiratory viral infections, Toxoplasma species, cryptosporidia, Strongyloides species, and encapsulated bacteria.

Practice Essentials

Practice Essentials An immunocompromised host is a patient who does not have the ability to respond normally to an infection due to an impaired or weakened immune system. This inability to fight infection can be caused by a number of conditions including illness and disease (eg, diabetes, HIV), malnutrition, and drugs.

Essential update: New guidelines from the IDSA recommend vaccination for immunocompromised patients According to new guidelines from the Infectious Diseases Society of America (IDSA), most immunocompromised patients should be vaccinated. The new guidelines are designed for health care professionals caring for patients with compromised immune systems due to HIV infection or AIDS, cancer, solid organ transplantation, stem cell transplantation, sickle cell disease or asplenia, congenital immune deficiencies, chronic inflammatory conditions, cochlear implants, or cerebrospinal fluid leaks.

[ 1, 2]Specific recommendations include the following: When possible, vaccines should be administered before planned immunosuppression. Live vaccines should be administered at least 4 weeks before immunosuppression and should be avoided within 2 weeks of beginning immunosuppression. Inactivated vaccines should be administered at least 2 weeks before immunosuppression is initiated.

Most immunocompromised patients 6 months of age or older should receive annual influenza vaccination as an injection; these patients should not receive live attenuated influenza vaccine administered as a nasal spray.

Influenza vaccine is unlikely to be of benefit in individuals who are receiving intensive chemotherapy or who have received anti-B-cell antibodies in the preceding 6 months. Immunocompetent persons living with immunocompromised patients can safely receive inactivated vaccines.

Individuals living with immunocompromised patients 6 months of age or older should receive annual influenza vaccine. Immunocompromising conditions Congenital conditions Congenital conditions most commonly affect the fetus and newborn. Classes of congenital conditions include the following: Syndromes B-cell defects Combined B-cell and T-cell defects T-cell defects Macrophage, cytokine, and miscellaneous defects Phagocyte deficiency or dysfunction Complement deficiencies Acquired conditions These conditions may interfere directly with the immune system or may disrupt barrier function.

Types of acquired conditions include the following: Malnutrition HIV infection Trauma Medical conditions Infectious complications Immunocompromised patients are susceptible to bacterial, fungal, and viral infections that healthy immune systems usually conquer. They are also susceptible to common infections of childhood. B-cell defects predispose patients to frequent sinopulmonary and respiratory tract infections and infections with nonenveloped viruses, parvovirus B19, and rotavirus. Almost any organism can cause infection in combined B- and T-cell defects. Patients often present with failure to thrive, thrush, and/or P jiroveci infection.

T-cell defects predispose to infections with Candida, Mycobacterium avium-intracellulare complex, herpesviruses, and P jiroveci infections. Phagocyte deficiency or dysfunction predisposes patients to infections with S aureus, Nocardia species, P aeruginosa, Serratia species, streptococci, other enteric organisms, and Candida, Burkholderia, Aspergillus, and Chromobacterium species.

Complement deficiency is associated with recurrent sinopulmonary infections and invasive infections due to encapsulated bacteria such as S pneumoniae, H influenzae and N meningitidis. Infectious diarrhea, pneumonia, tuberculosis, measles, malaria, salmonellosis, P jiroveci infection, and HIV are common causes of death among malnourished infants and children. In immunosuppression due to HIV infection a myriad of infections occur, particularly as immune function deteriorates.

Overview Much of the practice of pediatric infectious diseases now focuses on the treatment of the fetus, neonate, infant, child, and adolescent who have infections in the context of immunocompromise.

[ 3] Because of the vast scope of this topic, the interested reader is referred to appropriate reviews for exhaustive treatment of specific immunologic and immune-compromising disorders and infections. [ 4, 5] Further information is also available in textbooks of pediatric infectious diseases (some of which are devoted exclusively to this topic) as cited in the bibliography.

This review focusesonevaluation of the child with frequent infections (who likely has no immunocompromise), conditions leading to immunocompromise (congenital, acquired, and iatrogenic in broad terms), and the particular infections associated with these conditions. Most children examined in the office because of frequent infections have a series of benign, self-limited, largely viral infections in the context of parental or familial concern for an underlying immune problem or perception that the child is sickly.

The patient often seems to get sick more frequently than siblings and others. However, most children with frequent infections are immunologically healthy.

Careful questioning and evaluation frequently reveals antecedent events or problems that predispose the patient to such concerns (eg, the vulnerable child syndrome). Thorough history taking and physical examination, with a review of laboratory and radiographic results (which generally accompany the patient) almost always help in excluding clinically significant immunologic disorders.

In rare cases, Münchhausen syndrome or Münchhausen syndrome by proxy manifests as frequent or obscure infections (or suspicion of such infections). Secondary, or acquired, immunodeficiency is more common than primary immunodeficiency. Although the well child with frequent infections is seen in the outpatient office more often than one with immunocompromise, most hospitalized children have some immune-compromising condition. Next: The Child with Frequent Infections

? Getting Legionnaires' disease—a type of pneumonia carried by stagnant water. Avoid both by setting your water heater to just the right temperature. The DIY experts at Stack Exchange are here to help.

What's the Best Temperature for My Water Heater?

"What's the Best Temperature for My Water Heater? Tessa Miller11/15/13 5:00pm Filed to: crowdhacker 32 2What's worse than scalding yourself in the shower

When adjusting my hot water heater, what temperature should I set it to? Is the answer different if you have: concerns about diseases, a dishwasher, young children or elderly that can be easily burned, electric vs. gas heat, type of plumbing (e.g. PEX or Copper)? Also, is there a preferred technique to check the temperature of the water after adjusting it?

See the original question. A Goldilocks Water Heater ( Answered by SAJ14SAJ)There are two main and opposing risks: Too high, and users get scalded Too low, and you risk pathogens, particularly Legionella, which causes legionellosis (Legionnaires' disease)Minimum Temperature According to the paper Legionella and the prevention of legionellosis, found at the World Health Organization website, temperature affects the survival of Legionella as follows: Above 70 °C (158 °F): Legionella dies almost instantly At 60 °C (140 °F): 90% die in 2 minutes At 50 °C (122 °F): 90% die in 80–124 minutes, depending on strain At 48 to 50 °C (118 to 122 °F): Can survive but do not multiply32 to 42 °C (90 to 108 °F): Ideal growth range Dishwashers Most current-model dishwashers have a minimum requirement of 49 °C (120 °F).

Most have heaters and will heat the interior as needed. If yours is older you may want to check specifications. Dishwasher detergent varies, but ""works best between 50 and 60 °C"" seems to be a fairly common statement.

There is also cold-water detergent on the market that works at basically any temperature. Maximum Temperature Setting too high can scald someone using the water.

This is particularly easy because when you first open the tap, the water in the pipes has cooled down some, and so its temperature will raise (possibly dramatically) once the water from the tank reaches the point of use. Young children are at higher risk because their skin is thinner. Some people, especially the elderly, are at higher risk because they may be less sensitive and slower to move away from scalding water.

The Consumer Product Safety Commission (CPSC) recommends setting to 49 °C (120 °F). Piping Concerns From Legionella Prevention: Dead legs: Dead legs (branches that are capped off or rarely used) contain stagnant water that can be an ideal breeding ground for bacteria which can contaminate the entire system. This should not be surprising as the water in the dead leg would get warm, but never hot to the temperature of the main flow.

If unavoidable, a valve should be installed as close to the main line as possible (no more than 1 pipe diameter away) to minimize risk.

PEX vs. Copper: In a study, Legionella seemed to grow a bit faster in PEX than copper (over a period of 500 days), however, over a period of 800 days there was essentially no difference in growth and both pipes had identical biofilms formed inside them. Copper in theory would cool down faster than PEX, but given enough time (likely a couple hours), the temperature of both would cool to the ambient temperature.

There's a separate question that discusses if it's worthwhile to insulate pipes, but even with insulation, the water in the pipes will eventually cool to ambient. Conflicting Views From Heated Debate about Hot Water: The country’s top experts, represented on the Canadian Commission on Building and Fire Codes (CCBFC), have rejected the lower maximum hot water tank temperature of 49 C. In spite of this, trusted organizations are telling homeowners to lower their hot water tank temperature to 49 C as a precaution against scalds from tap water.

Some even offer tips on how to find the thermostat so you can adjust it yourself. The bottom line is that water must be stored at a high temperature as a precaution against bacteria.

It can be delivered from the tap at a lower temperature to prevent scalds. Conclusion The article Residential water heater temperature: 49 or 60 degrees Celsius?, published in the Canadian Journal of Infectious Diseases, concludes:""In our opinion, it is important to reduce both the risk of scalds and the risk of legionellosis associated with domestic water supplies. For water heaters servicing a single housing unit: Electric water heaters should be set at 60°C to limit the risk of Legionella contamination, and equipped with antiscald devices to deliver water at 49°C to the entire household.

Gas or oil water heaters should be set at 49°C, because the risk of scalding is greater with these devices.

For water heaters servicing multiple unit housing complexes: More complex water distribution systems are more likely to be contaminated, and the recommendations from the WHO should apply no matter what type of water heater is used: hot water must be stored at 60°C inside the water heater by ensuring, at least once a day, the temperature reaches at least 60°C in the entire tank.

Moreover, water should reach the tap at a temperature of at least 50°C. Taps in these buildings, especially in the bath or shower where most scalds occur, should be equipped with antiscald devices to decrease the water temperature to 49°C or less. ""The best scenario seems to be to install anti-scald mixing valves at each human point of use (eg, sinks, tubs): whether it be integrated in a shower valve, or installed under the sink.

The tank gets set to the WHO-recommended 60°C. Each human point-of-use is limited to the CPSC-recommended 49 °C (120 °F). You may even want it lower (eg, 110 °F) in kid's bathrooms. Other uses—dishwasher, washing machine, humidifier—can get the full 60°C with no issue.

The downside to this, of course, is cost: you need to install the valves on each hot water tap. For sinks, this is relatively easy to retrofit; for tubs/showers it may be more difficult. Disagree with the answer above? Have your own expertise to contribute? Check out the original post, and see more questions like this at Seasoned Advice, a question and answer site for contractors and serious DIYers. And if you've got your own problem that requires a solution, ask a question. You'll get an answer. (And it's free.) "

? Getting Legionnaires' disease—a type of pneumonia carried by stagnant water. Avoid both by setting your water heater to just the right temperature. The DIY experts at Stack Exchange are here to help.

"What's the Best Temperature for My Water Heater? Tessa Miller11/15/13 5:00pm Filed to: crowdhacker 32 2What's worse than scalding yourself in the shower

When adjusting my hot water heater, what temperature should I set it to? Is the answer different if you have: concerns about diseases, a dishwasher, young children or elderly that can be easily burned, electric vs. gas heat, type of plumbing (e.g. PEX or Copper)? Also, is there a preferred technique to check the temperature of the water after adjusting it?

See the original question. A Goldilocks Water Heater ( Answered by SAJ14SAJ)There are two main and opposing risks: Too high, and users get scalded Too low, and you risk pathogens, particularly Legionella, which causes legionellosis (Legionnaires' disease)Minimum Temperature According to the paper Legionella and the prevention of legionellosis, found at the World Health Organization website, temperature affects the survival of Legionella as follows: Above 70 °C (158 °F): Legionella dies almost instantly At 60 °C (140 °F): 90% die in 2 minutes At 50 °C (122 °F): 90% die in 80–124 minutes, depending on strain At 48 to 50 °C (118 to 122 °F): Can survive but do not multiply32 to 42 °C (90 to 108 °F): Ideal growth range Dishwashers Most current-model dishwashers have a minimum requirement of 49 °C (120 °F).

Most have heaters and will heat the interior as needed. If yours is older you may want to check specifications. Dishwasher detergent varies, but ""works best between 50 and 60 °C"" seems to be a fairly common statement.

There is also cold-water detergent on the market that works at basically any temperature. Maximum Temperature Setting too high can scald someone using the water.

This is particularly easy because when you first open the tap, the water in the pipes has cooled down some, and so its temperature will raise (possibly dramatically) once the water from the tank reaches the point of use. Young children are at higher risk because their skin is thinner. Some people, especially the elderly, are at higher risk because they may be less sensitive and slower to move away from scalding water.

The Consumer Product Safety Commission (CPSC) recommends setting to 49 °C (120 °F). Piping Concerns From Legionella Prevention: Dead legs: Dead legs (branches that are capped off or rarely used) contain stagnant water that can be an ideal breeding ground for bacteria which can contaminate the entire system. This should not be surprising as the water in the dead leg would get warm, but never hot to the temperature of the main flow.

If unavoidable, a valve should be installed as close to the main line as possible (no more than 1 pipe diameter away) to minimize risk.

PEX vs. Copper: In a study, Legionella seemed to grow a bit faster in PEX than copper (over a period of 500 days), however, over a period of 800 days there was essentially no difference in growth and both pipes had identical biofilms formed inside them. Copper in theory would cool down faster than PEX, but given enough time (likely a couple hours), the temperature of both would cool to the ambient temperature.

There's a separate question that discusses if it's worthwhile to insulate pipes, but even with insulation, the water in the pipes will eventually cool to ambient. Conflicting Views From Heated Debate about Hot Water: The country’s top experts, represented on the Canadian Commission on Building and Fire Codes (CCBFC), have rejected the lower maximum hot water tank temperature of 49 C. In spite of this, trusted organizations are telling homeowners to lower their hot water tank temperature to 49 C as a precaution against scalds from tap water.

Some even offer tips on how to find the thermostat so you can adjust it yourself. The bottom line is that water must be stored at a high temperature as a precaution against bacteria.

It can be delivered from the tap at a lower temperature to prevent scalds. Conclusion The article Residential water heater temperature: 49 or 60 degrees Celsius?, published in the Canadian Journal of Infectious Diseases, concludes:""In our opinion, it is important to reduce both the risk of scalds and the risk of legionellosis associated with domestic water supplies. For water heaters servicing a single housing unit: Electric water heaters should be set at 60°C to limit the risk of Legionella contamination, and equipped with antiscald devices to deliver water at 49°C to the entire household.

Gas or oil water heaters should be set at 49°C, because the risk of scalding is greater with these devices.

For water heaters servicing multiple unit housing complexes: More complex water distribution systems are more likely to be contaminated, and the recommendations from the WHO should apply no matter what type of water heater is used: hot water must be stored at 60°C inside the water heater by ensuring, at least once a day, the temperature reaches at least 60°C in the entire tank.

Moreover, water should reach the tap at a temperature of at least 50°C. Taps in these buildings, especially in the bath or shower where most scalds occur, should be equipped with antiscald devices to decrease the water temperature to 49°C or less. ""The best scenario seems to be to install anti-scald mixing valves at each human point of use (eg, sinks, tubs): whether it be integrated in a shower valve, or installed under the sink.

The tank gets set to the WHO-recommended 60°C. Each human point-of-use is limited to the CPSC-recommended 49 °C (120 °F). You may even want it lower (eg, 110 °F) in kid's bathrooms. Other uses—dishwasher, washing machine, humidifier—can get the full 60°C with no issue.

The downside to this, of course, is cost: you need to install the valves on each hot water tap. For sinks, this is relatively easy to retrofit; for tubs/showers it may be more difficult. Disagree with the answer above? Have your own expertise to contribute? Check out the original post, and see more questions like this at Seasoned Advice, a question and answer site for contractors and serious DIYers. And if you've got your own problem that requires a solution, ask a question. You'll get an answer. (And it's free.) "

A particular feature of Legionella is its dual host system allowing the intracellular growth in protozoa (amoebae), and during infection in human pulmonary alveolar macrophages. (8) Like macrophages, amoebae ingest L. pneumophila by phagocytosis, which can be mediated by amoebic-specific receptors.

Legionella pneumophila

Legionella pneumophilanavigation search This is a curated page. Report corrections to Microbewiki. Contents [ hide ]1 Taxonomic Classification2 Description and significance3 Genomic Structure4 Cell Structure and Metabolism5 Ecology6 Pathology7 Current Research8 References Taxonomic Classification Higher Order Taxa: Bacteria; Proteobacteria; Gammaproteobacteria; Legionellales; Legionellacaea; Legionella; Legionella pneumophila Description and significance The Legionellaceae are fastidious gram-negative bacteria that reside in aquatic environments all over the globe.

In their natural environment, the Legionellaceae are intracellular parasites of free-living protozoa. These organisms may also inhabit man-made water distribution systems. The family Legionellaceae consists of a single genus, Legionella.

More specifically, this genus includes the species Legionella pneumophila, which are non-encapsulated, aerobic bacilli. In addition to L. pneumophila, there are 41 other species in the genus and together these species divide into 64 serogroups.

Within the species L. pneumophila, human infection is caused primarily (but not exclusively) by a limited number of serogroups—serogroups 1, 4, and 6. L. pneumophila is the most frequent cause of human legionellosis, better known as Legionnaire’s disease in the Legionellaceae family. It is also a relatively common cause of community-acquired and nosocomial pneumonia in adults. (1) And L. pneumophila serogroup 1 alone is responsible for 70-90% of cases. (2)The Legionellaceae were not documented until 1976, when a detrimental outbreak of pneumonia occurred in Philadelphia at an American Legion Convention.

(Fraser et al., 1977; Tsai et al., 1979). Thirty four of the 221 people who became ill after exposure died within the first few weeks after the convention.

The culprit, L. pneumophila, was isolated first by inoculation of postmortem lung tissue into guinea pigs and then by subculture into a rich artificial medium (Mc Dade et al., 1977). Then by indirect immunofluorescent antibody assay, it was found that over 90% of those that fell ill had at least four times the concentration of antibody in the blood (fourfold rise in titer) against this organism.

The same method was used to screen previously saved sera from earlier outbreaks of unexplained respiratory disease and they discovered that a number of them were associated with seroconversion to L. pneumophila, including a “rickettsia-like” organism, isolated by guinea pig inoculation from the blood of a feverish patient in 1947, which today is recorded as the earliest known isolate of L. pneumophila.

(1)Genomic Structure The Legionella genome structure continues to undergo research. Three different genomes of L. pneumophila were completed over a span of three years.

First, Legionella pneumophila ssp. Pneumophila str. Philadelphia 1 (3,397,754 bp, 3002 genes) was completed in October 2001. Plasmid p LPP of Legionella pneumophila str. Paris was completed in October 2004; in addition to the full genome (3,503,610 bp, 3136 genes). Plasmid p LPL of Legionella pneumophila str. Lens was also completed in October 2004, in addition to the full genome (3,345,687 bp, 3001 genes).

(3)The genome of Legionella pneumophila str. Paris was found to contain 3,503,610 base pairs and contains about 3027 predicted protein-encoding genes.

The genome is a circular chromosome with an average GC content of 38%. In 2004, researchers analyzed the complete genome sequences of L. pneumophila Paris, an endemic strain that is predominantly found in France and L. pneumophila Lens, another endemic strain. The Lens strain is 3,345,687 base pairs long and contains about 2878 protein-encoding genes and like the Paris strain its genome is a circular chromosome with an average GC content of 38%.

The two strains differed in about 13% of their genome sequences having 3 different plasmids. The Paris strain is unique because it contains a type V secretion system and a 36 Kb sequence carried on a multicopy plasmid or integrated into a chromosome encodes its type IV secretion system. This ability for genes to move around increases the versatility in L. pneumophila. To alter host cell functions to its advantage L. pneumophila contains many genes that encode eukaryotic-like proteins or motifs. As a result, the genome reveals co-evolution of L. pneumophila as a fresh-water amoebae and a human pathogen.

(4)Cell Structure and Metabolism L. pneumophila is a gram-negative, non-encapsulated, aerobic bacillus with a single, polar flagellum. The organism is approximately 2µm in length and 0.3-0.9µm in width, but in nutrient-deficient media, it may become long and filamentous.

It is surrounded by a gram-negative cell wall and pili are sometimes identified. The cell envelope is composed of branched-chain fatty acids and distinctive ubiquinones, whose structural differences have been used to classify different Legionella species.

The outer-membrane is comprised of a lipopolysaccharide (LPS), which is “fully sequenced and found to have several novel features which have pathophysiologic consequence” and is noticeably less endotoxic than enterobacterial LPS since it has weak interactions with the CD14 receptor on monocytes, The interactions are probably inhibited by the long-chain fatty acids of L. pneumophila lipid A, which are two times the length of enterobacterial lipid A. A single, major protein also makes up the outer membrane and functions as a porin and as a target for human complement fixation. L. pneumophila serogroup 1LPS also has a repeating O antigen. It is a homopolymer of an uncommon sugar, called legionaminic acid.

”LPS is the immunodominant antigen of the Legionellaceae, and the O antigen is the determinant of serogroup specificity within the genus.” (5)Ecology All organisms interact with the environment they are in and with the organisms they share that environment with.

In one research study, the potable water distribution system was determined to be the culprit behind hospital-acquired Legionnaires’ disease. Researches hypothesized that the natural microbial population and sediment (aerosols or particulate mater) were, together, growth-promoting factors of L. pneumophila. A series of in vitro experiments proved that many factors supported and even improved the survival of L. pneumophila.

Results showed that water from the hot-water storage tank was a constant sustainer for the survival of L. pneumophila, as was the concentration of sediment in the water system.

Also, both the presence of bacteria and the combination of bacteria and sediment working together improved the survival of L. pneumophila. And lastly, the sediment was found to have nutritional value—it stimulated the growth of environmental microflora, which then stimulated the growth of L. pneumophila.

The results coincide with experimental observations that L. pneumophila prefer to grow and localize in hot, moist environments where there is a supply of nutrition from the sediment. Concluding, it was not surprising that L. pneumophila found their preferable environment to be the potable water system, where they formed interrelationships between temperature, sediment, and microflora.

From this data, it is clear that L. pneumophila interact with their environment and the organisms they share that environment with. (6)Pathology L. pneumophila can only be acquired from an environmental source; therefore, infection never occurs between humans or humans and animals. Another interesting thing is, unlike other pathogens that cause bacterial pneumonia, L. pneumophila do not inhabit the upper respiratory tract.

Once inhaled, they are small enough to avoid the defenses of the upper airway. In the lung, pulmonary alveolar macrophages (macrophages of the air sacs in the lung) and sometimes type II alveolar epithelial cells take up L. pneumophila where it begins to grow intracellularly.

It seems intracellular infection is necessary for producing infection because mutants of L. pneumophila are unable to cause disease.

This is true also because L. pneumophila is not sensitive to antimicrobials (e.g., penicillin, cephalosporin, aminoglycosides) that are excluded by the plasma membrane, and therefore, it is treated only with antibiotics that can enter the host cells (e.g., macrolides, quinolones, tetracyclines). (7)Then the bacteria undergo a series of events that begins with phagocytosis. Most, but not all strains of L. pneumophila are taken up by “coiling phagocytosis”—when the macrophage coils around the bacteria to take it up, which is mediated by the CR1 and CR3 receptors (complement receptors of the macrophage) with or without fixation of complement serum factors like C3.

Also during uptake the plasma membrane engulfing the bacteria is altered; some membrane proteins, like MHCI and II (both molecules that aid in immune response), are specifically excluded whereas others, like CR3 and 5’-nucleotidase are preserved. (7) Two hours later, the phagosome (the vacuole formed around the pathogen) is found near mitochondria, smooth vesicles, or the nuclear membrane.

Normally, phagosomes will fuse with lysosomes and pathogenic microorganisms are killed, but in this case acidification of the phagosome does not take place, and its membrane does not get late endosomal markers, like rab7 and LAMP-1. This results in the failure of phagosolysosomal fusion which allows bacteria to avoid intracellular killing. Mutants of L. pneumophila on the other hand cannot avoid it and are transported to the lysosome within 30 minutes of uptake. (7) Fully virulent organisms on the other hand will take up an endosome that has become enclosed by the rough ER (a response to cellular amino acid starvation i.e.

autophagy) 4 hours after uptake. It is by this endosome enclosure that bacterial multiplication proceeds. While the bacteria are multiplying inside their host cells, they also “begin to express flagella, motility, cellular toxicity, and sensitivity to physiologic concentrations of sodium chloride.” (7) The genes that mediate intracellular trafficking and necrosis (accidental cell death) are the same genes that introduce the cytotoxic phenotype of L. pneumophila. Introduction of cytotoxicity in response to cellular amino acid starvation in the host may be a key mechanism that signals the bacteria to exit host cells and infect new cells. (7)

A particular feature of Legionella is its dual host system allowing the intracellular growth in protozoa (amoebae), and during infection in human pulmonary alveolar macrophages. (8) Like macrophages, amoebae ingest L. pneumophila by phagocytosis, which can be mediated by amoebic-specific receptors.

After ingestion, the bacteria evade phagosolysosomal fusion and localize to a membrane-vesicle surrounded by endoplasmic reticulum where it grows and acquires motility before release from the cell. This growth process of L. pneumophila to infect mammalian phagocytes strongly supports the theory that it evolved from protozoa.

“Since L. pneumophila are not transmitted between mammalian hosts or return to the natural environment by infected individuals, this hypothesis explains why this pathogen is adapted to intracellular life in the human lung without any apparent selection for pathogenic traits in the microenvironment.” (7)The Mip gene, a 24 k Da bacterial envelope protein, was the first virulence determinant of L. pneumophila.

The consequence of a Mip mutation Is a 1.5 to 3 log reduction in infectivity of explanted alveolar macrophages, alveolar epithelial cells, and amoebae. (7)Iron is essential for all pathogenic bacteria. Without it, the growth of intracellular L. pneumophila becomes restricted. It was found that gamma-interferon restricts the growth of L. pneumophila by downregulating the expression transferring receptors on macrophages and the cellular concentration of ferritin. Naturally, L. pneumophila taken from iron-deficient cultures grown are defective in cellular infection.

L. pneumophila has a fur homolog, which regulates the expression of an aerobactin synthetase homolog. Even though siderophores have yet to be identified in L. pneumophila, a mutation of this iron acquisition gene will cut intracellular infection by 80-fold. (7)Studies on intracellular survival of L. pneumophila have shown two chromosomal regions to encode functions that are essential for establishing intracellular infection.

The genes have been designated icm (intracellular multiplication) by one group and dot (defect in organelle trafficking) by the other. Mutation in almost any of these genes results in either a complete loss of cellular infectivity. In all cases, the loss of infectivity is associated with a failure to evade phagolysosmal fusion, as well as a loss of the immediate contact cytotoxicity of L. pneumophila at high rates of infections.

Mutations in several of the dot-icm genes—not just those with sequence homology to known conjugation genes have been shown to terminate plasmid transfer.

These same mutations also result in loss of this toxicity coupled with the insertion of a pore into host cell membranes. The proteins encoded by these loci probably either combine to form the pore or participate in its transfer or both. (7)

Lastly, legionellosis is the infection caused by L. pneumophila and can cause either: Legionnaires' disease, which is characterized by fever, myalgia, cough, pneumonia, or Pontiac fever, a milder illness without pneumonia.

The symptoms of Legionnaire’s disease range from a mild cough and low fever to rapidly progressive pneumonia, coma, and death.

Early symptoms include slight fever, headache, aching joints and muscles, lack of energy or tiredness, and loss of appetite. Later symptoms include high fever, cough, difficulty breathing/shortness of breath, chills, chest pain, common gastrointestinal symptoms including vomiting, diarrhea, nausea, and abdominal pain.

The symptoms of Pontiac fever include flu-like symptoms such as fever, headache, tiredness, loss of appetite, muscle and joint pain, chills, nausea, and a dry cough. Patients usually reach full recovery within two to five days without medical attention and no deaths have been reported. (9)Current Research

Much of the research done on Legionella pneumophila is related to ecology and how it relates to the environment. Some studies compare L. pneumophila to other microorganisms. Other studies look at the cases of Legionellosis and investigate the causes of the outbreaks.

Legionella pneumophila

Legionella pneumophilanavigation search This is a curated page. Report corrections to Microbewiki. Contents [ hide ]1 Taxonomic Classification2 Description and significance3 Genomic Structure4 Cell Structure and Metabolism5 Ecology6 Pathology7 Current Research8 References Taxonomic Classification Higher Order Taxa: Bacteria; Proteobacteria; Gammaproteobacteria; Legionellales; Legionellacaea; Legionella; Legionella pneumophila Description and significance The Legionellaceae are fastidious gram-negative bacteria that reside in aquatic environments all over the globe.

In their natural environment, the Legionellaceae are intracellular parasites of free-living protozoa. These organisms may also inhabit man-made water distribution systems. The family Legionellaceae consists of a single genus, Legionella.

More specifically, this genus includes the species Legionella pneumophila, which are non-encapsulated, aerobic bacilli. In addition to L. pneumophila, there are 41 other species in the genus and together these species divide into 64 serogroups.

Within the species L. pneumophila, human infection is caused primarily (but not exclusively) by a limited number of serogroups—serogroups 1, 4, and 6. L. pneumophila is the most frequent cause of human legionellosis, better known as Legionnaire’s disease in the Legionellaceae family. It is also a relatively common cause of community-acquired and nosocomial pneumonia in adults. (1) And L. pneumophila serogroup 1 alone is responsible for 70-90% of cases. (2)The Legionellaceae were not documented until 1976, when a detrimental outbreak of pneumonia occurred in Philadelphia at an American Legion Convention.

(Fraser et al., 1977; Tsai et al., 1979). Thirty four of the 221 people who became ill after exposure died within the first few weeks after the convention.

The culprit, L. pneumophila, was isolated first by inoculation of postmortem lung tissue into guinea pigs and then by subculture into a rich artificial medium (Mc Dade et al., 1977). Then by indirect immunofluorescent antibody assay, it was found that over 90% of those that fell ill had at least four times the concentration of antibody in the blood (fourfold rise in titer) against this organism.

The same method was used to screen previously saved sera from earlier outbreaks of unexplained respiratory disease and they discovered that a number of them were associated with seroconversion to L. pneumophila, including a “rickettsia-like” organism, isolated by guinea pig inoculation from the blood of a feverish patient in 1947, which today is recorded as the earliest known isolate of L. pneumophila.

(1)Genomic Structure The Legionella genome structure continues to undergo research. Three different genomes of L. pneumophila were completed over a span of three years.

First, Legionella pneumophila ssp. Pneumophila str. Philadelphia 1 (3,397,754 bp, 3002 genes) was completed in October 2001. Plasmid p LPP of Legionella pneumophila str. Paris was completed in October 2004; in addition to the full genome (3,503,610 bp, 3136 genes). Plasmid p LPL of Legionella pneumophila str. Lens was also completed in October 2004, in addition to the full genome (3,345,687 bp, 3001 genes).

(3)The genome of Legionella pneumophila str. Paris was found to contain 3,503,610 base pairs and contains about 3027 predicted protein-encoding genes.

The genome is a circular chromosome with an average GC content of 38%. In 2004, researchers analyzed the complete genome sequences of L. pneumophila Paris, an endemic strain that is predominantly found in France and L. pneumophila Lens, another endemic strain. The Lens strain is 3,345,687 base pairs long and contains about 2878 protein-encoding genes and like the Paris strain its genome is a circular chromosome with an average GC content of 38%.

The two strains differed in about 13% of their genome sequences having 3 different plasmids. The Paris strain is unique because it contains a type V secretion system and a 36 Kb sequence carried on a multicopy plasmid or integrated into a chromosome encodes its type IV secretion system. This ability for genes to move around increases the versatility in L. pneumophila. To alter host cell functions to its advantage L. pneumophila contains many genes that encode eukaryotic-like proteins or motifs. As a result, the genome reveals co-evolution of L. pneumophila as a fresh-water amoebae and a human pathogen.

(4)Cell Structure and Metabolism L. pneumophila is a gram-negative, non-encapsulated, aerobic bacillus with a single, polar flagellum. The organism is approximately 2µm in length and 0.3-0.9µm in width, but in nutrient-deficient media, it may become long and filamentous.

It is surrounded by a gram-negative cell wall and pili are sometimes identified. The cell envelope is composed of branched-chain fatty acids and distinctive ubiquinones, whose structural differences have been used to classify different Legionella species.

The outer-membrane is comprised of a lipopolysaccharide (LPS), which is “fully sequenced and found to have several novel features which have pathophysiologic consequence” and is noticeably less endotoxic than enterobacterial LPS since it has weak interactions with the CD14 receptor on monocytes, The interactions are probably inhibited by the long-chain fatty acids of L. pneumophila lipid A, which are two times the length of enterobacterial lipid A. A single, major protein also makes up the outer membrane and functions as a porin and as a target for human complement fixation. L. pneumophila serogroup 1LPS also has a repeating O antigen. It is a homopolymer of an uncommon sugar, called legionaminic acid.

”LPS is the immunodominant antigen of the Legionellaceae, and the O antigen is the determinant of serogroup specificity within the genus.” (5)Ecology All organisms interact with the environment they are in and with the organisms they share that environment with.

In one research study, the potable water distribution system was determined to be the culprit behind hospital-acquired Legionnaires’ disease. Researches hypothesized that the natural microbial population and sediment (aerosols or particulate mater) were, together, growth-promoting factors of L. pneumophila. A series of in vitro experiments proved that many factors supported and even improved the survival of L. pneumophila.

Results showed that water from the hot-water storage tank was a constant sustainer for the survival of L. pneumophila, as was the concentration of sediment in the water system.

Also, both the presence of bacteria and the combination of bacteria and sediment working together improved the survival of L. pneumophila. And lastly, the sediment was found to have nutritional value—it stimulated the growth of environmental microflora, which then stimulated the growth of L. pneumophila.

The results coincide with experimental observations that L. pneumophila prefer to grow and localize in hot, moist environments where there is a supply of nutrition from the sediment. Concluding, it was not surprising that L. pneumophila found their preferable environment to be the potable water system, where they formed interrelationships between temperature, sediment, and microflora.

From this data, it is clear that L. pneumophila interact with their environment and the organisms they share that environment with. (6)Pathology L. pneumophila can only be acquired from an environmental source; therefore, infection never occurs between humans or humans and animals. Another interesting thing is, unlike other pathogens that cause bacterial pneumonia, L. pneumophila do not inhabit the upper respiratory tract.

Once inhaled, they are small enough to avoid the defenses of the upper airway. In the lung, pulmonary alveolar macrophages (macrophages of the air sacs in the lung) and sometimes type II alveolar epithelial cells take up L. pneumophila where it begins to grow intracellularly.

It seems intracellular infection is necessary for producing infection because mutants of L. pneumophila are unable to cause disease.

This is true also because L. pneumophila is not sensitive to antimicrobials (e.g., penicillin, cephalosporin, aminoglycosides) that are excluded by the plasma membrane, and therefore, it is treated only with antibiotics that can enter the host cells (e.g., macrolides, quinolones, tetracyclines). (7)Then the bacteria undergo a series of events that begins with phagocytosis. Most, but not all strains of L. pneumophila are taken up by “coiling phagocytosis”—when the macrophage coils around the bacteria to take it up, which is mediated by the CR1 and CR3 receptors (complement receptors of the macrophage) with or without fixation of complement serum factors like C3.

Also during uptake the plasma membrane engulfing the bacteria is altered; some membrane proteins, like MHCI and II (both molecules that aid in immune response), are specifically excluded whereas others, like CR3 and 5’-nucleotidase are preserved. (7) Two hours later, the phagosome (the vacuole formed around the pathogen) is found near mitochondria, smooth vesicles, or the nuclear membrane.

Normally, phagosomes will fuse with lysosomes and pathogenic microorganisms are killed, but in this case acidification of the phagosome does not take place, and its membrane does not get late endosomal markers, like rab7 and LAMP-1. This results in the failure of phagosolysosomal fusion which allows bacteria to avoid intracellular killing. Mutants of L. pneumophila on the other hand cannot avoid it and are transported to the lysosome within 30 minutes of uptake. (7) Fully virulent organisms on the other hand will take up an endosome that has become enclosed by the rough ER (a response to cellular amino acid starvation i.e.

autophagy) 4 hours after uptake. It is by this endosome enclosure that bacterial multiplication proceeds. While the bacteria are multiplying inside their host cells, they also “begin to express flagella, motility, cellular toxicity, and sensitivity to physiologic concentrations of sodium chloride.” (7) The genes that mediate intracellular trafficking and necrosis (accidental cell death) are the same genes that introduce the cytotoxic phenotype of L. pneumophila. Introduction of cytotoxicity in response to cellular amino acid starvation in the host may be a key mechanism that signals the bacteria to exit host cells and infect new cells. (7)

A particular feature of Legionella is its dual host system allowing the intracellular growth in protozoa (amoebae), and during infection in human pulmonary alveolar macrophages. (8) Like macrophages, amoebae ingest L. pneumophila by phagocytosis, which can be mediated by amoebic-specific receptors.

After ingestion, the bacteria evade phagosolysosomal fusion and localize to a membrane-vesicle surrounded by endoplasmic reticulum where it grows and acquires motility before release from the cell. This growth process of L. pneumophila to infect mammalian phagocytes strongly supports the theory that it evolved from protozoa.

“Since L. pneumophila are not transmitted between mammalian hosts or return to the natural environment by infected individuals, this hypothesis explains why this pathogen is adapted to intracellular life in the human lung without any apparent selection for pathogenic traits in the microenvironment.” (7)The Mip gene, a 24 k Da bacterial envelope protein, was the first virulence determinant of L. pneumophila.

The consequence of a Mip mutation Is a 1.5 to 3 log reduction in infectivity of explanted alveolar macrophages, alveolar epithelial cells, and amoebae. (7)Iron is essential for all pathogenic bacteria. Without it, the growth of intracellular L. pneumophila becomes restricted. It was found that gamma-interferon restricts the growth of L. pneumophila by downregulating the expression transferring receptors on macrophages and the cellular concentration of ferritin. Naturally, L. pneumophila taken from iron-deficient cultures grown are defective in cellular infection.

L. pneumophila has a fur homolog, which regulates the expression of an aerobactin synthetase homolog. Even though siderophores have yet to be identified in L. pneumophila, a mutation of this iron acquisition gene will cut intracellular infection by 80-fold. (7)Studies on intracellular survival of L. pneumophila have shown two chromosomal regions to encode functions that are essential for establishing intracellular infection.

The genes have been designated icm (intracellular multiplication) by one group and dot (defect in organelle trafficking) by the other. Mutation in almost any of these genes results in either a complete loss of cellular infectivity. In all cases, the loss of infectivity is associated with a failure to evade phagolysosmal fusion, as well as a loss of the immediate contact cytotoxicity of L. pneumophila at high rates of infections.

Mutations in several of the dot-icm genes—not just those with sequence homology to known conjugation genes have been shown to terminate plasmid transfer.

These same mutations also result in loss of this toxicity coupled with the insertion of a pore into host cell membranes. The proteins encoded by these loci probably either combine to form the pore or participate in its transfer or both. (7)

Lastly, legionellosis is the infection caused by L. pneumophila and can cause either: Legionnaires' disease, which is characterized by fever, myalgia, cough, pneumonia, or Pontiac fever, a milder illness without pneumonia.

The symptoms of Legionnaire’s disease range from a mild cough and low fever to rapidly progressive pneumonia, coma, and death.

Early symptoms include slight fever, headache, aching joints and muscles, lack of energy or tiredness, and loss of appetite. Later symptoms include high fever, cough, difficulty breathing/shortness of breath, chills, chest pain, common gastrointestinal symptoms including vomiting, diarrhea, nausea, and abdominal pain.

The symptoms of Pontiac fever include flu-like symptoms such as fever, headache, tiredness, loss of appetite, muscle and joint pain, chills, nausea, and a dry cough. Patients usually reach full recovery within two to five days without medical attention and no deaths have been reported. (9)Current Research

Much of the research done on Legionella pneumophila is related to ecology and how it relates to the environment. Some studies compare L. pneumophila to other microorganisms. Other studies look at the cases of Legionellosis and investigate the causes of the outbreaks.

s Invasion and intracellular replication of L. pneumophila within pulmonary cells in the alveoli are the hallmark of Legionnaires’ disease [30]. The alveolar wall is composed of macrophages and type I and type II epithelial cells.

ReviewCell biology of the intracellular infection by Legionella pneumophila

Microbes and Infection Volume 6, Issue 1, January 2004, Pages 129-139Review Cell biology of the intracellular infection by Legionella pneumophila Maëlle Molmeret a Dina M. Bitar b c Lihui Han b d Yousef Abu Kwaik a Show morehttps://doi.org/10.1016/j.micinf.2003.11.004 Get rights and content Abstract Legionella pneumophila has become a paradigm for facultative intracellular pathogens that modulate biogenesis of their phagosomes into replicative niches.

The ability to alter host cell biology and tailor it into a hospitable host for intracellular proliferation is at the crux of the mechanism of pathogenesis of Legionnaires’ disease. Previous article Next article Keywords Intracellular Dot/icm Secretion1. Introduction Legionella pneumophila, a Gram-negative bacillus ubiquitous in aquatic environments, is responsible for Legionnaires’ disease.

It is a facultative intracellular pathogen that can replicate within eukaryotic host cells such as protozoa and macrophages. In humans, L. pneumophila reaches the lungs after inhalation of contaminated aerosol droplets [1,2] ( Fig. 1 ). Once in the lungs, L. pneumophila is ingested by alveolar macrophages, which are the major site of bacterial replication.

This results in an acute and severe pneumonia, Legionnaires’ disease. Download full-size image Fig. 1. The environmental life of L. pneumophila within protozoa. (1) L. pneumophila from biofilms with other bacteria, or in suspension, infecting protozoa.

(2) Following entry, L. pneumophila resides in a membrane-bound vacuole that recruits host cell organelles, such as the mitochondria and the RER, and does not fuse with lysosomes. (3) Mutants such as dot/icm mutants fuse to lysosomes 3b. L. pneumophila replicates within specialized vacuoles and reaches large numbers 3a.

(4) The infectious particle is not known, but may include excreted legionella-filled vesicles, intact legionella-filled amoebae, or free legionellae that have lysed their host cell. (5) Transmission to humans occurs via mechanical means, such as faucets and showerheads. Infection in humans occurs by inhalation of the infectious particle and establishment of infection in the lungs.

(6) Legionellae that have escaped their host cell may survive in suspension for long periods of time, reinfect other protozoa, or recolonize biofilms. Reprinted from ASM News. 66 (10) (2000) 609–616. The unique intracellular fate of L. pneumophila is one of the interesting aspects of this organism.

Unlike phagosomes containing inert particles or avirulent bacteria, the L. pneumophila -containing vacuoles avoid the “default” endocytic pathway, recruiting rough endoplasmic reticulum (RER) and mitochondria, to reside in a specialized vacuole allowing intracellular replication [3–7] ( Fig. 2 ). The formation of this specialized vacuole is directed by the type IV secretion system encoded by the dot/icm genes. The dot (defect in organelle trafficking)/ icm (intracellular multiplication) loci consist of 23 genes located in two distinct regions of the L. pneumophila chromosome [8–10].

Analysis of the predicted amino acid sequences of the dot/icm genes has revealed several characteristics that indicate a role in conjugal transfer of DNA, which has been confirmed by conjugation studies [9,10]. This apparatus has also been shown to be involved in proper maturation of the L. pneumophila- containing phagosome in mammalian and protozoan cells, directing the biogenesis of the specialized vacuole in which Legionella replicates [11–13].

The dot/icm genes are also required for macropinocytosis in A/J mouse macrophages [14], upregulation of phagocytosis in human-derived macrophages [15], induction of apoptosis in macrophages [16–18] and pore formation-mediated cytotoxicity in both protozoan and mammalian cells [13,19–21].

Download full-size image Fig. 2. Transmission electron micrographs of the infection of A. polyphaga (top panel) and U937 macrophages (bottom panel) by L. pneumophila. Coiling phagocytosis (A and B); formation of the RER-surrounded phagosome (C and D); and late stages of the infection (E and F). Note that in E and F, there is no intact phagosomal membrane. Reprinted from ASM News. 66 (10) (2000) 609–616.2.

Growth phase-regulated virulence In contrast to exponentially growing bacteria, L. pneumophila obtained from post-exponential cultures expresses traits that are correlated with virulence, including sodium sensitivity, cytotoxicity, osmotic resistance, motility, and the capacity to evade phagosome–lysosome fusion [22–25]. During the replication phase within host cells, L. pneumophila is sodium resistant and aflagellated [22–25].

When L. pneumophila egresses from host cells, the bacteria are flagellated and sodium sensitive [22–25]. It has been hypothesized that amino acid limitation in vitro induces the virulent phenotype [22–25]. When L. pneumophila enters into post-exponential growth phase or is subjected to amino acid limitation, the bacteria accumulate the stringent response signal, guanosine 3′,5′-bispyrophosphate (pp Gpp) through the pp Gpp synthetase, Rel A [26].

When rel A from Escherichia coli is expressed in L. pneumophila, pp Gpp accumulates and the bacteria express virulent traits independently of nutrient supply or cell density [26]. The accumulation of pp Gpp increases the amount of the stationary-phase sigma factor Rpo S, which triggers the expression of the stationary-phase genes [26].

An rpo S mutant of L. pneumophila replicates within HL60 and THP-1 monocytic cell lines, but is attenuated in Acanthamoeba castellanii [27].

In bone marrow-derived macrophages from A/J mice, L. pneumophila rpo S mutants replicate poorly because they traffic rapidly to a late endosome-like compartment [26]. However, Bachman et al. used a different L. pneumophila strain, Lp02, whereas Hales et al. used JR32.

It has been shown that some genotypic and phenotypic differences exist between the AA100, JR32 and Lp01 stains, which are the most commonly used in the virulence studies [28]. AA100 is clearly the most virulent, whereas Lp01 is the least. Therefore, the differences between L. pneumophila strains and/or between the host cells may explain the different intracellular growth observed for the rpo S mutants.

Sodium sensitivity and maximal expression of flagellin also require Rpo S [26]. Therefore, some Rpo S-regulated traits could be critical for efficient transmission or infection in this amoebae model [27].

L. pneumophila in post-exponential phase becomes cytotoxic by an Rpo S-independent pathway [26]. To replicate efficiently in macrophages, both Rpo S-independent and -dependent mechanisms are utilized by L. pneumophila [26].

Thus, when nutrient levels and other conditions are favorable, L. pneumophila replicates within host cells, and when amino acids become rare, intracellular bacteria express several traits that permit escape from the host cell, survival in the environment and the transmission to a new host.

The rel A mutant, producing an undetectable level of pp Gpp in the cells during stationary phase, is unable to produce pigment as it becomes flagellated. Although a previous study has shown that Rpo S, which accumulates when Rel A is activated, is required for intracellular growth in A. castellanii [27], Zusman et al. [29] have shown that the rel A gene product is dispensable for intracellular growth in HL-60-derived human macrophages and in A. castellanii. Moreover, it has also been shown that Rel A and Rpo S have minor effects on expression of some of the dot/icm genes ( icm T, R, Q, P, M, J, F, V, W) [29]. Thus, the role of Rpo S in the intracellular infection seems to be host cell specific.3. Adherence and entry into mammalian cell

s Invasion and intracellular replication of L. pneumophila within pulmonary cells in the alveoli are the hallmark of Legionnaires’ disease [30]. The alveolar wall is composed of macrophages and type I and type II epithelial cells.

The attachment of L. pneumophila in macrophages has been shown to be mediated, at least in part, through attachment of complement-coated bacteria to the complement receptor [31], although non-complement-mediated uptake also occurs [32,33]. The host cell receptor involved in non-complement-mediated uptake in macrophages and epithelial cells is not known.

Uptake of L. pneumophila by monocytes and macrophages has been shown to occur through conventional and coiling phagocytosis [6,32,34–36] ( Fig. 2 ). Since heat-killed and formalin-killed L. pneumophila are also taken up by coiling phagocytosis [6] but are targeted to the lysosomes [7], this mode of uptake may not play a role in subsequent trafficking of the bacteria.

Many clinical isolates of L. pneumophila have been shown to be taken up exclusively by conventional phagocytosis [32,34]. In addition, other species of legionellae, such as L. micdadei, which is the second most common species of legionellae that causes Legionnaires’ disease, is taken up exclusively by conventional phagocytosis [34].

The bacterial ligand that mediates the coiling mode of phagocytosis is not known. Moreover, the phagocytic receptor that binds the bacteria seems to play some role in determining the fate of the intracellular bacteria, since opsonization with antibodies reduces intracellular growth [31,37,38].

Studies have focused on the genetic aspects of the uptake of L. pneumophila into its host cells. L. pneumophila mutants impaired in different loci, such as rtx A and enh C, display significantly reduced entry into host cells, compared with wild-type bacteria [39].

It has been shown recently that the enhanced phagocytosis of L. pneumophila by mammalian cells is dot/icm dependent [15]. Interestingly, the dot/icm genes delay uptake and induce macropinocytosis in A/J mouse macrophages [14]. With the exception of A/J mice, most of the inbred mouse strains are not permissive to L. pneumophila infection; neither are macrophages isolated from these mice [40,41].

Macropinosomes containing L. pneumophila in A/J mouse macrophages are induced transiently and shrink rapidly (5–15 min) [14], and this mode of uptake is linked to the lgn1 locus on chromosome 13 of mice [14,42,43]. In macrophages of non-permissive strains of mice, the macropinocytic uptake of L. pneumophila is reduced [14].

The lgn1 allele makes the bacteria behave as if they were lacking the dot/icm system [14]. Thus, the lgn1 allele is required for dot/icm -dependent macropinocytosis and delayed uptake by mouse macrophages [14]. Whether this mode of uptake plays a role in subsequent trafficking of L. pneumophila is not known.4. Intracellular fate of L. pneumophila4.1. Intracellular replication within host cells Similarly to the protozoan infection, within 5 min following entry of the bacteria into macrophages and monocytes, the L. pneumophila phagosome is surrounded by host cell organelles such as mitochondria, vesicles, and the RER [5,44,45] ( Fig.

2 ). Also similarly to the trafficking of L. pneumophila within protozoa [46], it has been shown that the phagosome within mammalian macrophages does not fuse to lysosomes [4,6,7] ( Fig.

2 ), at least at the early stage of the infection [47]. The role of the RER in the intracellular infection is not known, but the RER is not required as a source of proteins for the bacteria [48].

Interestingly, examination of the intracellular infection of macrophages, alveolar epithelial cells, and protozoa by another Legionella species, L. micdadei, showed that within all of these host cells, the bacteria were localized to RER-free phagosomes [49]. Whether other Legionella species replicate within RER-free phagosomes has still to be determined. Macrophages, peripheral blood monocytes, and alveolar epithelial cells support intracellular replication of L. pneumophila [37,50].

Although alveolar epithelial cells, which constitute more than 95% of the alveolar surface [50], have been shown to allow intracellular replication of L. pneumophila, their role in the pathogenesis has been largely overlooked.4.2. The dot/icm genes and their role in evasion of vesicle traffic The Dot/Icm type IV secretion system is the main L. pneumophila virulence system.

Because the Dot/Icm secretion system is ancestrally related to type IV secretion systems that mediate conjugal DNA transfer between bacteria [51], L. pneumophila may utilize this transporter to transfer macromolecules into the host cell to evade endocytic fusion [8,10]. The dot/icm loci may be involved in the insertion of a pore in the host cellular membrane through which the effector proteins are exported into the host cell [52,53].

The effector molecules involved in intracellular trafficking and evasion of the lysosomal fusion within mammalian cells are cis -acting on the phagosome but do not alter endocytic fusion in the rest of the cell [54]. With few exceptions, the function of individual Dot/Icm proteins is unknown. The Dot A protein was the first to be described [55].

It is a polytopic inner membrane protein with eight hydrophobic transmembrane domains [56]. The dot A mutants are defective in all virulence activities that require the Dot/Icm complex [12,45,53,55,57,58].

These data are supported by the fact that the Dot A sequence possesses significant similarities to that of Tra Y [59,60], a component of the type IV transporter required for conjugal transfer of plasmids Col Ib P9 and R64. However, Nagai and Roy [61] have shown that the Dot A protein is also secreted through the Dot/Icm transporter into the culture supernatant during growth of L. pneumophila in liquid broth via a functional type IV secretion system.

Electron micrographs also show that purified Dot A can form an oligomer [56,61]. As Dot H/Icm K and Dot O/Icm B in growing L. pneumophila cultures are mainly associated with the membranous fraction, and as dot/icm products may be required during direct contact with host cells, the location of Dot H and Dot O proteins on the surface of L. pneumophila has been examined [62].

These proteins are surface exposed and associated with a fibrous structure on L. pneumophila after exposure to bone marrow-derived macrophages.

In contrast, during broth culture, this fibrous structure is absent [62]. However, using dot A, dot B, dot H, dot O mutants, it has been shown that the exposure of Dot O/Dot H on the bacterial surface is not dependent on other Dot/Icm proteins, including the Dot H protein for the Dot O exposure, and vice versa [62].

This result shows that the surface exposure of Dot H and Dot O after contact with macrophages is not dependent on an intact Dot/Icm secretion system [62]. The surface exposure of these two proteins does not involve bacterial contact with the target cell, since bacteria incubated in medium that has been conditioned by bone marrow-derived macrophages for 24 h yield almost identical results [62].

In addition, Dot H and Dot O surface exposure on L. pneumophila requires intracellular growth of the bacteria in macrophages and is observed late in the infection process, mostly when there are more than 30 bacteria per phagosome [62]. In fact, surface-exposed Dot H and Dot O disappear after uptake but reappear following intracellular growth. The exposure of these two proteins increases L. pneumophila uptake into cells [62] and may be necessary to promote bacterial escape from the phagosome and to facilitate the initiation of a new infection in macrophages [62].

These data may also suggest that macrophage components are able to induce changes in the L. pneumophila envelope, and Dot H/Dot O export may occur as a response to the target macrophages just before uptake to allow efficient initiation of intracellular growth.

Dot/Icm proteins such as Icm R, Icm Q, Icm X or Icm W do not present sequence homology to other protein components of type IV secretion system [9,10,51]. Icm X, a periplasmic protein, is required for biogenesis of the replicative phagosomes containing L. pneumophila [63].

A truncated Icm X product is secreted into culture supernatants by wild-type L. pneumophila growing in liquid media, but the transport of the protein into eukaryotic host cells has not been detected [63]. Icm S and Icm W are small proteins required for the trafficking of the Legionella -containing phagosome, and may function as chaperones to help the secretion of proteins through the type IV secretion system [58,61].

It has also been shown that Icm S and Icm W interact, suggesting that they may be components of a protein complex that is required for modulating phagosome biogenesis [58]. The phagosomes of the icm S and icm W mutants fuse to lysosomes [58]. Interestingly, phagosomes harboring icm S and icm W mutants still recruit host vesicles including the RER.

It is still to be confirmed whether recruitment of host vesicles does not prevent the phagosome from lysosomal fusion [64]. The Icm R protein may also be a chaperone [58]. An icm R mutant can partially evade the endocytic pathway, but eventually fuses with the lysosomes [58].

These data suggest that Icm R may be a co-factor for another protein effector involved in evasion of lysosomal fusion [64]. The icm R mutant that evades endocytic fusion does not recruit host vesicles, and the phagosome is not surrounded by the RER [64]. Thus, effector molecules that recruit host cell vesicles may be different from the ones involved in evasion of the endocytic pathway [64].

Similarly to dot A and icm X mutants, an icm Q mutant is defective in all virulence activities [58]. Furthermore, the icm Q gene, like the icm R and icm S genes, encodes soluble protein. The Icm R and Icm Q proteins interact as protein chaperone-substrate.

The presence of Icm R that has chaperone characteristics (it is acidic, small and predicted to have a hydrophobic alpha-helix in its C-terminal domain) affects the physical state of Icm Q directly [65]. Icm R prevents Icm Q from participating in the formation of high-molecular-weight complexes by dissociating Icm Q homopolymers [65].4.3.

Recruitment of RERIn 1982 Katz and Hashemi [66] showed that the L. pneumophila -containing phagosome resembles the ER membrane. By electron microscopy, replicating L. pneumophila within macrophages was visualized located within organelles morphologically identical with the RER [66] ( Fig. 2 ). Later, several studies demonstrated that upon internalization of L. pneumophila by the host cell, the Legionella -containing vacuole recruits organelles such as vesicles, mitochondria and ER ( Fig.

2) [5,46,66,67]. Using fluorescent markers specific for the ER, it has been shown that the L. pneumophila -containing vacuoles may resemble nascent autophagosomes [12]. Autophagy is a cellular process for the degradation of unwanted organelles and cellular components during which the autophagosome is formed from the smooth ER and fuses to lysosomes [68]. The hypothesis that L. pneumophila exploits the autophagy machinery in host cells and establishes an intracellular niche favorable for replication [12] has been challenged recently (see below) [44,64].

Recent studies suggest that fusion [64] or the exchange of lipid bilayer with ER vesicles on the L. pneumophila -containing phagosome [44] occurs, allowing the phagosomal membrane to become as thin as the ER membrane, with similar characteristics [44,64]. It has been shown that, within 5 min of uptake, host vesicles come into contact with wild-type Legionella -containing phagosomes and flatten along the surface of the phagosome, and this process is completed within 15 min [44] and is dot/icm dependent [44].

This is consistent with earlier studies that have shown that after 4 h of infection, there are only a few vesicles associated with the phagosomal membrane, but there are ribosomes studding the phagosomal membrane [5].

In contrast, autophagy takes place within 1 h, and ribosomes, mitochondria, and the nuclear membrane are not attached to the autophagosomal membrane; neither are the tiny hairs that connect ER and L. pneumophila -containing phagosomes [44]. Interestingly, the thickness of the phagosomal membrane becomes similar to that of the ER membrane within 15 min [44], which doesn’t happen in the autophagy process.

Thus, within 15 min of infection, the phagosomal membrane resembles that of the ER. The ribosomes at 6 h stud the phagosomal membrane, and L. pneumophila is thought to be located within the RER [44].

However, these studies rely completely on the thickness of the membranes of the ER and the phagosome membranes to provide evidence that L. pneumophila is located within the RER [44]. Immunocytochemical studies should be performed to confirm these observations. It is likely that the recruitment of the ER may be involved in the biogenesis of the phagosome that is dependent on the type IV secretion system, since the dot/icm mutants are unable to recruit RER, and their phagosomes fuse to the lysosomes [12].

Interestingly, a recent study showed that recruitment of RER to forming-phagosomes may be part of regular phagocytosis [69]. Electron micrographs of latex beads and pathogens such as Salmonella within macrophages have shown that ER membranes fuse with plasmalemma, underneath the phagocytic cup, and successive waves of ER are recruited to the phagosomes of latex beads and bacteria.

In neutrophils, the bacteria are quickly killed, and the ER is not involved in the turnover of membrane for phagocytosis [69]. However, since the dot/icm system is essential for RER recruitment [12], it is likely that L. pneumophila utilizes a specific pathogen-regulated process to recruit vesicles, and this process is distinct from regular phagocytosis.4.4.

Interception of early vesicle traffic from the RERThe protein ADP ribosylation factor-1 (ARF1), a highly conserved small GTP-binding protein, which acts as a key regulator of vesicle traffic from ER to Golgi, is found on about 30% of the phagosomes that contain wild-type L. pneumophila but not dot/icm mutants [70].

These data suggest that a protein injected through the type IV secretion system may be required for ARF1 recruitment. Searching the L. pneumophila genome for proteins that have homology to ARF-specific guanine nucleotide exchange factors (GEFs), Nagai et al.

[70] have identified a protein, Ral F, that has a sec7-homology domain, known to be sufficient to stimulate the exchange of GDP for GTP. It has been shown that Ral F is injected through the phagosomal membrane by a process that requires the Dot/Icm system [70]. However, phagosomes containing ral F mutants that do not recruit ARF1 evade fusion to lysosomes, and the bacteria replicate intracellularly within macrophages and amoebae [70].

Thus, Ral F is not essential for transport of L. pneumophila to the ER [64,70]. It has been shown recently that the L. pneumophila -containing phagosome is a transitional ER (t ER)-derived organelle [71]. Its biogenesis involves intercepting early secretory vesicles exiting from t ER [71]. Vesicular transport from ER exit sites is not necessary for the recruitment of ARF to L. pneumophila -containing phagosomes.

The vesicular transport from ER exit sites is an ARF-dependent process used for remodeling the L. pneumophila -containing phagosome. The final stage of the biogenesis of the mature ER-derived vacuole is marked by the loss of ARF and the accumulation of calnexin.

Moreover, ral F mutants also mature in calnexin-positive RER-derived vacuole, similarly to the wild-type strain. The Ral F protein is not essential in phagosome transport, replicative organelle biogenesis or intracellular replication [71]. Subversion of the early secretory pathway is an effective way of gaining access to the ER lumen and exploiting translocation machinery of this environment [71].4.5.

The “trafficking” pore and the “egress” pore Kirby et al. [53] have described the pore-forming ability of L. pneumophila in host cell membranes. This was documented by lysis of macrophages and red blood cells, which is dependent on the Dot/Icm secretion system [53].

Since dot/icm mutants are defective in evasion of lysosomal fusion, it has been proposed that the pore-forming activity is required for export of effector molecules necessary for evasion of the lysosomal fusion [53].

Upon initial contact with the host cell, L. pneumophila may insert a pore into the plasma membrane to deliver bacterial effector molecules into the host cell [52,53]. This concept is supported by the fact that many dot/icm mutants are defective in both intracellular replication and pore formation-mediated cytotoxicity [52,53].

Moreover, some dot/icm mutants are defective in trafficking and intracellular replication but not in the pore-forming activity [72]. We have identified five spontaneous mutants that are unable to egress from the macrophages but are able to grow as well as the wild-type strains within these cells [20].

These mutants, designated rib (release of intracellular bacteria), are defective in the pore-forming toxin/activity as shown by the contact-dependent hemolysis assay and by permeability to propidium iodide upon infection of macrophages and epithelial cells [20].

The rib mutants are also defective in acute cytotoxic lethality to A/J mice and fail to cause alveolar inflammation [13,20] indicating a key role for the pore-forming toxin in the pulmonary pathology of the bacterium. We have further documented that the Rib toxin is not required for intracellular trafficking and replication [19–21]. In addition to defects in evasion of lysosomal fusion, dot/icm mutants are also defective in induction of apoptosis [18], enhancement of phagocytosis by human-derived macrophages [15] and induction of macropinocytic delayed uptake by A/J mouse macrophages [14].

In contrast, rib mutants are defective in pore-forming toxin but are not defective in evasion of lysosomal fusion, intracellular replication, or induction of apoptosis [18,20,21]. These observations may suggest that there are at least two pores inserted into host membranes through the type IV secretion system at different stages of the infection [73].

The first pore is the “invasion and trafficking pore”, which is inserted upon initial contact with the host cell to deliver effectors into the host cell cytoplasm and allow the establishment of the intracellular infection. The dot/icm genes necessary for the assembly of the secretion apparatus are constitutively expressed and are required for this step [27].

The second pore is the “egress pore”, which is triggered during the late stages of intracellular replication and is essential for lysis of the host cell ( Figs. 3 and 4 ) [20]. This is consistent with the fact that upon transition into the post-exponential growth in vitro, L. pneumophila becomes cytotoxic [24].

Thus, the rib mutants retain the “invasion and trafficking pore” but are defective in the “cytolysin/egress pore”, since they replicate within but fail to egress from the host cells ( Figs.

3 and 4 ). Download full-size image Fig. 3. The rib mutants’ defect in cytolysis of the host cell is due to a defect in necrosis-mediated killing. Representative transmission electron micrographs of infected U937 macrophages at 24 and 48 h post-infection by the wild-type strain AA100 and the GN229 mutant.

The original magnifications were 7000× and 5000× for the 24- and 48-h infections, respectively. Reprinted from [20]. Download full-size image Fig. 4. A model of growth phase-dependent cytolysis of mammalian cells by L. pneumophila upon termination of intracellular bacterial replication to egress from the spent host cell.

During early stages of formation of the mitochondria and RER-surrounded phagosome (A) and during exponential intracellular replication (B), expression of the pore-forming activity is turned off, but caspase-3-mediated apoptosis is triggered.

Upon transition to the post-exponential phase of growth, expression of the pore-forming activity is triggered, which results in insertions of pores in the phagosomal membrane first (C), leading to its disruption (D). This is followed by insertions of pores in the plasma membrane (E), leading to osmotic lysis of the cell and release of the intracellular bacteria.

Reprinted from [20]. The phenotype of the rib mutants is attributable to a point deletion in the icm T gene that is predicted to result in a truncated protein of 54 amino acids instead of the 86 amino acids of the native protein [13,21].

In contrast, an icm T null mutant is defective in both intracellular replication and pore formation [13,21,74]. It has been shown that icm T expression is induced at stationary phase compared with the exponential phase [75]. We have shown that Icm T is bifunctional and that the carboxy terminus is essential for the pore-forming “cytolysin/egress pore” activity, and the amino terminus is essential to export effectors involved in various pathogenic traits [13,21].

We hypothesized that upon transition to the post-exponential phase of growth, the Rib toxin activity is triggered, resulting in insertions of pores in the phagosomal membrane, leading to its disruption and bacterial egress into the cytoplasm ( Figs.

3 and 4 ). To test this hypothesis, we examined late stages of the intracellular infection of macrophages and amoebae by electron microscopy. Our data showed that disruption of the phagosomal membrane was detectable 12 h post-infection of both Acanthamoeba polyphaga and macrophages (unpublished data).

After 12 and 18 h post-infection in both host cells, vesicles and organelles from the host cytoplasm entered into the Legionella -containing phagosome.

Between 18 and 24 h, most of the bacteria present in this disrupted phagosomal membrane were surrounded by cytoplasmic organelles, and not by distinct phagosomal membrane (unpublished data). These data show that the phagosomal membrane is disrupted first, rather than undergoing lysis simultaneously with the plasma membrane.

Whether this disruption is the result of a mechanical process or linked to the pore-forming activity of the type IV secretion system [21,53,73], is not known. Our data are consistent with a previous study in which Katz and Hashemi [66] had observed on electron micrographs that when present in macrophages at numbers greater than 25 per cell, L. pneumophila was usually dispersed within the cytoplasm of the host cell.5.

Apoptotic or necrotic cell death5.1. Induction of apoptosis by L. pneumophila in mammalian but not protozoan host cells Apoptosis requires a cascade of activation of a family of cysteine proteases (caspases) that specifically cleave proteins after aspartate residues [76]. Among them, caspase-3 plays a central role, allowing caspase-activated DNase to enter the nucleus and degrade chromosomal DNA [77].

Muller et al. [78] have shown that L. pneumophila induces apoptosis in HL-60 human-derived macrophages after 24–48 h, at a multiplicity of infection (MOI) of 10–100. The induction of apoptosis in mammalian cells is mediated by activation of caspase-3 that is dose dependent and is maximal at 3 h post-infection at an MOI of 50 [16,17] ( Fig.

4 ). In alveolar epithelial cells and macrophages, the induction of apoptosis is dose dependent but not largely growth-phase regulated and can be induced by extracellular bacteria [16,17]. The dot/icm mutants of L. pneumophila are defective in inducing caspase-3 activation and, thus, apoptosis [16,18].

Therefore, the Dot/Icm type IV secretion system of L. pneumophila is essential for the induction of apoptosis in mammalian cells [16,18]. The pore-forming toxin is not required for the induction of apoptosis, but upon entry into the post-exponential growth phase, it enhances the ability of the bacteria to induce apoptosis [18]. Interestingly, L. pneumophila induces apoptosis in human phagocytes but not in protozoan host cells such as A. castellanii [19,79].

Moreover, although A. polyphaga is capable of undergoing apoptosis, including DNA fragmentation, upon stimulation by actinomycin D, L. pneumophila does not induce apoptosis in A. polyphaga [17,19].5.2. Induction of necrosis by L. pneumophila in mammalian and protozoan cells The dot/icm -regulated Rib pore-forming toxin is essential for L. pneumophila induction of necrosis, killing, and exiting the host cells [19–21].

At high MOI, mutants defective in the Rib pore-forming toxin replicate like the wild-type strains within the protozoan and mammalian cells but are trapped within these cells and cannot be released ( Figs.

3 and 4) [19,20]. The expression of the pore-forming activity by L. pneumophila grown in vitro and within macrophages is completely repressed during exponential growth but is temporarily activated upon entry into post-exponential phase ( Fig.

4) [20]. Therefore, the Rib pore-forming activity is not required for phagosomal trafficking and intracellular multiplication of L. pneumophila within the cells, but is essential for induction of cytolysis of the infected macrophages [19,20].

Thus, the C-terminus of Icm T is essential for pore formation-mediated cytolysis [20,21]. Experiments performed with an Icm T null mutant which is defective in intracellular trafficking, and multiplication in both protozoan and mammalian cells, suggest that Icm T is bifunctional [13,21]. The C-terminus of Icm T is essential for pore formation-mediated cytolysis in mammalian cells, and the N-terminus is required for intracellular trafficking [13].

It is unlikely that Icm T is an effector or a common regulator, but it is possible that this protein is a co-factor involved in the export of different substrates with roles in pore-forming toxicity and intracellular trafficking [13]. Effectors of this type IV secretion system remain to be identified.5.3. Egress of L. pneumophila The ability to lyse host cells and to egress from them is a fundamental step in the pathogenic cycle of intracellular bacteria and determines the overall consequences of the infection of an organism.

Apoptosis and necrosis are the two commonly observed types of cell death. Necrosis is characterized by physical damage causing cell death.

Apoptosis is a regulated suicide program of the cell, manifesting morphological and biochemical features distinct from those of necrosis [80]. Killing of mammalian cells by L. pneumophila has been proposed to occur in two phases [16,17] ( Fig.

4 ). In the first phase, L. pneumophila induces apoptosis in macrophages, monocytes and alveolar epithelial cells during the early stages of the infection [17,79], apoptosis which is mediated through the activation of caspase-3 [16]. Induction of apoptosis is largely independent of the bacterial growth phase [16]. The second phase is mediated through rapid induction of necrosis by L. pneumophila upon entry into the post-exponential phase of growth, when the bacteria become cytotoxic ( Fig.

4 ). Our working model of bacterial egress can be presented in three steps ( Fig. 4 ). First, upon exiting the exponential phase of intracellular growth, an “egress pore” is inserted into the phagosomal membrane, leading to its disruption.

Second, the bacteria egress into cytoplasm. Third, disruption of organelles and the plasma membrane occurs, culminating in lysis of the host cells and bacterial egress.5.4. The neuronal apoptosis inhibitory protein (Naip) and susceptibility of mice to L. pneumophila L. pneumophila is unable to replicate in macrophages derived from most inbred mouse strains, with the exception of the A/J strain [81].

The natural resistance of these mouse strains to infection with L. pneumophila is controlled by the expression of a single dominant locus mapped on mouse chromosome 13, designated lgn1 [41,43,81]. The intracellular growth of species other than L. pneumophila are not under lgn ’s control [82]. The mouse lgn1 region includes six copies of the neuronal apoptosis inhibitory protein ( naip) gene.

The Naip proteins have been shown to be direct inhibitors of caspases 3 and 7 [83]. Interestingly, the Naip proteins are less expressed in macrophages derived from permissive A/J mice than from the non-permissive inbred strains, but their expression is increased after the phagocytic events in both strains of mice [84]. This increase does not require intracellular replication, since the avirulent dot A mutant and the inert latex particles also cause an increase in naip expression [84].

This reduced naip expression in A/J macrophages may result in enhanced ability of L. pneumophila to induce apoptosis through activation of caspase-3 and thus, increased permissiveness to infection [84]. Recently, naip5, also known as birc1e (baculoviral inhibitory apoptosis protein repeat-containing 1), was shown to be the only gene responsible for susceptibility to Legionella [85,86]. In contrast to other Naip expression levels, Naip5 expression levels have shown large differences between A/J macrophages and non-permissive macrophages.

[85]. A bacterial artificial chromosome (BAC) transgenic line expressing a non-permissive allele of naip5 has exhibited a reduction in permissiveness to Legionella [85,86].

An antisense inhibitor of the translation of the m RNA of Naip5 has caused an increase in the permissiveness of permissive and non-permissive macrophages to Legionella [85]. These results indicate a role for birc1e/naip5 in macrophage resistance to L. pneumophila infection. The mechanism of action is not yet known. Although Naip differs from the classical IAPs [87], it was thought to belong to the inhibitor of apoptosis (IAP) family of anti-apoptotic proteins, which were first identified in baculoviruses [88].

A recent study has shown that Naip proteins are part of the nucleotide-binding oligomerization domain (NOD) proteins. NOD proteins are a large family of proteins involved in apoptosis and innate immunity [89–91]. Several NOD proteins have already been shown to be implicated in the activation of caspases such as APAF1, which is involved in activation of caspase 9 [92].

NOD1 and NOD2, also part of the NOD family, have been shown to mediate the recognition of specific Gram-negative bacterial components such as lipopolysaccharides (LPS) and peptidoglycan, once they are processed in the cytosol [90,93,94]. Most of the NOD family members contain three distinct functional domains. The first domain is the amino-terminal effector-binding domain (EBD), which is variable among NOD family members [89].

The EBD amino-terminal domain of the Naip proteins contains an N-terminal domain with 1–3 repeats of an approximately 65-amino-acid motif, termed the baculovirus IAP repeat (BIR) [88,90]. The role of BIRs in Naip remains to be determined, but it is thought to bind and inhibit caspase-3 [83].

The second domain is a central domain, designated NOD, which mediates self-oligomerization, required for the activation of downstream effector molecules. The third domain is a carboxy-terminal ligand-recognition domain (LRD), generally called LRR domain (leucine-rich repeats) [89,91].

Mammalian toll-like-receptors (TLRs) have multiple LRRs in the ectodomain. The LRD domain of Nod1 and Nod2 have been shown to be essential for LPS-mediated NF-κB activation, independently of TLR4, My D88 and TRAF6, which all together, mediate activation of NF-κB [93,94]. In fact, Nod1 and Nod2 seem to be the cytosolic counterparts of TLRs [91]. Activation of the TLRs initiates intracellular signaling cascades that culminate in the activation of NF-κB.

NF-κB has been referred to as a central mediator of the immune response, since its activation controls the expression of many inflammatory cytokines, chemokines, immune receptors, and cell surface adhesion molecules. It is also a central regulator of stress responses [95]. However, it is not known whether NAIP, which renders macrophages permissive to replication by L. pneumophila, or TLRs known to bind components of the bacterial surface (TLR4 in particular, for the LPS of the Gram-negative bacteria) on the surface of the host cell are involved in the regulation of innate immunity to L. pneumophila via the activation of NF-κB.

Naip has been shown to be less expressed in A/J macrophages than in non-permissive ones [84] and is a direct inhibitor of caspase-3 [83]. If Naip proteins mediate the activation of NF-κB, a lower concentration of Naip in the permissive macrophages may result in a decreased ability to activate NF-κB and in enhanced ability of L. pneumophila to induce apoptosis.

Therefore, Naip5 can potentially mediate resistance to L. pneumophila through two different pathways. First, it may function as an IAP-like protein to block caspase-3 activation, which is required for intracellular replication (Molmeret et al., 2003 unpublished). Second, Naip5 may function as a Nod-like protein that activates NF-κB to generate certain responses involved in apoptosis and/or innate immunity.6.

Conclusion The type IV secretion system is a key virulence system of L. pneumophila, allowing it to invade the host cells, replicate, evade the endocytic pathway, induce apoptosis, and egress from the host cells [13–21]. Not all the functions of the Dot/Icm proteins have been understood, and no effectors other than Ral F have yet been identified.

However, the Ral F protein is not essential in phagosome transport or replicative organelle biogenesis. Interestingly, L. pneumophila avoids phagosome–lysosome fusion within the first few minutes of the intracellular infection, and the phagosomes are converted into endoplasmic reticulum-derived organelles that support intracellular replication [44].

This process involves intercepting early secretory vesicles exiting from the transitional ER [71]. After 4 h, L. pneumophila starts to replicate within this replicative organelle. Between 8 and 18 h, the phagosomal membrane is gradually disrupted, and the bacteria become cytoplasmic and are dispersed among cytoplasmic organelles such as mitochondria and lysosomes prior to lysis of the host cell (Molmeret et al., submitted).

Further investigations should be focused on determination of whether the disruption of the phagosomal membrane is due to the action of a toxin.

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? - primarily cell mediated, with humoral immunity playing a minor role - bacteria are not killed until sensitized helper T (TH1) cells active parasitized macrophages - production of interferon-gamma (IFN-gamma) is critical for elimination of Legionella pneumophila interferon-gamma is the macrophage-activating factor

Legionella

60 terms bernsie Legionella Learn Flashcards Write Spell Test Match Gravity Advertisement Upgrade to remove ads Sort What outbreak illness event brought attention to Legionella pneumophila? When did it take place? Who did it affect and how did it affect them? - outbreak of severe pneumonia in a American Legion convention in Philadelphia - 1976 - caused many deaths in American Legion members that attended the convention Is Legionella pneumophila gram-positive or gram-negative?

gram-negative What 3 words can be used to describe the morphology of Legionella pneumophila? slender, pleomorphic rods How well does Legionella pneumophila stain with conventional dyes / common reagents?

poorly Does Legionella pneumophila bacteria grow on common laboratory media? no What 3-word phrase can be used to describe Legionella pneumophila? ubiquitous aquatic saprophyte What is the most notable Legionella species? Legionella pneumophila Is Legionella pneumophila fermentative?

no What word describes the nutritional requirements of Legionella pneumophila? fastidious What is a nutritional requirement of Legionella pneumophila (an amino acid)? L-cysteine (require media supplemented with L-cysteine and iron for primary isolation)What can enhance the growth of Legionella pneumophila?

iron salts (require media supplemented with L-cysteine and iron for primary isolation)In what cells in infected hosts and in what organisms is Legionella pneumophila capable of replicating? - alveolar macrophages, monocytes, alveolar epithelial cells - amoebae What type of cellular / organelle fusion does Legionella pneumophila prevent?

What 3 toxic substances do not kill Legionella pneumophila because of this prevention? - phagolysosome - superoxide, hydrogen peroxide, hydroxyl radicals What 2 diseases is Legionella pneumophila responsible for? Legionnaires' disease Pontiac fever How many genuses are in the family Legionellaceae? What is / are their name (s)? 1 genus - Legionella How many species are in the family Legionellaceae / genus Legionella? 50 species What percentage of all Legionella species have been implicated in human disease?

What percentage of all Legionella species are found in environmental sources? - 50% - 50%What percentage of all infections is caused by Legionella pneumophila? 90%Which 2 Legionella pneumophila serotypes are the most commonly isolated? 1 and 6What is Legionnaires' disease? pneumonia that may progress rapidly unless treated with appropriate antibiotics What is the mortality rate of Legionnaires' disease in previously healthy subjects?

10% (rate may be higher in those with nosocomial infection)What is Pontiac fever? brief, febrile influenza-like illness that may be slow to resolve fully, but does not cause death What is the size of Legionella pneumophila?

0.3 to 0.9 x 2 micrometers In what shape does Legionella pneumophila characteristically appear when observed in tissue? What do they look like in artificial media? - coccobacilli - up to 20 micrometers long (due to pleomorphism)What stain can be used on tissues in order to see Legionella pneumophila? Dieterle silver stain How would you characterize the oxygen requirements of Legionella pneumophila?

obligate aerobe What type of medium has been used as the basis for preliminary identification of clinical isolates? supplemented media (not conventional blood agar)Have Legionella pneumophila acquired multiple methods of acquiring iron from host cells or in vitro media? How does the loss of this ability affect the bacteria? - yes - loss of the ability leads to loss of virulence How and from what does Legionella pneumophila derive energy?

metabolism of amino acids In what population does Legionella species cause respiratory tract disease? susceptible people who inhale infectious aerosols What type of parasites are Legionellae? facultative intracellular parasites (can complete life cycle without depending on a host)What is critical for pathogenesis of Legionella pneumophila? ability to infect and replicate in macrophages What initiates the replicative cycle? What steps occur next?

- binding complement to an outer membrane porin protein and depositing complement component C3b on the bacterial surface - bacteria bind to CR3 complement receptors on mononuclear phagocytes - organisms penetrate cell via endocytosis - chemokine and cytokine release by infected macrophages --> severe inflammatory response - organisms proliferate in vacuole and produce proteolytic enzymes, phosphatase, lipase and nuclease - host cell is killed when vacuole is lysed What chemical are released by the infected macrophages that then causes a severe inflammatory response? chemokines and cytokines What enzymes are produced when Legionella pneumophila proliferates in the cell? proteolytic enzymes, phosphatase, lipase, nuclease Does Legionella pneumophila kill the cell? How? yes, when vacuole is lysed How would you characterize the immunity to Legionella pneumophila

What type of T cells help kill Legionella pneumophila in the body? sensitized helper T (TH1) cells Which interferon is critical for the elimination of Legionella pneumophila? interferon-gamma (macrophage-activating factor)What 3 types of infections is Legionella pneumophila capable of? sporadic, epidemic, nosocomial infections Where is Legionella pneumophila commonly found? natural bodies of water, cooling towers, condensers, water systems (including hospital systems)What is the annually estimated number of Legionella pneumophila infection cases in the U. S.?

10,000 - 20,000What patient populations are at high risk for Legionella pnuemophila symptomatic disease? - patients with compromised pulmonary function - patients with decreased cellular immunity (particularly transplant patients)What is the temperature range for optimum growth of Legionella pneumophila? 95 - 115 degrees Fahrenheit What are the temperature ranges for different growth/death patterns of Leigionella pneumophila?

all ranges are in degrees Fahrenheit 32 - 68: Legionella dormant 68 - 95: Legionella active 95 - ~110: Optimum growth range ~110 - 115: Legionella active 115 - 122: Legionella dormant 122 - 140: Slow death range 140 - 212: Fast death range Is microscopy sensitive to diagnosis of Legionella pneumophila?

no Which serogroup of Legionella pneumophila is sensitive to antigen tests? serogroup 1 (has poor sensitivity for other serogroups and species)What is the diagnostic test of choice?

culture on buffered charcoal yeast extract (BCYE) agar What must be demonstrated to diagnose Legionella pneumophila? How long can it take to develop and how long can it persist? - seroconversion - 6 months - months What test is as sensitive and specific as a culture test? nucleic acid amplification assay What diagnostic tests are used to detect the whole Legionella pneumophila organism? What is a corresponding appropriate specimen? - culture (sputum) - FAT (pathological material) - gene probe (not mentioned)What diagnostic test is used to detect Legionella pneumophila soluble antigen?

What is a corresponding appropriate specimen? - ELISA (urine)What diagnostic test is used to detect Legionella pneumophila antibody? What is a corresponding appropriate specimen? - FAT (serum) - ELISAWhat medication classes (with examples) are used to treat Legionella pneumophila?

newer macrolides (e.g. azithromycin, clarithromycin), fluoroquinolones (e.g. ciprofloxacin, levofloxacin), high-dose macrolinde (e.g. erythromycin, with or without rifampicin)What can you do to reduce risk of Legionella pneumophila disease? decrease environmental exposure What should environmental sources of Legionella pneumophila be treated with? hyperchlorination, super heating, copper-silver ionization Which serotype almost always causes human infection? serogroup 1In what 2 ways can Legionnaires' disease be diagnosed? - demonstrate organism in sputum - demonstrate soluble antigen in urine What is the key-point treatment of Legionella pneumophila? high-dose macrolide (e.g. erythromycin)What organism suppression techniques are central to control of the disease? suppression of the organism in air-conditioning systems and water supplies in public buildings

Gentamicin is an aminoglycoside antibiotic, used mostly to treat Gram-negative infections. However, it is not used for Neisseria gonorrhoeae, Neisseria meningitidis or Legionella pneumophila infections. It is synthesized by Micromonospora, a genus of Gram-positive bacteria widely distributed in water and soil.

"Print this Page Antimicrobial Agents in the Treatment of Infectious Disease (page 4) (This chapter has 6 pages)© Kenneth Todar, Ph DProtein synthesis inhibitors Many therapeutically useful antibiotics owe their action to inhibition of some step in the complex process of protein synthesis. Their attack is always at one of the events occurring on the ribosome and never at the stage of amino acid activation or attachment to a particular t RNA.

Most have an affinity or specificity for 70S (as opposed to 80S) ribosomes, and they achieve their selective toxicity in this manner. The most important antibiotics with this mode of action are the tetracyclines, chloramphenicol , the macrolides (e.g.

erythromycin) and the aminoglycosides (e.g. streptomycin). The aminoglycosides are products of Streptomyces species and are represented by streptomycin, kanamycin , tobramycin and gentamicin. These antibiotics exert their activity by binding to bacterial ribosomes and preventing the initiation of protein synthesis. Streptomycin binds to 30S subunit of the bacterial ribosome, specifically to the S12 protein which is involved in the initiation of protein synthesis.

Experimentally, streptomycin has been shown to prevent the initiation of protein synthesis by blocking the binding of initiator N-formylmethionine t RNA to the ribosome. It also prevents the normal dissociation of ribosomes into their subunits, leaving them mainly in their 70S form and preventing the formation of polysomes.

The overall effect of streptomycin seems to be one of distorting the ribosome so that it no longer can carry out its normal functions.

This evidently accounts for its antibacterial activity but does not explain its bactericidal effects, which distinguishes streptomycin and other aminoglycosides from most other protein synthesis inhibitors. Streptomycin is the first aminoglycoside antibiotic to be discovered, and was the first antibiotic to be used in treatment of tuberculosis. It was discovered in 1943, in the laboratory of Selman Waksman at Rutgers University. Waksman and his laboratory discovered several antibiotics, including actinomycin, streptomycin, and neomycin.

Streptomycin is derived from the bacterium, Streptomyces griseus. Streptomycin stops bacterial growth by inhibiting protein synthesis. Specifically, it binds to the 16S r RNA of the bacterial ribosome, interfering with the binding of formyl-methionyl-t RNA to the 30S subunit. This prevents initiation of protein synthesis. Kanamycin and tobramycin have been reported to bind to the ribosomal 30S subunit and to prevent it from joining to the 50S subunit during protein synthesis.

They may have a bactericidal effect because this leads to cytoplasmic accumulation of dissociated 30S subunits, which is apparently lethal to the cells. Aminoglycosides have been used against a wide variety of bacterial infections caused by Gram-positive and Gram-negative bacteria.

Streptomycin has been used extensively as a primary drug in the treatment of tuberculosis. Gentamicin is active against many strains of Gram-positive and Gram-negative bacteria, including some strains of Pseudomonas aeruginosa. Kanamycin is active at low concentrations against many Gram-positive bacteria, including penicillin-resistant staphylococci. Gentamicin and Tobramycin are mainstays for treatment of Pseudomonas infections. An unfortunate side effect of aminoglycosides has tended to restrict their usage: prolonged use is known to impair kidney function and cause damage to the auditory nerves leading to deafness.

Like all aminoglycosides, when gentamicin is given orally, it is not systemically active because it is not absorbed to any appreciable extent from the small intestine. It is useful in treatment of infections caused by Pseudomonas aeruginosa. The tetracyclines consist of eight related antibiotics which are all natural products of Streptomyces, although some can now be produced semisynthetically or synthetically. Tetracycline, chlortetracycline and doxycycline are the best known. The tetracyclines are broad-spectrum antibiotics with a wide range of activity against both Gram-positive and Gram-negative bacteria.

Pseudomonas aeruginosa is less sensitive but is generally susceptible to tetracycline concentrations that are obtainable in the bladder. The tetracyclines act by blocking the binding of aminoacyl t RNA to the A site on the ribosome. Tetracyclines inhibit protein synthesis on isolated 70S or 80S (eucaryotic) ribosomes, and in both cases, their effect is on the small ribosomal subunit.

However, most bacteria possess an active transport system for tetracycline that will allow intracellular accumulation of the antibiotic at concentrations 50 times as great as that in the medium.

This greatly enhances its antibacterial effectiveness and accounts for its specificity of action, since an effective concentration cannot be accumulated in animal cells. Thus a blood level of tetracycline which is harmless to animal tissues can halt protein synthesis in invading bacteria. The tetracyclines have a remarkably low toxicity and minimal side effects when taken by animals. The combination of their broad spectrum and low toxicity has led to their overuse and misuse by the medical community and the wide-spread development of resistance has reduced their effectiveness.

Nonetheless, tetracyclines still have some important uses, such as the use of doxycycline in the treatment of Lyme disease. Some newly discovered members of the tetracycline family (e.g. chelocardin) have been shown to act by inserting into the bacterial membrane, not by inhibiting protein synthesis.

The tetracycline core structure. The tetracyclines are a large family of antibiotics that were discovered as natural products of Streptomyces bacteria beginning in the late 1940s. Tetracycline sparked the development of many chemically altered antibiotics and in doing so has proved to be one of the most important discoveries made in the field of antibiotics.

It is a classic ""broad-spectrum antibiotic"" used to treat infections caused by Gram-positive and Gram-negative bacteria and some protozoa. Doxycycline is a semisynthetic tetracycline developed in the 1960s. It is frequently used to treat chronic prostatitis, sinusitis, syphilis, chlamydia, pelvic inflammatory disease, acne and rosacea. In addition, it is used in the treatment and prophylaxis of anthrax and in prophylaxis against malaria.

It is also effective against Yersinia pestis (the infectious agent of bubonic plague) and is prescribed for the treatment of Lyme disease, ehrlichiosis and Rocky Mountain spotted fever. Because doxycycline is one of the few medications that is effective in treating Rocky Mountain spotted fever (with the next best alternative being chloramphenicol), it is indicated even for use in children for this illness.

Chloramphenicol is a protein synthesis inhibitor that has a broad spectrum of activity but it exerts a bacteriostatic effect.

It is effective against intracellular parasites such as the rickettsiae. Unfortunately, aplastic anemia develops in a small proportion (1/50,000) of patients. Chloramphenicol was originally discovered and purified from the fermentation of a Streptomyces species, but currently it is produced entirely by chemical synthesis. Chloramphenicol inhibits the bacterial enzyme peptidyl transferase, thereby preventing the growth of the polypeptide chain during protein synthesis. Chemical structure of chloramphenicol Chloramphenicol is entirely selective for 70S ribosomes and does not affect 80S ribosomes.

Its unfortunate toxicity towards the small proportion of patients who receive it is in no way related to its effect on bacterial protein synthesis. However, since mitochondria originated from procaryotic cells and have 70S ribosomes, they are subject to inhibition by some of the protein synthesis inhibitors including chloramphenicol. This likely explains the toxicity of chloramphenicol. The eucaryotic cells most likely to be inhibited by chloramphenicol are those undergoing rapid multiplication, thereby rapidly synthesizing mitochondria. Such cells include the blood forming cells of the bone marrow, the inhibition of which could present as aplastic anemia.

Chloramphenicol was once a highly prescribed antibiotic and a number of deaths from anemia occurred before its use was curtailed. Now it is seldom used in human medicine except in life-threatening situations (e.g. typhoid fever).

The macrolide family of antibiotics is characterized by structures that contain large lactone rings linked through glycoside bonds with amino sugars. The most important members of the group are erythromycin and oleandomycin. Erythromycin is active against most Gram-positive bacteria, Neisseria,Legionella and Haemophilus, but not against the Enterobacteriaceae. Macrolides inhibit bacterial protein synthesis by binding to the 50S ribosomal subunit. Binding inhibits elongation of the protein by peptidyl transferase or prevents translocation of the ribosome or both.

Macrolides are bacteriostatic for most bacteria but are cidal for a few Gram-positive bacteria. Chemical structure of a macrolide antibiotic, erythromycin. Azithromycin, shown above, is a subclass of macrolide antibiotics. Azithromycin is one of the world's best-selling antibiotics. It is s derived from erythromycin, but it differs chemically from erythromycin in that a methyl-substituted nitrogen atom is incorporated into the lactone ring, thus making the lactone ring 15-membered.

Azithromycin is used to treat certain bacterial infections, most often bacteria causing middle ear infections, tonsillitis, throat infections, laryngitis, bronchitis, pneumonia and sinusitis. It is also effective against certain sexually transmitted diseases, such as non-gonococcal urethritis and cervicitis.

Lincomycin and clindamycin are a miscellaneous group of protein synthesis inhibitors with activity similar to the macrolides. Lincomycin has activity against Gram-positive bacteria and some Gram-negative bacteria ( Neisseria, H. influenzae ). Clindamycin is a derivative of lincomycin with the same range of antimicrobial activity, but it is considered more effective.

It is frequently used as a penicillin substitute and is effective against Gram-negative anaerobes (e.g. Bacteroides ). Clindamycin is a lincosamide antibiotic. It is usually used to treat infections with anaerobic bacteria but can also be used to treat some protozoal diseases, such as malaria.

It is a common topical treatment for acne, and can be useful against some methicillin-resistant Staphylococcus aureus (MRSA) infections. The most severe common adverse effect of clindamycin is Clostridium difficile -associated diarrhea (the most frequent cause of pseudomembranous colitis). Although this side-effect occurs with almost all antibiotics, including beta-lactam antibiotics, it is classically linked to clindamycin use.chapter continued Previous Page© Kenneth Todar, Ph. D. All rights reserved. - www.textbookofbacteriology.net "

The minimum temperature of hot water to prevent Legionella bacteria growth - The minimum temperature to prevent Legionella Bacteria growth is 122°F. Above 122°F and up to 131°F, Legionella bacteria survives, but will not multiply. At 131°F, it takes about 5 to 6 hours for the bacteria to die.

Hot water system temperatures and the code

I have noticed a lot of misquoting of the plumbing codes when it comes to hot water system temperatures and hot water system controls. There are a lot of people that think the model plumbing codes address domestic hot water system maximum storage temperatures. In fact, I am not aware of any model plumbing code that addresses minimum or maximum storage temperatures.

Misinterpreted codes There have been people claiming the maximum allowable storage temperature or thermostat setting on a water heater is 120°F). There is no such requirement in any model plumbing code. There have been claims the maximum temperature is 125°F based on the scalding temperature labels on the outside of most water heaters.

Again, there is no such requirement in any model plumbing code addressing the hot water storage or distribution temperature from a water heater.

The warning labels simply notify the owner or tenant that water temperatures in excess of 125°F can cause serious injuries and death and that children, the elderly and disabled people are at most risk.

The label also informs you that there are temperature limiting devices available and to refer to the installation and operation manual for more information. Domestic hot water storage and distribution temperatures are often one of the most misunderstood areas of the plumbing codes. The model codes list maximum hot water temperatures that can be delivered from various fixtures, but the storage and distribution temperatures have historically been left unaddressed in the plumbing codes.

From my attendance at the code hearings over the years, mandating temperatures can increase costs and has been seen as limiting design options. So, it is important for a domestic hot water system to be designed for the intended application, installed in accordance with the design and maintained in accordance with the design.

If any one of the links in the chain fails there could be problems. The code gives us temperature limitations for various plumbing fixtures like showers and bathtubs (a maximum of 120°F), and this is often misinterpreted as a maximum temperature setting for the water heater thermostat or the storage temperature.

This is one of the most common misinterpretations. The 2012 IPC has the following shower valve temperature requirement:424.3 Individual shower valves. Individual shower and tub-shower combination valves shall be balanced-pressure, thermostatic or combination balanced-pressure/thermostatic valves that conform to the requirements of ASSE 1016 or ASME A112.18.1/CSA B125.1 and shall be installed at the point of use.

Shower and tub-shower combination valves required by this section shall be equipped with a means to limit the maximum setting of the valve to 120°F (49°C), which shall be field adjusted in accordance with the manufacturer’s instructions.

In-line thermostatic valves shall not be utilized for compliance with this section. In the language in section 424.3 of the 2012 IPC, it is clear that the shower valve has an adjustment on it called a “maximum temperature limit-stop.” It must be adjusted after installation and before occupancy of the building where the contractor or owner must set and maintain the limit-stops seasonally for scald protection.

The reason they must be adjusted seasonally is because the incoming cold water temperature changes seasonally, which can affect the outlet or mixed water temperature setting. In discussions with many people on this issue, I have discovered that many people do not have a working knowledge of how shower valves are manufactured, designed, installed and maintained.

It is for this reason I have suggested ASSE work on a white paper to educate the public and the industry on how to set the maximum temperature limit-stops on shower valves and on other temperature limiting devices.

There are a few people that erroneously believe that the language in the code that states, “means to limit the maximum setting of the valve to 120°F can be accomplished with an adjustment of the thermostat dial on the water heater.”There are also people that believe that hot water system temperature control scald prevention can be accomplished by using a master thermostatic mixing valve at the water heater without setting the limit stops at the shower valves or without using point of use temperature limiting devices. Master mixing valves are not mandated in the model plumbing codes, but it is good design practice for a constant hot water supply temperature.

Domestic hot water systems are unique in that a change of equipment in one part of the system can and most likely will affect the performance of another part of the system.

Simply replacing a leaky water heater, circulating pump, balancing valve or mixing valve can significantly alter the system’s performance. I have investigated many scald incidents where the water heater was replaced and the new temperature setting was much higher which caused scald incidents.

There have also been incidents where the circulating pump stopped working, causing calls for “no hot water” the maintenance staff went to the mechanical room and cranked up the water heater thermostat. Then, when unsuspecting individuals finally got hot water, they were blasted with scalding hot water. There are several design issues that a domestic hot water system must address. Some of these are covered in the codes and some are not covered in the codes at this time.

They are as follows:1. Maximum Temperature Flowing from Fixture Outlet - The codes address maximum temperatures from Showers, maximum temperature flowing from a fixture to prevent scalding. As stated in the plumbing codes, the maximum temperature flowing from the fixture is not the maximum storage or distribution temperature.2.

The minimum temperature of hot water to prevent Legionella bacteria growth - The minimum temperature to prevent Legionella Bacteria growth is 122°F. Above 122°F and up to 131°F, Legionella bacteria survives, but will not multiply. At 131°F, it takes about 5 to 6 hours for the bacteria to die.

At 140°F, the bacteria dies in about 32 minutes. At 151°F, the bacteria dies instantly. The recommended minimum disinfection temperature is a few degrees above 151°F, which is 158°F for about 5 minutes. To prevent bacteria growth, a safety factor of a couple of degrees would require a minimum of 124°F at the coolest spot in the hot water distribution system.

The lowest temperature of hot water in a circulated hot water distribution system is always in the hot water return piping right before it connects back to the cold water inlet to the water heater.

A temperature gauge should be located just before the hot water return connection to be able to monitor the lowest hot water temperature in the system and allow maintenance staff to adjust the system temperatures at the source to maintain a temperature above the Legionella growth temperature. It is always a good idea to locate a temperature and pressure gauge at the top of each water riser and at the end of remote branches to record the temperatures and pressures in those locations for diagnostic purposes in larger buildings.

(Generally, I recommend this where the end of the domestic hot water supply pipe branch is more than 100 feet from the source. )Is there a minimum hot water storage temperature? No there is no code language addressing a minimum domestic hot water storage temperature. The plumbing codes define hot water as follows: Hot water - Water at a temperature greater than or equal to 110°F (43°C).

This does not mean it is good design to store the hot water at 110°F. Storing at 110°F would require a massive water heater tank, larger hot water pipes because there would be a greater percentage of hot water flowing through the hot water pipe vs the cold water pipe for the mixed temperature and it is in the ideal growth temperature range for Legionella bacteria growth.

Legionella bacteria grow and multiply between 68°F and 122°F; they reproduce rapidly and thrive between 95°F and 115°F. Below 68°F, the bacteria survives, but it does not multiply. From 115°F to about 122°F, the bacteria grow slowly.

From 123°F to 131°F, the bacteria survive but do not multiply. At 131°F, it takes about five to six hours for the bacteria to die. At 140°F, the bacteria dies in 32 minutes. At 151°F, it dies in two minutes. At 158°F and higher, the bacteria dies instantly.

One of the most widely accepted and preferred methods of controlling Legionella bacteria is to maintain the hot water system storage tank temperature at or above 135°F to 140°F. Unfortunately, the elevated temperature necessary to minimize the growth of and kill Legionella bacteria has the potential to cause serious scalding injuries.

(For more information on Legionella growth temperatures go to www.legionellaprevention.org. )There have been many green code and energy code proposals by well-intentioned individuals trying to limit hot water temperatures for energy conservation purposes. There are Legionella outbreaks that have been attributed to energy conservation efforts by maintenance staff and energy conservation programs that mandated turning the temperature down on water heaters to try and accomplish energy savings to reduce stand-by energy losses.

In other cases, the temperatures were turned down to try to prevent scalding. I have investigated many Legionella outbreaks associated with low hot water storage temperatures. There is no language in the model codes that addresses storage or distribution temperatures in domestic hot water systems.

Unfortunately, there are some local codes that have allowed the water heater thermostat to be reduced to 120°F to provide scald protection in showers and bathtubs in lieu of requiring shower valve products that meet the industry standards for temperature and/or pressure compensating shower valves and have adjustable temperature limit-stops to prevent scalding in showers or requiring temperature limiting valves that conform to the industry standards listed in the codes.

There is not a storage type water heater that I am aware of that has a thermostat that is capable of maintaining a constant and safe hot water outlet temperature. Water heaters should have their temperatures turned up and they a temperature actuated mixing valve should be provided on the outlet piping of the water heater.

This is because most of the thermostats on storage type water heaters are located near the bottom of the tank to sense the incoming cold water. The cold water connection is connected to the bottom of the tank through a dip tube or through a tank connection near the bottom of the water heater tank. Most water heater thermostats are not designed to accurately control the outlet temperature of a water heater.

They are designed to turn “on” and “off” the burner or energy input. There can be significant fluctuations of close to about 15 degrees above and below the set point, which can allow over 30 degrees of temperature fluctuation in the hot water tank from the “energy on” temperature to the “energy-off” temperature. What causes changes in hot water system temperatures? There are several factors that can cause changes in hot water system temperatures.

These factors include: usage or draw-down, heater design, thermostat design, system balancing issues, circulating pump issues, mixing valve set points, improper mixing valve piping, flow velocity in instantaneous water heaters, Insulation thickness and type, and many more issues that can affect the hot water system temperature.

The inherent design of many water heater thermostats has a built-in delay in responding to the water temperature in addition, intermittent short draws of a gallons or two of hot water by building occupants can cause cold water to be drawn into the bottom of a water heater causing the thermostat to cycle “on” and heat up the few gallons of cold water at the bottom of the tank.

The water heater is also overheating the less dense hot water that rises to the top of the tank. This phenomenon is known as thermal layering or stacking in a water heater. If the multiple short draws continue for several cycles, it can significantly overheat the water at the top of the tank.

It is for this reason model plumbing codes do not allow the thermostat on the water heater to be the final temperature control for scald prevention purposes.

It is not unusual to see temperature swings in excess of 30°F at the top of a water heater. This is why it is a good idea to have a master mixing valve, also known as a temperature actuated mixing valve, which conforms to ASSE 1017 or CSA B125 on the water heater outlet pipe.

Is there a maximum temperature limit for domestic water heaters? The model plumbing codes do not address a maximum storage temperature. For combined heating hot water and domestic hot water systems, when the heating hot water system exceeds 140°F the IPC code requires a temperature actuated mixing valve conforming to ASSE 1017 to limit the domestic hot water temperature to a maximum of 140°F.

That still does not address the maximum storage temperature in the hot water tank. Are there maximum temperature limits at various plumbing fixtures? Yes, because of scalding concerns various fixtures have maximum temperature limits for the water leaving the fixture outlet.

Over the years, I have served on many code ad hoc committees and standards committees for temperature control valve products and it has generally been agreed that the maximum safe hot water temperature for many fixtures was 120F°. This was because at 120°F it gives the bather about five minutes to get out of harm’s way before an irreversible burn injury would occur.

The time varies based on the thickness of the skin. Children, the elderly and handicapped persons are generally more at risk because they generally have reduced ability to react. Chapter 4 of the model plumbing codes cover specific requirements for plumbing fixtures. They are: A. Bidets Bidet’s are limited to 110°F in the model codes with the use of an ASSE 1070 device.

This standard has recently been harmonized as ASSE 1070-2014/ASME A112.1070-2014/CSA B125.70-14 Performance Requirements for Water Temperature Limiting Devices. The discharge water temperature from a bidet fitting should be limited to a maximum temperature of 110°F (43°C) by a water temperature limiting device conforming to the temperature limiting valves listed in the codes.

The ASSE 1070 standard was recently updated and Harmonized with CSA and ASME and will take several years to be listed in the model codes.

Engineers can be proactive by specifying the new harmonized standard now instead of waiting for it to be required in the 2018 code which will be adopted in many jurisdictions in 2019.

B. Tempered water for public hand-washing facilities Specifications for public hand washing facilities should require tempered water to public hand washing facilities should be limited to a maximum of 120°F and delivered through an approved water-temperature limiting device that conforms to ASSE 1070-2014/ASME A112.1070-2014/CSA B125.70-14.

C. Shower temperature limits Chapter 4 of the model plumbing codes covers individual shower valves and tub-shower combination valves and requires them to be balanced-pressure, thermostatic or combination balanced-pressure/thermostatic valves that conform to the requirements of ASSE 1016 or ASME A112.18.1/CSA B125.1 This standard was also recently harmonized and the new title is, “ASSE 1016-2011/ASME A112.1016-2011/CSA B125.16-2011.

(ASSE 1016) Performance.” Requirements for Automatic Compensating Valves for Individual Showers and Tub/Shower Combinations and shall be installed at the point of use. Shower and tub-shower combination valves required by this section shall be equipped with a means to limit the maximum setting at the valve to 120°F (49°C) or lower, which shall be field adjusted in accordance with the manufacturer’s instructions. In-line thermostatic valves including ASSE 1070 point-of-use mixing valves and ASSE 1017 master mixing valves should not be utilized for compliance with this section because they cannot address thermal shock associated with pressure imbalances in the system associated with fixture use.

This is especially important for this application because in a shower, the entire body is immersed in the stream of water and any sudden change in temperature can cause a slip and fall injury or a scald injury.

Mixing valves can reduce the hazard for scalds, but not thermal shock hazards. D. Gang showers Temperature limits and allowable devices for gang showers are covered in section 424.4 of the IPC. For single temperature installations the valve is typically set to a comfortable bathing temperature by the facility personnel at about 100°F to 105°F. The bather typically does not have individual temperature controls when an ASSE 1069 device is installed.

The bather would simply have an on/off valve or a metering button. Gang showers are common in schools, prisons, health clubs and other institutions applications. The temperature limit for this type of fixture is 120°Ffor gang showers, but that would not be a practical temperature setting. The typical temperature setting is at a comfortable bathing temperature between about 100°F and 105°F.

If individual shower controls are used and the showers are piped with both hot and cold water, the shower must have both hot and cold water supplied to it and then an ASSE 1016-2011/ASME A112.1016-2011/CSA B125.16-2011. Performance Requirements for Automatic Compensating Valves for Individual Showers and Tub/Shower Combinations (ASSE 1016) device would be appropriate to control the water temperature. An ASSE 1016 device has a maximum temperature limit stop that should be adjusted by the installer and seasonally readjusted by the maintenance staff to limit the maximum hot water temperature to 120°F it or less. E. Bathtubs and whirlpool bathtubs Bathtub and whirlpool bathtub valves should have the hot water supply limited to a maximum temperature of 120°F (49°C) by a water-temperature limiting device that conforms to ASSE 1070 or CSA B125.3, except where such protection is otherwise provided by a combination tub/shower valve in accordance with Section 424.3.

Is there a minimum hot water storage temperature for water heaters? The plumbing codes do not specifically address a minimum hot water storage temperature, but they define hot water as “water at a temperature greater than or equal to 110°F (43°C).

Unfortunately, 110°F is an ideal temperature for Legionella bacteria and other pathogens to grow. Also, if a water heater is set to 110°F, and designed for a 20 degree temperature difference across the system the fixtures at the end of the system would get water that is about 100°F and return water temperatures of about 90°F. Is there a code requirement to readjust the temperature limit stops if the hot water system temperatures are changed?

That could be argued, but there is not any language that addresses it specifically. However, there is code language that requires the components to be maintained in accordance with the manufacturer’s installation instructions.

So, it depends on if the manufacturer covers this language in their installation and maintenance literature. Some do and some don’t. Regardless of what the manufacturer’s literature says, if there is something that causes the hot water system temperatures to change, every shower valve and temperature limiting valve in the system should be readjusted to limit the hot water system temperatures to a safe temperature.

So, if a water heater is replaced, the installing contractor should wait until the hot water temperature is heated up to full hot water temperature and then go flow hot water from every shower valve in the facility and verify if the hot water limit stops are set properly.

If not, he can offer to readjust them for the homeowner for a price, or provide written instruction to the owner on how this procedure should be performed. This will then remove the liability form the contractor if there is a scald incident associated with a limit stop after he has performed work on the hot water system.

Good contractors will have this paperwork already printed up with the instructions on how this should be done.

If the owner does not want to take on this task, a fee can be charged for each valve that is readjusted to prevent scald injuries. The same procedure should be followed if someone simply readjusts the thermostat setting on the water heater. Hot water system commissioning checklist: 1. Verify the circulating pump is operating if one is installed. 2. Verify that the circulating pump flow direction is correct. 3. Document head pressure, flow and horsepower, voltage, phase, manufacturer and model number of the circulating pump.

4. Verify and document the set point of the thermostatic mixing valve (if a mixing valve is installed). Document the incoming cold water temperature, the incoming hot water temperature and the outlet temperature with a single fixture flowing downstream.

Verify that the temperature difference between the hot water and the tempered water meets the manufacturers required temperature differential requirements (5°F - 20°F). Bi-metal coil type mixing valves generally require a higher minimum flow rate or circulated flow and a temperature difference of at least 20°F.

5. Document manufacturer, model number and flow and temperature range of the mixing valve (if one is installed). 6. Verify if a thermal expansion tank or means to relieve thermal expansion is installed and properly sized and located in the cold water line to the water heater.

7. If both a circulating pump and thermostatic mixing valve are installed, verify that the return piping is properly installed in accordance with the mixing valve manufacturer’s installation instructions. 8. Run hot water from the farthest fixture from the hot water source until the hot water temperature stabilizes.

Document and record the maximum hot water system temperatures using a calibrated thermometer in a cup within 6 inches of the fixture outlet at the farthest fixture every 15 seconds until the temperature stabilizes for five consecutive readings. 9. If there is a temperature gauge near the end of the hot water return system, verify that the hot water return temperature is above 124°F to prevent Legionella bacteria from growing.

10. If the hot water return temperature is too low, adjust the thermostat on the water heater or the thermostatic mixing valve as required to get the desired hot water return temperature to avoid hot water system temperatures that are conducive to Legionella and other organic pathogen growth.

11. Record the maximum hot water system temperatures using a thermometer in a cup within 6 inches of the fixture outlet at all fixtures utilizing hot water. Record the temperatures every 15 seconds for five minutes or until the temperature has stabilized for five consecutive readings. 12. If any showers, tub/showers or other fixtures with code required temperature limits have a maximum hot water temperature that exceeds the code limit, readjust the limit stops or limiting device and re-perform the maximum temperature limit test.

13. If the owner does not want to perform the maximum temperature limit-stop tests to verify the temperatures are safe, provide documentation to the owner on how it should be done.

Also, provide the manufacturer’s installation and maintenance literature and have the owner sign off on a release advising them that you have made them aware of this requirement and that it is their responsibility to perform the limit-stop adjustments before occupancy and seasonally in accordance with the manufacturers installation instructions. Good system design would follow the temperature setting listed. Hot water should be stored at or above 140°F to minimize Legionella bacteria growth.

The system should have a mixing valve to establish a constant hot water delivery temperature with a circulating pump sized for a 10 degree temperature difference throughout the system.

If the system utilizes a bi-metal coil technology in the master mixing valve, a 20 degree temperature differential may be required for the valve to operate properly. The temperatures throughout a system with a 10 degree system temperature differential design should be as follows: 1. Hot water storage temperature in water heater (WH) = 150°F. 2. Hot water distribution temperature at master mixing valve (MV) outlet = 134°F.

3. Minimum Hot water return temp. at HWR conn. to CW inlet of WH/MV = 124°F. 4. Showers - Each shower will have a slightly different hot water supply temperature between 134°F and 129°F depending on where it is in the distribution system, the maximum temperature limit stop should be adjusted on all showers and tub/showers to a maximum of 110°F-115°F or as required (120°F max.)

5. All other fixtures requiring temperature limit protection - Each fixture will have a slightly different hot water supply temperature between 134°F and 129°F, depending on where it is in the distribution system, if a temperature at or below 120°F is required for scald protection a point-of-use mixing valve conforming to ASSE 1070 should be used.

The maximum temperature limit adjustment should be adjusted to limit the hot water to the required temperature at or below 120°F to prevent scalding (110°F at bidets. See code for various other temperature limits at fixtures). Ron George, CPD, is president of Plumb-Tech Design & Consulting Services LLC. Visit www. Plumb-Tech LLC.com. Engineers & Specifiers Plumbing Related Articles What are safe hot water temperatures? Domestic Hot Water Recirculation Systems A Hot Water System Balancing Act…Scald vs. Legionella Prevention, Part 1Related Products The Wholesaler Directory Listing - Premium Related Events89th Annual IAPMO Conference ASPE Convention & Expo AWWA Annual Conference & Expo Ron George Emergency fixtures and emergency fixture mixing valve standards, Part 1More from this author

Section I: What is Legionnaires' disease? Legionnaires' disease is a common name for one of the several illnesses caused by Legionnaires' disease bacteria (LDB). Legionnaires' disease is an infection of the lungs and is a form of pneumonia. More than 43 species of Legionella have been identified and more than 20 linked with human diseases.

"e Tools Home : Legionnaires' Disease Safety and Health Topic Page | Scope | FAQ | PDF | Credits Home Disease Recognition Potential Disease Sources Investigation Protocol Outbreak Response

Legionellosis is the term for the diseases produced by LDB. In addition to Legionnaires' disease, the same bacteria also causes a flu-like disease called Pontiac fever. Legionnaires' disease bacteria (LDB)What are LDB? What are the sources of exposure and transmission? Legionnaires' disease/Pontiac fever What are the symptoms? What are the incidence rates and risk factors?

How is Legionnaires' disease diagnosed and treated? What are LDB? Fig. 1: Legionella pneumophila Bacterium The Centers of Disease Control and Prevention (CDC) first identified Legionella pneumophila in 1977 as the cause of an outbreak of pneumonia that caused 34 deaths at a 1976 American Legion Convention in Philadelphia.

L. pneumophila had undoubtedly caused previous pneumonia outbreaks, but the organism's slow growth and special growth requirements prevented earlier discovery. The species of Legionella that have been associated with cases of Legionnaires' disease are called Legionnaires' disease bacteria (LDB). L. pneumophila is a gram-negative rod that exists in a number of distinguishable serogroups. Other species of Legionella cause legionellosis but L. pneumophila causes the majority of cases. L. pneumophila is also implicated in wound infections, pericarditis, and endocarditis without the presence of pneumonia.

Additional information (App I: A) on serogroups and subtypes is also available. What are the sources of exposure and transmission?

Fig. 2: Levels of LDB are low in natural environments Legionnaires' disease sources may include almost any warm water system or device including man-made or natural, that disseminates water, particularly as aerosols, sprays or mists and provides favorable conditions for LDB growth and amplification.

LDB are widely present at low levels in lakes, streams, rivers, freshwater ponds, and mud. However, the levels of LDB that are found in the natural environment are so low that it is unlikely that an individual will contract the disease from these sources. The risk of exposure increases when high concentrations of the organism grow in water systems. Legionnaires' disease only occurs in the presence of a contaminated water source.

Domestic (potable water) plumbing systems, cooling towers, and warm, stagnant water can provide ideal conditions for the growth of the organism. Fig. 3: Transmission may occur via inhalation or aspiration Disease transmission is most likely to occur via: Inhalation: of aerosols, fine sprays, mists or other microscopic droplets of water contaminated with LDB, providing direct access into the lungs.

Aspiration: such as may occur when choking or spontaneously during the drinking, ingesting, swallowing process. This allows oral fluids and particles to by-pass natural gag reflexes and enter into the respiratory tract and lungs instead of the esophagus and stomach.

There is no evidence that the diseases are transmitted from one person to another. What are the symptoms? Legionellosis is associated with two distinct illnesses: Legionnaires' disease, which is characterized by fever, myalgia, cough, pneumonia, and Pontiac fever, a milder illness without pneumonia. Legionnaires' disease has an incubation period (the time from exposure to the onset of symptoms) of 2 to 10 days.

Severity ranges from a mild cough and low fever to rapidly progressive pneumonia, coma, and death. Not all individuals with Legionnaires' disease experience the same symptoms. Fig. 4: Early symptoms may include fever, headache, and tiredness Early symptoms include slight fever, headache, aching joints and muscles, lack of energy or tiredness, and loss of appetite. Later symptoms include: High fever (102° to 105° F, or 39° to 41° C)Cough (dry at first, later producing phlegm)Difficulty in breathing or shortness of breath Chills Chest pain Common gastrointestinal symptoms include vomiting, diarrhea, nausea, and abdominal pain.

Pontiac fever is a non-pneumonia disease with a short incubation period of one to three days. Full recovery usually occurs in two to five days without medical intervention and no deaths have been reported.

Pontiac fever produces flu-like symptoms that may include fever, headache, tiredness, loss of appetite, muscle and joint pain, chills, nausea, and a dry cough.

Pontiac fever has been associated with exposure to non-viable LDB and may be a hypersensitivity response to bacterial or other antigens rather than an infection.

What are the incidence rates and risk factors? Fig. 5: People with an underlying illness or weakened immune system are most at risk The likelihood of contracting Legionnaires' disease depends on the level of contamination in the water source, the susceptibility of the person exposed, and the intensity of exposure. Unlike Legionnaires' disease, which occurs in approximately 5 percent or less of people who are exposed, Pontiac fever will occur in approximately 90 percent of those exposed.

The factors that cause the same organism to produce two illnesses with major differences in ""attack rate"" (the fraction of exposed persons who become infected) and severity are not known.

In the United States, Legionnaires' disease is fairly common and serious. LDB are one of the top three causes of non-epidemic, community-acquired pneumonia. It is estimated that over 25,000 cases of the illness occur each year and cause more than 4,000 deaths. The fatality rate is similar to that of other forms of pneumonia, approximately 15 percent. It is difficult to distinguish this disease from other forms of pneumonia; so many cases go unreported.

Legionnaires' disease is characterized as an ""opportunistic"" disease that attacks individuals who have an underlying illness or weakened immune system. The most susceptible people include: The elderly, smokers, and those on immunosuppressive therapy.

Individuals with chronic obstructive pulmonary disease (COPD), organ transplant patients, and people taking corticosteroid therapy. It is important to emphasize that relatively healthy individuals can be at risk of contracting disease. For additional information and current statistics, see Legionella (Legionnaires’ Disease and Pontiac Fever).

How is Legionnaires' disease diagnosed and treated? Fig. 6: Macrolides are the current drug of choice Legionnaires' disease is difficult to diagnose because the pneumonia caused by LDB is not easily distinguished from other forms of pneumonia. The Centers for Disease Control and Prevention (CDC) defines a confirmed case of Legionnaires' disease as a clinically compatible case that is confirmed by a laboratory.

A confirmed case requires a physician's diagnosis of pneumonia based on a chest x-ray and positive laboratory test results. A laboratory test is necessary for confirmation because the symptoms and x-ray evidence of Legionnaires' disease resemble those of other types of pneumonia.

The CDC laboratory criteria for diagnosis are: Isolation of LDB from respiratory secretions, lung tissue, pleural fluid, or other normally sterile fluids,Demonstration of a fourfold or greater rise in the reciprocal immunofluorescence antibody (IFA) titer to greater than or equal to 128 against Legionella pneumophila serogroup 1 between paired acute- and convalescent-phaseserum specimens,Detection of L. pneumophila serogroup 1 in respiratory secretions, lung tissue, or pleural fluid by direct fluorescent antibody testing,Demonstration of L. pneumophila serogroup 1 antigens in urine by radioimmunoassay or enzyme-linked immunosorbent assay, and For additional information and current statistics, see Top 10 Things Every Clinician Needs to Know About Legionellosis.

Legionnaires' disease treatment requires the use of antibiotics. Early treatment reduces the severity of symptoms and improves chances of recovery.

The drugs of choice belong to a class of antibiotics called macrolides. They include azithromycin, erythromycin, and clarithromycin. Additional information (App I: B) on diagnostic methods, including culture, direct fluorescent antibody (DFA) staining, and serology is also available. More: OSHA recommends a level one investigation when there is evidence of exposure to LDB. See Section III: A.

Investigation Protocols: Level One. A single antibody titer of 256 or higher indicates that a person previously was exposed to Legionella. Such individuals may have had an illness clinically compatible with Legionnaires' disease or may have had milder or no symptoms. OSHA recommends a level two investigation when more than one confirmed or possible case of Legionnaires' disease has been reported at a facility. See Section III: B. Investigation Protocols: Level Two. Additional Information: Guidelines for Prevention of Nosocomial Pneumonia.

Centers for Disease Control and Prevention (CDC), Morbidity and Mortality Weekly Report (MMWR) 46 (RR-1);1-79, (1997, January 3). See Appendix D, Procedure for Cleaning Cooling Towers and Related Equipment. Legionella 2003: An Update and Statement by the Association of Water Technologies (AWT) (PDF). Accessibility Assistance: Contact the OSHA Directorate of Technical Support and Emergency Management at (202) 693-2300 for assistance accessing PDF. Home | Disease Recognition | Potential Disease Sources | Investigation Protocol | Outbreak Responsee Tools Home : Legionnaires' Disease Safety and Health Topic Page | Scope | FAQ | PDF | Credits "

ón Causes and Common Sources of Infection Legionella is a type of bacterium found naturally in freshwater environments, like lakes and streams. It can become a health concern when it grows and spreads in human-made water systems like

Causes and Common Sources of Infection

On This Page Causes and Common Sources of Infection How It Spreads People at Increased Risk Español: Causas y transmisi

Showers and faucets Cooling towers (air-conditioning units for large buildings)Hot tubs that aren’t drained after each use Decorative fountains and water features Hot water tanks and heaters Large plumbing systems Home and car air-conditioning units do not use water to cool the air, so they are not a risk for Legionella growth.

How Legionella Affects Building Water Systems and People Learn four key steps that can lead to Legionella growing in building water systems and spreading to people.

How It Spreads After Legionella grows and multiplies in a building water system, that contaminated water then has to spread in droplets small enough for people to breathe in. People can get Legionnaires’ disease when they breathe in small droplets of water in the air that contain the bacteria.

Causes and Common Sources of Infection

dad Legionellosis (LEE-juh-nuh-low-sis) is a respiratory disease caused by Legionella bacteria. Sometimes the bacteria cause a serious type of pneumonia (lung infection) called Legionnaires’ disease. The bacteria can also cause a less serious infection called Pontiac fever that has symptoms similar to a mild case of the flu.

About the Disease

Español: Sobre la enferme

Causes, How it Spreads, and People at Increased Risk Explains where Legionella can be found, how people are exposed to it, and who is at increased risk for getting sick…Signs and Symptoms Lists signs and symptoms of Legionnaires’ disease and Pontiac fever…Diagnosis, Treatment, and Complications Describes tests performed to confirm infection, how legionellosis is treated, and possible complications that can arise…Prevention Explains the role water maintenance plays in preventing legionellosis…History and Disease Patterns Provides the history of legionellosis and explains disease patterns…Legionnaires’ Disease Fact Sheet [1 page] This fact sheet describes what Legionnaires’ disease is, its symptoms, how it’s spread and treated, and who is at increased risk.

This means that if your water is not Legionella tested, you run the risk of spreading the disease. In order to prevent all Legionella related illnesses it is important that you regularly monitor your water systems. This is especially important in industrial environments where Legionella can be found in abundance.

Why is Water Testing So Important?

Why is Water Testing So Important? By Jason E Stallard | Submitted On March 04, 20101

Water is something we all need regardless of where we live and what our lifestyles may be. Without good water supplies people can succumb to all types of illnesses, the majority of which can take lives. This is why water testing, especially of drinking water is so important. This is also true, if you have suspicions about your companies' water systems. People living in rural areas may often believe that the well water they use is 100% safe of all types of bacterium and viruses.

This is absolutely untrue, since there is no way of determining exactly how safe the water is until you test and analyze it. You need to test the water you are using to make sure that it is 100% safe of all pathogens before your family or business use it.

If there are contaminants, then a proper filtration method should be incorporated in order to make the water safe for use.

One of the tests you should put your water system through, is thorough Legionella testing. Legionella is a bacterium, which is found both in the air and in water. Unlike some other bacteria, it can survive at lower dissolved oxygen levels and is somewhat resistant to chlorine disinfection.

Certain plastics and organics can provide nutrients for growth. These attributes make our modern day plumbing systems a good habitat for the organism. Legionella are known to multiply pretty rapidly in cooling towers, humidifiers and water heaters. Water testing that has been conducted, has shown that Legionella bacteria can multiply from 10 per millilitre to well over 10,000 per millilitre within just one month.

Legionellosis, or Legionnaire's disease, is a type of pneumonia caused by Legionella bacteria. Legionnaires' disease is not contagious, and you cannot catch it from another person. The bacteria are common and grow in water.

UNITED STATES DEPARTMENT OF LABOR

"OSHA Technical Manual General Information Health Hazards Safety Hazards Construction Hazards Section III: Chapter 7Legionnaires' Disease Table of Contents: Introduction Disease Recognition Source Identification Investigation Protocol Controls Bibliography List of Appendices Appendix III:7-1. Employee Awareness Program Appendix III:7-2. Physical Survey and Water Sampling Protocol Appendix III:7-3. Water Sampling Guidelines Appendix III:7-4. Legionnaires' Disease Case Identification Appendix III:7-5.

Water Treatment Protocols for Facilities That Have Experienced a Legionnaires' Outbreak The mention of trade names, commercial products, or organizations does not imply endorsement by OSHA or the U. S. Government. I. Introduction This chapter provides information to assist industrial hygienists in the assessment of work sites for potential Legionnaires' disease. It provides information on disease recognition, investigation procedures to identify probable water sources, and control strategies. The primary focus of this document is on the control and prevention of contaminated water sources, not on case identification, an area of expertise primarily exercised by local health departments frequently in conjunction with the Centers for Disease Control and Prevention (CDC) in Atlanta.

Appendices include details on conducting an employee awareness program, water sampling protocols and guidelines for acceptable levels of the organism in water, procedures for identifying new cases of the disease, and water treatment and control strategies for facilities where an outbreak has occurred.

II. Disease Recognition A. Causative Agent Legionella pneumophila was first identified in 1977 by the CDC as the cause of an outbreak of pneumonia that caused 34 deaths at a 1976 American Legion Convention in Philadelphia.

L. pneumophila had undoubtedly caused previous pneumonia outbreaks, but the organism's slow growth and special growth requirements prevented earlier discovery. The diseases produced by Legionella are called legionellosis. More than 34 species of Legionella have been identified, and more than 20 linked with human diseases. L. pneumophila causes the pneumonia known as Legionnaires' disease and the flu-like Pontiac fever. L. pneumophila has also been implicated in wound infections, pericarditis, and endocarditis without the presence of pneumonia.

Because the majority of legionellosis is caused by L. pneumophila, this chapter will deal exclusively with that organism. Cases where other species of Legionella are involved in disease require actions similar to those to control Legionnaires' disease.

The L. pneumophila bacteria are gram-negative rods that exist in a number of distinguishable serogroups. Each serogroup contains further subtypes that have different surface structures on the cell membrane and can be distinguished by special tests.

Evidence indicates that some Legionella serogroups are more virulent than others. L. pneumophila serogroup 1 is the most frequently identified form of the bacterium isolated from patients with Legionnaires' disease, although other serogroups and subtypes of the bacterium are frequently isolated from water sources.

Serogroups 4 and 6 are the next most frequently linked with disease. B. Symptoms Legionnaires' disease has an incubation period of two to ten days. Severity ranges from a mild cough and low fever to rapidly progressive pneumonia and coma. Early symptoms include malaise, muscle aches, and slight headache.

Later symptoms include high fever (up to 105°F), a dry cough, and shortness of breath. Gastrointestinal symptoms including vomiting, diarrhea, nausea, and abdominal pain are common. The disease is treated with erythromycin or a combination of erythromycin and rifampin. Pontiac fever is a non-pneumonia, flu-like disease associated with, and likely caused by, the Legionella bacterium. This disease has an ""attack rate"" of 90% or higher among those exposed, and a short incubation period, 1-3 days.

Complete recovery usually occurs in 2-5 days without medical intervention. The factors that cause the same organism to produce two illnesses with major differences in attack rate and severity are not known.

C. Incidence In the U. S., Legionnaire's disease is considered to be fairly common and serious, and the Legionella organism is one of the top three causes of sporadic, community-acquired pneumonia. Because it is difficult to distinguish this disease from other forms of pneumonia, many cases go unreported. Approximately 1,000 cases are reported annually to the CDC, but it is estimated that over 25,000 cases of the illness occur each year and cause more than 4,000 deaths.

D. Risk Factors Legionnaires' disease is frequently characterized as an ""opportunistic"" disease that most frequently attacks individuals who have an underlying illness or weakened immune system.

The most susceptible include persons who are elderly, smokers, and immunosuppressed. Individuals with chronic obstructive pulmonary disease (COPD), organ transplant patients, and persons taking corticosteroid therapy are also at elevated risk. The attack rate for the average population is approximately 5% or less. The fatality rate is similar to that of other forms of pneumonia, approximately 15%. E. Diagnosis CDC guidelines define two types of cases of Legionelloses, probable and confirmed. A probable case of Legionnaire's disease is a person who experienced an illness clinically compatible with Legionnaire's and has a single antibody titer of 256 or higher (discussed below), and can be associated with a population of individuals who have experienced confirmed cases of the disease (outbreak).

A confirmed case of Legionella requires a physician's diagnosis of pneumonia based on a chest x-ray and positive laboratory test results. A laboratory test is necessary for confirmation because the symptoms and x-ray evidence of Legionnaires' disease resemble those of other types of pneumonia.

Various methods are used to confirm the presence of the disease. Culture of the Organism. The definitive laboratory method of confirming the presence of the disease is by culturing viable cells of Legionella from sputum, bronchial washing, or autopsy on special media.

Further identification of the cultured cells will identify the species and serogroup. Special tests may determine subtype of certain isolates. The sensitivity of this test to detect the disease is reported to be about 70%. Urine Antigen Test. The detection of antigen from L. pneumophila in the urine is considered a reliable measure of the disease. These antigenic materials may include L. pneumophila cells or portions of cells in the urine during and after the disease.

The presence of antigen in the urine is a strong indicator of the disease, and a patient may have a positive response for several months following the disease. The sensitivity of this test is limited because the only commercially available urinary antigen test detects only serogroup 1 forms of L. pneumophila. The CDC recommends only the radioimmunoassay (RIA) test because the latex antigen (LA) test has a high false-positive rate.

Fortunately, 80-90% of the clinically diagnosed cases are caused by serogroup 1. The absence of a positive urinary test is not proof that a patient did not have Legionnaires' disease, but merely indicates the absence of antigen in the urine at the time of the test.

Direct Fluorescent Antibody (DFA) Staining. Direct fluorescent antibody staining of lung aspirates can detect L. pneumophila. However, this test is frequently negative during the initial stages of the disease because few organisms are present in the aspirate or sputum. This test also requires an antigen-specific reagent. There are a multitude of serogroups and subtypes of L. pneumophila, and a test will be negative if the exact antigen-specific reagent is not included.

Serology (Antibody Titers)An increase in the antibody level in the serum of infected persons occurs several weeks after the onset of the disease.

A fourfold increase in the antibody titer coupled with a physician's diagnosis of pneumonia is considered a reliable indicator of disease. This is measured by comparing the antibody level four to eight weeks after onset (convalescent titer) to an initial (acute) titer at the beginning of the disease.

Pontiac fever also produces an elevated antibody titer, but the flu-like symptoms of this disease do not match those of Legionnaires' disease. Frequently only a convalescent titer has been measured from individuals who had symptoms of the disease.

For situations in which these cases are associated with an outbreak of Legionnaires' disease, a single titer of 256 to 1 or higher is generally used as a presumptive indication of disease (probable case). Antibody strength is determined by the number of dilutions of serum which elicit a positive antibody response.

The reciprocal value of the number of dilutions is the antibody titer. For example, an antibody titer of 256 means a positive antibody test of the patients's serum following serial dilutions of 1:2, then 1:4, then 1:16, etc., until the 1:256 dilution point is reached.

The indirect fluorescent antibody (IFA) test is the accepted diagnostic tool for demonstrating L. pneumophilia exposure. Another widely used test of antibody response is the enzyme-linked immunosorbent assay method (ELISA). CDC believes that direct comparison of results between IFA and ELISA is not reliable because there are insufficient data to compare the two.

The ELISA method has gained wide medical acceptance as a useful means of demonstrating exposure to Legionella. F. Transmission The likelihood of contracting Legionnaires' disease is related to the level of contamination in the water source, the susceptibility of the person exposed, and the intensity of exposure to the contaminated water. Disease transmission usually occurs via inhalation of an aerosol of water contaminated with the organism.

Aspiration of contaminated water into the lungs may also cause the disease. In the Philadelphia Legionnaires' disease outbreak, the hotel's cooling tower was identified as the likely source of the disease, although domestic water sources were not evaluated.

The disease has been associated with domestic hot-water systems in a number of outbreaks. In many instances it has been difficult to identify a likely source for aerosolization of the suspected water source. Although transmission of the disease other than through direct inhalation of aerosols may occur, the mechanisms are not clearly understood. The organism requires water, and the disease cannot occur in the absence of a contaminated water source. There is no evidence that the disease can be transmitted from one person to another. III. Source Identification A.

Conditions that Promote Growth L. pneumophila bacteria are widely distributed in water systems. They tend to grow in biofilms or slime on the surfaces of lakes, rivers and streams, and they are not eradicated by the chlorination used to purify domestic water systems.

Low and even nondetectable levels of the organism can colonize a water source and grow to high concentrations under the right conditions. Conditions that promote growth of the organism include heat, sediment, scale, and supporting (commensal) microflora in water. Common water organisms including algae, amoebae, and other bacteria appear to amplify Legionella growth by providing nutrients or harboring the organism.

Because of its ability to remain viable in domestic water systems, it is capable of rapid multiplication under the proper conditions.

Water conditions that tend to promote the growth of Legionella include:stagnation;temperatures between 20° and 50°C (68° - 122°F) (The optimal growth range is 35° - 46°C [95° - 115°F]);p H between 5.0 and 8.5;sediment that tends to promote growth of commensal microflora; andmicro-organisms including algae, flavobacteria, and Pseudomonas, which supply essential nutrients for growth of Legionella or harbor the organism (amoebae, protozoa).

B. Common Sources of Contaminated Water Water sources that frequently provide optimal conditions for growth of the organisms include:cooling towers, evaporative condensers, and fluid coolers that use evaporation to reject heat.

These include many industrial processes that use water to remove excess heat;domestic hot-water systems with water heaters that operate below 60°C (140°F) and deliver water to taps below 50°C (122°F);humidifiers and decorative fountains that create a water spray and use water at temperatures favorable to growth;spas and whirlpools;dental water lines, which are frequently maintained at temperature above 20°C (68°F) and sometimes as warm as 37°C (98.6°F) for patient comfort; andother sources including stagnant water in fire sprinkler systems and warm water for eye washes and safety showers.

Water stored below 20°C (68°F) is generally not a source for amplified L. pneumophila levels. However, high levels of bacteria have been measured in the water supplying ice machines.

The source of amplification in this case was thought to be heat from the condenser coil of the ice maker to the cold water supply. However, no cases of Legionnaires' disease have been linked to consumption of ice made from contaminated water. C. Monitoring Air. An air sample applied to special culture plates by an Andersen-type sampler sometimes demonstrates the presence of the organism in the air.

However, negative results are frequent because of the difficulty in maintaining viability of the organism on the culture plates. Air sampling for Legionella is strongly not recommended as a means of measuring potential exposure because of the high likelihood of false negatives.

Water. Analysis of water samples from a source suspected of being contaminated with L. pneumophila is a valuable means of identifying potential sources of the disease.

A qualified microbiological laboratory experienced in Legionella detection can determine the number of organisms present in colony forming units (CFU) per volume of water and can identify the different serogroups of Legionella pneumophila in the sample. Appendix III:7-2 provides details on the collection, storage, and shipping of water samples. D. Microbiological Analysis of Water Samples Cultured Samples.

Water samples are cultured on special buffered charcoal yeast extract (BCYE) culture media. Selective isolation processes to eliminate other microbial overgrowth can determine the number of CFU of L. pneumophila per milliliter of water.

This process of growth and isolation is time-consuming, and results typically require 7-14 days from the time of submission. Cultured samples can also be analyzed to identify specific serogroups. Matching the same serogroup and subtype of organism in the patient as found in a water source is considered strong evidence of an associated link. Direct Fluorescence Antibody (DFA). The number of organisms in a water sample can also be determined via direct fluorescence antibody (DFA) conjugate tests that stain the organism with a fluorescent dye.

This test is unable to distinguish between live and dead bacteria and may also have some cross-reactivity with other bacteria. Sample results can be available in one or two days, and this method can be useful in screening water samples. Use caution, however, in interpreting the results since the potential exists for both false positive and negative results.

DNA Amplification. A relatively new method for rapid, specific detection of the organism in water employs a polymerase chain reaction (PCR) process to amplify and then detect portions of DNA unique to L. pneumophila. This method can produce results in 1 day, and preliminary evidence indicates that its sensitivity and specificity are comparable to those of cell culture, which can take 10-14 days to obtain results. Further testing may lead to acceptance of this technique as the method of choice for monitoring water sources for contamination.

E. Interpretation of Sample Results The probability of infection with L. pneumophila is a function both of the intensity of the exposure dose and the level of host susceptibility. Because total eradication of Legionella may not be possible, an acceptable control strategy is to minimize the number of organisms present in a water source.

Ample evidence indicates that Legionella levels are readily controllable. A survey of over 1,000 cooling towers indicates that approximately 60% contained nondetectable levels of L. pneumophila when measured by DFA analysis for the number of organisms per milliliter of water (detection limit is 10 bacteria per milliliter of water). In another survey of 663 cooling towers, 57% contained Legionella that were not detected when measured by culture (detection limit less than 1 CFU/m L).

Other studies of domestic hot-water sources indicate that although the organism is common, especially in large hot-water systems, practical control measures can limit the potential for amplification. A private consulting firm and microbiological laboratory, Path Con Inc. of Norcross, Georgia, has introduced suggested guidelines for control of the organism based on the number of CFU of L. pneumophila per milliliter of water ( Appendix III:7-3 .)

These guidelines vary depending on the water source, a recognition by the authors that dose is related both to the potential for exposure and to concentration. For example, recommended exposure limits for contaminated water from a humidifier, which would involve direct exposure to an aerosol are lower than for a cooling tower where the opportunity for exposure is normally less. Work operations such as maintenance on cooling towers may involve direct exposure to cooling tower mist, and precautions to minimize exposure are always necessary.

The authors recognize that these guidelines are based on limited data, but they represent the best available information and must suffice until the dose effect of L. pneumophila is better understood. IV. Investigation Protocol A. Community Health Concerns It is important to remember that an outbreak of Legionnaires' disease among workers may have its origin in the community and may not be related to the work environment.

A Legionnaires' outbreak is both an occupational and a public-health concern, and the investigation may include local public health departments and the Centers for Disease Control (CDC).

To minimize employee risk and maximize the effectiveness of effort, close coordination among OSHA, other public agencies, and the employer is imperative. B. Types of Investigations The course of action chosen during an investigation of a facility should be based on the degree of certainty that the site is the source of a reported illness.

For this reason, two investigation protocols are based on differing levels of suspected risk for exposure to Legionella. It is important to remember that these procedures are provided only to assist in the investigation of potential Legionnaires' cases. Individual circumstances may require changes in the investigation. All cases require sound professional judgment in deciding the appropriate course of action.

A level-one investigation may be initiated when there is a probable basis for suspecting that workplace water sources are contaminated with Legionella, or when there is information that one case of Legionnaires' disease may exist. A level-two investigation should be conducted when more then one possible case of Legionnaires' disease has been reported at a facility. If two or more cases of the disease can be attributed to a work site, assume that a Legionnaires' disease outbreak has occurred.

If evidence indicates that the outbreak is still in progress (that is, at least one of the cases has occurred in the last 30 days), prompt actions should be undertaken to provide maximum protection to employees and eliminate the hazard.

Appendix III:7-5 includes examples of actions required to control water sources where an outbreak has occurred.

Both investigations follow the same general pattern and include a preliminary opening conference, a walk-through of the facility to conduct a physical assessment of the water systems, a more detailed examination of the systems including a review of maintenance records, assessment of findings, and a closing conference to present control actions based on the findings. C. Level-One Investigation Use the following procedure when Legionnaires' disease may be related to the work environment.

Step 1. Obtain an overview of all water systems at the facility. A facilities engineer or experienced member of the building maintenance staff should be available to explain system operation and assist in the walkthrough investigation.

This person should have a working knowledge of the system's design and current operation. The overview of the water systems should include plumbing systems, heating-ventilating-air-conditioning (HVAC) systems, and other water reservoirs.

A review of the plumbing system should include both hot and cold domestic water systems, water heaters, distribution pipes, water coolers, water treatment equipment, connections to process water systems protected (or unprotected) by backflow preventers, and storage tanks. The HVAC system review should include cooling towers, evaporative condensers, fluid coolers, humidifiers, direct evaporative air-cooling equipment, indirect evaporative air-cooling equipment, air washers for filtration, etc.

Note the location of the fresh-air intakes of the building's air-handling units relative to water sources such as the cooling towers. Investigate other potential sources of employee exposure including decorative fountains, plant misters, whirlpools, spas, tepid-water eye-washes and safety showers, humidifiers, and water for cooling industrial processes. Review maintenance records on water systems including water heaters and cooling towers. The records should include temperature checks of domestic water, visual and physical checks of cooling towers, and reports of cooling-tower water-quality assessment and chemical treatment.

Identify the locations of portions of the system in which water is allowed to stagnate such as storage tanks or unused plumbing pipe sections (""dead legs""), or infrequently used faucets.

Check for cross-connections between domestic and process water systems, and note the condition and type of back-flow prevention devices. Investigate recent major maintenance or changes in the system's operation. Determined if there were recent or frequent losses of water pressure from the incoming water supply due to line breakage or street repairs. The failure of a back-flow prevention device under loss of pressure can contaminate the system. Step 2.

Conduct a walk-through investigation of the facility. Equipment you will need includes a thermometer for measuring water temperatures, a flashlight, and a film or video camera to record observations. Measure and record the temperature of water drawn from each storage-type water heater in the facility.

This temperature may be significantly below the water heater's gauge temperature because of heat stratification. Note the presence of rust and scale in this water. Record the maximum temperature of water at faucets connected to each water heater on the system. Record temperatures at locations near, intermediate, and distant from the heaters. It may be necessary to run the water for several minutes before it reaches a temperature maximum.

Examine the water temperature and the potential for stagnation of cold-water storage tanks used for reserve capacity or to maintain hydrostatic pressure.

These should be protected from temperature extremes and covered to prevent contamination. Record the temperature of the domestic cold-water lines at various locations within the facility. Note both the initial temperature and the final equilibrium temperature on the cold-water line, and record the time required to reach equilibrium, because this can be an indicator of the amount of stagnation in the system.

Evaluate cooling towers, evaporative condensers, and fluid coolers for biofilm growth, scale buildup, and turbidity. Record the location of the tower relative to fresh-air intakes, kitchen exhausts, leaves, plant material, or other sources of organic material that might contribute to the growth of the organism.

Record the general condition of the cooling tower. Determine the presence and condition of drift eliminators, which are designed to limit the vapor release from the units, along with the basin temperature of the water in the cooling tower if it is currently being operated. If the cooling tower is operating and is suspected of being contaminated, wear appropriate respiratory protection in the form of a half-face piece respirator equipped with a HEPA or similar type of filter capable of effectively collecting one-micron particles during the examination of the system.

Note the location and evaluate the condition of the sumps for the cooling tower (s), evaporative condenser (s), and fluid cooler (s). These sumps are sometimes located indoors to protect them from freezing. Record the locations of any cross-connections between the cooling tower water system and any domestic water system.

These may supply a back-up source of cool water to refrigeration condenser units or serve to supply auxiliary cooling units. The lack of a regular maintenance schedule or water-treatment program for a cooling tower or evaporative condenser system strongly suggests a potential for Legionella contamination.

Step 3. Assess the results of the walkthrough investigation to determine the course of action. If no potential problems are identified, the operating temperatures measured at water heaters are 60°C (140°F) or above, and the delivery temperature at distant faucets is 50°C (122°F) or higher, no further action will be necessary.

However, if the system is poorly maintained and operating temperatures are below recommended minimums, then recommendations for corrective action should be made.

Step 4. Recommend control actions. Details of suggested control actions are discussed in Section E. These actions may include disinfection of the domestic water system via heat treatment, chlorination, or other means, and cleaning and disinfecting the cooling tower system according to the Wisconsin Division of Health protocol for ""Control of Legionella in Cooling Towers"" or a similar process for cleaning heat rejection systems that follows sound practices to minimize potential for Legionella growth.

Additional actions may include eliminating dead legs in the plumbing system, insulating plumbing lines and installing heat tracing to maintain proper temperatures in the system, eliminating rubber gaskets, and removing or frequently cleaning fixtures such as aerators and shower heads. Corrective actions limited to raising the water heater temperature without evaluating the system for points of stagnation, heat loss and gain, cross-contamination, and other factors that contribute to growth are generally not sufficient.

For a level-one investigation it is not recommended that water samples be collected to confirm the presence of Legionella in the system. The absence of proper operating conditions alone is sufficient for assuming that the water system can pose an unnecessary risk to the employees.

Take water samples after the completion of the control actions to confirm that the corrective measures were successful. The employer may also want to obtain samples before starting corrective actions to assess the extent of the problem. The employer should take necessary corrective actions even if the results of presampling are negative.

Water sampling can produce false negatives, a contaminated portion of the system may have been missed, and the absence of Legionella organisms at the time of sampling does not insure that the system will remain negative. If, after control actions, the Legionella levels in a water source exceed the guidelines in Appendix III:7-3, re-examine the water system to determine if potential contamination points within the system were overlooked and reassess control procedures to determine if they were performed properly. Repeat the procedures as needed until contamination levels meet the guidelines. D. Level-Two Investigation A level-two investigation is similar to a level-one investigation with several additional steps.

Supplemental actions include: (1) medical surveillance of all employees currently on sick leave to identify any new cases, (2) employee awareness training on the disease to minimize employee concerns and aid in early recognition of new cases, (3) assessment of past sick-leave absences for undetected cases of the disease, and (4) collection of water samples during the walkthrough assessment.

Step 1. Assess water systems as described for a level-one investigation. Step 2. Conduct a second walkthrough survey of the facility and collect water samples.

Estimate the size of the building and the number of water services during the initial walkthrough and prearrange supply and shipping of the required number of sterile sample containers with the appropriate laboratory. (See Appendix III:7-2 for water sampling procedures. )Step 3. Initiate an employee awareness program and monitor current sick leave for new cases.

It is important to ensure that employees understand the early symptoms of the disease and seek medical assistance promptly. It is imperative not to alarm the workers. It is equally important to stress the importance of the need to know the health status of all employees on sick leave.

(See Appendix III:7-1, Employee Awareness Program. )Step 4. Review worker absences to detect other cases.

This requires identification of all employees who took three or more consecutive days of sick leave from approximately six weeks before the case of Legionnaires' disease was identified up to the present. Request those employees who may have had pneumonia during this period to undergo additional voluntary tests for evidence of Legionnaires' disease. (See Appendix III:7-4, Case Identification. )Step 5. Assess results of worker absence survey and analysis of water systems. If evidence indicates more than one case of Legionnaires' disease at the workplace, then the site should be treated as having an outbreak.

Take immediate control of all water sources to eliminate potential for exposure, and take measures to eliminate the hazard. (See Appendix III:7-5 . )No action is necessary if the results of the investigation are negative, that is, (1) all water and HVAC systems are well maintained and in good operating condition; (2) all water sample results are negative or acceptably low ( Appendix III:7-3 ); and (3) no new cases of the disease have been identified at the work site. Under these circumstances, assume that the site is not the origin of the identified case. Step 6.

For recommended control actions, see the level-one investigation. Ongoing Outbreak If the evidence indicates that two or more cases of Legionnaires' disease have occurred at a site, and at least one of the cases was within the last 30 days, assume that an outbreak is in progress and requires a high-priority investigation and prompt action. Conduct a level-two investigation as outlined above, and take the following precautions to protect building occupants.

Immediately initiate control measures to prevent additional exposures to all water systems that have a reasonable potential for worker exposure including hot and cold domestic water, cooling towers, humidifiers, and any other potential sources of water exposure. Collect appropriate water samples to determine Legionella levels before shutting down the water systems ( Appendix III:7-2 ).

These sample results will be invaluable in establishing the cause of the outbreak. A member of the building maintenance or engineering staff who has a working knowledge of the system's design and current operation can explain how the water system operates and the proper procedure for a controlled shutdown.

These control actions need not require facility shutdown. Temporary provisions can allow work to continue: bottled water can be supplied for drinking, shutting off water heaters can eliminate hot-water access, and temporary cooling towers can allow work to continue. V. Controls A. General Discussion This section contains background information on water system operations and proper controls to prevent Legionella amplification.

This discussion encompasses a variety of water systems, some of which have not been implicated with outbreaks of Legionnaires' disease. Nevertheless, it is important to remember that any water system can be a source of disease if the water in it is subjected to conditions that promote growth of the organism.

Remember, however, that the primary sources of exposure to contaminated water are heat rejection systems (cooling towers, fluid coolers, etc.) and domestic hot-water systems. B. Cooling Towers, Evaporative Condensers, and Fluid Coolers The function of cooling towers, evaporative condensers, and fluid coolers is to reject heat from system fluids through evaporation.

Cooling towers remove heat from condenser water via direct-contact evaporation in a wet airstream. This cooled water circulates through the condenser side of a mechanical refrigeration unit to absorb heat. Evaporative condensers operate similarly, except that the refrigerant condenser coils are directly inside the wet air stream and water passing over the coils directly cools the refrigerant.

Fluid coolers are employed to reject heat from industrial processes, computer-room air conditioners, etc. Like evaporative condensers, fluid coolers have heat-exchanger coils directly in the wet air stream.

Because all of these systems use a fan to move air through a recirculated water system, a considerable amount of water vapor is introduced into the surroundings despite the presence of drift eliminators designed to limit vapor release.

In addition, this water may be in the ideal temperature range for Legionella growth, 20° - 50°C, 68° - 122°F. Inspection and Maintenance. Visual inspection and periodic maintenance of the system are the best ways to control growth of Legionella and related organisms.

Good maintenance is necessary both to control Legionella growth and for effective operation. The system should be properly monitored and maintained to prevent buildup of scale and sediment and bio-fouling, all of which support Legionella growth and reduce operating efficiency.

Biocide. Unfortunately, measurements of water quality such as total bacterial counts, total dissolved solids, and p H have not proven to be good indicators of Legionella levels in cooling towers. Periodic use of biocides is needed to ensure control of Legionella growth. Little information exists on the demonstrated effectiveness of many commercial biocides for preventing Legionella growth in actual operations.

Recent Australian studies indicate that Fentichlor [2,2'-thiobis (4-chlorophenol)] used weekly for 4 hours at 200 ppm, or bromo-chloro-dimethyl-hydantoin (BCD) in a slow-release cartridge at an initial concentration of 300 ppm are effective in controlling the growth of Legionella. There are no U. S. suppliers of Fentichlor, although the chemical is liscensed by the EPA for water treatment in cooling towers.

Towerbrom 60M TM, a chlorotriazine and sodium bromide salt mixture, has been reported to be effective when alternated with BCD for control of Legionella in U. S. studies of Legionella contamination of cooling towers.

The Australian study also indicates that quaternary ammonium compounds, widely used for control of bio-fouling in cooling towers, are not effective in controlling Legionella. Traditional oxidizing agents such as chlorine and bromine have been proven effective in controlling Legionella in cooling towers. Continuous chlorination at low free residual levels can be effective in controlling Legionella growth.

It is important, however, that the proper oxidant level be established and maintained because free residual chlorine above 1 ppm may be corrosive to metals in the system and may damage wood used in cooling towers; free residual levels below 1 ppm may not adequately control Legionella growth.

Chlorine also combines with organic substances in water to formtoxic by-products that are of environmental concern. Frequent monitoring and control of p H is essential for maintaining adequate levels of free residual chlorine. Above a p H of 8.0, chlorine effectiveness is greatly reduced. Proper control of p H will maintain the effectiveness of chlorination and minimize corrosion.

Bromine is an effective oxidizing biocide. It is frequently added as a bromide salt and generated by reaction with chlorine. Bromine's effectiveness is less dependent than chlorine on the p H of the water; it is less corrosive; and it also produces less toxic environmental by-products.

The effectiveness of any water-treatment regimen depends on the use of clean water. High concentrations of organic matter and dissolved solids in the water will reduce the effectiveness of any biocidal agent. Each sump should be equipped with a ""bleed,"" and make-up water should be supplied to reduce the concentration of dissolved solids.

Design One of the most effective means of controlling the growth of Legionella is to maintain sump water at a low temperature. Sump-water temperatures depend on tower design, heat load, flow rate, and ambient dry-bulb and wet-bulb temperatures. Under ideal conditions, sump-water temperatures in evaporative devices approach the ambient wet-bulb temperature, and that may be low enough to limit Legionella amplification.

System design should recognize the value of operating with low sump-water temperatures. High-efficiency drift eliminators are essential for all cooling towers. Older systems can usually be retrofitted with high-efficiency models. A well-designed and well-fitted drift eliminator can greatly reduce water loss and potential for exposure.

Other important design features include easy access or easily disassembled components to allow cleaning of internal components including the packing (fill). Enclosure of the system will prevent unnecessary drift of water vapor, and other design features to minimize the spray generated by these systems are also desirable.

Frequency of Cleaning. Cooling towers should be cleaned and disinfected at least twice a year. Normally this maintenance will be performed before initial start-up at the beginning of the cooling season and after shut-down in the fall.

Systems with heavy bio-fouling or high levels of Legionella may require additional cleaning. Any system that has been out of service for an extended period should be cleaned and disinfected. New systems require cleaning and disinfecting because construction material residue can contribute to Legionella growth. Wisconsin Protocol. Acceptable cleaning procedures include those described in the Wisconsin Protocol.

This procedure calls for an initial shock treatment with 50 ppm free residual (total) chlorine, addition of detergent to disperse bio-fouling, maintenance of 10 ppm chlorine for 24 hours, and a repeat of the cycle until there is no visual evidence of biofilms.

To prevent exposure during cleaning and maintenance, wear proper personal protective equipment: a Tyvek-type suit with a hood, protective gloves, and a properly fitted respirator with a high-efficiency particulate (HEPA) filter or a filter effective at removing one-micron particles.

Recordkeeping. A description of the operating system (which includes all components cooled by the system) and details of the make-up water to the system should be available. Written procedures for proper operation and maintenance of the system should indicate the use of scale and corrosion inhibitors, antifoaming agents, and biocides or chlorine use and should be readily available. Log books should list dates of inspections and cleanings, water-quality test results, and maintenance.

C. Domestic Hot-Water Systems Background. Domestic hot-water systems are frequently linked to Legionnaires' outbreaks. The term ""domestic"" applies to all nonprocess water used for lavatories, showers, drinking fountains, etc., in commercial, residential, and industrial settings. Disease transmission from domestic hot water may be by inhalation or aspiration of Legionella -contaminated aerosolized water.

Water heaters that are maintained below 60°C (140°F) and contain scale and sediment tend to harbor the bacteria and provide essential nutrients for commensal micro-organisms that foster growth of L. pneumophila. Large water heaters like those used in hospitals or industrial settings frequently contain cool zones near the base where cold water enters and scale and sediment accumulate. The temperature and sediment in these zones can provide ideal conditions for amplification of the organism.

Dead legs (i.e., sections of piping or plumbing that have been altered or capped such that water cannot flow through) and nonrecirculated plumbing lines that allow hot water to stagnate also provide areas for growth of the organism. Design. Water systems designed to recirculate water and minimize dead legs will reduce stagnation. If potential for scalding exists, appropriate, fail-safe scald-protection equipment should be employed. For example, pressure-independent, thermostatic mixing valves at delivery points can reduce delivery temperatures.

Point-of-use water heaters can eliminate stagnation of hot water in infrequently used lines. Proper insulation of hot-water lines and heat tracing of specific lines can help maintain distribution and delivery temperatures. Maintenance To minimize the growth of Legionella in the system, domestic hot water should be stored at a minimum of 60°C (140°F) and delivered at a minimum of 50°C (122°F) to all outlets.

The hot-water tank should be drained periodically to remove scale and sediment and cleaned with chlorine solution if possible. The tank must be thoroughly rinsed to remove excess chlorine before reuse. Eliminate dead legs when possible, or install heat tracing to maintain 50°C (122°F) in the lines.

Rubber or silicone gaskets provide nutrients for the bacteria, and removing them will help control growth of the organism. Frequent flushing of these lines should also reduce growth. Domestic hot-water recirculation pumps should run continuously. They should be excluded from energy conservation measures. Control Raising the water-heater temperature can control or eliminate Legionella growth.

Pasteurize the hot water system by raising the water-heater temperature to a minimum of 70°C (158°F) for 24 hours and then flushing each outlet for 20 minutes. It is important to flush all taps with the hot water because stagnant areas can ""re-seed"" the system. Exercise caution to avoid serious burns from the high water temperatures used in Pasteurization. Periodic chlorination of the system at the tank to produce 10 ppm free residual chlorine and flushing of all taps until a distinct odor of chlorine is evident is another means of control.

In-line chlorinators can be installed in the hot water line; however, chlorine is quite corrosive and will shorten the service life of metal plumbing.

Control of the p H is extremely important to ensure that there is adequate residual chlorine in the system. Alternative means to control Legionella growth include the use of metal ions such as copper or silver (which have a biocidal effect) in solution. Ozonization injects ozone into the water. Ultraviolet (UV) radiation also kills microorganisms. Commercial, in-line UV systems are effective and can be installed on incoming water lines or on recirculating systems, but stagnant zones may diminish the effectiveness of this treatment.

Scale buildup on the UV lamp surface can rapidly reduce light intensity and requires frequent maintenance to ensure effective operation. D. Domestic Cold-Water Systems Domestic cold water systems are not a major problem for Legionella growth.

Maintaining cold-water lines below 20°C will limit the potential for amplification of the bacteria. It is surprising, however, that elevated levels of Legionella have been measured in ice machines in hospitals. Cold-water lines near heat sources in the units are believed to have caused the amplification. Dental water lines have recently been recognized as common sources of water contaminated with high concentrations of microorganisms including Legionella.

However, to date an increased risk of disease among dental staff or patients has not been demonstrated.

Dental water line operating conditions are especially appropriate for Legionella proliferation because the water is stagnant a majority of the time, the narrow plastic tubing encourages biofilm formation, and the water temperature is usually 20°C (68°F) or higher--some systems maintain water at 37°C (98.6°F). Filtration of water at the point of use with replaceable, in-line, FDA-cleared, 0.22-microns pore sizes filters is recommended for minimizing risk to patients and staff in a dental facility. Water tanks that allow water to remain uncirculated for long periods can also promote growth of bacteria.

Such tanks should be eliminated or designed to reduce storage time to a day or less. They should also be covered to prevent contamination and protected from temperature extremes. Cross-contaminations of the domestic cold-water system with other systems should always be suspected.

All connections to process water should be protected by a plumbing code-approved device (e.g., back-flow preventer, air gap, etc.). If significant contamination of the domestic cold water system occurs, the source of contamination must be determined. Inspect the system for ""dead legs"" and areas where water may stagnate. Elimination of these sections or frequent flushing of taps to drain the stagnant areas may be necessary to limit growth of the organism. Insulate cold-water lines that are close to hot-water lines to reduce the temperature in the line. If the cold-water lines have significant contamination, hyperchlorination can eradicate Legionella.

Free chlorine levels of 20 to 50 ppm are allowed to remain for one hour at 50 ppm, or two hours at 20 ppm. Faucets are then allowed to run until the odor of chlorine is present, and the water is allowed to remain for approximately two hours.

E. HVAC Systems HVAC systems are not normally amplification sites for Legionella. The organism cannot survive without water, and a properly operated, well-maintained HVAC system is unlikely to be a source of problems.

However, the HVAC system can disseminate contaminated water aerosols. Water-aerosol sources are classified as either external or internal. External sources may emit contaminated aerosolized water that is drawn into a system's fresh-air intake. Mist discharged from cooling towers, evaporative condensers, and fluid coolers can be ingested by the HVAC fresh air intake.

When evaluating this path, you should consider:prevailing wind direction and velocity;building effects (e.g., low-pressure zones on leeward sides of buildings and on roof);architectural screen walls; anddistance from tower to intake. Fresh-air intake areaways, typically concrete plenums located at grade level, supply fresh air to air handlers in the basement or lower levels of buildings and can collect organic material (e.g.

leaves, dirt, etc.) and water from rain or irrigation. Do not ignore direct paths such as through an open window. The transmission path through the HVAC system is tortuous, and the bacteria may die from desiccation in the airstream or impact on internal surfaces like filters, duct lining, etc. When evaluating external sources, examine the potential for direct transmission. Internal sources may provide contaminated aerosolized water that is then disseminated by the air-distribution system.

Contaminated water can leak from pipes into HVAC ducts, where it can be aerosolized and distributed by the system. Potential sources of contaminated water include domestic water systems, fire-sprinklers, refrigeration condensers, etc.

HVAC system humidifiers can be hazards. Four types are common: Heated-pan humidifiers use a heat source to evaporate water from a pan open to the air stream. Intermittent use of the device coupled with a warm pan of water may support Legionella growth. Contaminant-free water is essential.

Direct steam-type humidifiers inject boiler-generated steam directly into the air stream. These systems normally operate above 70°C (158°F), and Legionella cannot survive at that temperature. Atomizing humidifiers use mechanical devices or pneumatic air to create a water mist that evaporates into the air stream. A contaminant-free water source is essential. Direct evaporative air coolers may be used as humidifiers. These devices mix water and air in direct contact to create a cool, wet air stream by evaporation.

These devices include sumps, which may stagnate when not in use. When draining properly, the water that passes through the condensate pans of cooling coils in an air handler is normally not a source of growth for the organism because of the low temperature of water condensate. Indirect evaporative air cooling in systems designed for dryer climates. One common design circulates cool water from a cooling tower sump through a water coil in the supply air stream.

If the coil develops a leak, then pumped cooling tower water will be injected directly into the supply air stream with potentially deleterious effects if the sump water is contaminated with Legionella.

Indirect evaporative air cooling is also found in air-to-air heat exchangers. One side of the heat exchanger is an evaporative-cooled wet air stream, and the other side supplies air for the conditioned space. If the heat exchanger leaks, the wet air stream can mix with supply air and cause problems if the wet air stream is contaminated with Legionella.

Many air-handling systems designed for dryer climates employ direct evaporative air cooling. Wet evaporative coolers, slinger air coolers and rotary air coolers common in commercial applications. These devices mix water and air in direct contact to create a cool, wet air stream by evaporation.

If these systems are using 100% outside air in a dry climate, the water sump temperature may be low and will not represent a significant risk. However, improperly operated and maintained systems that use warm, stagnant sump water can present problems.

Other equipment may also be potential sources of Legionella : Residential humidifiers are small, free-standing, portable units that use an internal fan and wet media to disseminate a wet air stream.

The sumps of these devices are frequently contaminated with Legionella. Daily cleaning is necessary to maintain acceptable water quality, but these units seldom receive appropriate maintenance, and their use in the commercial or industrial workplace is strongly discouraged. Computer room air conditioners typically include humidifiers and frequently are not well maintained.

They may contain a sump filled with contaminated water. The following are issues to consider when designing HVAC systems to minimize risk from Legionella contamination. Most apply to all types of microbial contamination. Minimize use of water reservoirs, sumps, and pans. Chemically untreated, stagnant, warm-water sources provide an ideal environment for Legionella growth.

Provide a way to drain water sumps when not in use, e.g., an electric solenoid valve on the sump drain. If an HVAC sump is used during the hours when a building is occupied, drain the sump during unoccupied hours. Provide a ""bleed"" for water sumps so that dissolved solids do not form sediments in the sump. Slope and drain sumps from the bottom so that all the water can drain out and allow the pan to dry.

Locate HVAC fresh-air intakes so that they do not draw the mist from a cooling tower, evaporative condenser, or fluid cooler into the system.

The American Conference of Governmental Industrial Hygienists publishes ""Guidelines For The Assessment Of Bioaerosols In The Indoor Environment,"" which lists recommended minimum distances between cooling towers and fresh-air intakes. Design indirect evaporative cooling systems with the knowledge that the failure of the heat exchanger will allow wet systems to mix with the air-distribution systems.

Use steam or atomizing humidifiers instead of units that use recirculated water. Do not use raw steam from the central heating boiler because it contains corrosion inhibitors and anti-scaling chemicals.

Atomizing humidifiers must have contaminant-free water. Operate all HVAC equipment as originally designed, and maintain it so that it can perform as designed. Test all HVAC equipment periodically to insure that it is performing as designed. Inactive sumps must be properly drained and bled to prevent accumulation of sediments. Maintenance failures can produce contaminated, stagnant water that can become an ideal environment for Legionella growth if heated (e.g., by sunlight).

VI. Bibliography American Water Works Association, A Procedure for Disinfecting Water Mains, AWWA C601, 1981; Denver CO. Best, M., A. Goetz, and V. L. Yu. ""Heat eradication measures for control of nosocomial Legionnaires' disease."" American Journal of Infection Control, 12, (1), 1984, pp.

26-30. Broadbent, C. R. ""Legionella in Cooling Towers: Practical Research, Design, Treatment and Control Guidelines."" Delivered at 1992 Inter. Symp. on Legionella, Amer. Society for Micro., Jan. 26-29, 1992, Orlando Fl. Chartered Institution of Building Services Engineers, Minimizing The Risk of Legionnaires' Disease, Delta House, 222 Balham High Rd., London 1987. England, A. C. et al. ""Sporadic legionellosis in the U. S.: the first 1000 cases."" Ann. Inter.

Med. 94, 1981, p. 164. Gilpin, R. W., A. M. Kaplan, and E. F. Goldstein ""Quantitation of Legionella pneumophila in one thousand commercial and industrial cooling towers."" Proceedings 48th Inter. Water Conference, Oct. 24-26, 1988, Pittsburgh, pp.13-19. Health and Safety Executive (UK), ""The Control of legionellosis including Legionnaires' disease.""

Health and Safety Series Booklet, HS (G)70, Library and Information Services, Broad Lane, Sheffield S37HQ, Tel: (0742) 752539. Health Department Victoria; Melbourne Australia, ""Guidelines for the Control of Legionnaires' Disease.""

Environmental Health Standards, 1989. Morris, G. K. and B. G. Shelton. Legionella in Environmental Samples: Hazard Analysis and Suggested Remedial Actions. March 1991, Pathogen Control Assoc., Norcross, Georgia. Muder, R. R., V. L. Yu, and A. H. Woo. ""Mode of transmission of Legionella pneumophila.""

Arch Intern Med, 146, (1986), pp. 1607-1612. Muraca, P., J. E. Stout, and V. L. Yu. ""Comparative assessment of chlorine, heat, ozone, and UV light for killing Legionella pneumophila within a model plumbing system."" Applied and Environmental Microbiology, 53, (2), 1987, p. 447-453. Muraca, P. W., V. L. Yu, and R. N. Goetz. ""Disinfection of water distribution systems for Legionella: a review of application procedures and methodologies."" Infect. Control Hosp. Epidemiol., 11, (2), 1990, pp. 79-88. Muraca, P. W., J. E. Stout, V. L. Yu, and Y. C. Ying.

""Legionnaires' disease in the work environment: implications for environmental health."" Am. Ind. Hyg. Assoc., 49, (11), 1988, pp. 584-590. Nalco Chemical Company. Cooling Water Chlorination, Technifax, TF-132, Nalco Chemical Co., Naperville, Illinois, 1986.

Nguyen, M. H., J. E. Stout, and V. L. Yu. ""Legionellosis."" Lower Respiratory Tract Infections, 5, (3), September 1991, pp. 561-584. Stout, J. E., V. L. Yu, and M. S. Muraca. ""Isolation of Legionella pneumophila from the cold water of hospital ice machines: implications for origin and transmission of the organism.""

Infection Control, 7786, (4), 1985, pp. 141-146. Stout, J. E., V. L. Yu, M. S. Muraca, J. Joly, N. Troup, and L. S. Tompkins. ""Potable water as a cause of sporadic cases of community-acquired Legionnaires' disease."" New England Journal of Medicine, 326, January 16, 1992, pp.

151-155. Wisconsin Division of Health. Control of Legionella in Cooling Towers: Summary Guidelines, June 1987, Wisconsin Department of Health and Social Sciences. Williams, J. F. et. al. ""Microbial contamination of dental unit waterlines: prevalance, intensity and microbiological characteristics.""

J. of American Dental Association, 124, October 1993, pp. 59-65. Appendix III:7-1. Employee Awareness Program The purpose of an employee awareness program is to inform the employees of the potential outbreak, and to educate them about the disease. This educational program should be part of a level-two investigation or for a Legionnaires' disease outbreak. This program is of critical importance to aid in early recognition of the disease. It is also important to help alleviate employee concerns about the disease. This program should supplement the case identification program to discover previously undetected cases of the illness at the work site.

The employer should implement the following elements of this program immediately upon recognition of more than one probable or confirmed case of disease in the work place: An initial employee training session which provides basic information about the disease and actions being taken to investigate the problem;An ongoing general information service to provide updates and answer questions that may arise among employees; and Medical and psychological counseling services when an outbreak has occurred.

Below is a sample letter and supplemental information on the disease that the employer can use for informing employees of a potential or actual outbreak. SAMPLE LETTER FROM EMPLOYER TO EMPLOYEESDATE: MEMO TO: ALL EMPLOYEESFROM: MANAGEMENT OFFICIALSUBJECT: Legionnaires' Disease On _________________, we were notified that one of the employees of our company had contracted legionellosis, commonly referred to as Legionnaires' disease.

The employee is assigned to _________________ on ___________ shift. We want to share with you some general information concerning the disease. In addition, we want to tell you what we are currently doing here at _____________________ to ensure all necessary steps are taken to address health concerns.

Legionellosis, or Legionnaire's disease, is a type of pneumonia caused by Legionella bacteria. Legionnaires' disease is not contagious, and you cannot catch it from another person. The bacteria are common and grow in water.

People often receive low-level exposure in the environment without getting sick. Legionellosis usually occurs only when someone who is already susceptible receives concentrated exposure to the bacteria. Persons who are heavy smokers, elderly, or whose ability to resist infection is reduced are more likely to contract Legionnaires' disease than healthy nonsmokers. According to the Centers for Disease Control in Atlanta, there are between 10,000 and 50,000 cases of Legionnaire's disease every year in the U. S. We are cooperating fully with local health officials who are investigating this matter.

Most cases of legionellosis are isolated and are not associated with an outbreak. To date, _____ case (s) of the disease has/have occurred among employees in this facility. To identify any other cases, we will review sick-leave records for the period ____________ to _____________. Employees who took more than three consecutive days of sick leave will be identified, and we will attempt to determine if any in that group experienced pneumonia-like symptoms (fever, shortness of breath, cough).

Those who used three or more consecutive days of sick leave during this period can expect to be contacted by a representative of our company for an interview. If you experienced a pneumonia-like illness in the past two months but used fewer then three consecutive days of sick leave, contact _________________ to arrange an interview. To assure that you are being protected during the interim, we are also instituting a medical surveillance program to identify any new or old cases.

Part of this surveillance will be to ask you a few questions about your illness when you call in sick to your supervisor. In addition, we are offering counseling and employee information services. If you would like to take advantage of these services or want more information, contact your manager.

For the present, please pay attention to the following important points: WHAT YOU SHOULD DO NOW: If you are not sick, there is no need for you to see a doctor. If you are now sick with a cough and fever: See your private doctor or contact __________ to arrange to see a _______________ physician.

Tell the physician that you work in a building that may be involved in a Legionnaires' disease outbreak. If you see a physician, notify _______________ so that your illness can be tracked. If you have any concerns or questions concerning this issue, please ask your manager.

Your health and safety are of great concern to us, and we will be grateful for your cooperation in this matter. As further information develops we will keep you informed. SAMPLE INFORMATION TO BE OBTAINED BY INTERVIEW WITH EMPLOYEES CALLING IN ON SICK LEAVEInterviewer:__________________________ Date:_______________SUPERVISOR SURVEY FORMWe are screening employee illnesses as a result of our Legionnaire's disease incident.

You are not obligated to participate in the survey, but your participation will help you and your fellow workers. We recommend that you see a physician if you currently have pneumonia-like symptoms such as severe chills, high fever, a cough, and difficult breathing.

Are you currently experiencing these symptoms? Yes_____ No_____ Prefer not to answer______If the answer to the question is ""No,"" do not complete the rest of this form. Thank you for your cooperation. If the answer is ""Yes,"" please read the statement below and complete the bottom half of this form (Employee name, etc). If you answer is ""Prefer not to answer,"" please complete ONLY the bottom half of this form (Employee name, etc).

STATEMENT: You will be contacted by ______________ to obtain additional information necessary to complete our survey. Thank you!Employee's Name _______________________________________________Work Telephone Number _______________________________Home Telephone Number _______________________________Shift: Day ___ Swing ___ Graveyard ___ Rotating ___Branch _______________________/Organization Code _______________Employee's Supervisor _____________________________________________Telephone Number _______________________________________________Date _____________________________________PLEASE FORWARD TO ________________ BY 10:00 am EACH DAYLegionnaires' Disease: Questions and Answers Background Legionnaires' disease is a common name for one of the several illnesses caused by Legionella bacteria.

Legionnaires' disease is an infection of the lungs that is a form of pneumonia. A person can develop Legionnaires' disease by inhaling water mist contaminated with Legionella.

Legionella bacteria are widely present at low levels in the environment: in lakes, streams, and ponds. At low levels the chance of getting Legionnaires' disease from a water source is very slight. The problem arises when high concentrations of the organism grow in water sources.

Water heaters, cooling towers, and warm, stagnant water can provide ideal conditions for the growth of the organism. Scientists have learned much about the disease and about the Legionella bacteria since it was first discovered in 1976.

The following questions and answers will help you learn more of what is currently known about Legionnaires' disease. What are the symptoms of Legionnaires' disease? Early symptoms of the illness are much like the flu. After a short time (in some cases a day or two), more severe pneumonia-like symptoms may appear. Not all individuals with Legionnaires' disease experience the same symptoms.

Some may have only flu-like symptoms, but to others the disease can be fatal. Early flu-like symptoms:slight feverheadacheaching joints and muscleslack of energy, tired feelingloss of appetite Common pneumonia-like symptoms:high fever (102° to 105°F, or 39° to 41°C)cough (dry at first, later producing phlegm)difficulty in breathing or shortness of breathchillschest pains How common is Legionnaires' disease?

It is estimated that in the United States there are between 10,000 and 50,000 cases each year. How does a person get Legionnaires' disease? A person must be exposed to water contaminated with Legionella bacteria. This exposure may happen by inhaling or drinking water contaminated with the Legionella bacteria.

For example, inhaling contaminated water mist from a cooling tower, a humidifier, or even a shower or sink can cause the disease. How soon after being exposed will a person develop symptoms of the disease? If infection occurs, disease symptoms usually appear within 2 to 10 days. Are some people at a higher risk of developing Legionnaires' disease? Yes, some people have lower resistance to disease and are more likely to develop Legionnaires' disease.

Some of the factors that can increase the risk of getting the disease include:organ transplants (kidney, heart, etc. );age (older persons are more likely to get disease);heavy smoking;weakened immune system (cancer patients, HIV-infected individuals);underlying medical problem (respiratory disease, diabetes, cancer, renal dialysis, etc. );certain drug therapies (corticosteroids); andheavy consumption of alcoholic beverages. Is Legionnaires' disease spread from person to person? No. Legionnaires' disease is not contagious and cannot be transmitted from one person to another.

What causes Legionnaires disease? Legionnaires' disease is caused by inhaling water contaminated with rod-shaped bacteria called Legionella pneumophila. There are over 30 different species of Legionella, many of which can cause disease. Legionella pneumophila is the most common species that causes disease.

Does everyone who inhales Legionella into the lungs develop Legionnaires' disease? No. Most people have resistance to the disease.

It is thought that fewer than 5 out of 100 persons exposed to water contaminated with Legionella will develop Legionnaires' disease. Is Legionnaires' disease easy to diagnose? No. The pneumonia caused by Legionella is not easy to distinguish from other forms of pneumonia.

A number of diagnostic tests allow a physician to identify the disease. These tests can be performed on a sample of sputum, blood, or urine. How is Legionnaires' disease treated? Erythromycin is currently the antibiotic of choice. Early treatment reduces the severity and improves chances for recovery. In many instances this antibiotic may be prescribed without the physician's knowledge that the disease is Legionnaires' because erythromycin is effective in treating a number of types of pneumonia. How did Legionnaires' disease get its name? Legionnaires' disease got its name from the first outbreak in which the organism was identified as the cause.

This outbreak occurred in 1976, in a Philadelphia hotel where the Pennsylvania American Legion was having a convention.

Over 200 Legionnaires and visitors at this convention developed pneumonia, and some died. From lung tissue, a newly discovered bacterium was found to be the cause of the pneumonia and was named Legionella pneumophila. Is Legionnaire's disease a new disease? No, Legionnaires' disease is not new, but it has only recently been identified. Unsolved pneumonia outbreaks that occurred before 1976 are now known to have been Legionnaires' disease.

Scientists are still studying this disease to learn more about it. Are Legionella bacteria widespread in the environment? Yes, studies have shown that these bacteria can be found in both natural and man-made water sources. Natural water sources including streams, rivers, freshwater ponds and lakes, and mud can contain the organism in low levels.

Could I get the disease from natural water sources? It is unlikely. In the natural environment the very low levels of this organism in water sources probably cannot cause disease.

What water conditions are best for growth of the organism? Warm, stagnant water provides ideal conditions for growth. At temperatures between 68° and 122°F the organism can multiply. Temperatures of 90°-105°F are ideal for growth. Rust (iron), scale, and other micro-organisms can also promote the growth of Legionella. What common types of water are of greatest concern?

Water mist from cooling towers or evaporative condensers, evaporative coolers (swamp coolers), humidifiers, misters, showers, faucets, and whirlpool baths can be contaminated with the organism and if inhaled or swallowed can cause the disease.

Can Legionnaires' disease be prevented? Yes. Avoiding water conditions that allow the organism to grow to high levels is the best means of prevention. Specific preventive steps include: Regularly maintain and clean cooling towers and evaporative condensers to prevent growth of Legionella.

This should include twice-yearly cleaning and periodic use of chlorine or other effective biocide. Maintain domestic water heaters at 140°F (60°C). The temperature of the water should be 122°F or higher at the faucet. Avoid conditions that allow water to stagnate. Large water-storage tanks exposed to sunlight can produce warm conditions favorable to high levels of Legionella.

Frequent flushing of unused water lines will help alleviate stagnation. Do you recommend that I operate my home water heater at 140°F? Probably not if you have small children or infirm elderly persons who could be at serious risk of being scalded by the hot water.

However, if you have persons living with you who are at high risk of contracting the disease, then operating the water heater at a minimum temperature of 140F is probably a good idea. What can be done if a water system is already contaminated or is suspected of being contaminated? Special cleaning procedures can eliminate Legionella from water sources.

In many cases these procedures involve the use of chlorine-producing chemicals or high water temperatures. Professional assistance should be sought before attempting to clean a water system. Can my home water heater also be a source of Legionella contamination?

Yes, but evidence indicates that smaller water systems such as those used in homes are not as likely to be infected with Legionella as larger systems in work places and public buildings. Can Legionella bacteria cause other diseases? Yes. In addition to Legionnaires' disease, the same bacteria also cause a flu-like disease called Pontiac fever. How does Pontiac fever differ from Legionnaires' disease? Unlike Legionnaires disease, which can be a serious and deadly form of pneumonia, Pontiac fever produces flu-like symptoms that may include fever, headache, tiredness, loss of appetite, muscle and joint pain, chills, nausea, and a dry cough.

Full recovery occurs in 2 to 5 days without antibiotics. No deaths have been reported from Pontiac fever. Are there other differences between Legionnaires' disease and Pontiac fever? Yes. Unlike Legionnaires' disease, which occurs in only a small percentage of persons who are exposed, Pontiac fever will occur in approximately 90% of those exposed.

In addition, the time between exposure to the organism and appearance of the disease (called the incubation period) is generally shorter for Pontiac fever than for Legionnaires' disease.

Symptoms of Pontiac fever can appear within one to three days after exposure. Appendix III:7-2. Physical Survey and Water Sampling Protocol *Arrange with the appropriate laboratory for supply and shipment of sterile sampling containers, and for analysis of water samples. During the initial walk-through, estimate the size of the building and the number of water services at the facility to determine the number of samples and the size of the purchase order.

When investigating the water services within a building, it will be helpful to obtain or prepare a simple schematic diagram of the water services. Note the following features: The location of the incoming supply and/or private source. The location of storage tanks, water treatment systems, and pumps.

The location of water heaters and boilers. The type of fittings used in the system (e.g., taps, showers, valves) and the material from which the pipework is made. The location of all cooling towers, evaporative condensers, and fluid coolers at the facility. The location and type of all systems served by the cooling tower water including sump tanks, condensers, and indirect evaporative cooling coils in air handling units.

The location of any evaporative cooling systems or humidifiers. The location of ornamental fountains, whirlpools, eye washes, safety showers, or other water sources within or near the facility.

Trace the route of the service from the point of entry of the water supply. Note the condition of pipes, jointing methods used, insulation, sources of heat, and the kind of insulation in water storage tanks. Also note carefully any disconnected fittings, ""dead legs,"" and cross-connections with other services. Once you have identified these features, take water samples from: The incoming water supply. Each storage tank and water heater.

A representative number of faucets for each of the hot and cold water systems in the facility. All cooling towers, evaporative condensers, humidifiers, spas, showers, etc. The water entering or leaving any other type of fitting or piece of equipment under particular suspicion.

It is important not to overlook any potential water sources in the building. Water from ice machines, hand spray bottles, decorative fountains, and for plastic injection molding equipment have been implicated in past outbreaks or have been found to be significantly contaminated. The ability to maintain an open mind is essential in conducting an investigation because of the variety of potential sources of contamination at a facility.

Water Sampling Procedure Wear appropriate respiratory protection in the form of a half-face piece respirator equipped with a HEPA filter or a similar type of filter media capable of effectively collecting particles in the one micron size range during the examination of water systems if a significant potential exists for exposure to high concentrations of contaminated aerosols. Collect samples in polypropylene (nalgene) containers (250 m L-1 L) that have been autoclaved at 121°C for 15 minutes. The microbiological laboratory that will analyze the samples should be able to provide the bottles.

A local hospital or state health department should be able to autoclave the bottles. It is important not to flush the system to be sampled before collecting samples. Collect at least a 250 m L sample. Measure the temperature of the sampled water. It is preferable to accomplished this by measuring the water stream flowing from the water source and not by placing the thermometer in the sample container.

To avoid cross-contamination of the samples, sanitize the thermometer with isopropyl alcohol before measuring the temperature of each sample. When measuring temperature from faucets, showers, water fountains, etc., record the initial water temperature, and then allow the fixture to discharge until the temperature stabilizes.

Record the initial and final temperatures, and the time needed to stabilize. Domestic Water Heaters Take a sample of water from the bottom drain. Collect a sample of water from the outlet pipe if the plumbing provides for access. Faucets and Showers Collect a ""before-flush"" (initial flow) sample of water. Collect an ""after-flush"" sample of water when the maximum temperature has been reached. The initial (before-flush) sample is intended to indicate the level of contamination at the sample point or fitting, and the final sample should reveal the quality of the water being supplied to the fitting.

Collect sterile-swab samples from faucets or shower heads by removing the fitting and vigorously swabbing the interior.

Swab samples may be positive for Legionella even when water samples from the source are negative. Sterile test tubes containing sterilized swabs are available for convenient sampling and shipping. Cooling Towers Take a sample from the incoming supply to the tower. Take samples from any storage tanks or reservoirs in the system (i.e., chilled-water return tanks or header tanks).

Take a sample from the basin of the cooling tower at a location distant from the incoming make-up water, and from the water returning from the circulation system at the point of entry to the tower. Take a sample of any standing water in the condensate trays or from the cooling coils. Humidifiers, Swamp Coolers, and Spas Take a sample from the water reservoirs. Sample the incoming water supply if it is accessible. For cooling towers, humidifiers, swamp coolers, and building water services, collect samples of sludge, slimes, or sediments, particularly where accumulations occur.

Take swabs of shower heads, pipes, and faucets and rehydrate from water taken from the sampling site. Swab areas of scale buildup (i.e., remove shower heads, faucet screens, and aerators). Use prepackaged sterile swabs and small glass or polypropylene bottles (autoclaved) for this purpose.

Sample Transportation Prepare samples for shipment carefully, as follows: Wrap vinyl tape clockwise around the neck of each bottle to hold its screw cap firmly in place and seal the interface between the cap and the bottle. Wrap absorbent paper around bottles, and place the bottles in a sealable (zip-lock) plastic bag. Place the sealed plastic bag in an insulated container (styrofoam chest or box).

Samples should not be refrigerated or shipped at reduced temperature. They should be protected from temperature extremes such as sunlight or other external heat or cold sources. Ship to laboratory using overnight mail. If shipping on a Friday, make arrangements for weekend receipt.

The samples should be stored at room temperature (20° ± 5°C) and processed within 2 days. Appendix III:7-3.

Water Sampling Guidelines [Adapted from George K. Morris, Ph D, and Brian G. Shelton, Pathcon Technical Bulletin 1.3, Legionella in Environmental Samples: Hazard Analysis and Suggested Remedial Actions, June 1991, Pathogen Control Associates, 270 Scientific Dr., Suite 3, Norcross, GA 30092]Use the following guidelines to assess the effectiveness of water system maintenance.

These guidelines are based on limited data and are subject to change. They are intended to apply only to water systems being used by healthy individuals and are not necessarily protective for persons who are immunocompromised. The levels requiring action vary for the source of exposure based on the assumption that some routes or exposure result in a greater dose to the lung.

For this reason, humidifiers and similar devices such as misters and evaporative condensers which produce an aerosol mist that can be directly inhaled should be controlled to lower levels. Remember that these numbers are only guidelines, and the goal is zero detectable Legionella in a water source.

Levels of Legionella equal to or greater than the values in the table constitute a need for action, as described below. Action 1 : Prompt cleaning and/or biocide treatment of the system. Action 2 : Immediate cleaning and/or biocide treatment.

Take prompt steps to prevent employee exposure. Table III:7-1. COLONY FORMING UNITS (CFU) OF LEGIONELLA PER MILLILITERAction Cooling tower Domestic water Humidifier110010121,00010010Appendix III:7-4. Legionnaires' Disease Case Identification The purpose of this phase of an investigation will be to identify cases of Legionnaires' disease among the workers.

The investigation will include identification of all employees who took three or more consecutive days of sick leave days from six weeks before the Legionnaires' case was identified to the present. Following a screening process, all employees who have been identified as having had pneumonia, or potentially having had pneumonia, during this period will be requested to undergo voluntary medical testing to detect evidence of Legionnaires' disease.

A physician's diagnosis of pneumonia or pneumonia-like symptoms that include a fever (101°F) and cough indicate a need for further evaluation. A sample program is described below. Examine sick leave records to identify all employees who used three or more consecutive days of sick leave from 6 weeks before the earliest known case to the present.

These employees will be interviewed. If it appears that an employee experienced a pneumonia-like illness, the attached surveillance questionnaire will be completed. Employees who feel that they might have had symptoms of Legionnaires' disease but did not use three or more consecutive days of sick leave should also be interviewed.

Employees who have experienced a pneumonia-like illness and have seen a physician should be requested to sign a medical release form to allow the company and/or OSHA to obtain additional information from the physician. The physicians of all employees who have seen a physician and have signed a medical release will be interviewed using the physician interview survey form (attached).

Employees participating in surveys such as the one described above must be informed of their Privacy Act rights as well as their right to protect their own medical information. Physician-patient confidentiality must not be violated. Necessary medical information may be communicated only with the patient's written permission.

When seeking employees' permission, clearly inform them that the purpose of obtaining a proper diagnosis and sharing this information with the Agency is to protect them and their fellow workers against the potential threat of legionellosis. All medical records will be handled in accordance with 29CFR 1913.10. It may be necessary for the CSHO to obtain medical releases from the employees interviewed so that amplifying information can be obtained from a company health unit or the employee's physician.

Arrangements similar to that described above should be sought for permanent contract employees controlled by separate contractor organizations in the building, e.g., janitors, cafeteria workers, security personnel. Based on an interview with the employee's physician, potential cases should be considered for a clinical test to detect additional cases. Most probably this will be a serological test to determine the antibody level of the individual. A single antibody titer of 1/256 or greater based on a physician's diagnosis of pneumonia should be interpreted as a probable case of Legionnaires' disease.

In the event that an antibody titer level for Legionella was obtained at the time of illness, or if serum collected from the patient at the early phase of the illness (acute phase) is available, then an antibody titer level should be determined from this sample to determine the convalescent to acute titer ratio.

A fourfold increase in this titer will be sufficient to confirm a case of Legionnaires' disease. Other diagnostic tests may also be appropriate. If the potential case occurred recently, then a urine antigen test may detect Legionella pneumophila serogroup-1 antigen.

A positive urine antigen test for a diagnosed pneumonia case is also accepted as evidence of a confirmed case. However, this test is available only for Legionella pneumophila serogroup-1 infections. Culture currently symptomatic individuals for Legionella.

A positive culture indicates confirmation. If this process detects one or more additional cases of disease, then the facility should be considered to have experienced an outbreak. The immediacy of the action will depend on whether the outbreak is ongoing or occurred 30 days or more in the past. Take prompt action to control exposure at the site if there is evidence that the outbreak is still occurring.

Whatever the circumstances, initiate control procedures and continue medical surveillance of the workforce to detect any new cases of disease and identify the water source responsible for the outbreak. HEALTH SURVEILLANCE QUESTIONNAIRE - LEGIONELLOSISRecords show that you took sick leave for three consecutive days or more.

We would like to ask a few questions. Name: (last)____________________, (first)__________________Age:______ Sex: ______ Work Location: ____________________Home Phone:___________ Work Phone:________________________Dates of absence (s):______________________________________Stated reason for absence:________________________________Ask about the following symptoms: Fever: Yes ____ No____ If yes, highest temperature _____Cough: Yes____ No ____Headache: Yes_____ No_____Diarrhea: Yes_____ No_____Shortness of breath: Yes ____ No ____Chest pain: Yes ____ No ____Did you see a physician about these symptoms?

Yes ___ No ___Was a chest x-ray taken? Yes_____ No_____Were you diagnosed as having pneumonia? Yes ___ No ___Were you tested for legionellosis? Yes_____ No_____Physician's name:______________________ Phone:_____________Physician's Address:______________________________________Were you admitted to a hospital?

Yes ____ No ____If yes, which hospital?_____________________________________Admission Date: _________________ Date released: __________Interviewer:________________________________ Date:______________PHYSICIAN SURVEY QUESTIONNAIRE - LEGIONELLOSISWe are calling to inform you that _______________________ is a patient of yours and an employee at ____________. He/she has signed a medical release giving us permission to contact you to obtain information about her/his recent illness.

This questionnaire will be used to determine if your patient's recent illness could be classified as a pneumonia that may have been caused by exposure to Legionella at the workplace. Name of Physician: ________________________________________Address:___________________________________________________Phone:_____________________________Date of visit (s): (1st)________ (2nd)________ (3rd)________What was the patient's complaint? :_________________________ ___________________________________________________________Cough? _____Yes _____No _____Unknown Short of breath? _____Yes _____No _____Unknown History of fever? _____Yes _____No _____Unknown Physical Findings: _________________________________________ ____________________________________________________________Abnormal chest or lung findings: ___________________________ ____________________________________________________________Rales? _____Yes _____No _____Not Examined Dyspnea? _____Yes _____No _____Not Examined Cyanosis? _____Yes _____No _____Not Examined Temperature ______Other: __________________________________________________Chest x-ray done?

Yes ___ No ___Findings: _____________________________________________Sputum culture? Yes ___ No ___Results: ______________________________________________Laboratory: ______________________________________________Sputum cultured for Legionella? Yes ___ No ___Laboratory: ______________________________________________Diagnostic testing? Yes ___ No ___Type of test: Urine Antigen Test, Direct Fluorescent Antibody Serology Tests: Indirect Fluorescent Antibody (IFA) ______ELISA ________Laboratory:____________________________________________Diagnosis or impression: _____________________________________EPIDEMIOLOGICAL QUESTIONNAIREBackground Employee's Name (last, first):_________________________ Age:_____ Gender:_____Home (city, zip):_____________________________________________________________Race/Ethnicity: white, black, native American, Hispanic, Asian, Other Are you currently taking any oral steroid medications? : Yes ___ No ___On what date did you first become ill? : ___ /___ /___How many days were you ill?

: _______Was anyone else in your family ill? : Yes ___ No ___If Yes, who? ______________________________________What symptoms did they have? ______________________________Since ___________, have any of your friends been diagnosed with pneumonia?

: Yes/No If Yes, who? _______________________________________________Work Exposure During the 10 days prior to your illness: Job Description: ________________________________________________Primary work area: ______________________________________________List all areas in _______ building where you spend any time: Area___________________________________________________________________________________________________________________________________________________________Hours per week___________________________________________________________________________________________________________________________________________________________Did you shower at work? : Yes ___ No ___If Yes, where and how may times per week? : _________________List all places you eat lunch:____________________________________List all places where you take a break: ____________________________List all restrooms you use: ________________________________________Do you smoke in the restrooms (or spend ""extra"" time, i.e., if a lounge is present): Yes ___ No ___If Yes, Where:_______________________________Did you attend any training courses outside of the building?

: Yes ___ No ___If Yes, where were they held? _______________________________Do you have a second job? : Yes ___ No ___If Yes, what job and where: ____________________________________________________________________Any other places that you have not mentioned where you spend time while on the job? :____________________________________________________________________Community Exposure (During the 10 days prior to your illness)Did you use any health clubs?

: Yes ___ No ___If Yes, which ones? : ________________________________________How many times?______________________________________________Did you use any hot tubs (whirlpool spas)?

: Yes ___ No ___If Yes, list which hot tubs and when used:_____________________________________________________________Did you attend any churches? : Yes ___ No ___If Yes, where________________________________________________How many times?____________Have you had any dental work performed? : Yes ___ No ___If Yes, where_________________________________________How many times?____________Which grocery stores did you go to? : _____________________________How often?__________________Did you go to the movies? : Yes ___ No ___If Yes, which one?

________________________________How often?____________Did you go to any shopping malls? : Yes ___ No ___If Yes, which one (s)?__________________________Did you go to any other public places which you feel might be significant (i.e. public meetings, schools etc.)? : Yes ___ No ___If Yes, where? ___________________________________________Appendix III:7-5. Water Treatment Protocols for Facilities That Have Experienced a Legionnaires' Outbreak Background This section describes actions required to abate the threat of further infection in a building in which an outbreak of Legionnaires' disease has occurred.

For purposes of this document, an ""outbreak of Legionnaires' disease"" may be said to exist when medically confirmed cases of Legionnaires' disease are epidemiologically associated with a building or some portion of a building. This usually means that two or more confirmed cases of Legionnaires' disease have been identified within a six-week period at the site.

Under most circumstances evacuation of the building is not recommended. It will be necessary, following confirmation of an outbreak, to isolate individuals who are at high risk of contracting the disease from all potential sources of infection. Individuals at high risk include the immunosuppressed, such as persons who have had organ transplants, individuals receiving chemotherapy including corticosteroids, and other individuals in poor health. In addition, a medical monitoring program must be instituted to track all workers currently on sick leave. Following these initial actions, the building must be inspected to identify all potential Legionella sources including the HVAC cooling systems (cooling towers, evaporative condensers), domestic water systems, humidifiers, and any sources of water that are maintained above 20°C (68°F) and has a potential for being aerosolized.

Before flushing or disinfecting the water in these suspected sources, take water samples for analysis to determine the predominant serotypes and subtypes of L. pneumophila in the water source and to determine the number of colony forming units (CFU) per unit of water.

This information will be helpful in identifying the source of the disease if the subtype of L. pneumophila has been identified in the afflicted worker population. Because of the 10-day to two-week delay in obtaining sample results, corrective action should begin immediately.

Because sampling for Legionella can be inconclusive, sampling results alone should not determine the appropriate course of action in a building where an outbreak has occurred. ALL POTENTIAL SOURCES OF CONTAMINATION WILL BE ASSUMED TO BE CONTAMINATED AND TREATED ACCORDINGLY IN THE EVENT THAT AN OUTBREAK HAS OCCURRED. Water sampling and testing must be in accordance with currently accepted, state-of-the-art procedures.

Treatment of potential sources of contamination following sampling is described below. After the treatment collect and analyze water samples for CFU of L. pneumophila to determine the effectiveness of the treatment.

Upon re-use of a water system following treatment, periodic maintenance and regular water sampling are essential to ensure that the maintenance continues to be effective. Included are proper maintenance procedures for controlling the organism in a facility's water sources.

Cooling Towers and Evaporative Condensers An HVAC condenser water system absorbs heat from the AC refrigeration units and rejects it to the atmosphere through evaporation in cooling towers. Evaporative condensers operate similarly to cooling towers except that refrigerant coils are inside the water path, and water passes over the coils to cool the refrigerant gas directly.

Because both cooling towers and evaporative condensers use a fan system to move air through a recirculated water system, they introduce a considerable amount of water vapor into the surroundings even with drift eliminators designed to limit vapor release.

In addition, this water is typically in the 20°-50°C (68°-122°F) range, ideal for L. pneumophila growth. Water Sampling Protocol. Before starting decontamination, collect an adequate number of water samples in sterile containers.

These samples should be cultured to determine the degree of contamination and the subtype of L. pneumophila before treatment. Collect at least three water samples (200 milliliters to 1 liter volume). Include water from the incoming make-up water supply, water from the basin of the unit most distant from the make-up water source, and recirculated water from the HVAC system at its point of return to the unit.

Clean-up Procedure Clean and disinfect the entire cooling system including attached chillers and/or storage tanks (sumps) following the ""Wisconsin Protocol"" Emergency Protocol, as follows:""Shock"" treat cooling tower water at 50 ppm free residual chlorine.

Add dispersant. Maintain 10 ppm chlorine for 24 hours. Drain system. Refill and repeat steps a through d. Inspect system for visual evidence of biofilm.

If found, repeat steps a through d. Perform mechanical cleaning (cooling tower design may require modified procedures). Refill system, bring chlorine to 10 ppm, and circulate for one hour. Flush system. Refill with clean water in accordance with an effective water treatment program. The unit is now ready to be returned to service. Identify and eliminate all water leaks into the cooling water system.

After completing step 1, sample the cooling water for analysis of CFU of L. pneumophila. The unit may be put into service provided the medical monitoring program has been implemented. If sample culture results indicate detectable levels of L. pneumophila, repeat chlorination and resample the water.

Once the nondetectable level for L. pneumophila has been achieved, institute maintenance as outlined in the Wisconsin Protocol to ensure continued safe and proper operation, as follows: Inspect equipment monthly. Drain and clean quarterly. Treat circulating water for control of microorganisms, scale, and corrosion. This should include systematic use of biocides and rust inhibitors, preferably supplied by continuous feed, and monthly microbiologic analysis to ensure control of bacteria.

Document operation and maintenance in a log or maintenance records book. Test cooling-system water at the following intervals to verify that there is no significant growth of Legionella, as follows: Test weekly for the first month after return to operation. Test every two weeks for the next two months. Test monthly for the next three months. The standard for Legionella concentration throughout the six months of monitoring is fewer than 10 CFU per milliliter (based on Path Con guidelines).

If no water samples exceed this level, monitoring may be suspended. The maintenance program must continue indefinitely. If any sample contains 10 or more CFU Legionella per milliliter, take immediate steps to reduce levels to acceptable limits. These steps may include increased frequency of application or concentration of biocides, p H adjustment, additional ""shock"" treatments, or any other action that reduces Legionella levels.

Take new water samples and begin the testing schedule again. Make the results of all water monitoring tests available to building occupants. Domestic Water Systems Domestic water systems are designed to provide heated water for washing, cleaning, consumption, etc. A large building may have multiple independent systems. These systems usually include a boiler or heater, a recirculating piping system, and pipes terminating in taps and fixtures.

Operating temperatures vary depending on system design, energy conservation programs, and intended use of the water. It is recommended that water heaters be kept at a minimum of 60°C (140°F) and all water be delivered at each outlet at a minimum of 50°C (122°F). It is essential to identify all parts of the domestic water systems where water may stagnate (e.g., ""dead legs"" or laterals that have been capped off, storage tanks that have ""dead zones"" or are not frequently used).

For treatment to be effective, the stagnant zones must be removed from the system. Rubber and plastic gaskets in the plumbing system may also serve as a Legionella growth medium. Eliminate or minimize use of these materials and substitute materials not conducive to Legionella growth. It is also important to identify and test the integrity of all backflow preventers to assure protection of domestic water from cross-contamination with process water through a building code-approved method. Water Sampling Protocol Collect water samples before beginning treatment to determine potential contamination. Draw 200 milliliters to 1 liter of water from the draw-off valve of all water heaters into a sterile container.

Check the temperature of the water in these units to determine if it is significantly lower than the set temperature. Sample a representative number of domestic hot-water faucets or outlets. It is important not to flush the faucet before taking a sample because the end section of the water system may be a source of contamination.

Collect a 200 milliliter to 1 liter ""preflush sample"" of the first hot water drawn from the outlet.

Allow the water to run and measure the temperature, and then collect a second, ""postflush"" sample when the water temperature is constant. Submit the water samples to a laboratory qualified to measure CFU of Legionella per milliliter of water. Use the clean-up procedure below to treat all hot-water systems that have either been tested and found to contain detectable levels of Legionella or have been assumed to be contaminated. Disinfect the system using any effective chemical, thermal, or other treatment method. For example: Pasteurize the hot water system by heating the water to at least 70°C (158°F) and maintain this temperature for a minimum of 24 hours.

While maintaining the temperature at 70°C (158°F), continuously flush each faucet on the system with hot water for 20 minutes. Use an accepted chemical disinfectant such as chlorine or an acceptable biocide treatment to clean the system.

Thoroughly flush the system after treatment to remove all traces of the corrosive and possibly toxic chemicals. Follow any other technique that has demonstrated effectiveness and safety. Maintain domestic water heaters at 60°C (140°F) and water delivered at the faucet at a minimum of 122°F (50°C). Where these temperatures cannot be maintained, control Legionella growth with a safe and effective alternative method.

After treatment, resample the hot water from each storage tank. If Legionella are detected, re-treat and resample the water system. If no measurable levels are found in this system and all other potential sources have also been addressed, go to the next step.

Test the domestic hot- or warm-water system for Legionella on the following schedule to assure that recontamination has not occurred: Weekly for the first month after resumption of operation. Every two weeks for the next two months. Monthly for the next three months. Use the Pathcon criteria for Legionella in domestic water systems during the monitoring period.

If 10 or more CFU per milliliter of water are present, re-treat the system according to steps 1-3 above. Resume weekly testing (step 4) after retreatment. If levels remain below 1 CFU per milliliter, no further monitoring is necessary. If the levels are between 1 and 9 CFU per milliliter, continue monthly sampling of the water indefinitely and continue efforts to determine the source of contamination.

Make test results available to building residents. Tepid Water Systems Warm-water systems or tepid water systems dilute domestic hot water from a water heater with cold water upstream from the outlet source are not recommended.

Warm water left in these lines is at ideal temperatures for amplification of L. pneumophila. Localized mixing at the source to temper very hot water is more acceptable. Another alternative is ""instantaneous"" point of delivery heating of water using individual steam heating systems at each outlet. Domestic Cold-Water Systems Domestic cold-water systems are designed to provide water for drinking, washing, cleaning, toilet flushing, etc.

These systems have not been a major source of concern for Legionnaires' disease because L. pneumophila will not amplify at low temperatures. cold-water storage and delivery should be at less than 20°C (68°F) to minimize potential for growth. cold-water lines near hot-water lines should be insulated. Try to eliminate stagnant places in the system as dead legs or storage tanks that are not routinely used.

Detectable levels of L. pneumophila in the system may indicate contamination of the source water supply and should represent the maximum allowable level in the system.

If sampling of the system indicates a level of contamination significantly greater than that of the incoming domestic water supply system, treat the system and identify the source of contamination or amplification. By definition, these systems have no provision for heating water, and therefore disinfection cannot be by heat treatment.

Follow the clean-up procedure below if cold-water systems are shown to contain measurable Legionella or are assumed to be contaminated. Clean-Up Procedure Clean and disinfect all cold water systems including storage tanks, drinking fountains, water lines, and water outlets, as follows: Use an accepted chemical disinfectant such as chlorine or other acceptable biocide.

Use any other technology that has been shown to be safe and effective. Ensure that cold-water systems are maintained so that conditions do not promote growth of Legionella.

Maintain temperatures at 20°C (68°F) and keep residual chlorine in the range of 1-2 ppm. In practice this level of chlorination may be objectionable and may also be excessively corrosive to metal pipes and containers. Take samples according to sampling guidelines. If analysis shows no detectable Legionella and all other potential sources have been addressed, go to the next step.

Flush all cold-water outlets and fountains for four minutes, twelve hours before re-entry. When steps a through d have been successfully completed, return the building to normal operation but test the domestic cold-water system for Legionella according to the following schedule: Weekly for the first month after resumption of operation.

Every two weeks for the next two months. Monthly for the next three months. The same criteria used for hot water systems described above will also be used for the cold-water system during the monitoring period.

Ten or more CFU per milliliter of water require retreatment of the system according to steps 1-3 above. Following retreatment, resume weekly testing and repeat the schedule outlined in step 5. If Legionella levels remain below 1 CFU per milliliter, additional monitoring is not necessary. If levels are between 1-9 CFU per milliliter, continue monthly sampling of the water source indefinitely and try to identify the source of contamination. Make monitoring results available to building occupants. HVAC Air Distribution Systems Under normal conditions HVAC systems are not likely to be sources of L. pneumophila unless water contaminated with the bacteria enters the system.

Under normal conditions, condensate pans on coiling coils should not serve as a water source in which amplification of the bacteria can occur because the temperature of the water is below 20°C (68°F). Improperly drained condenser pans may produce tepid conditions that can encourage microbial and fungal growth.

Proper maintenance will lessen problems related to other diseases such as humidifier fever and asthmatic responses, and will minimize the possibility of a Legionnaires' outbreak. Most probably, for a Legionnaires' disease outbreak to be linked directly with the HVAC system, Legionella -contaminated water must continuously enter the system, be aerosolized, and be delivered to building occupants. Examine the systems to rule out this possibility, as follows: Inspect the entire air distribution system (including return and exhaust systems) for visual evidence of water accumulation. Eliminate all water leaks and remove any standing water found in the system. Replace or eliminate any water-damaged insulation in the system. Operate the HVAC system using 100% outside air for 8 hours before returning the building to normal operation.

Sampling of air in the ducts to prove that the duct system is free of Legionella is not required and would be pointless. No reliable way to detect Legionella in the air is available, and Legionella can live only in water.

If the ducts are dry, they cannot serve as a source of Legionella. Following return of the building to normal operation, keep outside-air supply rates as high as possible for one month. At a minimum, the outdoor air requirements of ASHRAE Ventilation Standard 62-1989 must be met. Humidifiers and Misters Many HVAC systems supply humidified air to building occupants to maintain comfort. Improperly maintained humidifiers can be both amplifiers and disseminators of a variety of bioaerosols; however, generally the cool temperatures in HVAC systems are not conducive to growth of L. pneumophila.

cold-water humidifiers in HVAC systems must be connected to a domestic water source and provided with a drain line to remove the water. Stand-alone, console-type humidifiers that recirculate water for humidification should not be used because the water in these systems becomes contaminated with micro-organisms rapidly.

These stand-alone units have been linked to an outbreak of Legionnaires' disease in a hospital. Ideally, HVAC humidifiers should use steam injection systems that eliminate potential microbe problems. Cold-water humidifiers require rigorous maintenance to ensure that the water source does not contribute to potential problems. Since humidifiers discharge into HVAC air distribution systems, inspect for standing water and treat according to the HVAC Air Distribution System protocol above.

Where water in humidifiers has been sampled and shown to contain measurable Legionella, or where such water has been assumed to be contaminated with Legionella, use the following protocol: Disinfect water in piping or reservoirs feeding the humidifier with chlorine or other effective biocides.

Sample the humidifier water to assure ""kill"" of Legionella. Samples must have no detectable CFU of Legionella per milliliter of water. If one or more are detected, repeat treatment and sampling. Ensure that an adequate maintenance program is in effect to reduce the growth of Legionella.

Water storage temperatures should be above or below the 20° - 50°C (68° - 122°F) range, and the system must be kept clean. Before using the humidifier, flush the piping and/or reservoir thoroughly to remove biocides. When steps 1 through 4 have been successfully completed, return the humidifier to operation and test the unit's water system to detect recontamination with Legionella according to the schedule below: Weekly for the first month. Every two weeks for the next two months. Monthly for the next three months. The criterion for Legionella in humidifier water systems during monitoring is fewer than 1 CFU per milliliter. If no samples exceed the criterion, suspend monitoring and continue the maintenance program indefinitely. If any sample shows one or more CFU of Legionella per milliliter, retreat and retest the system according to the schedule above (step 5). Make monitoring results available to building occupants. "

Pneumonia is an infection of the lung. With atypical pneumonia, the infection is caused by different bacteria than the ones that cause typical pneumonia. These include Legionella pneumophila, Mycoplasma pneumoniae, and Chlamydophila pneumoniae. Atypical pneumonia also tends to have milder symptoms than typical pneumonia.

Atypical pneumonia

Definition

Causes Mycoplasma pneumonia is a type of atypical pneumonia. It is caused by the bacteria M. pneumoniae. It often affects people younger than age 40. Pneumonia due to chlamydia bacteria occurs year round.

It is usually mild. Pneumonia due to Legionella is seen more often in middle-aged and older adults, smokers, and those with chronic illnesses or a weak immune system. It can be more severe. This type of pneumonia is also called Legionnaire disease. Symptoms Pneumonia due to mycoplasma and chlamydophila bacteria is usually mild.

Pneumonia due to Legionella pneumophila gets worse during the first 4 to 6 days, and then improves over 4 to 5 days.

Even though symptoms will improve, it may take a while for them to go away completely. The most common symptoms of pneumonia are: Chills Cough (with Legionella pneumonia, you may cough up bloody mucus)Fever, which may be mild or high Shortness of breath (may only occur when you exert yourself)Other symptoms include: Chest pain that gets worse when you breathe deeply or cough Confusion, especially in older people or those with Legionella pneumonia Headache Loss of appetite, low energy, and fatigue Muscle aches and joint stiffness Sweating and clammy skin Less common symptoms include: Diarrhea (especially with Legionella pneumonia)Ear pain (with mycoplasma pneumonia)Eye pain or soreness (with mycoplasma pneumonia)Neck lump (with mycoplasma pneumonia)Rash (with mycoplasma pneumonia)Sore throat (with mycoplasma pneumonia)Exams and Tests People with suspected pneumonia should have a complete medical evaluation.

It may be hard for your health care provider to tell whether you have pneumonia or bronchitis, so you may need a chest x-ray.

Depending on how severe the illness is, other tests may be done, including: Arterial blood test Complete blood count (CBC)Blood cultures Blood tests to identify the specific bacteria Bronchoscopy (rarely needed)CT scan of the chest Open lung biopsy (only done in very serious illnesses when the diagnosis cannot be made from other sources)Sputum culture Urine test to check for Legionella bacteria Urine tests or a throat swab may also be done.

Treatment To feel better, you can take these self-care measures at home: Control your fever with aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs, such as ibuprofen or naproxen), or acetaminophen. DO NOT give aspirin to children. DO NOT take cough medicines without first talking to your doctor.

Cough medicines may make it harder for your body to cough up the extra sputum. Drink plenty of fluids to help loosen secretions and bring up phlegm. Get a lot of rest. Have someone else do household chores. Antibiotics are used to treat atypical pneumonia. You may be able to take antibiotics by mouth at home. If your condition is severe, you will likely be admitted to a hospital. There, you will be given antibiotics through a vein (intravenously), as well as oxygen. Antibiotics are used for 2 weeks or more Outlook (Prognosis)

Most patients with pneumonia due to mycoplasma or chlamydophila get better with the right antibiotics. Legionella pneumonia can be severe. It can lead to problems, especially in patients with kidney failure, diabetes, COPD, or a weak immune system.

st Legionnaires' disease: Introduction Legionnaires' disease: Legionnaires' disease, which is also known as Legionellosis, is a form of pneumonia. It is often called Legionnaires' disease because the first ... more about Legionnaires' disease. Legionnaires' disease: A severe respiratory disease which is caused by the Legionella pneumophila bacteria. The condition can result in pneumonia and can be life-threatening. More detailed information about the symptoms , causes, and treatments of Legionnaires' disease is available below.

Legionnaires' disease

"Legionnaires' disease Intro Symptoms Types Causes Tests Prognosis Treatment Misdiagnosis Videos Must Reads in Health Protecting Your Skin During Winter Watch: My Personal Psoriasis Journey Are You Getting The Best Cancer Care?

Keeping An Active Lifestyle With COPDLiver Disease? Find a Doc Who Treats PBCAre You Allergic To Your Clothes? Why Psoriasis Treatments Can Fail Legionnaires' disease: Legionnaires' disease: Introduction Symptoms Causes Treatments Alternative Treatments Misdiagnosis Testing & Diagnosis Home Testing Types Complications Prognosis Videos Research Latest Treatments Statistics Stories from Users Full Contents li

Symptoms of Legionnaires' disease Click to Check No symptoms - many people are not affected by the disease Flu-like symptoms Fever Chills Productive or non-productive coughmore symptoms...»See full list of 36 symptoms of Legionnaires' disease Treatments for Legionnaires' disease Hospitalization Antibiotics Intravenous antibiotics Erythromycin Erythromycin and rifampin - for immunocompromised patientsmore treatments...»See full list of 11 treatments for Legionnaires' disease Home Diagnostic Testing Home medical testing related to Legionnaires' disease: Cold & Flu: Home Testing: Home Fever Tests Home Ear Infection Test Kits Home Flu Testsmore...»Wrongly Diagnosed with Legionnaires' disease?

Misdiagnosis of Legionnaires' disease Failure to diagnose Legionnaires' disease Undiagnosed: Legionnaires' disease Legionnaires' disease: Related Patient Stories Legionnaires Prognosis Types of Legionnaires' disease Pontiac fever - milder form of legionellosismore types...»Read more about Types of Legionnaires' disease Diagnostic Tests for Legionnaires' disease Test for Legionnaires' disease in your own home Click for Tests Sputum culture Blood antibody testmore tests...»Read more about tests for Legionnaires' disease Legionnaires' disease: Complications Review possible medical complications related to Legionnaires' disease: Pneumonia Kidney problems Chest pains Pleurisy Deathmore complications...»Causes of Legionnaires' disease Read more about causes of Legionnaires' disease.

More information about causes of Legionnaires' disease: Medical news summaries relating to Causes of Legionnaires' disease Disease Topics Related To Legionnaires' disease Research the causes of these diseases that are similar to, or related to, Legionnaires' disease: Legionella pneumophila L pneumophila Atypical pneumonia Pulmonary infection Pontiac fevermore related diseases...»Legionnaires' disease: Undiagnosed Conditions Commonly undiagnosed diseases in related medical categories: Chronic Respiratory Disorders that may be Undiagnosed: Asthma -- Undiagnosed Allergies -- Undiagnosed COPD -- Undiagnosed Emphysema -- Undiagnosed Chronic Bronchitis -- Undiagnosed Lung Cancer -- Undiagnosed Sinusitis -- Undiagnosed Cystic Fibrosis -- Undiagnosed Obstructive Sleep Apnea -- Undiagnosedmore undiagnosed conditions...»Misdiagnosis and Legionnaires' disease Antibiotics often causes diarrhea: The use of antibiotics are very likely to cause some level of diarrhea in patients.

The reason is that antibiotics kill off not only ""bad""... read more »Sinusitis is overdiagnosed: There is a tendency to give a diagnosis of sinusitis , when the condition is really a harmless complication of another infection, such as a common cold .... read more »Whooping cough often undiagnosed: Although most children in the Western world have been immunized against whooping cough (also called "" pertussis ""), this protection wears off after about... read more »Read more about Misdiagnosis and Legionnaires' disease Legionnaires' disease: Research Doctors & Specialists Research related physicians and medical specialists: Ear, Nose & Throat Specialists: Otolaryngology (Ear, Nose & Throat)Pediatric Otolaryngology (Child Ear, Nose & Throat Specialist)Otology / Neurotology (Ear/Hearing Specialists)Plastic Surgery within the Head & Neckmore specialists...»Other doctor, physician and specialist research services: Rate Your Doctor Online Research Your Doctor Online Review Patient Surveys About Your Doctor Research local specialists including ratings, affiliations, and sanctions.

Hospitals & Clinics: Legionnaires' disease Research quality ratings and patient safety measures for medical facilities in specialties related to Legionnaires' disease: Lung Health (Pulmonology) -- Hospital Quality Ratingsmore hospital ratings...»Hospital & Clinic quality ratings »Choosing the Best Hospital: More general information, not necessarily in relation to Legionnaires' disease, on hospital performance and surgical care quality:50 Best Hospitals Report Outstanding Patient Experience Award Winning Hospitals Women's Health Best Hospitals Patient Safety Hospital Quality and Clinical Excellence Study (2009)Legionnaires' disease: Rare Types Rare types of diseases and disorders in related medical categories: Chronic Respiratory Disorders -- Rare Types: Asthma -- Rare Types Allergies -- Rare Types COPD -- Rare Types Emphysema -- Rare Types Chronic Bronchitis -- Rare Types Lung Cancer -- Rare Types Sinusitis -- Rare Types Cystic Fibrosis -- Rare Types Obstructive Sleep Apnea -- Rare Typesmore rare diseases...»Latest Treatments for Legionnaires' disease Azithromycin Clarithromycin Levofloxacin Ciprofloxacin Rifampinmore treatments...»See full list of 10 latest treatments for Legionnaires' disease Evidence Based Medicine Research for Legionnaires' disease Medical research articles related to Legionnaires' disease include: Guidelines for preventing health-care--associated pneumonia, 2003: recommendations of CDC and the Healthcare Infection Control Practices Advisory Committee.

Epidemiology of invasive group B streptococcal disease in the United States, 1999-2005. Comparison of annual and biannual mass antibiotic administration for elimination of infectious trachoma.

Rifampicin Consultant in Communicable Disease Control Rifampicin sodium Ccdcmore research...»Click here to find more evidence-based articles on the TRIP Database Legionnaires' disease: Animations Common Cold Common Cold - Pediatric More Legionnaires' disease animations & videos Prognosis for Legionnaires' disease Prognosis for Legionnaires' disease: Although Legionnaires' disease has a mortality rate of 5 to 15 percent, many people may be infected with the bacterium that causes the disease, yet not develop any symptoms.

(Source: excerpt from Legionnaires' Disease: NIEHS_1)More about prognosis of Legionnaires' disease Research about Legionnaires' disease Visit our research pages for current research about Legionnaires' disease treatments.

Statistics for Legionnaires' disease Medical statistics for Legionnaires' disease Prevalence and incidence statistics for Legionnaires' disease Death and Mortality statistics for Legionnaires' disease Society statistics for Legionnaires' disease Legionnaires' disease: Broader Related Topics Bacterial diseases Pneumonia Nosocomial infections Conditions involving a pathogenmore types...»Types of Legionnaires' disease Legionnaires' disease Message Boards Related forums and medical stories: Infectious Diseases (235)Rocky Mountain Spotted Fever Sharp needles like pain on skin.small pink spots on penisvery high titers Lymes-like symptoms.

Could someone please help me? More user stories User Interactive Forums Read about other experiences, ask a question about Legionnaires' disease, or answer someone else's question, on our message boards: I can not get a diagnosis. Please help. Tell us your medical story. Share your misdiagnosis story. What is the best treatment for this?

See all the forums. Article Excerpts about Legionnaires' disease Legionnaires' disease, which is also known as Legionellosis, is a form of pneumonia.

It is often called Legionnaires' disease because the first known outbreak occurred in the Bellevue Stratford Hotel that was hosting a convention of the Pennsylvania Department of the American Legion. In that outbreak, approximately 221 people contracted this previously unknown type of bacterial pneumonia, and 34 people died. The source of the bacterium was found to be contaminated water used to cool the air in the hotel's air conditioning system.

(Source: excerpt from Legionnaires' Disease: NIEHS_1)Definitions of Legionnaires' disease: A species of gram-negative, aerobic bacteria that is the causative agent of LEGIONNAIRES' DISEASE.

It has been isolated from numerous environmental sites as well as from human lung tissue, respiratory secretions, and blood.

- (Source - Diseases Database)Acute (sometimes fatal) lobar pneumonia caused by bacteria of a kind first recognized after an outbreak of the disease at an American Legion convention in Philadelphia in 1976; characterized by fever and muscle and chest pain and headache and chills and a dry cough - (Source - Word Net 2.1)Ophanet, a consortium of European partners, currently defines a condition rare when it affects 1 person per 2,000. They list Legionnaires' disease as a "" rare disease "". Source - Orphanet Contents for Legionnaires' disease: Legionnaires' disease What is Legionnaires' disease?

Prevalence and Incidence of Legionnaires' disease Videos related to Legionnaires' disease Prognosis of Legionnaires' disease Types of Legionnaires' disease Causes of Legionnaires' disease Risk Factors for Legionnaires' disease Symptoms of Legionnaires' disease Diagnostic Tests for Legionnaires' disease Home Testing and Legionnaires' disease Diagnosis of Legionnaires' disease Signs of Legionnaires' disease Complications of Legionnaires' disease Misdiagnosis of Legionnaires' disease Undiagnosed Legionnaires' disease Inheritance and Genetics of Legionnaires' disease Contagious: Legionnaires' disease Treatments for Legionnaires' disease Alternative Treatments for Legionnaires' disease Doctors and Medical Specialists for Legionnaires' disease Cure Research for Legionnaires' disease Statistics about Legionnaires' disease Statistics by Country for Legionnaires' disease Medical News Summaries About Legionnaires' disease Hospital Statistics for Legionnaires' disease Articles about Legionnaires' disease Glossary for Legionnaires' disease Images relating to Legionnaires' disease External links relating to Legionnaires' disease User Surveys and Discussion Forums Ask Question about Legionnaires' disease Related Legionnaires' disease Info Videos about Legionnaires' disease Forum Discussions about Legionnaires' disease Legionnaires Prognosis More information about Legionnaires' disease Legionnaires' disease: Introduction Symptoms Causes Treatments Alternative Treatments Misdiagnosis Testing & Diagnosis Home Testing Types Complications Prognosis» Next page: What is Legionnaires' disease?

Medical Tools & Articles: Tools & Services: Bookmark this page Symptom Search Symptom Checker Medical Dictionary Medical Articles: Disease & Treatments Search Misdiagnosis Center Full list of interesting articles Forums & Message Boards Ask or answer a question at the Boards: I cannot get a diagnosis. Please help. Tell us your medical story. Share your misdiagnosis story. What is the best treatment for my condition? See all the Boards. "

Landlords of residential accommodation have responsibilities for combating Legionnaires' Disease. Health and safety legislation requires that landlords carry out risk assessments for the Legionella bacteria which cause Legionnaires' Disease and thereafter maintain control measures to minimise the risk.

GUIDANCE ON LEGIONNAIRES' DISEASE FOR LANDLORDSV3-JW-12082015

GUIDANCE ON LEGIONNAIRES' DISEASE FOR LANDLORDSV3-JW-12082015

Most rented premises will be low risk but it is important that risk assessments are carried out and control measures introduced. This note is intended to give a brief guide to what the landlord should do. Further advice is available from the Health & Safety Executive.

What is Legionnaires' Disease? Legionnaires' Disease is a pneumonia like illness caused by the Legionella bacteria and can be fatal. The infection is caused by breathing in small droplets of water contaminated by the bacteria. The disease cannot be passed from one person to another.

Legionella bacteria are found in the natural environment and may contaminate and grow in water systems, including domestic hot and cold water systems. They survive low temperatures and thrive at temperatures between 20 - 45°C if the conditions are right.

They are killed by high temperatures at 60°C or above. WARNING - some consultants and letting agents are misinterpreting or misunderstanding landlord's responsibilities regarding legionella risks. They are claiming that Guidance from HSE is somehow new legislation imposing new requirements on residential landlords. This is wrong. The HSE themselves say that the legislation has not been changed and any misinterpretation/misunderstanding can impose unnecessary financial burdens on landlords where they have been charged for legionella testing certificates that they do not actually need.

HSE emphasise that legionella testing/sampling is generally not required in domestic hot water systems and then only in exceptional circumstances. Risk assessments Landlords are under a duty to ensure that the risk of exposure to tenants, residents and visitors by Legionella is properly assessed and controlled.

Normally there is no reason why the landlord should not carry out this risk assessment himself/herself so long as they are competent. Usually there will be no need to employ a consultant. The assessment should be a straight forward simple exercise in ordinary domestic premises. For most residential settings the risk assessment may well show the risks are low so long as simple control measures referred to in the next section are followed.

This will apply to houses or flats with small domestic type water systems where the water turnover is high. Provided the risk assessment shows that the risks are insignificant and the control measures are being properly managed no further action would be necessary.

It is important, however, to keep the assessment under review periodically in case anything changes to the system. The rest of this guide for Legionnaires' Disease contains useful information on the following topics: Carrying out risk assessments Control measures HSE Guidance The landlord/letting agent's responsibilities Reviewing the assessment To read the rest of this guide and have unlimited access to over 100 other guides and documents, join the RLA today or become a Guest member for free.

Members and Guests Only Login to access this guide. Log into your RLA Account Email Address Password Forgotten Password? Remember Me Login Join the RLAGet full access to over 120 Documents and Guides Become a Member Enter as a Guest Get reduced access to some Documents and Guides. Enter as Guest

Atypical pneumonia (viral pneumonia) is often caused by viruses, chlamydia (such as those caught from birds in psittacosis), mycoplasma or the Legionella bacillus of egionnaires disease. Atypical pneumonia also involves the nervous system and digestive tract to cause confusion, hallucinations and diarrhoea.

Pneumonia

"Pneumonia Posted on April 16, 2010 by James Pneumonia Natural Herb Kicks The Standard Drug Treatments To The Curb And Works Better With all of the respiratory problems being caused by increased pollution in our cities air, it is no wonder that the incidence of Pneumonia is increasing especially among the young adults and children. With Viral Pneumonia on the rise, there are little options the medical community can offer to help as there are few antiviral drugs available.

A natural herbal product is proving that nature really does know best and is beating the pants off of the standard drug treatment for both bacterial and viral pneumonia. Pneumonia Description Pneumonia is an infection of the lungs and you can become very sick and even require hospitalization. You can contract a case of pneumonia anytime in your daily life and especially if you are in the hospital.

Often you may contract pneumonia after you have had a bout of the flu or a cold. They have weakened your lungs and made you more susceptible to the infection. The two most common types of pneumonia are atypical pneumonia and bronchopneumonia.

Bronchopneumonia can result from the invasion of a variety of organisms because of the lowered resistance of the body and the poor circulation through the lungs. The base of the lungs and the bronchi become slowly infected and collapse, leading to stupor, confusion and eventually death. This is often the bacterial pneumonia that is the most common. Pneumonia is serious and life threatening and is especially a problem for pneumonia in children.

Very often a child may have walking pneumonia and not even be aware of it until the disease progresses far enough to cause serious problems. Pneumonia Symptoms Symptoms of pneumonia include high fever, flushed, dry skin, uncontrollable shivering, aching, malaise and a cough with viscid sputum.

You have chest pain, feel tired or weak, may have nausea and vomiting along with diarrhea. Respiration is rapid and shallow and often painful. Walking pneumonia has these symptoms also, but can start off with something feeling more like a simple chest cold and then progress to a very serious stage if not treated.

Pneumonia Treatment Options Treatment will depend largely on the severity of your symptoms. It can be as simple in young basically healthy adults as rest, good nutrition, and watching how the infection changes. Of course, this is the mildest case and will often clear up in less than a week. Always get plenty of rest and drink plenty of fluids to keep yourself hydrated.

For more serious cases, the typical option is to use antibiotics if the cause of the pneumonia is bacteria in nature. Should you have a viral pneumonia, then you will most likely NOT have any options from the standard medical community. There are only a very few types of viral pneumonia that they can treat such as Varicella Pneumonia. Fortunately there actually are herbal options that can address both bacterial and viral pneumonia and do work.

Keep in mind that should you take the antibiotics and saying that they are effective, you are essentially completely destroying your entire immune system and also the digestive system in the colon. This needs to be address as you are left unprotected during the time where you stop the antibiotics and your body is able to rebuild its immune system and digestive system bacteria.

Once again, there are herbal products that will address this issue and not leave you unprotected. What Actually Works For bacterial pneumonia, the success rate is quite high for antibiotic treatments or simple rest and taking care of yourself for mild infections. Keep in mind that any antibiotic treatment will have both side effects and a very negitive effect on your immune system. You have to weigh the benifit against the potential good. A natural herbal option is the better choice and it really does work.

Viral pneumonia, however, is a different story and has extremely limited help from the standard medical community with only a few virus strains having any sort of workable treatment.

However, there are herbal products that do work well against viral pneumonia and are much safer with no side effects like drugs. They are called Alligin and Pre Pro. Alligin is an all natural herbal product that acts effectively against BOTH bacterial and viral infectious agents and is able to eliminate them.

It has a proven track record and will work when you follow the recommended treatment protocals. Keep in mind that because this is a naturally based product, the results will be slower than you might have with drugs, but will actually do a more complete job in our opinion.

Also, the Alligin will not harm the benifical bacterial of the digestive track as does the antibiotics. A big plus. Along with the Alligin, you should consider using Pre Pro, a probiotic that will help boost your digestive syatem bacteria. This is important because having a robust digestive system is the first line of defense against other invading pathogens.

And even though what bacteria you have in your gut is not harmed by the Alligin, boosting it can only help your body to fight off the pneumonia or anything else that may come along too. Pneumonia Treatment Regimen Take 1800 mg (9 capsules) of Alligin capsules every day for at least 1 month and then reduce this gradually over the course of three months.

If symptoms persist continue with the higher dose. Buy Pneumonia Treatment Now When we find something that ""works"" in the real world, we will unabashedly tell you to go buy it and provide a way to do that if possible.

Why? - When a natural alternative product has demonstrated its effectiveness, then that product needs to be both supported and promoted.

By doing so, we hope to bring the benefits of the product to a larger number of people and with their help and interest attempt to keep that product available in the marketplace. Click ""our sponsors"" below to start today!Be Sociable, Share!Tweet Related Posts: Cough Hay Fever This entry was posted in Pneumonia, Respiatory Health and tagged Bacterial Pneumonia, Cough, Fever, Pneumonia, Pneumonia Children, Pneumonia Symptoms, Pneumonia Treatment, Symptoms of Pneumonia, Viral Pneumonia, Walking Pneumonia. Bookmark the permalink . "

ces Who We Work With H2O Legionella Control Services from Glasgow in Scotland provides professional, comprehensive legionella control services to clients around the UK.

H2O | Legionella Control Services

H2O | Legionella Control Services Legionella Risk Assessments, Water System Disinfection, Legionella Control Servi

NHSLetting Agents Housing Associations Property Management Companies Local Authorities Care Homes Hotels Pubs Higher Education Offices Manufacturing Production Areas Golf Clubs Caravan Parks What We Do H2O Legionella Control Services is a water treatment company that specialises in legionella control. Legionella Risk Assessments The first step in fulfilling your legal responsibilities is to carry out a full and thorough Legionella Risk Assessment.

We specialise in high quality risk assessments of all water systems which identify the level of risk within your building and provide measures necessary to control the risk through our site specific control programmes.

Find out more >>Landlord Risk Assessment Landlords in the private renting sector have a duty of care under the Health & Safety at Work Act and Control of Substances Hazardous to Health (COSHH) Regulations to ensure that the risk posed from legionella is formally recorded in a legionella risk assessment and measures to control any identified risk are duly carried out.

Find out more >>Cleaning & Disinfection Regular cleaning and disinfection of water systems is essential to control water hygiene as sludge, sediment and scale can build up in a water system and provide favourable conditions for the legionella bacteria to multiply.

Find out more >>What Our Customers Say About USH2o were appointed as the main contractor for undertaking legionella control service works for Comhairle nan Eilean Siar…The project consisted of undertaking risk assessments and associated remedial works….

In my opinion the contract was executed to a high standard and to the satisfaction of Comhairle nan Eilean Siar.

Read more in our case study section >>>Robert Maclennan Western Isles Council“We have worked closely with H2o for several years and can rely on them to deliver consistent results in critical services, provide operational solutions and a high quality service for us and our end customers.

They are a valued partner who are reactive and responsive to our needs, easy to deal with, take health and safety seriously and do what they say they are going to do”Lisa Connell Anglian Water Business“All of H2o’s staff that we have had experience of working with, ranging from risk assessor to water hygiene engineers, have been very professional and personable. I would have no hesitation in recommending H2o for any aspect of legionella control.”Brian Hume CFIOSHBalfour Beatty“I have used H20’s expertise for a number of years now both in Public and Private sectors.

The service and training courses are second to none and the people I work with are very knowledgeable and accommodating. In my experience they have repeatedly delivered contracts on time and within budget.”Scott Arthur Sodexo“During H2o’s regular service visits to maintain the chlorine dioxide dosing system I have found them to be very helpful and informative.

The pre-planned maintenance tasks are always completed on time and their reactive response has also been really good.”Paul Reid NHS Scotland Previous Next Contact Us Today H2O Legionella Control Services are ready to help. Speak to us today to find out more about the services we offer. >>>Where We Are H20 Legionella Control Services Caledonia House Evanton Drive Thornliebank Industrial Estate Glasgow G46 8JTContact Us Tel: 0141 571 2105E-mail: info@h2oscotland.com Twitter: @H2o LCSQuick Links Home About H2OServices Products Our Work Contact Us Tweets by @H2o LCS© Copyright - H2O Legionella Control Services - site build by www.onthespot.co.uk

It is difficult to distinguish Legionnaires' disease from other types of pneumonia by symptoms or radiologic findings alone; other tests are required for definitive diagnosis. Persons with Pontiac fever experience fever and muscle aches without pneumonia. They generally recover in two to five days without treatment.

Legionnaires' disease

"From Wikipedia, the free encyclopedianavigation search Legionnaires' disease Synonyms Legionellosis, [1] legion fever Transmission electron microscopy image of L. pneumophila, responsible for over 90% of Legionnaires' disease cases [2]Specialty Infectious disease, pulmonology Symptoms Cough, shortness of breath, fever, muscle pains, headaches [3]Usual onset 2–10 days after exposure [3]Causes Bacteria of the Legionella type (spread by contaminated mist) [4] [5]Risk factors Older age, history of smoking, chronic lung disease, poor immune function [6]Diagnostic method Urinary antigen test, sputum culture [7]Prevention Good maintenance of water systems [8]Treatment Antibiotics [9]Prognosis 10% risk of death [9]Frequency ~13,000 severe cases a year (US) [10]Legionnaires' disease is a form of atypical pneumonia caused by any type of Legionella bacteria. [4] Signs and symptoms include cough, shortness of breath, high fever, muscle pains, and headaches.

[3] Nausea, vomiting, and diarrhea may also occur. [1] This often begins two to ten days after exposure. [3]The bacterium is found naturally in fresh water. [5] It can contaminate hot water tanks, hot tubs, and cooling towers of large air conditioners. [5] It is usually spread by breathing in mist that contains the bacteria. [5] It can also occur when contaminated water is aspirated.

[5] It typically does not spread directly between people and most people who are exposed do not become infected. [5] Risk factors for infection include older age, history of smoking, chronic lung disease, and poor immune function. [6] It is recommended that those with severe pneumonia and those with pneumonia and a recent travel history be tested for the disease.

[11] Diagnosis is by a urinary antigen test and sputum culture. [7]There is no vaccine. [8] Prevention depends on good maintenance of water systems. [8] Treatment of Legionnaires' disease is with antibiotics. [9] Recommended agents include fluoroquinolones, azithromycin, or doxycycline.

[12] Hospitalization is often required. [11] About 10% of those who are infected die. [9]The number of cases that occur globally is not known. [1] It is estimated that Legionnaires' disease is the cause of between two and nine percent of pneumonia cases that are acquired outside of hospital. [1] There are an estimated 8,000 to 18,000 cases a year in the United States that require hospitalization.

[10] Outbreaks of disease account for a minority of cases. [1] [13] While it can occur any time of the year it is more common in the summer and fall. [10] The disease is named after the outbreak where it was first identified - the 1976 American Legion convention in Philadelphia.

[14]Contents [ hide ]1 Signs and symptoms2 Cause2.1 Transmission2.2 Reservoirs3 Mechanism4 Diagnosis5 Prevention6 Treatment7 Prognosis8 Epidemiology8.1 Outbreaks9 References10 External links Signs and symptoms [ edit]The length of time between exposure to the bacteria and the appearance of symptoms is generally two to ten days, but can rarely extend to as much as 20 days. [15] For the general population, among those exposed between 0.1 and 5% develop disease, while among those in hospital between 0.4 and 14% develop disease.

[15]Those with Legionnaires' disease usually have fever, chills, and a cough, which may be dry or may produce sputum. Almost all with Legionnaires' experience fever, while approximately half have cough with sputum, and one third cough up blood or bloody sputum. Some also have muscle aches, headache, tiredness, loss of appetite, loss of coordination ( ataxia ), chest pain, or diarrhea and vomiting. [16] Up to half of those with Legionnaires' have gastrointestinal symptoms, and almost half have neurological symptoms, [15] including confusion and impaired cognition. [17] ""Relative bradycardia "" may also be present, which is low or low-normal heart rate despite the presence of a fever. [18]Laboratory tests may show that kidney functions, liver functions and electrolyte levels are abnormal, which may include low sodium in the blood. Chest X-rays often show pneumonia with consolidation in the bottom portion of both lungs.

For Pontiac fever the time between exposure and symptoms is generally a few hours to two days. Cause [ edit]Over 90% of cases of Legionnaires' disease are caused by the bacteria Legionella pneumophila. Other types include L. longbeachae, L. feeleii, L. micdadei, and L. anisa. Transmission [ edit]Legionnaires' disease is usually spread by the breathing in of aerosolized water and/or soil contaminated with the Legionella bacteria.

[16] Experts have stated that Legionnaires' disease is not transmitted from person to person. [19] In 2014 there was one case of possible spread from someone sick to the caregiver.

[20] Rarely, it has been transmitted by direct contact between contaminated water and surgical wounds. [16] The bacteria grows best at warm temperatures. [5] It thrives at water temperatures between 25 and 45 °C (77 and 113 °F), with an optimum temperature of 35 °C (95 °F).

[21] Temperatures above 60 °C (140 °F) kill it. [22] Sources where temperatures allow the bacteria to thrive include hot water tanks, cooling towers, and evaporative condensers of large air conditioning systems, such as those commonly found in hotels and large office buildings.

[23] Though the first known outbreak was in Philadelphia, Pennsylvania, cases of legionellosis have occurred throughout the world. [15]Reservoirs [ edit]L. pneumophila thrives in aquatic systems where it is established within amoebae in a symbiotic relationship. [24] Legionella bacteria survive in water as intracellular parasites of water-dwelling protozoae, such as amoebae.

Amoebae are often part of biofilms, and once Legionella and infected amoebae are protected within a biofilm, they are particularly difficult to destroy. [16]In the built environment, central air conditioning systems in office buildings, hotels, and hospitals are sources of contaminated water. [21] Other places it can dwell include cooling towers used in industrial cooling systems, evaporative coolers, nebulizers, humidifiers, whirlpool spas, hot water systems, showers, windshield washers, fountains, room-air humidifiers, ice-making machines, and misting systems typically found in grocery-store produce sections.

[16] [25]The disease may also be transmitted from contaminated aerosols generated in hot tubs if the disinfection and maintenance program is not followed rigorously.

[26] Freshwater ponds, creeks, and ornamental fountains are potential sources of Legionella. [27] The disease is particularly associated with hotels, fountains, cruise ships, and hospitals with complex potable water systems and cooling systems. Respiratory care devices such as humidifiers and nebulizers used with contaminated tap water may contain Legionella species, so using sterile water is very important.

[28]Other sources include exposure to potting mix and compost. [29]Mechanism [ edit]Legionella enters the lung either by aspiration of contaminated water or inhalation of aerosolized contaminated water or soil.

In the lung, the bacteria are consumed by macrophages, a type of white blood cell, inside of which the Legionella bacteria multiply causing the death of the macrophage. Once the macrophage dies, the bacteria are released from the dead cell to infect other macrophages.

Virulent strains of Legionella kill macrophages by blocking the fusion of phagosomes with lysosomes inside the host cell; normally the bacteria are contained inside the phagosome, which merges with a lysosome, allowing enzymes and other chemicals to break down the invading bacteria.

[15]Diagnosis [ edit]Various stages of the disease: Chest radiograph (A) and high-resolution computed tomography (B) at hospital admission, repeat high-resolution computerized tomography of the chest a week after hospital admission (C, D), shown in a 42-year-old male with severe pneumonia caused by L. pneumophila serogroup 11a People of any age may suffer from Legionnaires' disease, but the illness most often affects middle-aged and older persons, particularly those who smoke cigarettes or have chronic lung disease.

Immunocompromised people are also at higher risk. Pontiac fever most commonly occurs in persons who are otherwise healthy. The most useful diagnostic tests detect the bacteria in coughed up mucus, find Legionella antigens in urine samples, or allow comparison of Legionella antibody levels in two blood samples taken 3 to 6 weeks apart.

A urine antigen test is simple, quick, and very reliable, but it will only detect Legionella pneumophila serogroup 1, which accounts for 70 percent of disease caused by L. pneumophila, which means use of the urine antigen test alone may miss as many as 30% of cases.

[21] This test was developed by Richard Kohler in 1982. [30] When dealing with Legionella pneumophila serogroup 1, the urine antigen test is useful for early detection of Legionnaire's disease and initiation of treatment, and has been helpful in early detection of outbreaks. However, it will not identify the specific subtypes, so it cannot be used to match the person with the environmental source of infection.

The Legionella bacteria can be cultured from sputum or other respiratory samples. Legionella stains poorly with Gram stain, stains positive with silver, and is cultured on charcoal yeast extract with iron and cysteine ( CYE agar ).

A significant under-reporting problem occurs with legionellosis. Even in countries with effective health services and readily available diagnostic testing, about 90 percent of cases of Legionnaires' disease are missed. This is partly due to Legionnaires' disease being a relatively rare form of pneumonia, which many clinicians may not have encountered before and thus may misdiagnose.

A further issue is that people with legionellosis can present with a wide range of symptoms, some of which (such as diarrhea) may distract clinicians from making a correct diagnosis.

[31]Prevention [ edit]Although the risk of Legionnaires' disease being spread by large-scale water systems cannot be eliminated, it can be greatly reduced by writing and enforcing a highly detailed, systematic water safety plan appropriate for the specific type of facility involved (office building, hospital, hotel, spa, cruise ship, etc.) [15] Some of the elements that such a plan may include are the following: Keeping water temperature either above or below the 20–50 °C (68–122 °F) range in which the Legionella bacterium thrives. Preventing stagnation, for example by removing from a network of pipes any sections that have no outlet (dead ends).

Where stagnation is unavoidable, for example when a wing of a hotel is closed for the off-season, systems must be thoroughly disinfected just prior to resuming normal operation. Preventing the buildup of biofilm, for example by not using (or by replacing) construction materials that encourage its development, and by reducing the quantity of nutrients for bacterial growth that enter the system.

Periodic disinfection of the system, by high heat or a chemical biocide, and the use of chlorination where appropriate. There is evidence that treatment of water with copper-silver ionization or ultraviolet light may also be effective. [32]System design (or renovation) that reduces the production of aerosols and reduces human exposure to them, for example by directing them well away from building air intakes.

An effective water safety plan will also cover such matters as training, record-keeping, communication among staff, contingency plans and management responsibilities. The format and content of the plan may be prescribed by public health laws or regulations. [15]Treatment [ edit]Effective antibiotics include most macrolides, tetracyclines, ketolides, and quinolones.

[16] Legionella multiply within the cell, so any effective treatment must have excellent intracellular penetration. Current treatments of choice are the respiratory tract quinolones ( levofloxacin, moxifloxacin, gemifloxacin) or newer macrolides ( azithromycin, clarithromycin, roxithromycin ).

The antibiotics used most frequently have been levofloxacin, doxycycline, and azithromycin. Macrolides (azithromycin) are used in all age groups, while tetracyclines (doxycycline) are prescribed for children above the age of 12 and quinolones (levofloxacin) above the age of 18.

Rifampicin can be used in combination with a quinolone or macrolide. It is uncertain whether rifampicin is an effective antibiotic to take for treatment. The Infectious Diseases Society of America does not recommend the use of rifampicin with added regimens.

Tetracyclines and erythromycin led to improved outcomes compared to other antibiotics in the original American Legion outbreak. These antibiotics are effective because they have excellent intracellular penetration in Legionella -infected cells. The recommended treatment is 5–10 days of levofloxacin or 3–5 days of azithromycin, but in people who are immunocompromised, have severe disease, or other pre-existing health conditions, longer antibiotic use may be necessary. [16] During outbreaks, prophylactic antibiotics have been successfully used to prevent Legionnaires' disease in high-risk individuals who have possibly been exposed.

[16]The mortality at the original American Legion convention in 1976 was high (29 deaths in 182 infected individuals [33]) because the antibiotics used (including penicillins, cephalosporins, and aminoglycosides) had poor intracellular penetration.

Mortality has plunged to less than 5% if therapy is started quickly. Delay in giving the appropriate antibiotic leads to higher mortality. Prognosis [ edit]The fatality rate of Legionnaires' disease has ranged from 5% to 30% during various outbreaks and approaches 50% for nosocomial infections, especially when treatment with antibiotics is delayed. [34] Hospital-acquired Legionella pneumonia has a fatality rate of 28%, and the principal source of infection in such cases is the drinking-water distribution system.

[35]Epidemiology [ edit]See also: 1976 Philadelphia Legionnaires' disease outbreak and List of Legionnaires' disease outbreaks Legionnaires' disease acquired its name in July 1976, when an outbreak of pneumonia occurred among people attending a convention of the American Legion at the Bellevue-Stratford Hotel in Philadelphia.

Of the 182 reported cases, mostly men, 29 died. [36] On January 18, 1977, the causative agent was identified as a previously unknown strain of bacteria, subsequently named Legionella, and the species that caused the outbreak was named Legionella pneumophila.

[37] [38]Outbreaks of Legionnaires' disease receive significant media attention. However, this disease usually occurs in single, isolated cases not associated with any recognized outbreak. When outbreaks do occur, they are usually in the summer and early autumn, though cases may occur at any time of year.

Most infections occur in those who are middle-aged or older. [34] National surveillance systems and research studies were established early, and in recent years [ when?] improved ascertainment and changes in clinical methods of diagnosis have contributed to an upsurge in reported cases in many countries.

Environmental studies continue to identify novel sources of infection, leading to regular revisions of guidelines and regulations. About 8,000 to 18,000 cases of Legionnaires' disease occur each year in the United States, according to the Bureau of Communicable Disease Control.

[39]Between 1995 and 2005, over 32,000 cases of Legionnaires' disease and more than 600 outbreaks were reported to the European Working Group for Legionella Infections The data on Legionella are limited in developing countries and Legionella -related illnesses likely are underdiagnosed worldwide. [15] Improvements in diagnosis and surveillance in developing countries would be expected to reveal far higher levels of morbidity and mortality than are currently recognised.

Similarly, improved diagnosis of human illness related to Legionella species and serogroups other than Legionella pneumophila would improve knowledge about their incidence and spread.

A 2011 study successfully used modeling to predict the likely number of cases during Legionnaires’ outbreaks based on symptom onset dates from past outbreaks. In this way, the eventual likely size of an outbreak can be predicted, enabling efficient and effective use of public health resources in managing an outbreak. [40]Outbreaks [ edit]See also: List of Legionnaires' disease outbreaks The first recognized cases of Legionnaires' disease occurred in 1976 in Philadelphia, Pennsylvania.

Among more than 2000 attendees of an American Legion convention held at the Bellevue-Stratford Hotel, 182 attendees contracted the disease and 29 of them died. [1]In April 1985, 175 people in Stafford, England, were admitted to the District or Kingsmead Stafford Hospitals with chest infection or pneumonia.

A total of 28 people died. Medical diagnosis showed that Legionnaires' disease was responsible and the immediate epidemiological investigation traced the source of the infection to the air-conditioning cooling tower on the roof of Stafford District Hospital. In March 1999, a large outbreak in the Netherlands occurred during the Westfriese Flora flower exhibition in Bovenkarspel; 318 people became ill and at least 32 people died.

This was the second-deadliest outbreak since the 1976 outbreak and possibly the deadliest as several people were buried before Legionnaires' disease had been diagnosed. The world's largest outbreak of Legionnaires' disease happened in July 2001 with people appearing at the hospital on July 7, in Murcia, Spain.

More than 800 suspected cases were recorded by the time the last case was treated on July 22; 636–696 of these cases were estimated and 449 confirmed (so, at least 16,000 people were exposed to the bacterium) and six died, a case-fatality rate around 1%. In late September 2005, 127 residents of a nursing home in Canada became ill with L. pneumophila. Within a week, 21 of the residents had died.

Culture results at first were negative, which is not unusual, as L. pneumophila is a fastidious bacterium, meaning it requires specific nutrients and/or living conditions in order to grow. The source of the outbreak was traced to the air-conditioning cooling towers on the nursing home's roof. As of 12 November 2014, 302 people have been hospitalized following an outbreak of Legionella in Portugal and 7 related deaths have been reported.

All cases, so far, have emerged in three civil parishes from the municipality of Vila Franca de Xira in the northern outskirts of Lisbon, Portugal and are being treated in hospitals of the Greater Lisbon area. The source is suspected to be located in the cooling towers of the fertilizer plant Fertibéria. [41]Twelve people were diagnosed with the disease in the Bronx, New York, in December 2014; the source was traced to contaminated cooling towers at a housing development.

[42] In July and August 2015, another, unrelated outbreak in the Bronx killed 12 people and made about 120 people sick; the cases arose from a cooling tower on top of a hotel. At the end of September another person died of the disease and 13 were sickened in yet another unrelated outbreak in the Bronx.

[43] The cooling towers from which the people were infected in the latter outbreak had been cleaned during the summer outbreak, raising concerns about how well the bacteria could be controlled. [44]On August 28, 2015, an outbreak of Legionnaire's disease was detected at San Quentin State Prison in Northern California.

81 people were sickened and the cause was sludge that had built up in cooling towers. [45]Between June 2015 and January 2016, 87 cases of Legionnaires' disease were reported by the Michigan Department of Health and Human Services for the city of Flint, Michigan and surrounding areas.

10 of those cases were fatal. [46]In November 2017, an outbreak was detected at Hospital de São Francisco Xavier, Lisbon, Portugal, with up to 53 people being diagnosed with the disease and five of them dying from it. [47]In Quincy, Illinois at the Illinois Veterans home a 2015 outbreak of the disease killed 12 people and sickened more than 50 others.

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n Legionellosis is a collective term for diseases caused by legionella bacteria including the most serious Legionnaires’ disease, as well as the similar but less serious conditions of Pontiac fever and Lochgoilhead fever.

What is Legionnaires' disease?

What is Legionnaires' disease? Contents Introduction Where does it come from? How do people get it? Symptoms and treatment Introductio

Legionnaires’ disease is a potentially fatal form of pneumonia and everyone is susceptible to infection.

The risk increases with age but some people are at higher risk including:people over 45 years of agesmokers and heavy drinkerspeople suffering from chronic respiratory or kidney diseasediabetes, lung and heart diseaseanyone with an impaired immune system The bacterium Legionella pneumophila and related bacteria are common in natural water sources such as rivers, lakes and reservoirs, but usually in low numbers. They may also be found in purpose-built water systems such as cooling towers, evaporative condensers, hot and cold water systems and spa pools.

If conditions are favourable, the bacteria may grow increasing the risks of Legionnaires’ disease and it is therefore important to control the risks by introducing appropriate measures outlined in Legionnaires' disease - The Control of Legionella bacteria in water systems (L8). Where does it come from? Legionella bacteria are widespread in natural water systems, e.g. rivers and ponds.

However, the conditions are rarely right for people to catch the disease from these sources. Outbreaks of the illness occur from exposure to legionella growing in purpose-built systems where water is maintained at a temperature high enough to encourage growth, e.g. cooling towers, evaporative condensers, hot and cold water systems and spa pools used in all sorts of premises (work and domestic).

How do people get it? People contract Legionnaires’ disease by inhaling small droplets of water (aerosols), suspended in the air, containing the bacteria.

Certain conditions increase the risk from legionella if:the water temperature in all or some parts of the system may be between 20-45 °C, which is suitable for growthit is possible for breathable water droplets to be created and dispersed e.g.

aerosol created by a cooling tower, or water outletswater is stored and/or re-circulatedthere are deposits that can support bacterial growth providing a source of nutrients for the organism e.g. rust, sludge, scale, organic matter and biofilms Cases of Legionnaires’ disease are often the result of infections caught in the UK, but a number of cases occur abroad. Useful advice on travel can be found from the European Working Group for Legionella Infections (EWGLI).

Most patients with pneumonia due to mycoplasma or chlamydophila get better with the right antibiotics. Legionella pneumonia can be severe. It can lead to problems, especially in patients with kidney failure, diabetes, COPD, or a weak immune system.

Atypical pneumonia

Definition

Pneumonia is an infection of the lung. With atypical pneumonia, the infection is caused by different bacteria than the ones that cause typical pneumonia. These include Legionella pneumophila, Mycoplasma pneumoniae, and Chlamydophila pneumoniae. Atypical pneumonia also tends to have milder symptoms than typical pneumonia.

Causes Mycoplasma pneumonia is a type of atypical pneumonia. It is caused by the bacteria M. pneumoniae. It often affects people younger than age 40. Pneumonia due to chlamydia bacteria occurs year round.

It is usually mild. Pneumonia due to Legionella is seen more often in middle-aged and older adults, smokers, and those with chronic illnesses or a weak immune system. It can be more severe. This type of pneumonia is also called Legionnaire disease. Symptoms Pneumonia due to mycoplasma and chlamydophila bacteria is usually mild.

Pneumonia due to Legionella pneumophila gets worse during the first 4 to 6 days, and then improves over 4 to 5 days.

It may be hard for your health care provider to tell whether you have pneumonia or bronchitis, so you may need a chest x-ray.

Depending on how severe the illness is, other tests may be done, including: Arterial blood test Complete blood count (CBC)Blood cultures Blood tests to identify the specific bacteria Bronchoscopy (rarely needed)CT scan of the chest Open lung biopsy (only done in very serious illnesses when the diagnosis cannot be made from other sources)Sputum culture Urine test to check for Legionella bacteria Urine tests or a throat swab may also be done.

Treatment To feel better, you can take these self-care measures at home: Control your fever with aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs, such as ibuprofen or naproxen), or acetaminophen. DO NOT give aspirin to children. DO NOT take cough medicines without first talking to your doctor.

Cough medicines may make it harder for your body to cough up the extra sputum. Drink plenty of fluids to help loosen secretions and bring up phlegm. Get a lot of rest. Have someone else do household chores. Antibiotics are used to treat atypical pneumonia. You may be able to take antibiotics by mouth at home. If your condition is severe, you will likely be admitted to a hospital. There, you will be given antibiotics through a vein (intravenously), as well as oxygen. Antibiotics are used for 2 weeks or more Outlook (Prognosis)

Pneumonia Duration of treatment: Community acquired-mild: 7-10days. // Gram negative (usually nosocomial): 3 to 6 weeks. // Staphylococcal: 3 to 4 weeks // Legionella, mycoplasma, chlamydia: 14 to 21 days.

Infection

// Lung abscess: 4 to 6 weeks. Possible therapeutic alternatives Community-acquired Pneumonia (CAP): (outpatient therapy) Adult patient Pneumonia: Community acquired.

(outpatient therapy) Adult patient Common pathogens OUTPATIENTNo co-morbidities: Azithromycin 500 mg x1, then 250 mg once daily OR azithromycin 2 gm (XR) x 1 dose (OR)Clarithromycin 500mg orally twice daily or 1gram (XR) orally once daily x 7 days (OR)Doxycycline 100mg orally twice daily Co-morbidities present: Levofloxacin 750 mg once daily x 5 days (OR)moxifloxacin 400mg po qd x 7-10days (OR)Azithromycin 500 mg x1, then 250 mg once daily PLUS [ Augmentin XR* 1000/62.5 mg 2 tablets orally twice daily or Cefdinir 300 mg orally twice daily or Cefpodoxime 200 mg orally twice daily or Cefprozil 500 mg orally twice daily] x 7 days *AUGMENTIN XR is contraindicated in patients with a creatinine clearance of < 30 m L/min.

and in hemodialysis patients Community acquired PNEUMONIA - Adult (any age) Common pathogens Hospitalized patient: Azithromycin 500mg IV once daily PLUS Ceftriaxone 1 gram q24h (OR) Azithromycin 500mg IV once daily PLUS Ertapenem 1 gram q24h (OR) Monotherapy: Levofloxacin 750 mg IV/PO once daily (OR) Moxifloxacin 400mg IV qd.

ICU patient (CAP): [ Ceftriaxone 1-2 grams IV q24h OR Ampicillin-sulbactam (Unasyn) 1.5-3.0 grams ivpb q6h]PLUS [Azithromycin 500mg IV once daily OR Levofloxacin 750 mg IV/PO once daily (OR) Moxifloxacin 400mg IV qd.]

PLUS Vancomycin - (patient-specific regimen - trough goal 15-20 mcg/ml)Hospital-acquired PNEUMONIA (HAP)Hospital-acquired PNEUMONIA (HAP) (nosocomial) Common pathogens Multi -drug resistance unlikely Ceftriaxone 1-2 grams IV q24h ORAmpicillin-sulbactam (Unasyn) 3.0 grams ivpb q6h ORLevofloxacin 750 mg IV/PO once daily Multi -drug resistance LIKELYPiperacillin-tazobactam 3.375g ivpb q6h ORCefepime 2 grams IV every 12 hours ORMeropenem 1 gm IV q8h PLUS (If MRSA suspected) Vancomycin - (patient-specific regimen - trough goal 15-20 mcg/ml)Aspiration pneumonia Common pathogens Community acquired: Clindamycin 600mg ivpb every 6 to 8 hours or Augmentin 875mg PO bid or 500mg tid x 10 days Hospital acquired: Piperacillin-tazobactam 3.375g ivpb q6h ORAmpicillin-sulbactam (Unasyn) 1.5-3.0 grams ivpb q6h.

ORCefoxitin 2 grams ivpb q6-8h or Cefotetan 1-2 grams IV q12h. OR [ Cefotaxime 2g ivpb q8h or Ceftriaxone 2 grams ivpb q24h] + Clindamycin 600mg IV q6-8h.

ORClindamycin 600mg IV q6-8h + [ Ciprofloxacin 400mg IV q12h or Levofloxacin 500 - 750mg IV qd. ]Hospital acquired: (Cover most common pathogens + possibility of aspiration) Common pathogens Piperacillin-tazobactam 3.375 grams IV every 6 hours + Ciprofloxacin 400mg IV q12h or Cefepime 2 grams IV every 12 hours + Clindamycin 600mg IV every 6 hours.

V entilator-associated pneumonia (VAP) (Mild to moderate infection AND multi-drug resistance unlikely): Common pathogens Ceftriaxone 1-2 grams IV q24h ORAmpicillin-sulbactam (Unasyn) 3.0 grams ivpb q6h ORLevofloxacin 750 mg IV/PO once daily ORErtapenem 1 gm IV q24h PLUS (If MRSA suspected) Vancomycin - (patient-specific regimen - trough goal 15-20 mcg/ml) (Severe infection OR multi-drug resistance LIKELY): Common pathogens Cefepime 2 grams IV every 12 hours OR Piperacillin-tazobactam 4.5 grams IV Q6H OR Meropenem 1 gm IV q8h PLUS Vancomycin - (patient-specific regimen - trough goal 15-20 mcg/ml) PLUS Ciprofloxacin 400mg IV q8h OR Levofloxacin 750 mg IV/PO once daily OR Aminoglycoside (Tobra) - patient-specific regimen.

Images References - Infectious Disease Section Infectious Disease References Disclaimer The authors make no claims of the accuracy of the information contained herein; and these suggested doses are not a substitute for clinical judgement. Neither Global RPh Inc. nor any other party involved in the preparation of this program shall be liable for any special, consequential, or exemplary damages resulting in whole or part from any user's use of or reliance upon this material. PLEASE READ THE DISCLAIMER CAREFULLY BEFORE ACCESSING OR USING THIS SITE. BY ACCESSING OR USING THIS SITE, YOU AGREE TO BE BOUND BY THE TERMS AND CONDITIONS SET FORTH IN THE DISCLAIMER. Read the disclaimer

)n. An acute, sometimes fatal respiratory disease caused by a bacterium of the genus Legionella, especially L. pneumophila, and characterized by severe pneumonia, headache,and a dry cough.

Legionnaires' disease

"Legionnaires' disease Also found in: Thesaurus, Medical, Legal, Encyclopedia, Wikipedia. Related to Legionnaires' disease: pneumonia, Pontiac fever, Legionellosis Le·gion·naires' disease (lē′jə-nârz′

[ So called because it was first recognized when an outbreak occurred during an American Legion Convention in Philadelphia in 1976 . ]American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.legionnaires'′ disease`n.a form of pneumonia caused by bacteria of the genus Legionella, esp.

L. pneumophila,typically acquired by inhaling airborne droplets from a contaminated water supply. [so called from its first reported occurrence, at an American Legion convention in Philadelphia in 1976]Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved. Legionnaires' disease A pneumonia-like infection caught through the inhalation of airborne droplets in a wateryatmosphere.

Dictionary of Unfamiliar Words by Diagram Group Copyright © 2008 by Diagram Visual Information Limited Thesaurus Antonyms Related Words Synonyms Legend: Switch to new thesaurus Noun 1. Legionnaires' disease - acute (sometimes fatal) lobar pneumonia caused by bacteria of a kind first recognized after an outbreak of the disease at an American Legion convention in Philadelphia in 1976; characterized by fever and muscle and chest pain and headacheand chills and a dry coughlobar pneumonia - pneumonia affecting one or more lobes of the lung; commonlydue to streptococcal infection Based on Word Net 3.0, Farlex clipart collection.

© 2003-2012 Princeton University, Farlex Inc. Translations Select a language:legionnaíres' diseasen.

enfermedad de los legionarios, enfermedad infecciosa grave, a veces letal, que se caracteriza por pulmonía, tos seca, dolor muscular y a veces síntomas gastrointestinales. English-Spanish Medical Dictionary © Farlex 2012Want to thank TFD for its existence? Tell a friend about us, add a link to this page, or visit the webmaster's page for free fun content . Link to this page:Legionnaires' diseaseFacebook Twitter "

]The genus Legionella is a pathogenic group of Gram-negative bacteria that includes the species L. pneumophila, causing legionellosis [3] (all illnesses caused by Legionella) including a pneumonia-type illness called Legionnaires' disease and a mild flu-like illness called Pontiac fever.

Legionella

"From Wikipedia, the free encyclopedianavigation search Legionella Legionella sp. under UV light Scientific classification Domain: Bacteria Phylum: Proteobacteria Class: Gammaproteobacteria Order: Legionellales Family: Legionellaceae Genus: Legionella Brenner et al.

1979Species Legionella adelaidensis [1]Legionella anisa [1]Legionella beliardensis [1]Legionella birminghamensis [1]Legionella bozemanae [1]Legionella brunensis [1]Legionella busanensis [1]Legionella cardiaca [1]Legionella cherrii [1]Legionella cincinnatiensis [1]Legionella clemsonensis [2]Legionella donaldsonii [1]Legionella drancourtii [1]Legionella dresdenensis [1]Legionella drozanskii [1]Legionella dumoffii [1]Legionella erythra [1]Legionella fairfieldensis [1]Legionella fallonii [1]Legionella feeleii [1]Legionella geestiana [1]Legionella genomospecies 1 Legionella gormanii [1]Legionella gratiana [1]Legionella gresilensis [1]Legionella hackeliae [1]Legionella impletisoli [1]Legionella israelensis [1]Legionella jamestowniensis [1]Candidatus Legionella jeonii Legionella jordanis [1]Legionella lansingensis [1]Legionella londiniensis [1]Legionella longbeachae [1]Legionella lytica [1]Legionella maceachernii [1]Legionella massiliensis [1]Legionella micdadei [1]Legionella monrovica [1]Legionella moravica [1]Legionella nagasakiensis [1]Legionella nautarum [1]Legionella norrlandica [1]Legionella oakridgensis [1]Legionella parisiensis [1]Legionella pittsburghensis [1]Legionella pneumophila [1]Legionella quateirensis [1]Legionella quinlivanii [1]Legionella rowbothamii [1]Legionella rubrilucens [1]Legionella sainthelensi [1]Legionella santicrucis [1]Legionella shakespearei [1]Legionella spiritensis [1]Legionella steelei [1]Legionella steigerwaltii [1]Legionella saoudiensis [1]Legionella taurinensis [1]Legionella thermalis [1]Legionella tucsonensis [1]Legionella tunisiensis [1]Legionella wadsworthii [1]Legionella waltersii [1]Legionella worsleiensis [1]Legionella yabuuchiae [1

[3]Legionella may be visualized with a silver stain or cultured in cysteine-containing media such as buffered charcoal yeast extract agar. It is common in many environments, including soil and aquatic systems, with at least 50 species and 70 serogroups identified.

The bacterium, however, is not transmissible from person to person: [4] furthermore, most people exposed to the bacteria do not become ill. [5]The side chains of the cell wall carry the bases responsible for the somatic antigen specificity of these organisms. The chemical composition of these side chains both with respect to components and arrangement of the different sugars determines the nature of the somatic or O antigen determinants, which are essential means of serologically classifying many Gram-negative bacteria.

Legionella acquired its name after an outbreak of a then-unknown ""mystery disease"" sickened 221 persons, causing 34 deaths.

The outbreak was first noticed among people attending a convention of the American Legion —an association of U. S. military veterans. The convention occurred in Philadelphia during the U. S. Bicentennial year in July 21–24, 1976. This epidemic among U. S. war veterans, occurring in the same city as—and within days of the 200th anniversary of—the signing of the Declaration of Independence, was widely publicized and caused great concern in the United States.

[6]On January 18, 1977, the causative agent was identified as a previously unknown bacterium subsequently named Legionella.

See Legionnaires' disease for full details. Contents [ hide ]1 Detection2 Pathogenesis2.1 Sources of Legionella2.2 Airborne transmission from cooling towers2.3 Vaccine research3 Molecular biology4 Legionella control4.1 Chlorine4.2 Copper-silver ionization4.3 Chlorine dioxide4.4 Moist heat sterilization4.5 European standards5 Weaponization6 See also7 References8 External links Detection [ edit]Legionella is traditionally detected by culture on buffered charcoal yeast extract agar. Legionella requires the presence of cysteine and iron to grow, so does not grow on common blood agar media used for laboratory-based total viable counts or on-site dipslides.

Common laboratory procedures for the detection of Legionella in water [7] concentrate the bacteria (by centrifugation and/or filtration through 0.2-μm filters) before inoculation onto a charcoal yeast extract agar containing selective agents (e.g. glycine, vancomycin, polymixin, cyclohexamide, GVPC) to suppress other flora in the sample. Heat or acid treatment are also used to reduce interference from other microbes in the sample.

After incubation for up to 10 days, suspect colonies are confirmed as Legionella if they grow on buffered charcoal yeast extract agar containing cysteine, but not on agar without cysteine added. Immunological techniques are then commonly used to determine the species and/or serogroups of bacteria present in the sample.

Although the plating method is quite specific for most species of Legionella, one study has shown that a coculture method that accounts for the close relationship with amoebae may be more sensitive since it can detect the presence of the bacteria even when masked by its presence inside the amoeba.

[8] Consequently, the clinical and environmental prevalence of the bacteria is likely to be underestimated due to the current lab methodology. Many hospitals use the Legionella urinary antigen test for initial detection when Legionella pneumonia is suspected. Some of the advantages offered by this test are that the results can be obtained in hours rather than the several days required for culture, and that a urine specimen is generally more easily obtained than a sputum specimen.

Disadvantages are that the urine antigen test only detects antigen of Legionella pneumophila serogroup 1 (LP1); only a culture will detect infection by non-LP1 strains or other Legionella species and that isolates of Legionella are not obtained, which impairs public health investigations of outbreaks. [9]New techniques for the rapid detection of Legionella in water samples have been developed, including the use of polymerase chain reaction and rapid immunological assays.

These technologies can typically provide much faster results. Government public health surveillance has demonstrated increasing proportions of drinking water–associated outbreaks, specifically in healthcare settings. [10]Pathogenesis [ edit]A Legionella pneumophila bacterium (green) caught by a Vermamoeba vermiformis amoeba (orange)In the natural environment, Legionella lives within amoebae such as Acanthamoeba spp., Naegleria spp., and Vermamoeba vermiformis, or other protozoa such as Tetrahymena pyriformis.

[11]Upon inhalation, the bacteria can infect alveolar macrophages, where the bacteria can replicate. This results in Legionnaires' disease and the less severe illness Pontiac fever. Legionella transmission is via inhalation of water droplets from a contaminated source that has allowed the organism to grow and spread (e.g., cooling towers). Transmission also occurs less commonly via aspiration of drinking water from an infected source. Person-to-person transmission has not been demonstrated; [4] though, it could be possible in rare cases.

[12]Once inside a host, the incubation period may be up to two weeks. Prodromal symptoms are flu-like, including fever, chills, and dry cough. Advanced stages of the disease cause problems with the gastrointestinal tract and the nervous system and lead to diarrhea and nausea. Other advanced symptoms of pneumonia may also present. However, the disease is generally not a threat to most healthy individuals, and tends to lead to severe symptoms more often in immunocompromised hosts and the elderly.

Consequently, the water systems of hospitals and nursing homes should be periodically monitored. The Texas Department of State Health services provides recommendations for hospitals to detect and prevent the spread of hospital acquired disease due to Legionella infection. [13] According to Infection Control and Hospital Epidemiology, hospital-acquired Legionella pneumonia has a fatality rate of 28%, and the source is the water distribution system.

[14]Legionella species typically exist in nature at low concentrations, in groundwater, lakes, and streams. They reproduce after entering man-made equipment, given the right environmental conditions. [ citation needed] In the United States, the disease affects between 8,000 and 18,000 individuals a year.

[15]Sources of Legionella [ edit]Documented sources include cooling towers, [16] swimming pools (especially in Scandinavian countries), domestic water systems and showers, ice-making machines, [17] refrigerated cabinets, whirlpool spas, [18] [19] hot springs, [20] fountains, [21] dental equipment, [22] soil, [23] automobile windshield washer fluid, [24] and industrial coolant. [25]Airborne transmission from cooling towers [ edit]The largest [26] and most common source of Legionnaires' disease outbreaks are cooling towers (heat rejection equipment used in air conditioning and industrial cooling water systems) primarily because of the risk for widespread circulation.

Many governmental agencies, cooling tower manufacturers, and industrial trade organisations have developed design and maintenance guidelines for controlling the growth and proliferation of Legionella within cooling towers.

Research in the Journal of Infectious Diseases (2006) provided evidence that L. pneumophila, the causative agent of Legionnaires' disease, can travel at least 6 km from its source by airborne spread.

It was previously believed that transmission of the bacterium was restricted to much shorter distances. A team of French scientists reviewed the details of an epidemic of Legionnaires' disease that took place in Pas-de-Calais, northern France, in 2003–2004. Of 86 confirmed cases during the outbreak, 18 resulted in death. The source of infection was identified as a cooling tower in a petrochemical plant, and an analysis of those affected in the outbreak revealed that some infected people lived as far as 6–7 km from the plant.

[27]Vaccine research [ edit]No vaccine is available for legionellosis. Vaccination studies using heat-killed or acetone-killed cells have been carried out in guinea pigs, which were then given Legionella intraperitoneally or by aerosol.

Both vaccines were shown to give moderately high levels of protection. Protection was dose-dependent and correlated with antibody levels as measured by enzyme-linked immunosorbent assay to an outer membrane antigen and by indirect immunofluorescence to heat-killed cells.

[ citation needed] However, a licensed vaccine for people in the US is most probably still many years away. [ citation needed]Molecular biology [ edit]Legionella has been discovered to be a genetically diverse species with 7-11% of genes strain-specific. The molecular function of some of the proven virulence factors of Legionella have been discovered.

[28]Legionella control [ edit]Control of Legionella growth can occur through chemical or thermal methods. The more expensive [ citation needed] of these two options is temperature control—i.e., keeping all cold water below 25 °C (78 °F) and all hot water above 51 °C (124 °F).

The high cost incurred with this method arises from the extensive retrofitting required for existing complex distribution systems in large facilities and the energy cost of chilling or heating the water and maintaining the required temperatures at all times and at all distal points within the system.

Temperature affects the survival of Legionella as follows: [3]Above 70 °C (158 °F) – Legionella dies almost instantly At 60 °C (140 °F) – 90% die in 2 minutes ( Decimal reduction time (D) = 2 minutes)At 50 °C (122 °F) – 90% die in 80–124 minutes, depending on strain ( Decimal reduction time (D) = 80–124 minutes)48 to 50 °C (118 to 122 °F) – can survive but do not multiply32 to 42 °C (90 to 108 °F) – ideal growth range25 to 45 °C (77 to 113 °F) – growth range Below 20 °C (68 °F) – can survive, even below freezing, but are dormant Other temperature sensitivity [29] [30]60 to 70 °C (140 to 158 °F) to 80 °C (176 °F) – Disinfection range66 °C (151 °F) – Legionella dies within 2 minutes60 °C (140 °F) – Legionella dies within 32 minutes55 °C (131 °F) – Legionella dies within 5 to 6 hours Chlorine [ edit]A very effective chemical treatment is chlorine.

For systems with marginal issues, chlorine provides effective results at 0.5 ppm [ citation needed] residual in the hot water system.

For systems with significant Legionella problems, temporary shock chlorination—where levels are raised to higher than 2 ppm for a period of 24 hours or more and then returned to 0.5 ppm may be effective.

[ citation needed] Hyperchlorination can also be used where the water system is taken out of service and the chlorine residual is raised to 50 ppm or higher at all distal points for 24 hours or more. The system is then flushed and returned to 0.5 ppm chlorine prior to being placed back into service.

These high levels of chlorine penetrate biofilm, killing both the Legionella bacteria and the host organisms. Annual hyperchlorination can be an effective part of a comprehensive Legionella preventive action plan. [31]Copper-silver ionization [ edit]Industrial-size copper-silver ionization is recognized by the U. S. Environmental Protection Agency and WHO for Legionella control and prevention.

[ citation needed] Copper and silver ion concentrations must be maintained at optimal levels, taking into account both water flow and overall water usage, to control Legionella. The disinfection function within all of a facility's water distribution network occurs within 30 to 45 days. [ citation needed] Key engineering features such as 10 amps per ion chamber cell and automated variable voltage outputs having no less than 100 VDC are but a few of the required features for proper Legionella control and prevention, using a specific, nonreferenced copper-silver system.

Swimming pool ion generators are not designed for potable water treatment. Questions remain whether the silver and copper ion concentrations required for effective control of symbiotic hosts could exceed those allowed under the U. S. Safe Drinking Water Act's Lead and Copper Rule.

In any case, any facility or public water system using copper-silver for disinfection should monitor its copper and silver ion concentrations to ensure they are within intended levels – both minimum and maximum. Further, no current standards for silver in the EU and other regions allow use of this technology.

Copper-silver ionization is an effective process to control Legionella in potable water distribution systems found in health facilities, hotels, nursing homes, and most large buildings. However, it is not intended for cooling towers because of p H levels greater than 8.6, that cause ionic copper to precipitate. Furthermore, tolytriazole, a common additive in cooling water treatment, could bind the copper making it ineffective. In 2003, researchers who heavily support ionization developed a validation process that supports their research on ionization.

Ionization became the first such hospital disinfection process to have fulfilled a proposed four-step modality evaluation; by then it had been adopted by over 100 hospitals.

[32] Additional studies indicate ionization is superior to thermal eradication. [33]Chlorine dioxide [ edit]Chlorine dioxide has been approved by the U. S. Environmental Protection Agency as a primary disinfectant of potable water since 1945.

Chlorine dioxide does not produce any carcinogenic byproducts like chlorine when used in the purification of drinking water that contains natural organic compounds such as humic and fulvic acids, chlorine tends to form halogenated disinfection by-products such as trihalomethanes. Drinking water containing such disinfection by-products has been shown to increase the risk of cancer.

Cl O2 works differently to chlorine; its action is one of pure oxidation rather than halogenation, so these halogenated by-products are not formed. [34] Chlorine dioxide is not a restricted heavy metal like copper. It has proven excellent control of Legionella in cold and hot water systems and its ability as a biocide is not affected by p H, or any water corrosion inhibitors such as silica or phosphate.

Monochloramine is an alternative. Like chlorine and chlorine dioxide, monochloramine is approved Environmental Protection Agency as a primary potable water disinfectant.

Environmental Protection Agency registration requires a biocide label which lists toxicity and other data required for all registered biocides. If the product is being sold as a biocide, then the manufacturer is legally required to supply a biocide label, and the purchaser is legally required to apply the biocide per the biocide label.

When first applied to a system, chlorine dioxide can be added at disinfection levels of 2 ppm for 6 hours to clean up a system. This will not remove all biofilm, but will effectively remediate the system of Legionella. [ citation needed]Moist heat sterilization [ edit]Moist heat sterilization ( superheating to 140 °F (60 °C) and flushing) is a nonchemical treatment that typically must be repeated every 3–5 weeks.

European standards [ edit]Several European countries established the European Working Group for Legionella Infections [35] to share knowledge and experience about monitoring potential sources of Legionella.

The working group has published guidelines about the actions to be taken to limit the number of colony-forming units (that is, live bacteria that are able to multiply) of Legionella per litre: Legionella bacteria CFU/litre Action required (35 samples per facility are required, including 20 water and 10 swabs)1000 or less System under controlmore than 1000 up to 10,000 Review program operation: The count should be confirmed by immediate resampling.

If a similar count is found again, a review of the control measures and risk assessment should be carried out to identify any remedial actions.more than 10,000 Implement corrective action: The system should immediately be resampled. It should then be ""shot dosed"" with an appropriate biocide, as a precaution. The risk assessment and control measures should be reviewed to identify remedial actions.

(150+ CFU/ml in healthcare facilities or nursing homes require immediate action. )Monitoring guidelines are stated in Approved Code of Practice L8 in the UK. These are not mandatory, but are widely regarded as so. An employer or property owner must follow an Approved Code of Practice, or achieve the same result. Failure to show monitoring records to at least this standard has resulted in several high-profile prosecutions, e.g.

Nalco + Bulmers – neither could prove a sufficient scheme to be in place whilst investigating an outbreak, therefore both were fined about £300,000GBP.

Important case law in this area is R v Trustees of the Science Museum 3 All ER 853, (1993) 1 WLR 1171 [36]Employers and those responsible for premises within the UK are required under Control of Substances Hazardous to Health to undertake an assessment of the risks arising from Legionella. This risk assessment may be very simple for low risk premises, however for larger or higher risk properties may include a narrative of the site, asset register, simplified schematic drawings, recommendations on compliance, and a proposed monitoring scheme.

[37]The L8 Approved Code of Practice recommends that the risk assessment should be reviewed at least every 2 years and whenever a reason exists to suspect it is no longer valid, such as water systems have been amended or modified, or if the use of the water system has changed, or if there is reason to suspect that Legionella control measures are no longer working.

Weaponization [ edit]It has been suggested that Legionella could be used as a weapon, and indeed genetic modification of Legionella pneumophila has been shown where the mortality rate in infected animals can be increased to nearly 100%.

[38] [39] [40] A former Soviet bioengineer, Sergei Popov, stated in 2000 that his team experimented with genetically enhanced bioweapons, including Legionella. [40] Popov worked as a lead researcher at the Vector Institute from 1976 to 1986, then at Obolensk until 1992, when he defected to the West. He later divulged much of the Soviet biological weapons program and settled in the United States. ""Safe Hot Water Temperature"" (PDF). Archived from the original (PDF) on 2011-06-26. See also [ edit]Environmental microbiology Microbiomes of the built environment References [ edit]^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad aeaf ag ah ai aj ak al am an ao ap aq ar as at au av aw ax ay az babb bc bd be bf bg bh bi bj bk Parte, A. C. ""Legionella"".

www.bacterio.net.^ Palmer, Allison; Painter, Joseph; Hassler, Hayley; Richards, Vincent P.; Bruce, Terri; Morrison, Shatavia; Brown, Ellen; Kozak-Muiznieks, Natalia A.; Lucas, Claressa; Mc Nealy, Tamara L. (1 October 2016). ""Legionella clemsonensis sp. nov.: a green fluorescing Legionella strain from a patient with pneumonia"". Microbiol Immunol. 60 (10): 694–701. doi: 10.1111/1348-0421.12439 – via Wiley Online Library.^ a b c Legionella and the prevention of legionellosis (PDF).^ a b Winn WC (1996).

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Euro Surveillance. 17 (37). PMID 22995431.^ Campese C, Roche D, Clément C, et al. (July 2010). ""Cluster of Legionnaires' disease associated with a public whirlpool spa, France, April-May 2010"". Euro Surveillance. 15 (26). PMID 20619131.^ Kurosawa H, Fujita M, Kobatake S, et al. (January 2010).

""A case of Legionella pneumonia linked to a hot spring facility in Gunma Prefecture, Japan"". Japanese Journal of Infectious Diseases. 63 (1): 78–9. PMID 20093771.^ Palmore TN, Stock F, White M, et al. (August 2009). ""A cluster of cases of nosocomial legionnaires disease linked to a contaminated hospital decorative water fountain"".

Infection Control and Hospital Epidemiology. 30 (8): 764–8. doi: 10.1086/598855. PMC 2886954. PMID 19580436.^ Kadaifciler DG, Cotuk A (June 2014). ""Microbial contamination of dental unit waterlines and effect on quality of indoor air"". Environmental Monitoring and Assessment.

186 (6): 3431–44. doi: 10.1007/s10661-014-3628-6. PMID 24469014.^ Infection Due to Legionella Species Other Than L. pneumophila Barry S. Fields*, Robert F. Benson, and Richard E. Besser http://cid.oxfordjournals.org/content/35/8/990.full^ American Society for Microbiology, Windshield washer fluid a source of Legionnaires: Found in most school buses^ RR910 - Survival of Legionella pneumophila in metalworking fluids http://www.hse.gov.uk/research/rrhtm/rr910.htm^ García-Fulgueiras, Ana; Navarro, Carmen; Fenoll, Daniel; et al. (August 2003). ""Legionnaires' Disease Outbreak in Murcia, Spain"". Emerging Infectious Diseases. 9 (8): 915–921. doi: 10.3201/eid0908.030337. Retrieved June 16, 2017.^ Nguyen TM, Ilef D, Jarraud S, et al.

(January 2006). ""A community-wide outbreak of legionnaires disease linked to industrial cooling towers--how far can contaminated aerosols spread?"". The Journal of Infectious Diseases. 193 (1): 102–11. doi: 10.1086/498575. PMID 16323138.^ Raychaudhury S, Farelli JD, Montminy TP, et al. (April 2009). ""Structure and function of interacting Icm R-Icm Q domains from a type IVb secretion system in Legionella pneumophila"". Structure. 17 (4): 590–601. doi: 10.1016/j.str.2009.02.011. PMC 2693034. PMID 19368892.^ ""Safe Hot Water Temperature"" (PDF). Archived from the original (PDF) on 2011-06-26.^ ""Employers Guide to the control of Legionella "" (PDF).^ Reiff, Fred (22 January 2010). ""Legionella Control in Institutional Water Systems"". Water Quality and Health Council. Retrieved 18 January 2017.^ Stout & Yu 2003 "" (1) Demonstrated efficacy of Legionella eradication in vitro using laboratory assays, (2) anecdotal experiences in preventing legionnaires’ disease in individual hospitals, (3) controlled studies in individual hospitals, and (4) validation in confirmatory reports from multiple hospitals during a prolonged time. ""^ Block 2001.^ Legionella Control With Chlorine Dioxide. Retrieved from https://feedwater.co.uk/legionella-control-services/^ ""European Working Group for Legionella Infections"".^ Whittaker, Howard. ""The Law & Legionella (& HSE's Enforcement strategy)"" (PDF).^ ""HSE -Legionnaires' disease - What you must do"".^ Bhargava, Pushpa M. (December 1, 2008). ""The Growing Planetary Threat From Biological Weapons and Terrorism"". aina.org. Assyrian International News Agency. Retrieved June 16, 2017.^ Gilsdorf JR, Zilinskas RA (April 2005). ""New considerations in infectious disease outbreaks: the threat of genetically modified microbes"". Clinical Infectious Diseases. 40 (8): 1160–5. doi: 10.1086/428843. JSTOR 4463254. PMID 15791517.^ a b ""Interview—Serguei Popov"". November 1, 2000. Archived from the original on September 27, 2011. Retrieved June 16, 2017. External links [ edit]European Working Group for Legionella Infections Centers for Disease Control and Prevention - Procedure for Cleaning Cooling Towers and Related Equipment (pages 239 and 240 of 249)California Energy Commission - Cooling Water Management Program Guidelines For Wet and Hybrid Cooling Towers at Power Plants ASHRAE Guideline Guidelines for Control of Legionella in Ornamental Fountains Employers Guidelines for prevention of Legionella Biology portal Taxon identifiers Wd: Q158013 Eo L: 83152 EPPO: 1LEGIG GBIF: 3223036 ITIS: 957462 NCBI: 445Wo RMS: 571336Categories: Bacterial diseases Bacteria genera Industrial hygiene Gram-negative bacteria Pathogenic bacteria Legionellales "

Legionnaires' disease at a Winston-Salem nursing home. The confirmed cases were found at Oak Forest Health Rehabilitation off Highway 66. Officials said the cases were contracted within the last month. Legionnaires' disease is a severe form of pneumonia, a lung inflammation caused by infection. The disease is caused by a bacterium known as legionella, according to the Mayo Clinic.

Officials confirm 3 cases of Legionnairesâ disease at Winston-Salem nursing home

"NETWORK ERRORCannot Contact Server RELOAD YOUR SCREEN OR TRY SELECTING A DIFFERENT VIDEOWINSTON-SALEM, N. C. -- Forsyth County officials have confirmed three cases of

Health officials say two of the victims are responding well to antibiotics and didn't show any symptoms on Monday. The third victim remains in the hospital with other health issues. ""It usually takes two to 14 days to manifest symptoms in patients,"" said Tim Darnell, an infectious disease physician with Novant Health. Darnell says symptoms include a cough, shortness of breath, high fever, muscle aches, chest pains and typically affect older adults and those with lung disease and low immune systems.

""It can lead to death in approximately five to 10 percent of the people who become infected with it but most people who are exposed to it don’t even become ill with the infection.

""The bacteria was found in the facility's water supply, officials confirmed. Residents have been told to not drink or bathe with the water. Control measures taken by Oak Forest include the suspension of new admissions and some visit restrictions to the facility. Additional measures being taken include minimizing exposure to water from the facility by using bottled water for drinking, mouth rinsing, brushing teeth, and shaving.

The facility has also performed water superheating by turning hot water tank and boilers to 160 degrees for three hours then purging the water lines for at least five minutes.

The disease is not spread from person-to-person, but rather through inhaling the bacteria. ""I got a phone call .... that the water was bad inside of Oak Forest,"" said Mary Thompson. Her 96-year-old grandmother is a resident at the facility. With visitors now being restricted Thompson is concerned for her grandmother and family members that have visited recently.

""I have grand-kids and my family and I want to make sure we are safe also. ""Although prompt treatment with antibiotics usually cures Legionnaires' disease, some people continue to experience problems after treatment, according to the Mayo Clinic. State health officials recently confirmed two cases of the disease in Wilson, raising the total count to seven. The Wilson Times reports the N. C. Department of Health and Human Services identified the two cases at Longleaf Neuro-Medical Treatment Center.

Officials said the second confirmed case of the disease is what is described as a ""retrospective case, no longer symptomatic, discovered during routine testing after the initial discovery and diagnosis. ""Officials told the Associated Press Longleaf has put internal control measures in place to protect residents, visitors and staff. They are currently not taking any new clients and some visitor restrictions are in place. Filed in: News Facebook Twitter Email "

Medical Definition of Legionnaire disease Our Legionnaires' Disease Main Article provides a comprehensive look at the who, what, when and how of Legionnaires' Disease Legionnaire disease: A disease due to the bacteria Legionella pneumophila found in plumbing, shower heads and water-storage tanks. Outbreaks of Legionella pneumonia have been attributed to evaporative condensers and cooling towers.

Medical Definition of Legionnaire disease

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The bacteria thrives in the mist sprayed from air-conditioning ducts and so it can infest an entire building or airplane.

Travelers are especially vulnerable in the closed space within a plane. Home hot water pipes have also been found to be a common source of the disease. The bacteria flourish at temperatures between 90 and 105 degrees and so can grow in the slimy gunk lining residential hot water pipes.

People contract the bacteria by inhaling drops of water while showering, washing or even drinking. Legionnaire disease can cause a massive pneumonia associated with collapse of the respiratory function. It can be an overwhelming and sometimes fatal illness. The disease was first identified as a sequel of the 1976 convention of the American Legion in some of the Legionnaires who had attended the convention.

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ion Legionnaires' disease is a type of pneumonia caused by Legionella bacteria. The bacterialspecies responsible for Legionnaires' disease is L. pneumophila. Major symptoms include fever, chills, muscle aches, and a cough that is initially nonproductive.

Legionnaires' disease

"Correct all you're your grammar errors instantly. Try it now. Legionnaires' disease Also found in: Dictionary, Thesaurus, Legal, Encyclopedia, Wikipedia. Related to Legionnaires' disease: pneumonia, Pontiac fever, Legionellosis Legionnaires' Disease Definit

Definitive diagnosis relies on specific laboratory tests for the bacteria, bacterial antigens, or antibodies produced by the body'simmune system. As with other types of pneumonia, Legionnaires' disease poses the greatestthreat to people who are elderly, ill, or immunocompromised. Description Legionella bacteria were first identified as a cause of pneumonia in 1976, following an outbreak of pneumonia among people who had attended an American Legion convention in Philadelphia,Pennsylvania.

This eponymous outbreak prompted further investigation into Legionella and it wasdiscovered that earlier unexplained pneumonia outbreaks were linked to the bacteria. The earliestcases of Legionnaires' disease were shown to have occurred in 1965, but samples of the bacteriaexist from 1947.

Exposure to the Legionella bacteria doesn't necessarily lead to infection. According to somestudies, an estimated 5-10% of the American population show serologic evidence of exposure,the majority of whom do not develop symptoms of an infection. Legionella bacteria account for 2-15% of the total number of pneumonia cases requiring hospitalization in the United States.

There are at least 40 types of Legionella bacteria, half of which are capable of producing disease in humans. A disease that arises from infection by Legionella bacteria is referred to as legionellosis. The L. pneumophila bacterium, the root cause of Legionnaires' disease, causes90% of legionellosis cases. The second most common cause of legionellosis is the L. micdadeibacterium, which produces the Philadelphia pneumonia-causing agent.

Approximately 10,000-40,000 people in the United States develop Legionnaires' diseaseannually. The people who are the most likely to become ill are over age 50. The risk is greater forpeople who suffer from health conditions such as malignancy, diabetes, lung disease, or kidney disease. Other risk factors include immunosuppressive therapy and cigarette smoking. Legionnaires' disease has occurred in children, but typically it has been confined to newbornsreceiving respiratory therapy, children who have had recent operations, and children who areimmunosuppressed.

People with HIV infection and AIDS do not seem to contract Legionnaires'disease with any greater frequency than the rest of the population, however, if contracted, thedisease is likely to be more severe compared to other cases.

Cases of Legionnaires' disease that occur in conjunction with an outbreak, or epidemic, are morelikely to be diagnosed quickly. Early diagnosis aids effective and successful treatment. Duringepidemic outbreaks, fatalities have ranged from 5% for previously healthy individuals to 24% forindividuals with underlying illnesses.

Sporadic cases (that is, cases unrelated to a wideroutbreak) are harder to detect and treatment may be delayed pending an accurate diagnosis. The overall fatality rate for sporadic cases ranges from 10-19%. The outlook is bleaker in severecases that require respiratory support or dialysis. In such cases, fatality may reach 67%. Causes and symptoms Legionnaires' disease is caused by inhaling Legionella bacteria from the environment.

Typically,the bacteria are dispersed in aerosols of contaminated water. These aerosols are produced by devices in which warm water can stagnate, such as air-conditioning cooling towers, humidifiers,shower heads, and faucets.

There have also been cases linked to whirlpool spa baths and watermisters in grocery store produce departments. Aspiration of contaminated water is also a potential source of infection, particularly in hospital-acquired cases of Legionnaires' disease. There is no evidence of person-to-person transmission of Legionnaires' disease. Once the bacteria are in the lungs, cellular representatives of the body's immune system (alveolar macrophages) congregate to destroy the invaders.

The typical macrophage defense is to phagocytose the invader and demolish it in a process analogous to swallowing and digestingit. However, the Legionella bacteria survive being phagocytosed. Instead of being destroyedwithin the macrophage, they grow and replicate, eventually killing the macrophage. When themacrophage dies, many new Legionella bacteria are released into the lungs and worsen theinfection.

Legionnaires' disease develops 2-10 days after exposure to the bacteria. Early symptomsinclude lethargy, headaches, fever, chills, muscle aches, and a lack of appetite. Respiratorysymptoms such as coughing or congestion are usually absent. As the disease progresses, a dry, hacking cough develops and may become productive after a few days. In about a third of Legionnaires' disease cases, blood is present in the sputum. Half of the people who develop Legionnaires' disease suffer shortness of breath and a third complain of breathing-related chestpain.

The fever can become quite high, reaching 104 °F (40 °C) in many cases, and may be accompanied by a decreased heart rate. Although the pneumonia affects the lungs, Legionnaires' disease is accompanied by symptomsthat affect other areas of the body.

About half the victims experience diarrhea and a quarterhave nausea and vomiting and abdominal pain. In about 10% of cases, acute renal failure andscanty urine production accompany the disease. Changes in mental status, such as disorientation, confusion, and hallucinations, also occur in about a quarter of cases. In addition to Legionnaires' disease, L. pneumophila legionellosis also includes a milder disease,Pontiac fever.

Unlike Legionnaires' disease, Pontiac fever does not involve the lower respiratorytract. The symptoms usually appear within 36 hours of exposure and include fever, headache, muscle aches, and lethargy. Symptoms last only a few days and medical intervention is notnecessary. Diagnosis The symptoms of Legionnaires' disease are common to many types of pneumonia and diagnosis of sporadic cases can be difficult. The symptoms and chest x rays that confirm a case of pneumonia are not useful in differentiating between Legionnaires' disease and other pneumonias.

If a pneumonia case involves multisystem symptoms, such as diarrhea and vomiting, and an initially dry cough, laboratory tests are done to definitively identify L. pneumophila as the cause of the infection. If Legionnaires' disease is suspected, several tests are available to reveal or indicate thepresence of L. pneumophila bacteria in the body.

Since the immune system creates antibodiesagainst infectious agents, examining the blood for these indicators is a key test. The level of immunoglobulins, or antibody molecules, in the blood reveals the presence of infection. In microscopic examination of the patient's sputum, a fluorescent stain linked to antibodies against L. pneumophila can uncover the presence of the bacteria. Other means of revealing the bacteria'spresence from patient sputum samples include isolation of the organism on culture media or detection of the bacteria by DNA probe.

Another test detects L. pneumophila antigens in theurine. Treatment Most cases of Legionella pneumonia show improvement within 12-48 hours of starting antibiotictherapy. The antibiotic of choice has been erythromycin, sometimes paired with a secondantibiotic, rifampin. Tetracycline, alone or with rifampin, is also used to treat Legionnaires'disease, but has had more mixed success in comparison to erythromycin.

Other antibioticsthat have been used successfully to combat Legionella include doxycycline, clarithromycin,fluorinated quinolones, and trimethoprim/sulfamethoxazole. The type of antibiotic prescribed by the doctor depends on several factors including the severity of infection, potential allergies, and interaction with previously prescribed drugs. For example,erythromycin interacts with warfarin, a blood thinner. Several drugs, such as penicillins andcephalosporins, are ineffective against the infection.

Although they may be deadly to thebacteria in laboratory tests, their chemical structure prevents them from being absorbed into theareas of the lung where the bacteria are present.

In severe cases with complications, antibiotic therapy may be joined by respiratory support. If renal failure occurs, dialysis is required until renal function is recovered. Prognosis Appropriate medical treatment has a major impact on recovery from Legionnaires' disease. Outcome is also linked to the victim's general health and absence of complications. If the patientsurvives the infection, recovery from Legionnaires' disease is complete. Similar to other types of pneumonia, severe cases of Legionnaires' disease may cause scarring in the lung tissue as a result of the infection.

Renal failure, if it occurs, is reversible and renal function returns as thepatient's health improves. Occasionally, fatigue and weakness may linger for several monthsafter the infection has been successfully treated.

Prevention Since the bacteria thrive in warm stagnant water, regularly disinfecting ductwork, pipes, andother areas that may serve as breeding areas is the best method for preventing outbreaks of Legionnaires' disease.

Most outbreaks of Legionnaires' disease can be traced to specific points of exposure, such as hospitals, hotels, and other places where people gather. Sporadic casesare harder to determine and there is insufficient evidence to point to exposure in individualhomes. Resources Periodicals Shuman, H. A., et al. ""Intracellular Multiplication of Legionella pneumophila: Human Pathogen of Accidental Tourist?""

Current Topics in Microbiology and Immunology 225 (1998): 99. Key terms Antibody — A molecule created by the immune system in response to the presence of an antigen. It serves to recognize the invader and help defend the body from infection. Antigen — A molecule, such as a protein, which is associated with a particular infectious agent. The immune system uses this molecule as the identifying characteristic of the infectious invader. Culture — A laboratory system for growing bacteria for further study.

DNA probe — An agent that binds directly to a predefined sequence of nucleic acids. Immunocompromised — Refers to conditions in which the immune system is not functioningproperly and cannot adequately protect the body from infection. Immunoglobulin — The protein molecule that serves as the primary building block of antibodies. Immunosuppressive therapy — Medical treatment in which the immune system is purposefully thwarted. Such treatment is necessary, for example, to prevent organ rejection in transplant cases. Legionellosis — A disease caused by infection with a Legionella bacterium. Media — Substance which contains all the nutrients necessary for bacteria to grow in a culture. Phagocytosis — The ""ingestion"" of a piece of matter by a cell.

Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.legionnaires' disease [ le-jun-ārz´] a pulmonary form of legionellosis, resulting from infection with Legionella pneumophila. Thedisease acquired its name from an outbreak that occurred during the 1976 convention of the American Legion in Philadelphia.

The gram-negative bacillus causing the disease was isolated fromthe lungs of four persons who attended the convention, contracted the disease, and died from it. Theprevalence of legionnaires' disease is not certain but it is estimated that about 7 per cent of theannual cases of pneumonia in the United States are caused by L. pneumophila.

Approximately 70 per cent of those cases occur in epidemic form, while the remainder are sporadic infections. Thedisease is seen most often in middle-aged to elderly men who are cigarette smokers or areimmunocompromised. osha has published guidelines to protect workers at risk of being exposed in theworkplace. Specific diagnostic tests include both direct and indirect fluorescent testing for antibodies against L. pneumophila.

Other laboratory tests reveal mild leukocytosis; elevated erythrocyte sedimentationrate; increased liver enzymes, especially lactate dehydrogenase; elevated blood urea nitrogen; andabnormal blood gases showing hypoxemia and hypocarbia. The pulmonary symptoms are typical of pneumonia, but patients do not respond to the usualtherapy for pneumonia and there can be permanent lung damage.

Possible nonpulmonarycomplications include liver damage, altered levels of consciousness owing to neuronal involvement,and renal abnormalities that can require renal dialysis. Treatment consists of antibiotic therapy with macrolides and quinolones. Other antibiotics may also be effective. erythromycin was formerly often used but is no longer the drug of choice. Severehypoxia requires mechanical ventilation and oxygen therapy. Isolation of the patient is notconsidered to be necessary; however, respiratory precautions are indicated. Supportive measures to help the patient cope with high fever, nausea and vomiting, and renal failure are essentialcomponents of patient care.

See also pneumonia. Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved. Le·gion·naires' dis·easean acute infectious disease, caused by Legionella pneumophila, with prodromal influenzalikesymptoms and a rapidly rising high fever, followed by severe pneumonia and production of usually nonpurulent sputum, and sometimes mental confusion, hepatic fatty changes, andrenal tubular degeneration.

It has a high case-fatality rate; acquired from contaminated water,usually by aerosolization rather than being transmitted from person-to-person. Synonym (s): legionellosis [American Legion convention, in Philadelphia in 1976, at which many delegates were so affected]Farlex Partner Medical Dictionary © Farlex 2012Legionnaires' disease (lē′jə-nârz′)n. An acute, sometimes fatal respiratory disease caused by a bacterium of the genus Legionella, especially L. pneumophila, and characterized by severe pneumonia, headache,and a dry cough.

The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved. Legionnaires' disease [lē′jənerz′]Etymology: American Legionan acute bacterial pneumonia caused by infection with Legionella pneumophila.

It is characterized by an influenzalike illness followed within a week by high fever, chills, muscleaches, and headache. The symptoms may progress to dry cough, pleurisy, and sometimesdiarrhea. Usually the disease is self-limited, but mortality has been 15% to 20% in a fewlocalized epidemics.

Contaminated air-conditioning cooling towers and warm stagnant watersupplies, including water vaporizers, water sonicators, whirlpool spas, and showers, may be sources of organisms. Person-to-person contagion has not occurred. Risk of infection is increased by the presence of other conditions, such as cardiopulmonary diseases.

Treatmentincludes supportive care and antibiotic therapy. Also called legionellosis. Mosby's Medical Dictionary, 9th edition. © 2009, Elsevier. Le·gion·naires' dis·ease ( lē'jŏ-nārz' di-zēz') An acute infectious disease, caused by various species of Legionella pneumophila, withprodromal influenzalike symptoms and a rapidly rising high fever, followed by severepneumonia and production of usually nonpurulent sputum, and sometimes mental confusion,hepatic fatty changes, and renal tubular degeneration. It has a high case-fatality rate;acquired from contaminated water, usually by aerosolization rather than transmission fromperson to person.

[American Legion convention, in Philadelphia in 1976, at which many delegates took sick]Medical Dictionary for the Health Professions and Nursing © Farlex 2012Legionnaires' disease A type of PNEUMONIA caused by Legionella bacteriawhich can propagate in warm, moist places such as air-conditioning towers and are spread into theair in water droplets.

The disease features headache, muscle aches, diarrhoea, cough, high fever,pneumonia, mental confusion, and kidney and liver damage.

The lungs may suffer irremediabledamage, and this is the common cause of death. The death rate is about 4%. Most deaths occuramong the elderly, the infirm, heavy smokers and heavy drinkers. Treatment is by antibiotics such as ERYTHROMYCIN and RIFAMPICIN.

The disease was first recognized in members of the American Legion attending a convention in a hotel in Pennsylvania in 1976.

Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005Legionnaires’ Disease DRGCategory:177Mean LOS: 8.2 days Description: MEDICAL: Respiratory Infections and Inflammations With Major CCDRGCategory:207Mean LOS: 14.6 days Description: MEDICAL: Respiratory System Diagnosis With Ventilator Support 96+ Hours DRGCategory:208Mean LOS: 7 days Description: MEDICAL: Respiratory System Diagnosis With Ventilator Support < 96 Hours DRGCategory:3Mean LOS: 34.5 days Description: SURGICAL: Tracheostomy With MV 96+ Hours or Primary Diagnosis Except for Face, Mouth, and Neck With Major Operating Room Procedure Legionnaires’ disease is an acute bronchopneumonia that was named because of a major outbreak at the 1976 American Legion Convention in Philadelphia, in which 235 American Legionnairescontracted the disease and 34 persons died.

It is now known as the most common type of atypicalpneumonia in hospitalized patients and the second most common cause of community-acquiredbacterial pneumonia.

Outbreaks occur in late summer and early fall, and they may be epidemic or confined to a small number of cases. Approximately 18,000 cases occur each year in the United States. Legionnaires’ disease has an incubation period of 2 to 10 days and is characterized by patchypulmonary infiltrates, lung consolidation, and flu-like symptoms.

Pneumonia is the presentingclinical syndrome in more than 95% of cases. Legionnaires’ disease is spread by direct alveolarinfection with the gram-negative bacterium Legionella pneumophila. From the initial site, theinfection spreads through the bronchi and through the blood and lymphatic systems.

Bacteremiaoccurs in about 30% of the patients and is the source of nonrespiratory infections in most patients. Complications are extensive and serious with Legionnaires’ disease. Hypoxemia and acuterespiratory failure can result from the severe case of pneumonia. The disease can also causehypotension and hyponatremia as a result of salt and water loss. Central nervous systeminvolvement is seen in almost 30% of patients.

Renal involvement, which ranges from interstitialnephritis to renal failure, may occur. Untreated immunosuppressed patients have a mortality rate of 80%; untreated patients with no immune system compromise have a mortality rate of 25%. Causes L. pneumophila is an aerobic, gram-negative bacillus that seems to be transmitted by air. It is usually classified as a saprophytic water bacterium because it is natural to bodies of water such as rivers, lakes, streams, and thermally polluted waters.

Elevated temperatures (96.8°F to 158°C)enhance growth of the bacterium. L. pneumophila is also found in habitats such as cooling towers,evaporative condensers, and water distribution centers, and it also has been found in soil samplesand at excavation sites. Pathogenic microorganisms can enter the lung by aspiration, directinhalation, or dissemination from another focus of infection.

Genetic considerations Although Legionnaire’s disease is the result of infection by L. pneumophila, susceptibility has beenassociated with variants in the Toll-like receptor-5 (TLR5) gene. Gender, ethnic/racial, and life span considerations Legionnaires’ disease is three times more common in men than in women; it is uncommon in children.

At-risk groups include middle-aged or elderly people; patients with a chronic underlyingdisease such as chronic obstructive pulmonary disease, diabetes mellitus, or chronic renal failure;patients with immunosuppressive disorders such as lymphoma or who receive corticosteroids afterorgan transplantation; people with alcohol dependence; and cigarette smokers. There are no knownracial or ethnic considerations. Global health considerations Legionnaires’ disease has been reported throughout the globe and on all populated continents. Assessment History Ask about malaise, aching muscles, anorexia, headache, high fever, or recurrent chills. Establish a history of chest pain or coughing, which begins as a nonproductive cough but eventually becomesproductive.

Ask the patient about gastrointestinal symptoms such as diarrhea, nausea, andvomiting. Because the central nervous system is involved in about 30% of cases, ask the family or significant others if the patient has experienced recent confusion or decreased level of consciousness.

Determine if the patient has been close to a river, lake, or stream, which might have resulted in possible exposure to the bacteria. Establish a work history of employment at an excavation site or water distribution center, in a cooling tower, or near an evaporative condenser.

Ask if the patientworks or lives in a facility with central air conditioning or humidifiers. Ask if the patient has used a respiratory apparatus or a nasogastric tube in the recent past. Physical examination Common symptoms include mild headache, cough, muscle aches, high fever, and chills. Note any neurological signs, such as altered level of consciousness, confusion, or coma. Inspectthe patient’s sputum, which may be grayish or rust-colored, nonpurulent, and occasionally bloodstreaked.

Note the respiratory rate, which may be rapid and accompanied by dyspnea. Determine the breathing; fine or coarse crackles may be audible depending on the stage of thedisease process.

Auscultate the blood pressure and heart rate; note that some patients developsevere hypotension and bradycardia. Percuss the chest for dullness over areas of secretions andconsolidation or pleural effusions. Palpate the peripheral pulses to determine strength. Psychosocial A previously healthy person with a possible minor upper respiratory infection is at risk for life-threatening complications, such as multiple organ failure.

Assess the patient’s ability to cope with a sudden illness. Assess the patient’s level of anxiety and fear. Diagnostic highlights Test Normal Result Abnormality With Condition Explanation Sputum cultureand sensitivity Negative Presence of L. pneumophila Identify infectingorganisms Chest x-ray Air-filledlungs Area of increased density of a lungsegment, lobe, or entire lung Identifies the location andextent of infection Other Tests: Urinalysis, serology for Legionella (urine antigen testing, indirect fluorescent antibodystudies), arterial blood gases, pulse oximetry, complete blood count, blood urea nitrogen,creatinine, serum electrolytes Primary nursing diagnosis Diagnosis Infection related to the presence of bacteria Outcomes Immune status; Risk control; Risk detection; Nutrition status; Treatment behavior: Illness or injury;Hydration; Knowledge: Infection control Interventions Infection control; Infection protection; Surveillance; Fluid/electrolyte management; Medicationmanagement; Temperature regulation Planning and implementation Collaborativepharmacologic.

Antibiotics can be administered before test results are available. Generally,primary therapy is either levofloxacin or azithromycin. Erythromycin, sometimes in combination withrifampin, is also used, but the gastrointestinal effects of both the disease and drug can be cumulative and problematic. Intravenous fluids and electrolyte therapy may be considered when thepatient has fluid volume deficit.

Careful monitoring of fluid balance is required because of thepossible renal complications from interstitial nephritis or renal failure. If renal failure does ensue, thepatient may require temporary renal dialysis. Oxygen per cannula at 2 to 4 L/minute is effective with many patients, although in some patientswith respiratory insufficiency, it is necessary to proceed with intubation and assisted ventilation. Atelectasis may occur at any stage of the pneumonia. Pleural effusion may occur, which mayrequire a diagnostic thoracentesis and a chest tube.

The patient may need continuous pulseoximetry to monitor the response to mechanical ventilation and suctioning. Continuous cardiacmonitoring and hourly urine outputs may be necessary to assess the patient’s response to thedisease.

Pharmacologic highlights Medication or Drug Class Dosage Description Rationale Antibiotics Varieswith drug Levofloxacin (Levaquin),azithromycin (Zithromax),erythromycin,doxycycline Halt division of bacteria, thereby limiting infection Rifampin600mg/day, PO or IVAntitubercular Manages severe disease, such as multilobarpneumonia, respiratory failure, endocarditis, or severeimmunosuppression; if erythromycin is contraindicatedbecause of allergy, rifampin may be used alone or combined with doxycycline or cotrimoxazole Other Treatment: Antipyretics Independent The most important intervention is improvement of airway patency.

Retained secretions interfere withgas exchange and may cause slow resolution of the disease. Encourage a high level of fluid intake up to 3 L/day to assist in loosening pulmonary secretions and to replace fluid lost via fever anddiaphoresis. Provide meticulous sterile technique during endotracheal suctioning of the patient. Chest physiotherapy may be prescribed to assist with loosening and mobilizing secretions.

To maintain the patient’s comfort, keep the patient protected from drafts. Institute fever-reducingmeasures if necessary. To ease the patient’s breathing, raise the head of the bed at least 45 degrees and support the patient’s arms with pillows.

Provide mouth and skin care and emotionalsupport. Include the patient and family in planning care and allow them to make choices. Evidence-Based Practice and Health Policy Schuetz, P., Haubitz, S., Christ-Crain, M., Albrich, W. C., Zimmer, W., & Mueller, B.

(2013). Hyponatremia and anti-diuretic hormone in Legionnaires’ disease. BMC Infectious Diseases, 13, 585. doi 10.1186/1471-2334-13-585Investigators conducted a prospective cohort study among 873 pneumonia patients, of which 27 were positive for L. pneumophila, and found that patients with Legionnaires’ disease may be at increased risk for hyponatremia.

Sodium levels were significantly lower in the patients with Legionnaires’ disease (mean, 131.6mmom/L; SD, ± 0.9) when compared with patients without the disease (mean, 135.4 mmom/L;SD, ± 0.2) ( p < 0.001). A greater proportion of patients with Legionnaires’ disease had sodium levels below 130 mmol/Lwhen compared with patients without the disease (44.4% versus 8.2%; p < 0.001). Documentation guidelines Physical findings: Vital signs, head-to-toe assessment, rate of breathing, breath sounds,description of sputum Response to treatments such as chest physiotherapy, oxygen, antipyretics, and fluid therapy Presence of complications: Hypotension, dehydration, chest pain, changes in patterns of urination, laboratory findings Discharge and home healthcare guidelines Explain the medications to the patient, including the route, dosage, side effects, and need for takingall antibiotics until they are gone.

Explain food and drug interactions. Provide information on smoking-cessation programs. Note the source of the patient’s Legionnaires’ disease; if the causewas from within a patient’s home or workplace, recommend appropriate action to prevent recurrenceand decrease chances of further outbreaks. Instruct the patient to contact the physician if she or he has a fever or worsening pleuritic pain. Stress the need to go immediately to the nearest emergencydepartment if the patient becomes acutely short of breath.

Diseases and Disorders, © 2011 Farlex and Partners Le·gion·naires' dis·ease ( lē'jŏ-nārz' di-zēz') Acute infectious disease, caused by Legionella pneumophila, with prodromal influenzalikesymptoms and a rapidly rising high fever, followed by severe pneumonia and production of usually nonpurulent sputum, and sometimes mental confusion, hepatic fatty changes, andrenal tubular degeneration.

It has a high case-fatality rate; acquired from contaminated water,usually by aerosolization rather than being transmitted from person-to-person.

[American Legion convention, in Philadelphia in 1976, at which many delegates took sick]Medical Dictionary for the Dental Professions © Farlex 2012Legionnaires' disease,n.pr an acute bacterial pneumonia caused by infection with L. pneumophila and characterized by an influenza-like illness followed within a week by highfever, chills, muscle aches, and headache. Contaminated air-conditioning cooling towers andstagnant water supplies, including water vaporizers and water sonicators, may be a source of organisms. Mosby's Dental Dictionary, 2nd edition. © 2008 Elsevier, Inc. All rights reserved. Want to thank TFD for its existence? Tell a friend about us, add a link to this page, or visit the webmaster's page for free fun content . Link to this page:Legionnaires' diseaseFacebook Twitter Finally, Farlex brings you all the rules of English grammar, all in one place, explained in simple terms. The Farlex Grammar Bookis available now in paperback and e Book formats. "

: pneumonia that is caused by a bacterium of the genus Legionella ( L. pneumophila ), that is characterized initially by symptoms resembling influenza (as malaise, headache, and muscular aches) followed by high fever, cough, diarrhea, lobar pneumonia, and mental confusion, and that may be fatal especially in elderly and immunocompromised ind

Le gion naires' disease

Le gion naires' diseasenoun Le·gion·naires' disease \ ˌlē-jə-ˈnerz- \variants: or less commonly Legionnaire's disease Trending Now:oligarch glib depose omnibus acrimony ALLTime Traveler!

Explore the year a word first appeared Definition of Legionnaires' disease: pneumonia that is caused by a bacterium ( Legionella pneumophila ), is characterized initially by symptoms resembling influenza (as malaise, headache, and muscular aches) followed by high fever, cough, diarrhea, severe pneumonia, and mental confusion, and that may be fatal especially in elderly and immunocompromised individuals See Legionnaires' disease defined for English-language learners Origin and Etymology of legionnaires' diseasefrom its first recognized occurrence at an American Legion convention in 1976NEW!

Time Traveler First Known Use: 1976See Words from the same year LEGIONNAIRES' DISEASE Defined for English Language Learners Legionnaires' diseasenoun Definition of Legionnaires' disease for English Language Learners: a serious disease of the lungs that is caused by bacteria Medical Dictionary Legionnaires' diseasenounvariants: also Legionnaire's diseasemedical Definition of Legionnaires' disease

ividuals — see pontiac fever Learn More about legionnaires' disease See words that rhyme with Legionnaires' disease Seen and Heard What made you want to look up Legionnaires' disease? Please tell us where you read or heard it (including the quote, if possible).show

Since that time, it has been recognized that the disease occurs in both epidemic and endemic forms, and that sporadic cases are not readily differentiated from other respiratory infections by clinical symptoms. It is estimated that about 25,000 to 100,000 Legionella infections occur annually.

Useful For

Useful For An adjunct to culture for the presumptive diagnosis of past or current Legionnaires disease ( Legionella pneumophila serogroup 1)Clinical Information Legionnaires disease, named after the outbreak in 1976 at the American Legion convention in Philadelphia, is caused by Legionella pneumophila and is an acute febrile respiratory illness ranging in severity from mild illness to fatal pneumonia.

Known risk factors include immunosuppression, cigarette smoking, alcohol consumption, and concomitant pulmonary disease.

The resulting mortality rate, which ranges up to 40% in untreated immunocompetent patients, can be lowered if the disease can be rapidly diagnosed and appropriate antimicrobial therapy instituted early. L pneumophila is estimated to be responsible for 80% to 85% of reported cases of Legionella infections with the majority of cases being caused by L pneumophila serogroup 1 alone.

A variety of laboratory techniques (culture, direct fluorescent antibody, DNA probes, immunoassay, antigen detection), using a variety of specimen types (respiratory specimens, serum, urine), have been used to help diagnose Legionella pneumonia. Respiratory specimens are preferred. Unfortunately, one of the presenting signs of Legionnaires disease is the relative lack of productive sputum.

This necessitates the use of invasive procedures to obtain adequate specimens (eg, bronchial washing, transtracheal aspirate, lung biopsy) in many patients. Serology may also be used, but is often retrospective in natu

re. It was shown as early as 1979 that a specific soluble antigen was present in the urine of patients with Legionnaires disease. (1) The presence of Legionella antigen in urine makes this an ideal specimen for collection, transport, and subsequent detection in early, as well as later, stages of the disease.

Useful For

Similar to tetracycline, doxycycline is highly efficacious against: Mycoplasma pneumoniae, Ureaplasma urealyticum, Actinomyces, Chlymadia pneumonia, C.trachomatis, C.psittaci, Rickettsia, Coxiella burnetii, Legionella species, spirochetes like Treponema pallidum, Borrelia recurrentis and burgdorferi.

Antibiotic Drugs

Antibiotic Drugs Doxycycline Doxycycline is a broad spectrum semisynthetic tetracyclines. Chemical structure The molecular formula is C22H24N2O8, HCl, ½ C2H6O, ½ H2O and molecular weight is 512.9Mechanism of action Tetracycline is a bacteriostatic drug acts by binding reversibly to the 30S subunit of the bacterial ribosome.

This inhibits addition of amino acids to the growing peptide resulting in inhibition of protein synthesis. Site of action Pharmacokinetics Absorption of doxycycline is not significantly affected by milk or food, but co-administration of antacids or mineral supplements should be avoided. Its long half-life permits once daily dosing. Antimicrobial spectrum Doxycycline has static action against a varied range of aerobic and anaerobic gram-positive and gram-negative bacteria.

Doxycycline is effective against sensitive strains of staphylococci, bacteroides spp., propionibacterium, peptococcus, asexual erythrocytic forms of plasmodium falciparum, mycoplasma pneumonia, chlymadia pneumonia, c.trachomatis and many more. Indications and uses Doxycycline is drug of choice for treatment of suspected or proven Rocky Mountain spotted fever. Doxycycline is used for treatment of falciparum malaria resistant to chloroquine, acne vulgaris, community-acquired pneumonia, lymphogranuloma venereum etc.

Doxycycline can also be used for prophylaxis of malaria and leptospirosis. Administration and dosage Condition Dosage Adults& children > 45 kg Children> 8 years Non-serious infection 100 mg 12 hourly followed by a maintenance dose of 100 mg/day 4.4 mg/kg, divided into 2 doses on 1st day, followed by 2.2 mg/kg as single daily dose or divided into 2 doses on subsequent days. Serious /chronic infection 100 mg 12 hourly 4.4 mg/kg daily Precautions, contraindications and warnings Caution in patients with liver impairment.

Doxycycline should be taken with glass of water to reduce risk of oesophageal injury. Contraindicated in children <8 years, pregnancy and lactation, patients suffering from porphyria, severe hepatic dysfunction and with known hypersensitivity to doxycycline.

Adverse effects Nausea, vomiting, and diarrhea are most common side effects of tetracycline. Other side effects are brown discoloration of the teeth, anorexia, epigastric distress, stomatitis, sore throat, glossitis, black hairy tongue, dysphagia, esophagitis, esophageal ulcers, pancreatitis, liver toxicity, kidney toxicity, photosensitization. Technical Description on Doxycycline Doxycycline is a semisynthetic tetracycline – class antibiotic. Chemical structure Doxycycline is a synthetic antibiotic produced from oxytetracycline. Molecular formula of doxycycline is C22H24N2O8, HCl, ½ C2H6O, ½ H2O and MW is 512.9.

The structure of doxycycline is: Preparations available Doxycycline is available as different salts: Doxycycline HCl (hyclate), doxycycline carrageenate, doxycycline phosphate and doxycycline monohydrate.

Oral: 20, 50, 75, 100 mg tablets and capsules; powder to reconstitute for 25 mg/5 m L suspension; 50 mg/5 m L syrup Parenteral: 100, 200 mg powder to reconstitute for injection Mechanism of action Like other tetracyclines doxycycline is primarily bacteriostatic.

They enter gram negative bacteria by passive diffusion through the porin channels and gram positive bacteria and other organisms by energy-dependent active transport. It is concentrated intracellularly by vulnerable cells. Tetracyclines after entering the cell are bound reversibly to the 30S subunit of the ribosomes of bacteria.

Here the aminoacyl-t RNA is prevented from attaching to the acceptor site which is present on the ribosomal complex of m RNA. This leads to inhibition of the process of adding amino acids to the emerging peptide. The carrier involved in the active transport is absent in the mammalian cells and also tetracyclines do not bind to mammalian 60S or 30S ribosomes. These two factors are responsible for the selective toxicity of tetracyclines to the microbes. In vitro studies have reported that doxycycline inhibits collagenase activity.

Other studies have also reported that doxycycline decreases the raised collagenase activity in the gingival crevicular fluid of patients with adult periodontitis.

The clinical significance of these findings is not known. Site of action Antimicrobial Action Like other tetracyclines doxycycline is bacteriostatic with action against a varied range of aerobic and anaerobic gram-positive and gram-negative bacteria. Antimicrobial activity specific to doxycycline: Doxycycline has retained excellent levels of activity against staphylococci, including methicillin-resistant Staphylococcus aureus (MRSA). A number of anaerobes (Bacteroides, Propionibacterium, Peptococcus) are sensitive to doxycycline. Asexual erythrocytic forms of P. falciparum are sensitive to doxycycline whereas the gametocytes are not sensitive. Doxycycline can be active against some tetracycline-resistant isolates.

It is also effective against: Some atypical mycobacteria and some non-tubercular strains and plasmodium. It is active against the following gram negative bacteria: H. ducreyi, H. influenzae, Campylobacter jejuni, Vibrio cholerae, Legionella pneumophila, Francisella tularensis, and Pasteurella multocida. Calymmatobacterium granulomatis, Brucella abortus, Helicobacter pylori, Propionobacterium acnes, Burkholderia pseudomallei, Y. pestis and enterocolitica, Enterobacteriaceae are resistant.

Pseudomona aeroginosa, Kleibsella, Proteus, Salmonella, Shigella, Bacteroids fragilis are not inhibited Following gram positive bacteria are also susceptible: Bacillus anthracis and Listeria monocytogens Clostridium perfringens and C.tetani Resistance Resistance to tetracycline is generally inducible and mainly mediated by plasmids.

Resistance to tetracycline occurs due to any of the three mechanisms: Enhanced efflux or diminished influx of tetracycline due to an dynamic pump which transports protein;Ribosome fortification due to formation of proteins that hinders attachment of tetracycline to the ribosome. Enzymatic inhibition. Pharmacokinetics Doxycycline is absorbed well after oral administration and food does not interfere with the absorption.

But co-administration of antacids or mineral supplements should be avoided. Maximal concentration is achieved after two hours. Concentrations in plasma are equivalent whether doxycycline is given orally or parenterally. Plasma protein binding is about 80 to 90%. Its t1/2 is ranges from 12 to 24 hours. Lipid solubility of doxycycline is greater than tetracycline. Doxycycline has extensive tissue distribution. Doxycycline is largely excreted unchanged both in the bile and urine. Unlike other tetracyclines doxycycline is excreted from thebody by organs other than the kidney. Therapeutic Uses It can be prescribed over other tetracyclines as it has a prolonged t1/2 and good oral absorption and it can be given in persons with kidney dysfunction.

The specific uses of doxycycline are: Doxycycline's decent activity against S. pneumoniae and H. influenzae and excellent activity against atypical pathogens such as Mycoplasma and Chlamydophilia pneumoniae make it an effective single agent for empirical therapy of community-acquired pneumonia in the outpatient setting or as an adjunct to cephalosporin-based therapy for inpatients.

Doxycycline (300 mg as single administration) is effective in decreasing stool volume and eradicating Vibrio cholerae from the stool within 48 hours.

Doxycycline (100 mg BD for 21 days) is first-line therapy for treatment of lymphogranuloma venereum. Doxycycline is preferred over other tetracyclines for venereal diseases in males and females caused by Chlamydia trachomatis. Non-pregnant females allergic to penicillin who have primary, secondary, or latent syphilis can be treated with doxycycline, 100 mg orally twice daily for 2 weeks Doxycycline is the drug of choice for treatment of suspected or proven Rocky Mountain spotted fever in adults and in children, including those <9 years of age, in whom the risk of staining of permanent teeth is outweighed by the seriousness of this potentially fatal infection.

Doxycycline has better antiprotozoal activity and can be given with quinine in the management of falciparum malaria resistant to chloroquine. It is used in non-endemic areas for the treatment of chloroquine-resistant falciparum malaria in an oral dose of 200 mg daily for at least 7 days after treatment with quinine.

Doxycycline 100 mg daily may be used for prophylaxis of malaria in areas of high risk or where multidrug resistance exists, and can be used prophylactically for up to 2 years. For the prophylaxis of leptospirosis, 200 mg may be given orally once a week throughout exposure for up to 21 days and 200 mg is also given when leaving the area of infection risk.

Doxycycline, 100 mg every 12 hours (2.2 mg/kg every 12 hours for children weighing <45 kg), is indicated for prevention or treatment of anthrax. Doxycycline in combination with rifampin or streptomycin is effective for acute and chronic infections caused by Brucella melitensis, Brucella suis, and Brucella abortus.

Doxycyline hyclate is indicated specifically for use as an adjunct to scaling and root planing to promote attachment level gain and to reduce pocket depth in patients with adult periodontitis. Solutions of doxycycline are also used for malignant effusions. Administration and dosage Doxycycline is typically given orally as the base or its numerous salts, usually the hyclate. Doses are expressed in terms of doxycycline; doxycycline hyclate 115 mg is equivalent to about 100 mg of anhydrous doxycycline.

Doxycycline capsules and tablets should be given with plenty of fluid, with the patient in an upright position, and well before going to bed. If gastric irritation occurs, it can be given with food or milk. Dispersible tablets or liquid formulations are advisable in elderly patients.

If oral therapy is not possible, doxycycline hyclate may be given by slow IV infusion of a solution containing 0.1 to 1 mg/m L, in equivalent doses over 1 to 4 hours.

Dosage Condition Dosage Adults& children > 45 kg Children> 8 years Non-serious infection 100 mg 12 hourly followed by a maintenance dose of 100 mg/day 4.4 mg/kg, divided into 2 doses on 1st day, followed by 2.2 mg/kg as single daily dose or divided into 2 doses on subsequent days.

Serious /chronic infection 100 mg 12 hourly 4.4 mg/kg daily Interactions Specific interactions are: Unlike other tetracyclines, doxycycline binding to calcium is less but its absorption can be affected by Fe2+, aluminium, Zn, Mg2+ and bismuth. Chronic alcohol consumption, rifampicin, and anticonvulsants like phenytoin, phenobarbitone and carbamazepine enhance metabolism of doxycycline due to induction of hepatic microsomal enzymes. Most of the interactions which are similar to other tetracyclines are: As it inhibits enterohepatic circulation, concurrent use may lead failure of oral contraceptive pills.

Dose of anticoagulants should be reduced as tetracyclines may lead to a reduction in the prothrombin action in plasma. Simultaneous use of the anaesthetic methoxyflurane may lead to kidney toxicity which may result in death. Tetracyclines being bacteriostatic may hinder bactericidal activity of penicillin; hence avoid giving tetracyclines with penicillin.

It should be avoided with diuretics as blood urea may increase. Tetracyclines inhibits intestinal flora that produces vitamin K, and therefore may potentiate the anticoagulant effects of warfarin. There have been reports of pseudotumor cerebri (benign intracranial hyper tension) associated with the concomitant use of isotretinoin and tetracyclines. Contraindications Hypersensitivity to any of the tetracyclines. Children less than 8 years of age.

Pregnancy and lactation Porphyria Severe hepatic dysfunction Special Precautions Impaired hepatic function;History or predisposition to oral candidiasis. Should be taken with at least a glass of water in an upright position to reduce the risk of oesophageal injury.

Pregnancy: Doxycycline penetrates the placental barrier. Lactation: Tetracyclines are found in breast milk. Adverse Effects Gastrointestinal Vomiting and loose stools are most commonly responsible for stoppage of tetracyclines. Other effects seen are: Anorexia, epigastric distress, stomatitis, sore throat, glossitis, black hairy tongue, dysphagia, esophagitis, oesophageal ulcers, and pancreatitis.

Tetracyclines can lead to modification of the commensal flora in the intestines and lead to killing of the sensitive commensal microorganisms and it can lead to increased multiplication of clostridium, candidial species, pseudomonas, staphylococcal species.

Liver Toxicity It can cause deterioration of liver function, particularly in patients with pre-existing liver insufficiency and during pregnancy. Liver necrosis can be seen with large IV dose (greater than four gm). Also hepatic necrosis is more common in pregnancy and can be fatal. Bony Structures and Teeth Tetracyclines bound readily to calcium in teeth or recently formed bone in young aged children. It results in permanent brown discoloration of the teeth. If a tetracycline is consumed in pregnancy, it gets deposited in the developing teeth of the foetus, which can result in development of dysplastic enamel, discoloured teeth and increased fluorescence.

The developing bone in the foetus can also be deposited tetracycline leading to stunting of growth or other deformities. Photosensitization Systemically administered tetracyclines, can induce sensitivity to sunlight or ultraviolet light. Onycholysis and pigmentation of the nails may develop. Vestibular Reactions Giddiness, vertigo, and vomiting can be seen. Other side effects Long-term therapy may produce increased WBC count, lymphocytes, and thrombocytopenic purpura. It may cause increased intracranial pressure in young infants, even when given in the usual therapeutic doses. Continue on to the next page, Ertapenem Back to Top

Lastly, legionellosis is the infection caused by L. pneumophila and can cause either: Legionnaires' disease, which is characterized by fever, myalgia, cough, pneumonia, or Pontiac fever, a milder illness without pneumonia.

Legionella pneumophila

Legionella pneumophilanavigation search This is a curated page. Report corrections to Microbewiki. Contents [ hide ]1 Taxonomic Classification2 Description and significance3 Genomic Structure4 Cell Structure and Metabolism5 Ecology6 Pathology7 Current Research8 References Taxonomic Classification Higher Order Taxa: Bacteria; Proteobacteria; Gammaproteobacteria; Legionellales; Legionellacaea; Legionella; Legionella pneumophila Description and significance The Legionellaceae are fastidious gram-negative bacteria that reside in aquatic environments all over the globe.

In their natural environment, the Legionellaceae are intracellular parasites of free-living protozoa. These organisms may also inhabit man-made water distribution systems. The family Legionellaceae consists of a single genus, Legionella.

More specifically, this genus includes the species Legionella pneumophila, which are non-encapsulated, aerobic bacilli. In addition to L. pneumophila, there are 41 other species in the genus and together these species divide into 64 serogroups.

Within the species L. pneumophila, human infection is caused primarily (but not exclusively) by a limited number of serogroups—serogroups 1, 4, and 6. L. pneumophila is the most frequent cause of human legionellosis, better known as Legionnaire’s disease in the Legionellaceae family. It is also a relatively common cause of community-acquired and nosocomial pneumonia in adults. (1) And L. pneumophila serogroup 1 alone is responsible for 70-90% of cases. (2)The Legionellaceae were not documented until 1976, when a detrimental outbreak of pneumonia occurred in Philadelphia at an American Legion Convention.

(Fraser et al., 1977; Tsai et al., 1979). Thirty four of the 221 people who became ill after exposure died within the first few weeks after the convention.

The culprit, L. pneumophila, was isolated first by inoculation of postmortem lung tissue into guinea pigs and then by subculture into a rich artificial medium (Mc Dade et al., 1977). Then by indirect immunofluorescent antibody assay, it was found that over 90% of those that fell ill had at least four times the concentration of antibody in the blood (fourfold rise in titer) against this organism.

The same method was used to screen previously saved sera from earlier outbreaks of unexplained respiratory disease and they discovered that a number of them were associated with seroconversion to L. pneumophila, including a “rickettsia-like” organism, isolated by guinea pig inoculation from the blood of a feverish patient in 1947, which today is recorded as the earliest known isolate of L. pneumophila.

(1)Genomic Structure The Legionella genome structure continues to undergo research. Three different genomes of L. pneumophila were completed over a span of three years.

First, Legionella pneumophila ssp. Pneumophila str. Philadelphia 1 (3,397,754 bp, 3002 genes) was completed in October 2001. Plasmid p LPP of Legionella pneumophila str. Paris was completed in October 2004; in addition to the full genome (3,503,610 bp, 3136 genes). Plasmid p LPL of Legionella pneumophila str. Lens was also completed in October 2004, in addition to the full genome (3,345,687 bp, 3001 genes).

(3)The genome of Legionella pneumophila str. Paris was found to contain 3,503,610 base pairs and contains about 3027 predicted protein-encoding genes.

The genome is a circular chromosome with an average GC content of 38%. In 2004, researchers analyzed the complete genome sequences of L. pneumophila Paris, an endemic strain that is predominantly found in France and L. pneumophila Lens, another endemic strain. The Lens strain is 3,345,687 base pairs long and contains about 2878 protein-encoding genes and like the Paris strain its genome is a circular chromosome with an average GC content of 38%.

The two strains differed in about 13% of their genome sequences having 3 different plasmids. The Paris strain is unique because it contains a type V secretion system and a 36 Kb sequence carried on a multicopy plasmid or integrated into a chromosome encodes its type IV secretion system. This ability for genes to move around increases the versatility in L. pneumophila. To alter host cell functions to its advantage L. pneumophila contains many genes that encode eukaryotic-like proteins or motifs. As a result, the genome reveals co-evolution of L. pneumophila as a fresh-water amoebae and a human pathogen.

(4)Cell Structure and Metabolism L. pneumophila is a gram-negative, non-encapsulated, aerobic bacillus with a single, polar flagellum. The organism is approximately 2µm in length and 0.3-0.9µm in width, but in nutrient-deficient media, it may become long and filamentous.

It is surrounded by a gram-negative cell wall and pili are sometimes identified. The cell envelope is composed of branched-chain fatty acids and distinctive ubiquinones, whose structural differences have been used to classify different Legionella species.

The outer-membrane is comprised of a lipopolysaccharide (LPS), which is “fully sequenced and found to have several novel features which have pathophysiologic consequence” and is noticeably less endotoxic than enterobacterial LPS since it has weak interactions with the CD14 receptor on monocytes, The interactions are probably inhibited by the long-chain fatty acids of L. pneumophila lipid A, which are two times the length of enterobacterial lipid A. A single, major protein also makes up the outer membrane and functions as a porin and as a target for human complement fixation. L. pneumophila serogroup 1LPS also has a repeating O antigen. It is a homopolymer of an uncommon sugar, called legionaminic acid.

”LPS is the immunodominant antigen of the Legionellaceae, and the O antigen is the determinant of serogroup specificity within the genus.” (5)Ecology All organisms interact with the environment they are in and with the organisms they share that environment with.

In one research study, the potable water distribution system was determined to be the culprit behind hospital-acquired Legionnaires’ disease. Researches hypothesized that the natural microbial population and sediment (aerosols or particulate mater) were, together, growth-promoting factors of L. pneumophila. A series of in vitro experiments proved that many factors supported and even improved the survival of L. pneumophila.

Results showed that water from the hot-water storage tank was a constant sustainer for the survival of L. pneumophila, as was the concentration of sediment in the water system.

Also, both the presence of bacteria and the combination of bacteria and sediment working together improved the survival of L. pneumophila. And lastly, the sediment was found to have nutritional value—it stimulated the growth of environmental microflora, which then stimulated the growth of L. pneumophila.

The results coincide with experimental observations that L. pneumophila prefer to grow and localize in hot, moist environments where there is a supply of nutrition from the sediment. Concluding, it was not surprising that L. pneumophila found their preferable environment to be the potable water system, where they formed interrelationships between temperature, sediment, and microflora.

From this data, it is clear that L. pneumophila interact with their environment and the organisms they share that environment with. (6)Pathology L. pneumophila can only be acquired from an environmental source; therefore, infection never occurs between humans or humans and animals. Another interesting thing is, unlike other pathogens that cause bacterial pneumonia, L. pneumophila do not inhabit the upper respiratory tract.

Once inhaled, they are small enough to avoid the defenses of the upper airway. In the lung, pulmonary alveolar macrophages (macrophages of the air sacs in the lung) and sometimes type II alveolar epithelial cells take up L. pneumophila where it begins to grow intracellularly.

It seems intracellular infection is necessary for producing infection because mutants of L. pneumophila are unable to cause disease.

This is true also because L. pneumophila is not sensitive to antimicrobials (e.g., penicillin, cephalosporin, aminoglycosides) that are excluded by the plasma membrane, and therefore, it is treated only with antibiotics that can enter the host cells (e.g., macrolides, quinolones, tetracyclines). (7)Then the bacteria undergo a series of events that begins with phagocytosis. Most, but not all strains of L. pneumophila are taken up by “coiling phagocytosis”—when the macrophage coils around the bacteria to take it up, which is mediated by the CR1 and CR3 receptors (complement receptors of the macrophage) with or without fixation of complement serum factors like C3.

Also during uptake the plasma membrane engulfing the bacteria is altered; some membrane proteins, like MHCI and II (both molecules that aid in immune response), are specifically excluded whereas others, like CR3 and 5’-nucleotidase are preserved. (7) Two hours later, the phagosome (the vacuole formed around the pathogen) is found near mitochondria, smooth vesicles, or the nuclear membrane.

Normally, phagosomes will fuse with lysosomes and pathogenic microorganisms are killed, but in this case acidification of the phagosome does not take place, and its membrane does not get late endosomal markers, like rab7 and LAMP-1. This results in the failure of phagosolysosomal fusion which allows bacteria to avoid intracellular killing. Mutants of L. pneumophila on the other hand cannot avoid it and are transported to the lysosome within 30 minutes of uptake. (7) Fully virulent organisms on the other hand will take up an endosome that has become enclosed by the rough ER (a response to cellular amino acid starvation i.e.

autophagy) 4 hours after uptake. It is by this endosome enclosure that bacterial multiplication proceeds. While the bacteria are multiplying inside their host cells, they also “begin to express flagella, motility, cellular toxicity, and sensitivity to physiologic concentrations of sodium chloride.” (7) The genes that mediate intracellular trafficking and necrosis (accidental cell death) are the same genes that introduce the cytotoxic phenotype of L. pneumophila. Introduction of cytotoxicity in response to cellular amino acid starvation in the host may be a key mechanism that signals the bacteria to exit host cells and infect new cells. (7)

A particular feature of Legionella is its dual host system allowing the intracellular growth in protozoa (amoebae), and during infection in human pulmonary alveolar macrophages. (8) Like macrophages, amoebae ingest L. pneumophila by phagocytosis, which can be mediated by amoebic-specific receptors.

After ingestion, the bacteria evade phagosolysosomal fusion and localize to a membrane-vesicle surrounded by endoplasmic reticulum where it grows and acquires motility before release from the cell. This growth process of L. pneumophila to infect mammalian phagocytes strongly supports the theory that it evolved from protozoa.

“Since L. pneumophila are not transmitted between mammalian hosts or return to the natural environment by infected individuals, this hypothesis explains why this pathogen is adapted to intracellular life in the human lung without any apparent selection for pathogenic traits in the microenvironment.” (7)The Mip gene, a 24 k Da bacterial envelope protein, was the first virulence determinant of L. pneumophila.

The consequence of a Mip mutation Is a 1.5 to 3 log reduction in infectivity of explanted alveolar macrophages, alveolar epithelial cells, and amoebae. (7)Iron is essential for all pathogenic bacteria. Without it, the growth of intracellular L. pneumophila becomes restricted. It was found that gamma-interferon restricts the growth of L. pneumophila by downregulating the expression transferring receptors on macrophages and the cellular concentration of ferritin. Naturally, L. pneumophila taken from iron-deficient cultures grown are defective in cellular infection.

L. pneumophila has a fur homolog, which regulates the expression of an aerobactin synthetase homolog. Even though siderophores have yet to be identified in L. pneumophila, a mutation of this iron acquisition gene will cut intracellular infection by 80-fold. (7)Studies on intracellular survival of L. pneumophila have shown two chromosomal regions to encode functions that are essential for establishing intracellular infection.

The genes have been designated icm (intracellular multiplication) by one group and dot (defect in organelle trafficking) by the other. Mutation in almost any of these genes results in either a complete loss of cellular infectivity. In all cases, the loss of infectivity is associated with a failure to evade phagolysosmal fusion, as well as a loss of the immediate contact cytotoxicity of L. pneumophila at high rates of infections.

Mutations in several of the dot-icm genes—not just those with sequence homology to known conjugation genes have been shown to terminate plasmid transfer.

These same mutations also result in loss of this toxicity coupled with the insertion of a pore into host cell membranes. The proteins encoded by these loci probably either combine to form the pore or participate in its transfer or both. (7)

Lastly, legionellosis is the infection caused by L. pneumophila and can cause either: Legionnaires' disease, which is characterized by fever, myalgia, cough, pneumonia, or Pontiac fever, a milder illness without pneumonia.

The symptoms of Legionnaire’s disease range from a mild cough and low fever to rapidly progressive pneumonia, coma, and death.

Early symptoms include slight fever, headache, aching joints and muscles, lack of energy or tiredness, and loss of appetite. Later symptoms include high fever, cough, difficulty breathing/shortness of breath, chills, chest pain, common gastrointestinal symptoms including vomiting, diarrhea, nausea, and abdominal pain.

The symptoms of Pontiac fever include flu-like symptoms such as fever, headache, tiredness, loss of appetite, muscle and joint pain, chills, nausea, and a dry cough. Patients usually reach full recovery within two to five days without medical attention and no deaths have been reported. (9)Current Research

Much of the research done on Legionella pneumophila is related to ecology and how it relates to the environment. Some studies compare L. pneumophila to other microorganisms. Other studies look at the cases of Legionellosis and investigate the causes of the outbreaks.

More specifically, this genus includes the species Legionella pneumophila, which are non-encapsulated, aerobic bacilli. In addition to L. pneumophila, there are 41 other species in the genus and together these species divide into 64 serogroups.

Legionella pneumophila

Legionella pneumophilanavigation search This is a curated page. Report corrections to Microbewiki. Contents [ hide ]1 Taxonomic Classification2 Description and significance3 Genomic Structure4 Cell Structure and Metabolism5 Ecology6 Pathology7 Current Research8 References Taxonomic Classification Higher Order Taxa: Bacteria; Proteobacteria; Gammaproteobacteria; Legionellales; Legionellacaea; Legionella; Legionella pneumophila Description and significance The Legionellaceae are fastidious gram-negative bacteria that reside in aquatic environments all over the globe.

In their natural environment, the Legionellaceae are intracellular parasites of free-living protozoa. These organisms may also inhabit man-made water distribution systems. The family Legionellaceae consists of a single genus, Legionella.

Within the species L. pneumophila, human infection is caused primarily (but not exclusively) by a limited number of serogroups—serogroups 1, 4, and 6. L. pneumophila is the most frequent cause of human legionellosis, better known as Legionnaire’s disease in the Legionellaceae family. It is also a relatively common cause of community-acquired and nosocomial pneumonia in adults. (1) And L. pneumophila serogroup 1 alone is responsible for 70-90% of cases. (2)The Legionellaceae were not documented until 1976, when a detrimental outbreak of pneumonia occurred in Philadelphia at an American Legion Convention.

(Fraser et al., 1977; Tsai et al., 1979). Thirty four of the 221 people who became ill after exposure died within the first few weeks after the convention.

The culprit, L. pneumophila, was isolated first by inoculation of postmortem lung tissue into guinea pigs and then by subculture into a rich artificial medium (Mc Dade et al., 1977). Then by indirect immunofluorescent antibody assay, it was found that over 90% of those that fell ill had at least four times the concentration of antibody in the blood (fourfold rise in titer) against this organism.

The same method was used to screen previously saved sera from earlier outbreaks of unexplained respiratory disease and they discovered that a number of them were associated with seroconversion to L. pneumophila, including a “rickettsia-like” organism, isolated by guinea pig inoculation from the blood of a feverish patient in 1947, which today is recorded as the earliest known isolate of L. pneumophila.

(1)Genomic Structure The Legionella genome structure continues to undergo research. Three different genomes of L. pneumophila were completed over a span of three years.

First, Legionella pneumophila ssp. Pneumophila str. Philadelphia 1 (3,397,754 bp, 3002 genes) was completed in October 2001. Plasmid p LPP of Legionella pneumophila str. Paris was completed in October 2004; in addition to the full genome (3,503,610 bp, 3136 genes). Plasmid p LPL of Legionella pneumophila str. Lens was also completed in October 2004, in addition to the full genome (3,345,687 bp, 3001 genes).

(3)The genome of Legionella pneumophila str. Paris was found to contain 3,503,610 base pairs and contains about 3027 predicted protein-encoding genes.

The genome is a circular chromosome with an average GC content of 38%. In 2004, researchers analyzed the complete genome sequences of L. pneumophila Paris, an endemic strain that is predominantly found in France and L. pneumophila Lens, another endemic strain. The Lens strain is 3,345,687 base pairs long and contains about 2878 protein-encoding genes and like the Paris strain its genome is a circular chromosome with an average GC content of 38%.

The two strains differed in about 13% of their genome sequences having 3 different plasmids. The Paris strain is unique because it contains a type V secretion system and a 36 Kb sequence carried on a multicopy plasmid or integrated into a chromosome encodes its type IV secretion system. This ability for genes to move around increases the versatility in L. pneumophila. To alter host cell functions to its advantage L. pneumophila contains many genes that encode eukaryotic-like proteins or motifs. As a result, the genome reveals co-evolution of L. pneumophila as a fresh-water amoebae and a human pathogen.

(4)Cell Structure and Metabolism L. pneumophila is a gram-negative, non-encapsulated, aerobic bacillus with a single, polar flagellum. The organism is approximately 2µm in length and 0.3-0.9µm in width, but in nutrient-deficient media, it may become long and filamentous.

It is surrounded by a gram-negative cell wall and pili are sometimes identified. The cell envelope is composed of branched-chain fatty acids and distinctive ubiquinones, whose structural differences have been used to classify different Legionella species.

The outer-membrane is comprised of a lipopolysaccharide (LPS), which is “fully sequenced and found to have several novel features which have pathophysiologic consequence” and is noticeably less endotoxic than enterobacterial LPS since it has weak interactions with the CD14 receptor on monocytes, The interactions are probably inhibited by the long-chain fatty acids of L. pneumophila lipid A, which are two times the length of enterobacterial lipid A. A single, major protein also makes up the outer membrane and functions as a porin and as a target for human complement fixation. L. pneumophila serogroup 1LPS also has a repeating O antigen. It is a homopolymer of an uncommon sugar, called legionaminic acid.

”LPS is the immunodominant antigen of the Legionellaceae, and the O antigen is the determinant of serogroup specificity within the genus.” (5)Ecology All organisms interact with the environment they are in and with the organisms they share that environment with.

In one research study, the potable water distribution system was determined to be the culprit behind hospital-acquired Legionnaires’ disease. Researches hypothesized that the natural microbial population and sediment (aerosols or particulate mater) were, together, growth-promoting factors of L. pneumophila. A series of in vitro experiments proved that many factors supported and even improved the survival of L. pneumophila.

Results showed that water from the hot-water storage tank was a constant sustainer for the survival of L. pneumophila, as was the concentration of sediment in the water system.

Also, both the presence of bacteria and the combination of bacteria and sediment working together improved the survival of L. pneumophila. And lastly, the sediment was found to have nutritional value—it stimulated the growth of environmental microflora, which then stimulated the growth of L. pneumophila.

The results coincide with experimental observations that L. pneumophila prefer to grow and localize in hot, moist environments where there is a supply of nutrition from the sediment. Concluding, it was not surprising that L. pneumophila found their preferable environment to be the potable water system, where they formed interrelationships between temperature, sediment, and microflora.

From this data, it is clear that L. pneumophila interact with their environment and the organisms they share that environment with. (6)Pathology L. pneumophila can only be acquired from an environmental source; therefore, infection never occurs between humans or humans and animals. Another interesting thing is, unlike other pathogens that cause bacterial pneumonia, L. pneumophila do not inhabit the upper respiratory tract.

Once inhaled, they are small enough to avoid the defenses of the upper airway. In the lung, pulmonary alveolar macrophages (macrophages of the air sacs in the lung) and sometimes type II alveolar epithelial cells take up L. pneumophila where it begins to grow intracellularly.

It seems intracellular infection is necessary for producing infection because mutants of L. pneumophila are unable to cause disease.

This is true also because L. pneumophila is not sensitive to antimicrobials (e.g., penicillin, cephalosporin, aminoglycosides) that are excluded by the plasma membrane, and therefore, it is treated only with antibiotics that can enter the host cells (e.g., macrolides, quinolones, tetracyclines). (7)Then the bacteria undergo a series of events that begins with phagocytosis. Most, but not all strains of L. pneumophila are taken up by “coiling phagocytosis”—when the macrophage coils around the bacteria to take it up, which is mediated by the CR1 and CR3 receptors (complement receptors of the macrophage) with or without fixation of complement serum factors like C3.

Also during uptake the plasma membrane engulfing the bacteria is altered; some membrane proteins, like MHCI and II (both molecules that aid in immune response), are specifically excluded whereas others, like CR3 and 5’-nucleotidase are preserved. (7) Two hours later, the phagosome (the vacuole formed around the pathogen) is found near mitochondria, smooth vesicles, or the nuclear membrane.

Normally, phagosomes will fuse with lysosomes and pathogenic microorganisms are killed, but in this case acidification of the phagosome does not take place, and its membrane does not get late endosomal markers, like rab7 and LAMP-1. This results in the failure of phagosolysosomal fusion which allows bacteria to avoid intracellular killing. Mutants of L. pneumophila on the other hand cannot avoid it and are transported to the lysosome within 30 minutes of uptake. (7) Fully virulent organisms on the other hand will take up an endosome that has become enclosed by the rough ER (a response to cellular amino acid starvation i.e.

autophagy) 4 hours after uptake. It is by this endosome enclosure that bacterial multiplication proceeds. While the bacteria are multiplying inside their host cells, they also “begin to express flagella, motility, cellular toxicity, and sensitivity to physiologic concentrations of sodium chloride.” (7) The genes that mediate intracellular trafficking and necrosis (accidental cell death) are the same genes that introduce the cytotoxic phenotype of L. pneumophila. Introduction of cytotoxicity in response to cellular amino acid starvation in the host may be a key mechanism that signals the bacteria to exit host cells and infect new cells. (7)

A particular feature of Legionella is its dual host system allowing the intracellular growth in protozoa (amoebae), and during infection in human pulmonary alveolar macrophages. (8) Like macrophages, amoebae ingest L. pneumophila by phagocytosis, which can be mediated by amoebic-specific receptors.

After ingestion, the bacteria evade phagosolysosomal fusion and localize to a membrane-vesicle surrounded by endoplasmic reticulum where it grows and acquires motility before release from the cell. This growth process of L. pneumophila to infect mammalian phagocytes strongly supports the theory that it evolved from protozoa.

“Since L. pneumophila are not transmitted between mammalian hosts or return to the natural environment by infected individuals, this hypothesis explains why this pathogen is adapted to intracellular life in the human lung without any apparent selection for pathogenic traits in the microenvironment.” (7)The Mip gene, a 24 k Da bacterial envelope protein, was the first virulence determinant of L. pneumophila.

The consequence of a Mip mutation Is a 1.5 to 3 log reduction in infectivity of explanted alveolar macrophages, alveolar epithelial cells, and amoebae. (7)Iron is essential for all pathogenic bacteria. Without it, the growth of intracellular L. pneumophila becomes restricted. It was found that gamma-interferon restricts the growth of L. pneumophila by downregulating the expression transferring receptors on macrophages and the cellular concentration of ferritin. Naturally, L. pneumophila taken from iron-deficient cultures grown are defective in cellular infection.

L. pneumophila has a fur homolog, which regulates the expression of an aerobactin synthetase homolog. Even though siderophores have yet to be identified in L. pneumophila, a mutation of this iron acquisition gene will cut intracellular infection by 80-fold. (7)Studies on intracellular survival of L. pneumophila have shown two chromosomal regions to encode functions that are essential for establishing intracellular infection.

The genes have been designated icm (intracellular multiplication) by one group and dot (defect in organelle trafficking) by the other. Mutation in almost any of these genes results in either a complete loss of cellular infectivity. In all cases, the loss of infectivity is associated with a failure to evade phagolysosmal fusion, as well as a loss of the immediate contact cytotoxicity of L. pneumophila at high rates of infections.

Mutations in several of the dot-icm genes—not just those with sequence homology to known conjugation genes have been shown to terminate plasmid transfer.

These same mutations also result in loss of this toxicity coupled with the insertion of a pore into host cell membranes. The proteins encoded by these loci probably either combine to form the pore or participate in its transfer or both. (7)

Lastly, legionellosis is the infection caused by L. pneumophila and can cause either: Legionnaires' disease, which is characterized by fever, myalgia, cough, pneumonia, or Pontiac fever, a milder illness without pneumonia.

The symptoms of Legionnaire’s disease range from a mild cough and low fever to rapidly progressive pneumonia, coma, and death.

Early symptoms include slight fever, headache, aching joints and muscles, lack of energy or tiredness, and loss of appetite. Later symptoms include high fever, cough, difficulty breathing/shortness of breath, chills, chest pain, common gastrointestinal symptoms including vomiting, diarrhea, nausea, and abdominal pain.

The symptoms of Pontiac fever include flu-like symptoms such as fever, headache, tiredness, loss of appetite, muscle and joint pain, chills, nausea, and a dry cough. Patients usually reach full recovery within two to five days without medical attention and no deaths have been reported. (9)Current Research

Much of the research done on Legionella pneumophila is related to ecology and how it relates to the environment. Some studies compare L. pneumophila to other microorganisms. Other studies look at the cases of Legionellosis and investigate the causes of the outbreaks.

Although several other species of the genus Legionella were subsequently identified, L pneumophila is the most frequent cause of human legionellosis and a relatively common cause of community-acquired and nosocomial pneumonia in adults.

Background

Sections Overview Background Pathophysiology Epidemiology Show All Presentation DDx Workup Treatment Medication Follow-up References Background

Legionnaires disease (LD) was recognized in 1976 after an outbreak of pneumonia at an American Legion convention in Philadelphia. Soon after, the etiologic agent was identified as a fastidious gram-negative bacillus and named Legionella pneumophila.

Background

apy Timely laboratory diagnosis of M. pneumoniae and other causes of atypical pneumonia ( Chlamydia pneumoniae, Legionella pneumoniae, Chlamydia psittaci) usually is not available.

Mycoplasma pneumoniae

M icrobiology Mycoplasma pneumoniae is a Mollicute, a class of bacteria that lack a cell wall. The class includes organisms that are both commensals and pathogens for animals and plants, but the human is the only known host for M. pneumoniae. Lack of a cell wall makes it possible to grow M. pneumoniae in the laboratory on cell-free media only if it is supplemented with sterols and other nutrients provided by yeast extract and animal serum.

E pidemiology M. pneumoniae was first recognized as a human pathogen when it was isolated from adults with atypical pneumonia syndrome ( 9, 12 ). Other causes of this syndrome include respiratory viruses, Legionella species, Chlamydia pneumoniae, and Chlamydia psittaci. M. pneumoniae causes respiratory infection in children of all ages, adolescents, and adults in the second through the fourth decades of life.

Upper respiratory symptoms are its most common manifestation in children less than 5 years of age ( 1, 15, 16 ). Pneumonia due to M. pneumoniae has been shown to be responsible for approximately 20% of the lower respiratory tract disease seen in junior high and high school students and up to 50% in college students and young adults ( 10, 14, 16, 18, 29 ). Prevalence of M. pneumoniae infection may vary according to population and diagnostic methods used. M. pneumoniae infection tends to show cyclic epidemics every 3-5 years; these outbreaks are particularly likely to occur in summer or early fall ( 1, 13, 20, 26 ). C l inical Manifestations M. pneumoniae causes upper and lower respiratory tract infections. The onset is gradual and fever and cough are the most common presenting manifestations. The cough is usually nonproductive and can be prolonged and severe. With the exception of headache, systemic symptoms such as chills, gastrointestinal manifestations, myalgias are uncommon.

Symptoms and severity of illness due to M. pneumoniae was similar in younger and older patients, and the mortality rate was low, even in the elderly ( 4, 28 ).

The Japanese Respiratory Society (JRS) guidelines on CAP included five parameters for differentiation between atypical ( M. pneumoniae) and bacterial ( S. pneumoniae) pneumonia. These parameters were: 1) persistent cough, 2) limited auscultatory findings on chest examination, 3) minimal sputum production, 4) a peripheral white blood cell count below 10,000/mm3.

5) nonsevere co-morbid illnesses. Based on prospective data from 4532 patients with CAP included in the German CAP Competence Network (CAPNETZ), the authors found that patients with M. pneumoniae pneumonia were significantly younger, had less co-morbidity, presented with a less severe disease, showed a lower inflammatory response in terms of leukocyte counts and CRP values, and had better outcomes ( 43 ).

Cao and coauthors also demonstrated that compared with bacterial and viral pneumonia, CAP patients infected with M. pneumoniae were younger, had lower PSI score, and less likely to have adequate sputum for gram stain and culture ( 5 ). Though effective in reducing symptoms, antibiotic therapy does not reliably eradicate shedding of M. pneumoniae.

When initiated within the first 3-4 days of illness, antibiotics are beneficial in both adults and children with lower respiratory tract disease ( 17, 40, 41 ), though their impact on upper respiratory tract symptoms has not been well studied. Shedding of the organism from the respiratory tract may persist for weeks to months, even in patients with minimal or no symptoms, and even after appropriate antibiotic therapy ( 39, 41 ). Extrapulmonary Manifestations: A wide variety of skin manifestations has been reported – the most common being erythema multiforme (Stevens-Johnson syndrome).

Vascular complications include Raynaud’s phenomenon and vascular occlusion with infarction. Cardiac abnormalities have been reported in hospitalized patients with arrhythmias being the most common manifestation. Arthritis, neurological manifestations, hepatitis, pancreatitis, and ocular disease have also been reported.

Most reports are anecdotal and disease is usually attributed to M. pneumoniae on the basis of antibody testing alone; however, isolation of the organism from blood, CSF, synovial fluid, and skin lesions in some patients attests to the fact that dissemination can occur. The pathogenesis of these manifestations is unknown, but immunological reactions and cold agglutinins have been postulated. L a boratory Diagnosis When sputum is available, Gram stain shows leukocytes, but no predominant bacteria. Conventional culture using pleuropneumonia-like organism (PPLO) broth, which requires more than 2 weeks, has not been carried out routinely.

Compared with serologic tests, or molecular techniques, sensitivity of culture may be 60-70% ( 21, 30 ). Culture methods are only used for study of resistance in M. pneumoniae. Serological methods are now frequently used for diagnosis of M. pneumoniae infections.

But reliable diagnosis of M. pneumoniae infections still can not be made on the basis of single acute-phase sera; paired sera obtained during acute and convalescent phases in order to demonstrate rises in antibody titers; fourfold increase is thought to be significant ( 3, 34 ).

Neither culture nor serologic testing can provide timely information for guiding choice of chemotherapeutic agents to use for early intervention.

Cold agglutinins are Ig M antibodies that may appear in the second week of illness. They are detected at a titer of greater than 1:64 in 50-75% of patients with pneumonia due to M pneumoniae, but the test is nonspecific rendering it more of historical value than of clinical utility.

PCR diagnosis is already available in some centers, will become increasingly available, and is likely to replace serodiagnosis in the longer term. Real-time PCR has both high sensitivity and high specificity and can detect pathogen DNA even when damaged by empirical administration of antibiotics.

Sensitivity (60-100%) and specificity (96.7-100%) of real-time PCR are both higher than those of serologic assays for M. pneumoniae ( 11, 19, 34 ). Almost all PCR-positive cases (>90%) also were confirmed serologically ( 31, 34 ). Where available, PCR of sputum or lower respiratory tract sample should be the method of choice for the diagnosis of M. pneumoniae.

In the absence of sputum, a throat swab for M. pneumoniae PCR is recommended. P a thogenesis M. pneumoniae is spread through respiratory droplets and attaches to ciliated respiratory epithelial cells via an attachment protein.

Toxins are produced, leading to ciliostasis and eventual desquamation of ciliated epithelial cells. Macrophages and polymorphonuclear leukocytes contribute to the inflammatory exudates in the upper, and in the case of pneumonia, the lower respiratory tract. S U SCEPTIBILITY IN VITRO AND IN VIVOSingle Drug Intrinsically, absence of cell walls in M. pneumoniae confers resistance to β-lactams.

M. pneumoniae usually are sensitive to all macrolides, ketolides and tetracyclines ( Table 1 ). Macrolide resistant M. pneumoniae isolates possessing a neucleolide mutation in 23S r RNA first were isolated from pediatric patients with CAP from Japan 2001 ( 33 ).

In Japanese adult CAP patients, macrolide resistant strains first were isolated in 2007 ( 23 ). Emergence of macrolide resistant isolates has not been reported not only in Japan, but also in other countries, including France, the USA, Denmark, and China.

A notably high isolation rate of macrolide resistant strains both from pediatric patients (90%) and adult patients (68.7%) was reported in China ( 6, 27) ( Table 2) Tetracyclines are administrated for treatment of M. pneumoniae infections in adults and in pediatric patients > 8 years, but development of resistance to tetracyclines has not yet been reported.

Telithromycin is the first of a new family of antimicrobials, the ketolides, to be approved for use in treatment of community-acquired pneumonia. MICs for minocycline and fluoroquinolones in macrolide resistant strains were equivalent to those in susceptible strains. No strains having resistance to minocycline and fluoroquinolones have been observed among clinical isolates.

However, emergence of infections with fluoroquinolone-resistant M. pneumoniae might occur, considering the increasing use fluoroquinolone prescription rate among adult patients. Combination Drugs Susceptibility of M. pneumoniae to single drug therapy has made it unnecessary to study susceptibilities using combination drugs. AN TIMICROBIAL THERAPYDr ug of Choice Macrolides usually are considered the first-line choice for the treatment of M. pneumoniae infection. Treatment of M. pneumoniae pneumonia with clarithromycin or azithromycin results in clinical benefit equal to that seen with erythromycin therapy ( 7, 8, 37, 38) and a three-day regimen of azithromycin appears to be as effective as five days ( 37 ).

Microbiologic cure has not been carefully compared in these studies, but because the clinical significance of bacteriologic persistence is not known, eradication may not be an appropriate measure for effectiveness. Treatment of M. pneumoniae pneumonia with roxithromycin resulted in good to excellent results in 12 of 13 patients and eradication of the organism in 4 of the 6 patients cultured ( 24 ).

Early studies in adults indicated that both erythromycin and tetracycline were more effective than placebo ( 25) or penicillin ( 35, 39) in reducing duration of symptoms, hospitalization, and abnormal chest x-ray in young adults (military recruits and college students) with M. pneumoniae pneumonia. Etiology was documented by culture and/or paired anti-mycoplasmal antibody response in these studies.

In children less impressive benefits from antibiotic therapy have been demonstrated ( 17, 36 ). Initiation of therapy within the first five days of illness is important for the achievement of maximal benefit. A lternative Therapy At present, there is limited evidence on the clinical significance of macrolide-resistant M. pneumoniae infection among pediatric patients. Suzuki and coworkers showed that the total febrile days and the number of febrile days during macrolide administration were longer in patients infected by macrolide-resistant M. pneumoniae ( 33 ). In this study, duration of therapy and time to resolution of fever were significantly longer in those infected with resistant strains. No clinical improvement was seen 72 hours after initiation of azithromycin in patients infected with M. pneumoniae with MIC ≥ 2μg/ml of azithromycin. When macrolides are ineffective against M. pneumoniae infection, tetracycline or doxycycline are alternative agents. Respiratory tract fluoroquinolones, such as moxifloxacin, levofloxacin, sparfloxacin, and gemifloxacin may be used for adult patients with macrolide resistant M. pneumoniae infections. Fluoroquinolones are not licensed for use in children. E m piric Ther

apy Timely laboratory diagnosis of M. pneumoniae and other causes of atypical pneumonia ( Chlamydia pneumoniae, Legionella pneumoniae, Chlamydia psittaci) usually is not available.

Presumptive antibiotic therapy should be selected based on expected effectiveness against these pathogens as well as against the typical bacterial causes of pneumonia ( Streptococcus pneumoniae, Moraxella catarrhalis, Haemophilus influenzae ). Treatment guidelines for adults with community-acquired pneumonia ( 2) recommend a macrolide, one of the fluoroquinolones with substantial activity against S. pneumoniae, or doxycycline, for patients who do not require hospitalization. Addition of a beta-lactam antibiotic or single drug therapy using a fluoroquinolone with increased activity against S. pneumoniae is recommended for those who require hospitalization.

Clinical trails of t elithromycin indicate that it should be expected to be as effective as the macrolides or the quinolones in treating community-acquired pneumonia. Recommended antibiotic doses are listed in Table 3. E xtrapulmonary Disease The role of antibiotic therapy in treatment of extrapulmonary M. pneumoniae disease has not been well studied. Though immune mechanisms are purported to have a role in hemolysis, CNS involvement, and arthritis, corticosteroid therapy has not been shown to be of benefit.

Underlying Diseases Patients with sickle cell disease have been shown to have more severe and prolonged respiratory tract symptoms when infected with M. pneumoniae than do otherwise healthy individuals. Presumptive antibiotic therapy for community-acquired pneumoniae in such patients should include therapy effective against M. pneumoniae.

Mycoplasmas other than M. pneumoniae have been found to cause arthritis and invasive disease in immunocompromised patients, but underlying immunodeficiency and immunosuppressive therapy have not been consistently found to be predisposing factors for complications associated with M. pneumoniae infection. A D JUNCTIVE THERAPYSymptomatic therapy (non-steroidal anti-inflammatory medications) may be useful early in the course of infection to relieve fever, headache, and sore throat.

Antitussive agents generally provide little relief from the prolonged cough. E N DPOINTS FOR MONITORING THERAPYAntibiotic therapy results in only modest improvement in cough, fever, myalgia, and other systemic complaints compared to untreated infection.

With or without therapy the cough persists well beyond the resolution of generalized illness. As is the case with most causes of community-acquired pneumonia, the chest x-ray may remain abnormal for 4-6 weeks following acute infection. V A CCINESThere is no available vaccine to prevent M. pneumoniae infection. P R EVENTIONMycoplasma pneumoniae infection of household and other close contacts is frequent. Because prophylaxis using tetracycline or azithromycin may be of some benefit in preventing household spread, their use may be considered if such contacts have underlying respiratory conditions or sickle cell disease.

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Simultaneous detection of pathogens in clinical samples from patients with community-acquired pneumonia by real-time PCR with pathogen-specific molecular beacon probes. J Clin Microbiol. 2006;44:1440–6. [Pub Med]3 2. Niitu Y, Hasegawa S, Suetake T, Kubota H, Komatsu S, Horikawa M. Resistance of Mycoplasma pneumoniae to erythromycin and other antibiotics.

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Mycoplasma pneumoniae: Acute illness, antibiotics and subsequent pulmonary function. Arch Dis Child 1984;59:1034-1037. [Pub Med]3 7. Schönwald S, Skerk V, Petricevic I, Car V, Majerus-Misic L, Gunjaca M. Comparison of three-day and five-day courses of azithromycin in the treatment of atypical pneumonia. Eur J Clin Microbiol Infect Dis 1991;10:877-880. [Pub Med]3 8. Schönwald S, Gunjaca M, Kolacny-Babic L, Car V, Gosev M. Comparison of azithromycin and erythromycin in the treatment of atypical pneumonias.

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la. Deadly: A conceptual image of Legionella Pneumophila bacteria, which causes Legionnaires' Disease Scotland's health secretary said the number of cases could still rise, despite a chemical clean-up of the industrial site thought to be responsible.

Fears mount of another Legionnaires' outbreak as toll hits 80 after eight more people are diagnosed with the deadly disease

"Fears mount of another Legionnaires' outbreak as toll hits 80 after eight more people are diagnosed with the deadly disease Leading Legionnaire’s expert claimed cash-strapped firms were deliberately falsifying safety logs and said the practice could have devastating consequences Bacteria thought to have been transmitted via droplets of infected water from cloud of gas rising into the air Health chiefs questioned over delay in investigating all possible avenues Labourer Robert Air, 56, died from deadly bug in Edinburgh Royal Infirmary Tens of thousands at risk as epidemic could spread 44 square miles from source Symptoms include coughing, chest pains, fever and chills By Patricia Kane for Mail Online and Marc Horne Published: 15:03 EDT, 5 June 2012 | Updated: 20:15 EDT, 9 June 201220View comments A further eight people were yesterday confirmed to be suffering from Legionnaire’s disease as the deadly outbreak continued to take its toll.

It means 36 people have now been struck down by the bug – which has already caused the death of one man – with a further 44 in Edinburgh waiting for test results confirming whether they are also infected with the waterborne virus. Of the 80 confirmed and suspected cases, 15 are in intensive care and 27 are in general wards. A further 16 cases are being treated in the community and a number of people have already been discharged from hospital.

Scroll down for video Checks: An Edinburgh distillery yesterday, one of the possible sources of the Legionnaires disease outbreak The new figures came as experts warned of a fresh wave of outbreaks.

They blame cutbacks on health inspectors, coupled with recession-hit companies neglecting safety measures, for creating the ideal conditions for potentially lethal bacteria to thrive. One leading Legionnaire’s expert claimed firms were deliberately falsifying safety logs and said the practice could have devastating consequences.

Public health consultant David Harper said outbreak prevention measures had slipped to dangerous levels and were not policed as rigorously as they should be. He said: ‘Local environmental health officers have been cut back, which means we may see more outbreaks of Legionnaire’s.

When times are tight, maintenance is one of the first things to be cut. This goes right across the board – at hospitals, hotels and any facility which has water systems, air-conditioning or cooling towers.‘Businesses are ticking boxes and saying they are doing all these checks, but in reality not all of them are.

They are gambling with peoples’ lives.’The source of the Edinburgh outbreak has yet to be identified but health authorities believe the bacteria found its way into one of 16 cooling towers in the south-west of the city.

The towers, thought to be responsible for the worst outbreak of its kind for 30 years, have all now been chemically treated.

RELATED ARTICLESPrevious 1 2 Next The girl who can't stop eating: Young woman with rare... Man accused of starving and torturing his daughter, 15, who... Gardeners warned to wash their hands after using compost as... Share this article The first case of the disease was discovered last Tuesday.

The victims range in age from 33 to 76, with men more affected than women. The only link between them is an association with south-west Edinburgh. Last night, a Health and Safety Executive spokesman said: ‘We have maintained the broad number of inspectors and other staff over the past five years.

It is wrong to claim numbers have been significantly reduced.’Yesterday, Scottish Health Secretary Nicola Sturgeon said: ‘The risk to the public remains low. I want to stress this bacteria is not passed on person to person or by drinking water.’A whisky distillery last night found itself at the centre of the Legionnaires’ disease outbreak after failing safety checks on a cooling tower. The North British Distillery Company was yesterday served with an Improvement Notice by the Health and Safety Executive (HSE). The watchdog found the firm’s tower had not been properly treated with chemicals to kill bacteria, including legionel

An HSE statement said the improvement notice does not mean the tower concerned is where the outbreak originated. T he firm has already taken all three of its cooling towers at the site out of operation. Scottish Health Secretary Nicola Sturgeon has said it is 'not always possible to conclusively determine the precise source of an outbreak'.

The dead man has been named locally as Robert Air, 56, from the Seafield area of Edinburgh, who had reportedly been working as a labourer on a building site in Gorgie before becoming unwell.

A nother 14 patients are critically ill in intensive care following the outbreak, with 28 cases confirmed and 46 suspected.

Ten people have now been discharged from hospital. RELATED ARTICLESPrevious 1 2 Next The girl who can't stop eating: Young woman with rare... Man accused of starving and torturing his daughter, 15, who... Gardeners warned to wash their hands after using compost as... Share this article I t can take up to two weeks for people to show symptoms after being infected with the disease. The potentially fatal infection could spread up to 44 square miles from the source, affecting tens of thousands of people. Two patients are being treated outside of the NHS Lothian area - in the Highlands and in the North of England.

Ms Sturgeon said: 'I want to stress that, although these patients are being treated elsewhere, they are considered part of the south-west Edinburgh outbreak.

They have had association with the affected area. Outbreak: A man in his 50s has died and 15 people are in a critical condition after an outbreak of Legionnaires' at the Edinburgh Royal Infirmary'I would hope that over the next few days those investigations will start to deliver more specific answers on where the source of the outbreak might be.

'Legionnaires’ is a potentially fatal lung infection caused by the Legionella bacteria. It is caught by breathing in contaminated water droplets and cannot be spread from person to person. Scottish health authorities believe the bacteria may have found their way into one of several cooling towers in the south-west of Edinburgh. The tower then emitted a cloud of vapour with the bacteria in the tiny water droplets. The outbreak is believed to be the worst of its kind to hit Scotland for 30 years.

Most of the victims diagnosed so far are men aged from their mid-thirties to mid-eighties, mainly living in the Dalry, Gorgie and Saughton areas in the south-west of the city.

All those affected are men and women aged between 33 and 74. A spokesman from the North British Distillery in Edinburgh said: 'Our thoughts are clearly with the families of those affected by this situation.

'The North British Distillery is actively working with the relevant authorities on the matter and supporting their ongoing inquiries to ascertain the source of the Legionella bacteria. A map showing the location of the Legionnaires' disease outbreak'Industrial cooling towers are only one potential source of infection, and the North British Distillery is one of a number of sites in the area with industrial cooling towers.

'The site has been inspected and nothing of concern was found. However, we are awaiting the results of the analysis of the samples taken by Edinburgh City Council Environmental Health Department.

'We wish to reassure the local community that we will comply fully with any guidance issued by the relevant agencies. 'Ms Sturgeon said 16 cooling towers identified as possible sources of the outbreak were chemically treated last week and a fresh round of chemical treatment is under way in the capital.

She said: ‘No link has been identified between these patients other than a general association with the affected area in the south-west of Edinburgh. 'What that does is underline the view that the source of this infection is an outdoor community source and not an indoor-specific source, such as… a spa in a hotel.

Dr Duncan Mc Cormick, chairman of NHS Lothian’s incident management team said: 'We’re doing everything we can in terms of early diagnosis, appropriate treatment and intensive care, but I think we can’t rule out any further deaths at this stage.

'Legionnaires’ is three times more common in men than women and mostly affects the over 50s. The elderly, smokers, and those with cancer, diabetes and kidney disease are also at higher risk.

KILLER BUG SPREADS LIKE WILDFIRE THROUGH WATER SUPPLYLegionnaires' disease is a potentially fatal lung infection caused by the bacteria legionella. The bacteria is commonly found in any freshwater areas but can sometimes find its way into artificial water supply systems.

It is contracted when small droplets of contaminated water in the air are breathed in, but is not spread from person to person. The elderly, smokers, diabetes sufferers, those with kidney disease and cancer patients are most at risk, and men are three times more likely to contract the disease than women.

Symptoms of the disease include headaches, muscle pain, high fever, chills, a persistent cough, shortness of breath, chest pains and sometimes vomiting and diarrhoea. About half of those who contract the disease experience changes to their mental state, such as confusion. Symptoms can start between two and 14 days after exposure. The disease is treated by intravenous antibiotics. Around 10% of people victims will die from arising complications. Large buildings such as hotels, hospitals and museums are more vulnerable to contamination because they have larger, more complex water supply systems, which can let the contamination spread quickly.

Initial symptoms include muscle pain, a fever, a persistent cough, chest pains and sometimes vomiting and diarrhoea.

Although it can be treated by antibiotics, about one in ten patients will die. Once it has infected your lungs, Legionnaires' causes a persistent cough and the coughing up of mucus or possibly blood followed by chest pains, and sometimes vomiting and diarrhoea.

Around half of those with the disease risk changes to their mental state, and may find themselves confused. It is so called because it was identified at a hotel hosting a convention of the American Legion veterans organisation in Philadelphia in 1976. 'I would like to express my sincere condolences to the family of the patient who died,' said Dr Mc Cormick.'

I would urge anyone who develops symptoms of Legionnaires' disease to contact NHS 24 or their GP. 'People who fall into certain risk groups, these are males who are adults, who have an alcohol, drinking habit and have an underlying illness such as diabetes, or heart disease or lung disease - these people are at greater risk. 'These people should be very much aware that if they start feeling symptoms of flu-like illness, together with diarrhoea, cough and confusion, they should be consulting their GP or NHS 24 as soon as possible.

'The first case was identified on Monday May 28, and since then the numbers have soared. Dr Mc Cormick said there was no threat to the city's public water supply. 'The public water supply in Edinburgh is extremely closely monitored and in addition it's not possible to contract Legionnaires' disease through drinking water.

'It's contracted through the inhalation of water vapour in the form of an aerosol and that doesn't and that doesn't happen through drinking water supplies. 'VIDEO: Latest update from Scottish Health Secretary Nicola Sturgeon Health Secretary Nicola Sturgeon update on Legionnaires outbreak Loaded Progress 0:00/0:00Advertisement Share or comment on this article Most watched News videos Embed this Bizarre looking sea creature washes up on beach in Thailand Man is gored to death during the running of the bulls in Spain Dramatic footage shows moment 15-year-old is shot in...

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Russell Crowe reminisces about doing shots of bourbon out of Johnny Cash's 1986 Grammy award with pal Ed Sheeran Advertisement Sporty style! Iggy Azalea keeps it cozy in black sweatpants and satin jacket after meeting with Tyga in LA Looking very very casual on night out Proving them wrong: Sharon Stone, 60, names the two Hollywood icons who told her A-list fame would not last as she enjoys comeback EXCLUSIVE: G'day, old mate!

Prince Charles catches up with a school friend he hasn't seen in 50 YEARS while greeting crowds in Australia Spot on style!

Nicki Minaj covers her curves in polka dot blouse and ripped jeans while jetting out of LAX Went for a noticeably understated look Busy Philipps is overjoyed to locate her daughter's lost stuffed bear, days after sharing her distress when she realized she'd left him behind in a Hawaii hotel Amelia Gray is joined by mother Lisa Rinna on beach in Mexico after the teen revealed she used to be anorexic Praised for being 'strong' and talking about it Laura Prepon and Ben Foster debut their baby for very first time during NYC stroll The 38-year-old actress gave birth to daughter in summer of 2017Timeless star Abigail Spencer flaunts beach body in black swimsuit on getaway with beau Josh Pence The couple looked smitten with each other Duff Goldman is engaged to girlfriend Johnna Colbry... and proposed to her using butcher's twine Took to Instagram to hearken the news Stella Mc Cartney nails off-duty chic as she wraps up in a grey jacket and blue jumper for flight to LAX Proved her own sartorial credentials Advertisement Zoe Saldana reveals husband Marco Perego is 'part of the #Me Too group' as she says she's had to 'work harder' in Hollywood due to her race Jenny Mc Carthy flaunts her bright blue hair as she carries her beloved pet pooch in a Louis Vuitton bag in New York Making a bold statement Amber Heard shows caring side on Syrian refugee visit and says they reminded her of 'real strength' Star visited the Zaatari Refugee Camp Prince Charles and Camilla make a secret stop on their Australian jaunt - but you'll never guess where they chose to visit They went to a farm Lucy Hale showcases hint of svelte torso in eye-catching sportswear as she hits the gym in style Snapped while leaving the gym Prince Philip's hip operation is to get in shape for Harry and Meghan's wedding... and the Royal Windsor Horse show Otherwise in fine health Bikini blogger Devin Brugman displays her eye-popping cleavage and enviable curves in tiny two-piece as she soaks up sun in Tulum, Mexico EXCLUSIVE: Colin Farrell checks into Arizona rehab center after celebrating 12 years of sobriety to seek help 'before going down rabbit hole again'Selena Gomez leaves Pilates class carrying bible... as former flame Justin Bieber 'wants her back' As it's revealed Justin Bieber 'misses her'Ricky Gervais dresses down in a gray fleece and jogging bottoms... after thanking fans for 'overwhelming' praise for Humanity stand-up special Advertisement Gwyneth Paltrow and Chris Martin PICTURE EXCLUSIVE: Friendly exes enjoy a casual stroll in Paris Continued to prove they are friendly exes Stocking up on baby brands?

Heavily pregnant Kate is spotted loading grocery bags into her Range Rover after stopping off at a store in Norfolk Amal Clooney steps out in a leather trench as she leaves Columbia Law School after stint as visiting professor The 40-year-old looked typically chic'This smacks of Kendra missing the spotlight': Wendy Williams BLASTS Kendra Wilkinson over Hank Baskett split Talk queen sounded off Tyra Banks poses proudly with her mother after admitting to undergoing nose job in candid memoir The mother-daughter team posed proudly Producer claims 'very powerful people' tried to stop his movie about Chappaquiddick when Ted Kennedy crashed his car and left a young woman to drown Leighton Meester unveils stunning new platinum blonde lob after seven-hour salon visit Spent seven hours with a color specialist Revealed: Queen Elizabeth's grandson Peter Phillips was paid $1million for overseeing monarch's 90th birthday street party in London Princess Anne's son Ronnie Ortiz-Magro of Jersey Shore and girlfriend Jen Harley welcome their first child together Reality star is officially a father to a baby girl Vivica A Fox says she needed to develop 'thick skin' and be 'scrappy' to survive in Hollywood Dished on life lessons, previous jobs, and advised the audience Teen Mom's Maci Bookout accuses ex Ryan of 'threatening to hurt her' after showing up at son's little league game 'under the influence of [heroin]'Did her love for Hollywood and his Alabama roots create a divide?

Jenna Dewan hit Oscars party solo while Channing Tatum stayed away Tori Spelling posts fun throwback images to wish Beverly Hills, 90210 pal Jennie Garth happy birthday They both look very toned and slender Kate Winslet seen with husband Ned Rocknroll and son Bear at the airport in New York as they take night-flight together Wrapped up warm Kourtney Kardashian, 38, looks happy during Big Sur trip with beau Younes Bendjima, 24 The 38-year-old reality star shared makeup-free pics hiking in the woods'I'm 46 - and I don't mind looking 46': Savannah Guthrie insists critics won't stop her aging gracefully - but admits she 'isn't above' more Botox Don't give up on marriage Kylie - just give up on second-rate men!

As singer Minogue, 49, says being a bride isn't for her we look back at her past relationships Azealia Banks smiles as she leaves NYC courtroom during two-year long 'boob-biting' case She bit the breast of a nightclub bouncer'It blows, but I'm stuck!'

Married at First Sight star whose spouse of six weeks refuses to have sex admits he hates being 'constantly rejected''Ariana Grande is the rudest celebrity!'

Cover Girl's first male spokesmodel accuses popstar of 'BULLYING' after she unfollowed him after 'racist' tweet Jennifer Lawrence shows toned stomach in crop top and loose pants to bar hop with gal pal in New York The 27-year-old actress was ready for a night out Halsey says she and rapper boyfriend G-Eazy rely on each other in 'moments of self-doubt' during Wonderland interview Talking to Wonderland As Coachella kicks off next Friday, FEMAIL rounds up the top four celeb-inspired festival looks to have YOU hitting this year's music circuit in style Stranger Things creators Duffer brothers SUED over claims they stole the idea for their Netflix show Writer Charlie Kessler claimed in new lawsuit EXCLUSIVE: Relieved Chelsea Clinton takes three-year-old daughter Charlotte to school after tweeting about 'a small health scare' with her 'little loved one'Kim Kardashian is 'shocked' North is so 'warm' with her baby sister Chicago and 'loves' her so much 'They love her,' said the star Kylie Minogue's ex Joshua Sasse makes thinly-veiled dig at singer in cryptic post... as she admits to 'breakdown' over split Hitting back Vanessa Trump is pictured on school run in NYC after putting on brave face for cameras at White House Easter Egg Roll with estranged husband Don Jr Shopping for a new arrival?

Princess Caroline of Hanover's daughter-in-law Tatiana Santo Domingo debuts 'bump' amid rumors she is pregnant Jessica Alba sports white coat as costar Gabrielle Union dons camouflage jacket on Bad Boys spinoff Beuautiful pair were on set in Los Angeles Kendall Jenner rides a horse in front of picturesque Château de Chambord in France She recently revealed that horses help her with her anxiety Emily Ratajkowski parades her enviable cleavage in a plunging green swimsuit as she puffs on suspicious-looking cigarette in racy snap Adele got ORDAINED to marry comedian pal Alan Carr and his boyfriend Paul Drayton in the backyard of her Los Angeles home Singer played priest Jay Z reveals he 'cried' after his mother Gloria came out as gay because he was thrilled to see her happy Rapper was talking to David Letterman Brielle Biermann goes 'back to blonde' after splitting from pro baseball player beau Michael Kopech Change can be a good thing Kylie Jenner is nearly unrecognizable in top ponytail, thick eyebrows and red lips to plug makeup Excited for new product to come out Porn star Ron Jeremy crashes car outside a Hollywood bar days after being cleared of sexual assault Had his eyes checked with a torch by an officer Get ready for Meghan Markle's FIRST trip down the aisle!

Details of Suits star's on-screen wedding revealed, as show creator vows a 'happy ending'The Walking Dead's Jeffrey Dean Morgan sports new wild and bushy beard as he talks about delivering his two children on Jimmy Kimmel Padma Lakshmi rocks black leather jacket and tight white sweater dress ahead of Wendy Williams Show The 47-year-old headed into NYC studio Tiffani Thiessen, 44, tells Harry Connick Jr she had a crush on him during Beverly Hills, 90210 era The then teen was crazy for croooner Selma Blair tears up as she recalls first love who died suddenly in college on Hollywood Medium The 45-year-old actress turned to Tyler Henry Cops rush to home of Austin Powers star Verne Troyer after friend calls 911 saying he is 'drunk and suicidal' Star was taken away for a medical examination The Corrs singer Andrea, 43, flaunts her abs in skimpy bikini as she enjoys Barbados holiday with her children Showcased her envy-inducing figure Queen of the snack aisle!

Video of a young Meghan Markle starring in a Tostitos chips commercial at start of her caereer resurfaces online Model Kaia Gerber, 16, returns to work in Paris following Miami break after walking 22 shows this year Kaia Gerber, 16, was seen arriving in France Flood hell for Clooneys: Star's Thames-side home is swamped by the river as rain soaks Britain (but don't worry George, spring weather is on way)The Upper East Side bolthole where Matt Lauer learned he was being FIRED from Today is being sold by the disgraced anchor for $7.35MControversial You Tube star Logan Paul is cited by Yosemite park rangers after he and his friends are caught sitting in tents on top of his modified school bus Channing Tatum and Jenna Dewan split: Inside the couple's make or break vacation... four months before announcing their shock separation Lisa Rinna's daughter Amelia Gray 'happy' after fans call her 'brave' for sharing anorexia struggle Teen opened up about eating disorder Lily-Rose Depp and Ash Stymest split: Actress calls it quits from her British model beau of two years Johnny Depp's 18-year-old daughter Romee Strijd seems to have bad day as Victoria's Secret model pouts in New York City with boyfriend Laurens van Leeuwen Wore animal print coat Tessa Thompson glams up in nude chiffon gown on carousel... and discusses Westworld and Thor roles Returning as Valkyrie?

Kim Zolciak shares picture of x-ray featuring heart device more than two years after she suffered a mini-stroke Star took to Instagram Abby Lee Miller sports Dance Moms shirt at halfway house after losing 100lbs following prison stint Reality star, 52, covered up her new figure Cardi B hits back at model suing her in $5 million lawsuit for unauthorized image of him on album She is being sued by model Kevin Brophy Melissa Mc Carthy tells AARP magazine it's 'dumb' to focus on women's bodies so much... after losing 75lbs Actress spoke out EXCLUSIVE: Jane the Virgin actress Greice Santo gets a thumbs up from producer David Foster as she releases first single aimed at empowering women Kendall Jenner draws attention to her slender frame in fitted black corset as she steps out in Paris The statuesque model was in high spirits'Seeing skin is sexy!'

Online fitness star with 30 MILLION followers reveals key to her body confidence as she flaunts toned physique in Guess campaign Amanda Seyfried proves she's a natural beauty as she goes makeup-free to friend's LA party Recently celebrated her daughter's first birthday Queen Elizabeth's husband Prince Philip, 96, is admitted to hospital for planned hip surgery after missing three public appearances in 10 days Jenna Dewan and Channing Tatum SPLIT: Couple announce their nine-year marriage is over in a shock statement 'Lovingly' separated Nina Agdal goes NAKED: Leonardo Di Caprio's model ex displays envy-inducing figure in sexy woodland snap Stripped off for shoot Julianne Hough is sporty stylish in all black as she gets in an early morning workout in LA DWTS judge looked naturally gorgeous Gigi Hadid flashes toned midriff in sheer leggings and cropped sweater on New York outing The recently single star looked cheerful Game Of Thrones star Sophie Turner wraps up for low-key outing with fiancé Joe Jonas as they take their pet pooch Porky for a walk in London'I am still in love': Barbara Bush gives a rare and intimate glimpse into her 72-year marriage, as she pays tribute to her 'thoughtful and loving' husband Jenna Dewan hinted at marriage strain weeks before split from Channing Tatum... amid claims he moved out of family home MONTHS ago Bryan Cranston 'doesn't miss playing Walter White' but Aaron Paul is 'open' for Breaking Bad prequel Much loved show Bob Marley's granddaughter Zuri, 22, flashes bra in provocative V Magazine shoot as she discusses plans to forge her own path in music industry Rob Kardashian 'fears for daughter Dream's safety' after Blac Chyna's Six Flags brawl and romance with teenage rapper Expressed his dismay Advertisement DON'T MISSCrown Princess Mary of Denmark offers her youngest son a reassuring hug on the Swiss slopes as the Danish royals descend on glitzy Verbier Film industry pioneer behind Picnic At Hanging Rock Gil Brealey dies aged 85 following a glittering four decade-long career EXCLUSIVE: 'They're nice people, but they don't know anything!'

How Ivanka and Jared were ridiculed by White House staff for being 'all puppies and rainbows'Halle Berry, 51, is doting mom as she enjoys magical day out with her son Maceo, 4, at Disneyland Pair had fun time at California theme park Furious Bella Hadid hits back at 'jealous' troll who accused her and best friend Kendall Jenner of having plastic surgery Social media spat Will Ferrell calls Joaquin Phoenix 'a little b**ch' during outrageous magazine interview Talking about his role in Gladiator His royal high-trot!

Prince Edward heads out on a hack with daughter Lady Louise at Windsor castle after joining the royal family for Easter celebrations Melrose Place star Jamie Luner, 46, accused of sexually assaulting a 16-year-old boy in 1998 along with her male makeup artist by drugging him EXCLUSIVE: 'Friend' of Bill Cosby sex accuser Andrea Constand is approved to be witness for the DEFENSE as jury selection for comic's retrial continues Fashion's 'ice queen' dethroned?

Anna Wintour is set to 'leave her job as Vogue Editor-in-Chief this summer' - after 30 YEARS at the helm Chanel comes under fire for using Cindy Crawford's 'barely dressed' daughter Kaia Gerber, 16, to star in its latest handbag campaign'Back to reality': Hugh Jackman laments last night in paradise as he watches the sunset with his wife Deborra-Lee and two children Going 'back to reality'Is Duchess Kate expecting a boy?

The baby clues behind the royal bumps... and how Prince Edward's wife Sophie Wessex proved one theory'I was exhausted, disillusioned, and totally in shock': Jessica Biel reveals trauma of giving birth to son Silas by emergency C-Section Plans fell apart'We had a small health scare tonight': Chelsea Clinton reveals one of her two children had to be treated after suffering a sudden illness Blake Lively dazzles as she joins Ryan Reynolds at A Quiet Place premiere after laughing off claims of marital trouble Put on a devoted show King Juan Carlos of Spain is joined by his wife and son King Felipe as he marks the 25th anniversary of his father's death with a royal mass Hoda Kotb reveals she was bullied over her 'frizzy hair, glasses, and weird name' as a girl - but says embracing her flaws enabled her to 'get all her blessings'Sofia Richie wears platform boots for lunch date with her dad Lionel's girlfriend Lisa Parisa Wasn't done with family obligations Aziz Ansari is spotted for the first time since woman, 23, gave polarizing interview claiming the Master of None star left her feeling 'violated'Naomi Watts, 49, showcases her incredible swimsuit body and make-up free complexion as she holidays in Mexico Beach break Emily Blunt's pregnant sister Felicity joins husband Stanley Tucci at A Quiet Place premiere in New York City Happy couple Christie Brinkley's daughter Alexa Ray Joel flaunts her VERY ample assets in a low-cut lacy black top as she steps out in New York for dinner Meghan's Monaco muse!

Bride-to-be takes inspiration from Princess Charlene's love of sleek tailoring, black pants and modern royal style Bust move! Kim Kardashian flashes cleavage in plunging top as she rocks massive shades on Instagram She has long enjoyed playing up her curves Surprise!

Free Willy's 11-year-old child star Jason James Richter is thrust back into the spotlight for the 25th ANNIVERSARY of the epic movie The countdown begins!

Meghan Markle's mom looks busy outside her California home as the soon-to-be newlyweds sit out Easter services with Queen Elizabeth Blac Chyna promotes marijuana pipe and says she's going to 'chill' after Six Flags altercation Caught in amusement park fight controversy Aubrey Plaza turns heads in plunging black velvet dress for Legion season two premiere after being linked to Justin Theroux Stunning Iggy Azalea says we should 'stop assuming everyone's into monogamy' as she discusses 'complex and fluid' relationships Romance on the brain Ted Nugent doubles down on David Hogg attacks: NRA board member calls Parkland shooting survivor 'brainwashed' for his gun control views Katy Perry ends her playful 'love triangle' on American Idol as singer Trevor Holmes fails to reach top 24 The 33-year-old pop star played up her heartbreak They're back!

Chloe Kohanski, Chris Blue and other past champs return to The Voice as special advisers for Knockouts Helping contenders Playboy model Carla Howe flashes major sideboob as she goes braless in glittering pink dress in London She always turns heads on a night out'It felt like I didn't get a chance to say goodbye': Sterling K Brown reveals his secret agony as he accepts historic SAG Award He lost his father Jenna Dewan marriage split: Actress still wears wedding ring hours before announcing separation from husband Channing Tatum Things are heating up!

Demi Lovato locks lips with Kehlani during steamy bed serenade at New Jersey concert Tour has proven to be on the raunchy side Vanderpump Rules: Kristen Doute and James Kenndy argue after 'hooking up' rumor spreads in Mexico Extremely volatile relationship Jenna Dewan and Channing Tatum split: Internet goes into a meltdown as Hollywood couple announce the end of their nine-year marriage Viola Davis scares off burglars during attempted break in at her home Actress has been 'left shaken' following the home invasion Glee star Chord Overstreet buys a bouquet of flowers as he steps out after confirming Emma Watson romance Smitten'Queen of festival style!'

Elsa Pataky cuts a bohemian figure in a cleavage-baring top and Acubra hat as she attends Bluesfest with her kids PICTURE EXCLUSIVE: Tom Hardy shaves his head in preparation for his Al Capone biopic which begins filming soon Chicago gangster Piers Morgan and Joan Collins pose for a snap as they enjoy a double date night with their respective partners in Los Angeles Joining forces Justin Theroux goes solo to afterparty for A Quiet Place in New York City... after being linked to Aubrey Plaza following split from Jennifer Aniston Keri Russell turns heads in furry hat and leopard print boots to as she pays a visit to Apple Genius Bar for tech help Seeking assistance Make-up free Ariel Winter ditches the glamour as she goes shopping in all-white ensemble in Los Angeles Dressed down Blac Chyna's Magic Mountain meltdown 'leads Kardashian family to worry about Dream's safety' TV clan's 'biggest concern is Dream Dwayne 'The Rock' Johnson reveals he's got a crush on Oscar-winning actress Frances Mc Dormand... and plans to MARRY her Unlikely pair April Love Geary bares cleavage in selfie as she shares video of Robin Thicke cuddling baby Mia She left little to the imagination Rebel Wilson makes a stylish arrival in chic pastel coat as she enjoys dinner date at Craig's with a male friend Dining in style Selma Blair has no hard feelings on losing out to rival actress Katie Holmes for Dawson's Creek role of Joey Potter Iconic role Winnie Harlow prides herself on being part of the 'big shift' with beauty standards in the fashion industry Covers ELLE Magazine's April issue Rock with you!

Paris Jackson looks hippie chic for lunch date with Gary Oldman's son Charlie in Hollywood She beats to her own drum just like her dad Making some noise!

Emily Blunt looks stunning in strapless dress as she's joined by John Krasinski at NYC premiere of A Quiet Place Jersey Shore meets Geordie Shore: US and UK reality stars unite for a booze-soaked trip on the London Eye Snooki, JWoww and Pauly D were flying flag Zayn Malik divides fans as he reveals cropped green hair and matching contact lenses in heavily filtered social media post Gigi Hadid's singer ex'Her boyfriend ran up and hit me': Blac Chyna's teenage beau YBN Almighty Jay 'punched woman' during Six Flags altercation Shock allegations Blac Chyna was provoked into Six Flags melee after woman called her 'hood rat' after touching Dream The 29-year-old was set off by the derogatory term Billie Lourd pays tribute to her late grandmother Debbie Reynolds on her 86th birthday with sweet Instagram post Family ties'She lived a good life': Jennifer Garner posts touching tribute to her deceased pet chicken Regina George on Instagram Sad moment Sun smart!

Hugh Jackman covers up from head-to-toe during a break on a tropical island... after revealing he's undergone six skin cancer scare surgeries Alec Baldwin, 59, wears pink bunny ears on Easter outing with his pregnant wife Hilaria, 34, in New York City Getting into the spirit Blake Lively is feminine in floral as she takes her daughter to Martha Stewart's annual Easter lunch Made the prestigious guest list Nicky Hilton wraps her slender stems in shiny black leggings and covers up in a beige faux fur coat while prancing around town with a pal Tiger Woods embroiled in legal battle with his ex-girlfriend days before Masters 'over NDA she signed when they broke up after he cheated on her'Who's that girl?

Tobey Maguire and mystery woman in a crop top emerge from workout at LA gym He stayed hydrated with a water bottle in tow Troubled RHOBH star Kim Richards owes $118k in back taxes to the State Of California The reality persona, 53, was served liens for the years 2013 and 2014Mel B divorce: Family brands Spice Girls singer a 'liar and a narcissist who refused to visit her dying father' Accused of ignoring repeated requests Candice Swanepoel EXCLUSIVE: model shows off baby bump in cheeky red bikini on vacation with family Looked completely at ease Jessie James Decker welcomes her THIRD child with football star husband Eric Decker The Eric & Jessie stars are already parents to a boy and a girl She believes in her dad!

Chrissy Teigen's adorable daughter Luna smiles on family outing with Jesus Christ Superstar sensation John Legend Leonardo Di Caprio's ex Toni Garrn flaunts fit figure... day after going topless during Miami trip Sported a blue Solid And Striped swimsuit Jenna Fischer hollers at waiting fans as she arrives at Jimmy Kimmel Live!

taping in statement red blouse and low-key jeans Casual Eliza Coupe and health guru husband Darin Olien getting divorced after nearly four years of marriage The 36-year-old actress wants to end marriage She's a real Sinner!

Selena Gomez leaves Pilates with bible in hand while wearing a sweatshirt with a religious message Working on her spirit Lisa Rinna's daughter Amelia Gray reveals past struggle with anorexia as she posts a bikini photo The budding model looked fantastic Chest amazing!

Cardi B takes the plunge as she canoodles with Offset in new Bartier Cardi music video The star was looking fantastic Kendra Wilkinson and Hank Baskett pictured WITHOUT their wedding rings as he moves out of their home Confirmed the split at the start of the week Taylor Swift's accused stalker sentenced to 10 years probation for violating protective order Must remain a mile away from the star Karlie Kloss reveals she has 'really amazing friendships'... but forgets to mention BFF Taylor Swift Victoria's Secret angel made glaring omission Rita Ora dresses as a sexy Easter bunny as she eats chocolate eggs in underwear and playful rabbit ears Looking sexy in a small t-shirt'I've blown it': Keith Urban 'desperate to return to The Voice Australia... admitting that leaving the show for American Idol was a big regret'Kiss me quick!

Jordana Brewster smooches producer husband Andrew Form at A Quiet Place premiere in NYC Getting close Jared Leto gets swarmed with fans while promoting his band Thirty Seconds To Mars' new album America Multi-talented Instinct showrunner apologizes for episode with 'unintentional' parallels to former Fox show Bones Explored the murder of an Amish teen Kendra Wilkinson CONFIRMS she is splitting from husband Hank Baskett in tearful Instagram post '10 years.

I did everything I could,' she said in clip Lunch date with mom and dad! Natalie Portman rocks hoodie and black leggings as she takes her parents out for breakfast date Completely relaxing Not so Humble abode!

Kendrick Lamar purchases $2.65million mansion in Calabasas... but only as an investment Compton native Kaia Gerber makes a splash in a red twist-front bandeau bikini during Miami family vacation Refreshing dip at the W South Beach pool A-Thor-able!

Chris Hemsworth dotes on his young children who carry toy hammers like his famous Marvel character as they hang out at the beach'No way!'

Selena Gomez would 'NEVER' have asked The Weeknd to donate a kidney for her life-saving surgery Clarified the speculation after singer's new song Alice Cooper, 70, reveals how he almost hanged himself on stage in gallows stunt gone wrong Almost died during London show in 1988Ed Sheeran seeks to toss lawsuit claiming he 'stole' Faith Hill and Tim Mc Graw hit Rest Of Our Life The British star said it was completely his Famous friends!

Late INXS rocker Michael Hutchence's daughter Tiger Lily enjoys night out with Australian musician Nick Cave's actor son Earl A beautiful tribute: MAC Cosmetics is set to launch a make up line inspired by singer Aaliyah, 17 years after the R&B star died in a tragic plane crash Is Meghan's father swotting up on UK before the big day? Thomas Markle is pictured with a British guidebook as wedding preparations heat up Kelly Brook on body confidence: Model reveals she is happier than ever with her figure and isn't bothered by 'saggy boobs' or weight gain Sarah Jessica Parker, 53, is youthful in grey as she plays salesperson at opening of NYC pop-up shop Channels her inner Carrie Bradshaw'I was in shock.

She really just came for me': Woman 'attacked' by Blac Chyna with stroller at Six Flags claims she only patted Dream's hand Tiffany Trump looks pretty in a pastel pink coat as she joins her dad at White House Easter Egg Roll while Ivanka skips event for family break in Wyoming Kylie Minogue, 50, admits to having a nervous breakdown after splitting from her fiance last year... but decides her time for marriage has passed Tennis legend Boris Becker's wife Lilly, 41, showcases her curves in a skintight white swimsuit as she takes a dip in Miami Looks a beach babe Katy Perry flashes Jesus tattoo on her wrist on Easter Sunday amid real estate row with nuns The 33-year-old star is the daughter of pastors'You'd die if I told you who it was!'

Kaley Cuoco reveals she dumped famous ex because he was such a bad TIPPER - so just who is her 'cheap' ex?

Roseanne reaches 25 million viewers for its debut episode... six million more than first anticipated Rebooted show has been a big hit Karlie Kloss makes rare sighting with beau Joshua Kushner... after revealing why she's so 'private' They have been dating since 2012Mathew Knowles 'laughed so hard' when he saw 'firecracker' daughter Solange fight son-in-law Jay-Z Addressed a certain infamous family feud Andie Mac Dowell, 59, has 'no shame' with sex scenes in new film and 'yoga, sleep' keeps her a size 4 Actress romps with Chris O'Dowd in flick Lisa Rinna, 54, displays toned figure in skimpy orange bikini after Real Housewives of Beverly Hills fight Actress took to Snapchat to show off body Double twinning!

Jessica Simpson matches floral dresses with daughter Maxwell as Eric and Ace also pair up in cute Easter family snap Arnold Schwarzenegger tweets 'I'm back...

I woke up' and says he is 'filled with gratitude' after emergency open-heart surgery Khloe Kardashian wants her daughter to inherit her famous 'butt'... as well as her 'business savvy' Reality star's kid is due any day now Kathy Griffin is back on US tour after strong reaction to her photo of a bloodied Donald Trump head...which she plans to laugh about her shows Kim Kardashian says pregnant Khloe is too 'freaked out' to hear about 'nipples, breastfeeding' She also said that they are closer than ever now Jennifer Lawrence sports leather cap and long blazer on an afternoon walk with her dog in New York Actress ept warm in the brisk spring weather Today co-stars Jenna Bush Hager and Hoda Kotb whisk their kids away, as Savannah Guthrie celebrates with her family at home in New York Kyle Richards, 49, proves she's still a pinup as she poses in string bikini for eye-popping selfie Real Housewives Of Beverly Hills star Hilary Duff celebrates Easter by throwing a lavish dinner party for her pregnant older sister Haylie Siblings shared Instagram snaps Tori Spelling celebrates Easter with her family... after 'mental breakdown' and three police calls Actress-turned-reality star is 45 next month'I do have sympathy': Bachelor's Arie Luyendyk Jr apologizes after being slammed for April Fools gag involving 'pregnant' fiancee Lauren Jamie-Lynn Sigler wraps her arms around newborn son Jack as she enjoys downtime with family in LA She gave birth to her second child in January Nina Agdal shows off her model frame in racy bras and briefs as she poses for sizzling lingerie shoot with Leonisa Sizzling photos Lucy Hale models chic hoodie as she carries dog at LA airport... after visiting family in Memphis Adorable two-year-old Maltipoo Elvis Love on the lawn!

Trump praises First Lady Melania for organizing Easter Egg Roll at the White House and gives her a kiss for the cameras Sting and Shaggy are branded 'drunk dads at a wedding' as Lorraine viewers go wild for their 'random' collaboration on British daytime show Tia Mowry dons flowing pink frock over pregnant belly for family-filled baby shower in Beverly Hills The 39-year-old actress was all-smiles Rory Mc Ilroy, a Canadian hockey star and top chef: New book looks into Meghan Markle's rumored past romances before she met Prince Harry Why YOU won't be able to live without one of these A-list-approved jackets that are so hip even likes of Alessandra Ambrosio and Gigi Hadid can't resist them Ashley Olsen catches up with her old pal Jonah Hill during Easter stroll in New York City The were spotted out and about in the chilly city with a gal pal Leslie Mann says daughter is 'talking about' dropping out of college but insists she can 'teach her everything she needs to know'EXCLUSIVE: 'Melania knows who the bulls*** artists are and the guys looking out for themselves and not Trump - and she lets him know'Incredible footage shows Blac Chyna appear to throw Dream's stroller at woman before being held back during huge melee at Six Flags park Nearly 100 potential jurors are cut from Bill Cosby's sex assault retrial as dozens reveal they already have an opinion on comic's innocence or guilt John Legend leaves NYC with Chrissy Teigen and their daughter Luna in a silk robe... after winning performance in Jesus Christ Superstar Live'It was like the least surprising thing!'

Seth Rogen says porn star Stormy Daniels told him about alleged Donald Trump affair over a decade ago Justin Theroux hugs Paul Rudd in NYC... as 'he has barely spoken to Jennifer Aniston since split' Newly single actor was dressed casually Donald Trump Jr and estranged wife Vanessa smile and laugh as they put on a united front while taking their kids to the White House Easter Egg Roll Hair-raising!

Jared Leto, 46, sports vibrant colorful blue track pants and a seriously shaggy beard for an afternoon stroll in New York City Willow Smith celebrates Easter by wrapping her long dreadlocks in beautiful pastel-colored ribbons Will and Jada's daughter is now 17'I feel like an a**hole': Busy Philipps breaks down in TEARS as she admits she left her nine-year-old daughter's beloved teddy bears in a Hawaii hotel Alessandra Ambrosio and ex-fiance Jamie Mazur spent Easter together for sake of their two kids She recently split with her fiance of 10 years Jennifer Lopez and Alex Rodriguez: Superstar couple hold hands as they enjoy Easter dinner date in West Hollywood Dined at Craig's Doutzen Kroes admits she's 'lucky' she was born beautiful as she says modeling biz is 'calculating' She is one of the world's leading fashion models Gigi Hadid nails casual dressing in a beige jacket and roll neck jumper as she tackles the snow in New York Didn't let a touch of wintry weather get in the way Bikini-clad Elsa Pataky, 41, shares a kiss with hubby Chris Hemsworth as he grabs her pert derrière on the beach in Australia with Matt Damon EXCLUSIVE: Did Liev Schreiber's girlfriend skip March For Our Lives because she's pro-gun?

Photos show beauty queen and family posing with rifles Blac Chyna says she's 'all love' and posts video of daughter Dream hugging her brother at Six Flags just moments before she THREW a stroller at a woman'A perfect morning!

': Makeup-free Jennifer Garner leaves Ben Affleck with the kids as she hikes with a cute blonde pal in the hills of Hawaii Farrah Abraham sports baby blue floral dress and slides for Easter brunch with nine-year-old daughter Sophia in Los Angeles Made a cute duo REVEALED: Don Jr. and estranged wife Vanessa spent Easter TOGETHER with kids as his alleged ex- lover Aubrey O'Day marks holiday with sassy pics Romeo Beckham, 15, gets private tennis lesson with former World No 1 Caroline Wozniacki in Miami David and Victoria's teen son Meghan Markle's tortoiseshell sunglasses are FINALLY back in stock - six months after they sold out when she wore them on her first official outing with Harry'It's powerful, but simple': Hugh Jackman reveals the secret behind his unbreakable marriage to wife Deborra-lee Furness as they celebrate 22 years She can't stop!

Miley Cyrus goes braless in see-through dress and gets spanked by the Easter bunny in risque videos Sexy photo session Drake sports 'album hour' dark circles under his eyes... as his legal battle with Detail heats up R&B star grabbed a bite to eat in Calabasas Inside the decadent Kardashian-Jenner Easter: KUWTK stars celebrate with gold eggs, a 10ft tall flower bunny and a CASH HUNT for the kids Chrissy Teigen brings up Bill O'Reilly's sexual harassment settlement as she hits back at the former Fox News host for mocking NBC's Jesus Christ Superstar Daddy's little girl!

Bradley Cooper kisses one-year-old daughter Lea at Easter party with model mom Irina Shayk Easter party in Brentwood, California Today's headlines Most Read Immigrant You Tube shooter went to a gun range HOURS before opening fire on tech campus with her legally held... Pictured: Lesbian mom caught on camera buying groceries just hours before driving her car off a cliff... White House declares mission to crush ISIS in Syria is 'coming to a rapid end' but WON'T say when the 2,000... Mark Zuckerberg admits Facebook scans the contents of ALL your private Messenger texts in the latest blow to... Stormy Daniels' lawyer demands the Treasury release details of a $130,000 payment she received from Trump's... Markets plunge on news of China's tit-for-tat 25 per cent tariffs after Trump insists America 'can't lose'...'He choked me to the point I couldn't breathe': Cop recounts how pastor and his wife attacked him as he...'My heart is broken - the system failed to protect these children': Woman who reported lesbian couple for... Facebook finally lets you remove third-party 'vampire apps' in BULK to prevent them from using your data:...'What's up, Chapo?'

Former DEA agent reveals what he said when he caught the notorious drug lord in 2014 as... Coach brother of two-time taekwondo gold medalist Steven Lopez is banned for sexual misconduct with a minor Ryan Murphy AXES plan to feature Bill Clinton, Monica Lewinsky sex scandal on American Crime Story Wonderful moment delighted baby elephant can be heard GIGGLING with joy as she plays with her keepers Atlanta parents sue after claiming their special needs son, 16, was raped in a bathroom by a student who... Mystery of how birds navigate is solved: Scientists discover eye proteins that allow them to SEE the Earth's...

Growing up on the lam: Drug smuggler's daughter reveals the reality of a childhood on the run - living in 13... Facebook refuses to promise strong European-style privacy protections for US users as it continues to battle... Fed up with Facebook? Take a 5-day break: 'Vacations' from the scandal-hit site reduce people's stress... Young couple 'ran a $240-an-hour BROTHEL for ""older generous gentlemen"" out of their home where three young...

Experts warn NYC could come down like a house of cards if a 5.0 earthquake struck along the 125th Street... Is YOUR sex style out of date?

Tracey Cox reveals the raunchy trends WOMEN are bringing to the bedroom -... Suspect in You Tube headquarters rampage becomes only the TENTH female active shooter since 2000Donald Trump Jr attacks You Tube for deleting the 'liberal vegan' shooter's online profile - and suggests the...'After Las Vegas, Parkland and Pulse you would have thought we'd see the end of this': Doctor who treated... You Tube shooter quoted Hitler in chilling rants about free speech, attacked the site for bilking her and... Quick-thinking Carl's Jr supervisor, 21, saved woman shot in You Tube attack by making a tourniquet from a...'Child abuse, lies and MURDER': Inside the desperate world of You Tube wannabes who think they will become...'The cops didn't do their job': You Tube shooter's brother blames police who released his sister hours after... Twitter CEO slams Trump for sending 'thoughts and prayers' after You Tube shooting and calls on president to... MORE HEADLINESAdvertisement From the Makers of Candy Crush Farm Heroes Saga, the #4 Game on i Tunes.

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