Legionnaires' Disease: It's In The Water
For an disease that’s not been around very long, Legionnaires’ disease has caused a significant amount of illness, and in some cases, death. During 2017, outbreaks have occurred in the U.S. in California, Texas, Washington, Minnesota, Tennessee, New York, Ohio, and Florida. Overseas outbreaks include Australia, Spain, England, Dubai, Hong Kong, and Japan. In 2015, 6,000 cases were reported in the U.S.
In July of 1976, the American Legion held a conference in Philadelphia. By August 12, 31 people had become infected with this mysterious illness and 2 had died. In all, 34 of the 221 people who fell ill died. It wasn’t until January of 1977 that researchers were able to pinpoint the source. The bacterium was named Legionella pneumophila, after the American Legion convention.
Legionella are gram-negative, rod-shaped bacteria. There are over 40 known species. The majority of human infections are caused by Legionella pneumophila. Legionella is an aquatic bacteria that can be naturally found in freshwater environments. It becomes a health concern when it grows and spreads in human-made water systems, such as
· Showers and faucets
· Cooling towers (air-conditioning units for large buildings)
· Hot tubs
· 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.
After Legionella grows and multiplies in a water system, the contaminated water is spread in droplets small enough for people to breathe in. People can get Legionnaires’ disease when they breathe in these contaminated droplets. In general, people do not spread Legionnaires’ disease to other people. However, this may be possible in rare cases.
Legionellosis is a respiratory disease caused by Legionella bacteria. It causes a serious type of pneumonia (lung infection) called Legionnaires’ disease.
Legionnaires' disease can have symptoms like many other forms of pneumonia, so it can be hard to diagnose at first. Signs can include:
· Cough, which may be contain blood
· Shortness of breath
· High fever
· Muscle aches
These symptoms usually begin 2 to 10 days after being exposed to the bacteria, but people should watch for symptoms for about 2 weeks after exposure.
A milder form of the disease is known as Pontiac fever/disease. The first identified cases occurred in 1968 in Pontiac, Michigan, among people who worked at and visited the city’s health department. It is an acute, influenza-like illness usually lasting 2–5 days. The incubation period is from a few and up to 48 hours. The main symptoms are fever, chills, headache, fatigue, and muscle pain. No deaths are associated with this type of infection.
Legionnaires' disease requires treatment with antibiotics (drugs that kill bacteria in the body), and in most cases, can be treated successfully. Healthy people usually get better after being sick, but hospitalization is often required. Possible complications include lung failure and death. About 1 out of every 10 people who get sick from Legionnaires’ disease will die.
The key to preventing legionellosis is maintenance of the water systems in which Legionella grow.
- Legionella grows best in warm water, like the water temperatures used in hot tubs. Disinfectant and other chemical levels in hot tubs should be checked regularly. Hot tubs should be cleaned as recommended by the manufacturer
- Guidelines for reducing the risk of Legionella growth and spread are available for those who maintain and manage building water systems, including systems for potable (water for drinking and showering), non-potable, and recreational water from ASHRAE®, a not-for-profit organization that develops standards and guidelines for industries that design, manufacture, and maintain building systems
- The risk of contracting Legionnaires' disease from a home water system remains low for healthy individuals. Healthy adults don't appear to be at high risk even when living in homes with contaminated water supplies. A 2004 study, funded by the Enivronmental Protection Agency, showed that those individuals who acquired Legionnaires' disease from home water systems were more than 70 years old or had an underlying disease such as cancer, leukemia or HIV. Testing is the only way to determine if your home drinking water systems has Legionella
- While the overall risk is low, there are some sporadic cases
of Legionnaires' disease from home potable water. You can contract Legionnaires' disease from drinking water through aspiration ("water going down the wrong pipe") or aerosolization via a humidifier or whirlpool spa. Showering hasn't been shown to be a major disseminator of Legionella
There are no vaccines that can prevent Legionnaires' disease. Most healthy individuals do not become infected with Legionella bacteria after exposure. People at higher risk of getting sick are:
· Older people (usually 50 years of age or older)
· Current or former smokers
· Those with a chronic lung disease (like COPD or emphysema)
· Those with a weak immune system from diseases like cancer, diabetes, or kidney failure
· People who take drugs that suppress (weaken) the immune system (like after a transplant operation or chemotherapy)