What is Legionnaires' disease?

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Friday, May 24, 2019

NEW YORK CITY (WABC) -- Legionnaires' disease is a severe form of pneumonia - lung inflammation usually caused by infection.

Legionnaires' disease is caused by a bacterium known as legionella.

You can't catch legionnaires' disease from person-to-person contact. Instead, most people get legionnaires' disease from inhaling the bacteria.

Legionella bacterium can also cause Pontiac fever, a milder illness resembling the flu.

Outdoors, Legionella bacteria survive in soil and water and rarely cause infections.

Indoors, Legionella bacteria multiply in water systems such as air conditioners, hot tubs, etc.

(Source: Mayo Clinic)

Legionnaires' disease usually develops two to 10 days after exposure to legionella bacteria. It frequently begins with the following signs and symptoms:


-Muscle pain


-High fever

Within a couple of days, other symptoms may develop:

-Cough (may sometimes bring up mucus or blood)

-Shortness of breath

-Gastrointestinal symptoms, such as nausea, vomiting and diarrhea


-Chest pain


-Loss of appetite

Although legionnaires' disease primarily affects the lungs, it occasionally can cause infections in wounds and in other parts of the body, including the heart.

See your doctor if you think you've been exposed to legionella bacteria.


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