About Legionnaires’ Disease
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Legionellosis Fact Sheet (PDF)
What is Legionnaires’ disease?
- Legionnaires’ disease is a lung infection caused by the bacteria Legionella pneumophila.
- The bacteria is found in water.
- Legionnaires’ disease was named for the first recognized outbreak at a 1976 convention of the American Legion in Philadelphia.
What are the symptoms?
- Symptoms include:
- muscle aches
- loss of appetite
- and coughing
- These symptoms are followed by high fever (102-105°F), pneumonia, and occasionally abdominal pain and diarrhea.
How is it spread?
- Legionnaires’ disease is spread by water droplets in the air that contain Legionella bacteria.
- People can get sick if they breathe in water droplets that contain the bacteria.
- Persons can be exposed to these water droplets in their homes, at work, in hospitals, or in other public places.
- Legionella organisms are found in many types of water systems and reproduce in high numbers in warm water (95-115°F), such as certain plumbing systems, hot water tanks, cooling towers, large air conditioning systems, and hot tubs.
- Legionnaires’ disease is not spread from person to person.
Who is at risk?
- Legionnaires’ disease occurs worldwide, especially in persons over 50 years of age.
- Other risk factors include smoking; male gender; chronic lung disease; suppressed or weakened immune system due to organ transplant, cancer, kidney disease, or AIDS.
How is it diagnosed?
- Diagnosis of Legionnaires’ disease requires testing for Legionella bacteria. This is not often done when someone goes to a clinic or hospital with fever and pneumonia.
- As a result, Legionnaires’ disease often goes undiagnosed.
- A urine test is the most common type of test used to diagnose Legionnaires’ disease.
How is it treated?
- Most cases can be successfully treated with antibiotics.
- However, about 1 out of every 10 people who get sick with Legionnaires’ disease will die.