- Legionella bacteria can cause Legionnaires’ disease or Pontiac fever, collectively known as legionellosis.
- The bacterium was named after an outbreak in 1976, when many people who went to a Philadelphia convention of the American Legion got sick with pneumonia (lung infection).
- An estimated 8,000 to 18,000 people need care in a hospital due to Legionnaires’ disease each year in the United States.1
- Most people with Legionnaires’ disease will have pneumonia since the Legionella bacteria grow and thrive in the lungs.
- People get Legionnaires’ disease or Pontiac fever when they breathe in a mist or vapor (small droplets of water in the air) that has been contaminated with Legionella.
- Legionellosis is not spread from person to person.
- Legionella are found naturally in the environment, usually in warm water.
- Keeping Legionella out of buildings’ water supplies and cooling towers, as well as pools, hot tubs, and fountains, is key to preventing infection.