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 such as 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. That contaminated water then has to spread in droplets small enough for people to breathe in.
Legionnaires’ disease is very similar to other types of pneumonia. Symptoms usually begin 2 to 10 days after being exposed to the bacteria, but it can take longer so people should watch for symptoms for about 2 weeks after exposure. These symptoms may include:
- Shortness of breath
- Muscle aches