Legionella is the bacteria that causes the respiratory disease Legionellosis. Sometimes a more serious form of the disease occurs, called Legionnaires’ disease, which is a type of pneumonia. There is also a less serious form of infection called Pontiac fever, which has symptoms similar to a mild flu.
Most healthy people do not get sick with Legionnaires’ disease even after being exposed to the bacteria. However, people over the age of 50, people with weakened immune systems, and smokers have a greater risk of contracting the disease.
Legionella occurs naturally in freshwater environments such as lakes and streams. The bacteria becomes a health concern when it grows and spreads in human-made water systems with the most common sources of infection being shower water, cooling towers (used in air conditioning), decorative fountains, hot tubs, and large plumbing systems. In most cases, Legionella is spread through water droplets in the air.
If you suspect your water is contaminated, contact a state certified laboratory about getting your water tested.
Well maintained systems reduce the risk of growing and spreading Legionella.