
Causes, How it Spreads, and People at Increased Risk Causes and Common Sources of Infection How it Spreads People at Increased Risk Español: Causas y transmisión Causes and Common Sources of Infection 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 like Hot tubs that aren’t drained after each use Hot water tanks and heaters Cooling towers (air-conditioning units for large buildings) Home and car air-conditioning units do not use water to cool the air, so they are not a risk for Legionella growth. This bacterium grows best in warm water. After Legionella grows and multiplies in a building water system, that contaminated water then has to spread in droplets small enough for people to breathe in. People are exposed to Legionella when they breathe in mist (small droplets of water in the air) containing the bacteria.

One example might be from breathing in droplets sprayed from a hot tub that has not been properly cleaned and disinfected. Less commonly, Legionella can be spread by aspiration of drinking water, which is when water “goes down the wrong pipe,” into the trachea (windpipe) and lungs instead of down the digestive tract.
how do i tell how big my ac unit isPeople at increased risk of aspiration include those with swallowing difficulties.
water around ac unitIn general, Legionnaires’ disease and Pontiac fever are not spread from one person to another.
where to buy a central ac unitHowever, this may be possible in rare cases. If you have reason to believe you were exposed to the bacteria, talk to your doctor or local health department.