Legionnaires' disease is a severe form of pneumonia lung inflammation usually caused by infection.
It's caused by a bacterium known as legionella.
Most people catch Legionnaires' disease by inhaling the bacteria from water or soil.
Legionnaires' disease is a type of pneumonia caused by legionella bacteria.
Legionnaires' disease doesn't spread from person to person. Instead, the bacteria spreads through mist, such as from air-conditioning units for large buildings.
Adults over the age of 50 and people with weak immune systems, chronic lung disease, or heavy tobacco use are most at risk.
Many people exposed to the bacteria don't develop symptoms.
Those who do develop symptoms may experience cough, fever, chills, shortness of breath, muscle aches, headaches, and diarrhea.
Legionnaire's disease can be treated with antibiotics.