Legionnaires’ (LEE-juh-nares) disease is a very serious type of pneumonia (lung infection) caused by bacteria called Legionella. If you develop pneumonia symptoms and may have been exposed to Legionella, see a doctor right away. Be sure to mention if you have used a hot tub, spent any nights away from home, or stayed in a hospital in the last two weeks.
Please see the below fact sheet provided by CDC to get useful and potentially life-saving information on this disease.