by Rick Alan
Legionnaires disease is a lung infection. It is a form of pneumonia. It got its name from an outbreak at the American Legionnaires Convention in 1976.
This disease is caused by specific bacteria. The bacteria are most often found in sources of standing water. It may be found in cooling towers, HVAC systems, and air conditioners.
Legionnaires disease can be contracted by breathing water vapor from a standing water source that contains the bacteria.
The infection is not spread from one person to another.
Factors that may increase the chances of Legionnaires disease:
Symptoms may include:
Your doctor will ask about your symptoms and medical history. A physical exam will be done.
Your doctor may need pictures of your chest. This can be done with a chest x-ray.
Your doctor may need tests of your bodily fluids. This can be done with:
This disease is usually treated with antibiotics.
Proper design, maintenance, and cleaning of high-risk areas can reduce the risk of spreading the disease. This includes any area with standing water.
Centers for Disease Control and Prevention
National Institute of Environmental Health Sciences
Nova Scotia Health Authority
Public Health Agency of Canada
Arcavi L, Benowitz NL. Cigarette smoking and infection. Arch Intern Med. 2004;164(20):2206-2216.
Community-acquired pneumonia in adults. EBSCO DynaMed Plus website. Available at: http://www.dynamed... . Updated December 18, 2017. Accessed February 16, 2018.
Legionella infections. EBSCO DynaMed Plus website. Available at: http://www.dynamed... . Updated May 20, 2016. Accessed February 16, 2018.
Legionella infections. Merck Manual Professional Version website. Available at:
...(Click grey area to select URL)
Updated May 2016. Accessed February 16, 2018.
Legionella (Legionnaires' disease and Pontiac fever). Centers for Disease Control and Prevention website. Available at: https://www.cdc.gov/legionella/about/index.html. Updated May 31, 2016. Accessed February 16, 2018.
Last reviewed March 2018 by EBSCO Medical Review Board David L. Horn, MD, FACP
Last Updated: 5/2/2014
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