Legionnaires 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.

The bacteria enters the body through the lungs. It is inhaled in water vapor from a contaminated water source. The infection does not pass from person to person.

The Lungs

Risk Factors

Factors that may increase the chances of Legionnaires disease include:

Advanced age
Smoking
Chronic lung disease
Weakened immune system
Kidney failure
Diabetes
Taking cortisone or other immunosuppressive drugs
History of organ transplant

Symptoms

Symptoms may include:

Fatigue
Fever (often high)
Chills and muscle aches
Cough
Headache
Nausea and vomiting
Diarrhea

Diagnosis

Your doctor will ask about your symptoms and medical history. A physical exam will be done. A chest x-ray may be done to get images of the lungs. Blood and coughed fluid may also be tested to look for the cause of the infection.

Treatment

Antibiotics can help to clear the infection.

Prevention

Proper design, maintenance, and cleaning of high-risk areas can reduce the risk of spreading the disease. This includes any area with standing water.

RESOURCES:

Centers for Disease Control and Prevention
https://www.cdc.gov

National Institute of Environmental Health Sciences
https://www.niehs.nih.gov

CANADIAN RESOURCES:

Nova Scotia Health Authority
http://www.nshealth.ca

Public Health Agency of Canada
https://www.canada.ca

References:

Legionella infections. EBSCO DynaMed Plus website. Available at: http://www.dynamed... . Updated October 4, 2019. Accessed October 4, 2019.

Legionella infections. Merck Manual Professional Version website. Available at:
...(Click grey area to select URL)
Updated May 2016. Accessed October 4, 2019.

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 October 4, 2019.

Last reviewed October 2019 by EBSCO Medical Review Board David L. Horn, MD, FACP
Last Updated: 10/4/2019

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