Overview

Definition

Legionnaires disease is a lung infection. It is a form of pneumonia.

Causes

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
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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

SymptomsandDiagnosis

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.

Treatments

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.

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

Edits to original content made by Denver Health.

a (Legionnaires Pneumonia)

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.com/topics/dmp~AN~T904756/Legionella-infections  . Updated October 4, 2019. Accessed October 4, 2019.

Legionella infections. Merck Manual Professional Version website. Available at: http://www.merckmanuals.com/professional/infectious-diseases/gram-negative-bacilli/legionella-infections. 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.