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.

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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

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.