Legionnaires Disease

Legionnaires Disease is a rare form of pneumonia, or lung infection. It got its name after the disease struck at the American Legionnaires Convention in 1976.

Causes

Legionnaires Disease is caused by the bacterium Legionella pneumophilia. The bacteria are most often found in sources of standing water. Examples include cooling towers, HVAC systems and air conditioners. It can also be found in soil, such as potting soil.
Legionnaires Disease can be contracted by:
  • Breathing water vapor from a standing water source that contains Legionella bacterium
  • Breathing dust from soil containing Legionella bacterium
This disease does not appear to spread from person to person.

Risk Factors

A risk factor is something that increases your chance of getting a disease or condition.
  • Advanced age
  • Sex: Male
  • Smoking
  • Excessive alcohol intake
  • Chronic lung disease
  • Weakened immune system
  • Taking cortisone drugs
  • Surgery
  • Organ transplant
  • Working with soil, especially newly tilled soil or potting soil

Symptoms

Symptoms include:
  • Fatigue
  • Fever (often high)
  • Chills and muscle aches
  • Dry cough
  • Cough, with or without sputum/phlegm
  • Chest pain with coughing or breathing
  • Loss of appetite
  • Headache
Symptoms that develop if the infection becomes serious include:
  • Shortness of breath
  • Abdominal pain
  • Nausea, vomiting, or diarrhea
  • Mental problems, confusion, or memory loss

Diagnosis

The doctor will ask about your symptoms and medical history, and perform a physical exam.
Tests may include:
  • Blood tests – to look for high or rising antibodies to Legionella bacteria
  • Sputum tests – to stain or culture the mucus from deep inside your lungs. This may help identify the cause of the infection.
  • Urine tests – to check for Legionella proteins in the urine
  • Chest x-ray – to help diagnose pneumonia or lung infection

Treatment

Legionnaires Disease is usually treated with antibiotics. Drugs like quinolone, erythromycin, or tetracycline are commonly prescribed. In very severe cases, a drug called rifampin may be given. Initial therapy is usually given by vein.