About the Disease
Legionnaires' disease is a severe, often lethal, form of pneumonia. It's caused by the bacterium Legionella pneumophila found in both potable and nonpotable water systems. Each year, an estimated 10,000 to 18,000 people are infected with the Legionella bacteria in the United States.
It is not uncommon for patients with Legionnaires' disease to be admitted to the intensive care unit. Some will suffer long-term impaired health-related quality of life. A study of outbreak survivors showed persistence of fatigue (75%), neurologic symptoms (66%) and neuromuscular symptoms (63%) in months after an outbreak. See Share Your Story for a first-hand account of the severity of this disease.
Is Legionnaires' disease contagious?
Legionnaires' disease is not contagious. No special precautions are necessary. The disease is transmitted via drinking water, not by infected persons. (So it differs from SARS and influenza where masks must be worn). Likewise, women who are pregnant and their fetuses have nothing to fear from patients with Legionnaires' disease.