Legionellosis

Legionellosis is a reportable disease in Oklahoma. Legionellosis is an infection caused by the bacteria Legionella. Legionellosis can present as two distinct illnesses; Pontiac fever, a self-limited, flu-like illness; and Legionnaires’ disease, the more severe form involving pneumonia. The severity of the illness can be mild or result in pneumonia. Most cases occur as single isolated events, however outbreaks have been noted.

Pontiac fever is characterized by fever, chills, headache, fatigue, and muscle aches. Symptoms usually occur within five to 66 hours after exposure and resolve within two to five days from onset of illness. Symptoms of legionnaires' disease include fever, chills, cough, loss of appetite, tiredness, muscle aches, and pneumonia. Chest X-rays are needed to confirm the presence of pneumonia. The symptoms usually begin 2 to 10 days after exposure to the bacteria. Legionnaires’ disease most commonly affects those who have chronic lung disease, and underlying medical conditions that lower their immune system. Antibiotics are prescribed to treat Legionnaires’ disease, while Pontiac fever requires no specific treatment.

Legionella bacteria are ubiquitous in natural and manmade water environments, and multiply in the presence of warm water temperatures (25° to 45° C). The bacteria grow best in warm water sources, such as hot tubs, cooling towers, hot water tanks, large plumbing systems, or parts of the air-conditioning systems of large buildings. Exposure to Legionella occurs by breathing in a mist or vapor from a water source such as a hot tub or cooling tower that is contaminated with the bacteria. Legionella is not spread from person to person.

What can be done to prevent legionellosis?
Prevention of legionellosis is based upon proper maintenance of heating, cooling and plumbing systems. Commercial cooling towers should be drained when not in use and cleaned periodically to remove scale and sediment. Hot water tanks should be maintained at 122^oF to prevent growth of the bacteria. Persons with hot tubs and whirlpool baths should take special care to keep them clean and free of Legionella bacteria.

ADS Resources:
Legionellosis Fact Sheet  En Español
Pontiac Fever Fact Sheet

Other Resources:
CDC Legionellosis
EPA Drinking Water Advisory

Surveillance Resources:
Legionellosis Incidence Rate
Legionellosis Summary Data