legionnaires' disease

Pneumonia-like disease, so called because it was first identified when it broke out at a convention of the American Legion in Philadelphia in 1976. Legionnaires' disease is caused by the bacterium Legionella pneumophila, which breeds in warm water (for example, in the cooling towers of air-conditioning systems). It is spread in minute water droplets, which may be inhaled. The disease can be treated successfully with antibiotics, though mortality can be high in elderly patients.