Legionellosis comprises two distinct diseases caused by the bacterium Legionella pneumophila: Legionnaires’ disease and Pontiac fever. Individuals are typically infected by breathing in droplets of water that originate in building water systems contaminated with L. pneumophila. Approximately 10 percent of cases of Legionnaires’ disease are fatal. According to OSHA, approximately 6,000 cases of legionellosis are reported in the U.S. each year. See OSHA’s revised legionellosis page for more information.
Related: The article “The New Age of Legionella” in the June/July 2015 issue of The Synergist discusses the AIHA guidance document Recognition, Evaluation, and Control of Legionella in Building Water Systems.