Nosocomial (Health Care-Associated) Legionnaire's Disease.

Nosocomial Legionnaire's disease is most frequently associated with presence of the organism in hospital water systems. Patients are often susceptible as a result of age, underlying comorbidities, or immunosuppression. Prevention focuses on reducing the reservoir within water systems and includes super heating, ultraviolent light, chlorination, silver-copper ionization, and distal filtration. This article reviews the epidemiology of health care-associated Legionnaire's disease, reviews characteristics of several health care-associated outbreaks, and discusses strategies to prevent health care-associated infection.