IN 1996, two hospitals reported sustained transmission of nosocomial Legionnaires disease (LD). The hot water distribution systems in each hospital were implicated as the sources of infection. This report summarizes investigations in these two hospitals by hospital personnel, state and local health officials, and CDC and efforts to control transmission.
In 1996, eight cases of nosocomial LD were diagnosed among cardiac and bone marrow transplant patients at hospital X. Possible nosocomial LD was first reported at hospital X in 1979, but no source had been identified. Intensified surveillance for nosocomial LD was initiated after the first three case-patients were identified in 1996.A case of definite nosocomial LD in a hospital X patient was defined as respiratory illness with a new infiltrate on chest roentgenogram occurring after ≥10 days of continuous hospitalization for a nonpneumonia illness and laboratory confirmation of legionellae infection