Postoperative infections following cardiac surgery: association with an environmental reservoir in a cardiothoracic intensive care unit.

During 1981, 39 nosocomial infections occurred in 27 of 223 patients undergoing cardiac surgery in the North Carolina Memorial Hospital. The peak attack rate (23.7%) occurred in August and September compared to 10.1% in January through July. A case-control study demonstrated that the only risk factor common to poor and stable health groups compared to controls was duration of stay in the cardiothoracic intensive care unit (CTICU). Microbiologic studies of the environment, personnel and patients showed that colonization or infection of patients occurred 1 to 6 days after admission to the CTICU and that nosocomial pathogens were found: 1) in and around the unit's soiled utility sink, 2) in pooled handwashing cultures of unit personnel, and 3) on contaminated clean hands and air near the soiled utility sink, plus nearby bedside air only while the water in the sink was running. Environmental and personnel hand contamination by soiled utility sink aerosols likely contributed to these infections. Infection control measures, including discontinued use of the soiled utility sink, resulted in a significantly lower infection rate (5.6%).