Abstract
An outbreak of MRSA occurred in two wards of our medical center, which is an acute-care hospital. Ward A is an intensive care unit and Ward B is a ward for many burn inpatients. Both the wards treat high-risk inpatients with infections. An environmental investigation to identify the MRSA infection source and route was carried out using bacteriological test samples obtained from the wards. The strains isolated from the patients with MRSA infection were also detected from the touch panel of an artificial respirator in Ward A, and from the surrounding environment and a shower-related instrument used to treat patients with MRSA infection in Ward B. Since the MRSA infection was considered to have spread among patients in the environment of both wards, countermeasures against the spread of MRSA were taken, especially centering on environmental improvement. No newly detected MRSA strains were observed in the two wards after the countermeasures were taken, and the outbreak of MRSA infection was terminated after the one-month observation period. Routine environmental investigation is not usually necessary, but since identical strains of MRSA were detected from patients and the surrounding environment in the two wards, urgent countermeasures were taken, especially centering on the environmental improvement, and the outbreak of MRSA was terminated. These results suggest that an outbreak of MRSA can be prevented within an extremely narrow range by immediate environmental investigation using sufficient information collected at the time of the outbreak.
