[Transmission of methicillin-resistant Staphylococcus aureus in a hospital for aged and chronically ill inpatients].

When we tested bacterial contamination in the linens of aged or chronically ill inpatients in a general hospital (114 beds), 11 out of 60 patients were found to have methicillin-resistant Staphylococcus aureus (MRSA). Two of these were MRSA infections. Furthermore, 6 patients mostly elderly and with chronic diseases, were newly infected with MRSA after this surveillance period. So as to clarify the transmission route of MRSA in the hospital, we classified 12 MRSA strains into 4 types by several criteria such as types of coagulase, enterotoxin, toxic-shock syndrome toxin, sensitivity to antibiotics, plasmid contents, and restriction endonuclease digestion patterns of chromosomal DNAs. At the same time, we followed up the movement of patients in wards and conditions of patient contact with medical staff in the hospital. The data obtained revealed a specific correlation between one of the MRSA strains and a doctor, suggesting a contribution from medical staff to the transmission of MRSA in the hospital. It is necessary, therefore, to practice more careful protection procedures against bacterial infection especially in hospitals for aged and chronically ill patients who are vulnerable to various infectious agents.