A PROLONGED OUTBREAK OF METHICILLIN-RESISTANT STAPHYLOCOCCUS-AUREUS IN THE BURN UNIT OF A TERTIARY MEDICAL-CENTER

OBJECTIVE: To report an outbreak of methicillin-resistant Staphylococc us aureus (MRSA) in our burn unit and the steps we used to eradicate t he organism. DESIGN AND SETTING: Outbreak investigation in the burn un it of a 900-bed tertiary-care medical center. OUTBREAK: Between March and June 1993, MRSA was isolated from 10 patients in our burn unit. Al l isolates had identical antibiograms and chromosomal DNA patterns. CO NTROL MEASURES: Infection control personnel encouraged healthcare work ers to wash their hands after each patient contact. The unit cohorted all infected or colonized patients, placed each affected patient in is olation, and, if possible, transferred the patient to another unit. De spite these measures, new cases occurred. Infection control personnel obtained nares cultures from 56 healthcare workers, 3 of whom carried the epidemic MRSA strain. One healthcare worker cared for six affected patients, and one cared for five patients. We treated the three healt hcare workers with mupirocin. Subsequently, no additional patients bec ame colonized or infected with the epidemic MRSA strain. CONCLUSIONS: The outbreak ended after we treated healthcare workers who carried the epidemic strain with mupirocin. This approach is not appropriate in a ll settings. However, we felt it was justified in this case because of a persistent problem after less intrusive measures.