Patients colonized or infected with methicillin-resistant Staphylococcus aureus (MRSA) in a Surgical Intensive Care Unit and Surgical Intermediate Care Unit were placed either in Strict Isolation or cared for with modified isolation precautions. The assignment was determined by the unit in which they were hospitalized. Units were changed from one form of isolation to the other and served as their own controls.
Over a 4-month study period, the rate of MRSA transmission did not change when the type of isolation precautions were altered. The ratio of colonized to infected patients also remained constant. Infected patients were usually first detected by clinical specimens, while colonized patients were usually detected by surveillance cultures performed under the study protocol.
Following the study, all hospitalized patients with MRSA were placed in modified isolation precautions. Total new acquisitions of MRSA in the hospital have decreased over the subsequent 6-month period.