Modelling the usefulness of a dedicated cohort facility to prevent the dissemination of MRSA.

The aim of this retrospective study was to determine whether or not a surgical dedicated cohort facility, mainly dedicated to the care of orthopaedic patients, can control the risk of infection caused by methicillin-resistant Staphylococcus aureus (MRSA). We tested this hypothesis on the orthopaedic surgery ward of a university-affiliated public hospital with 1228 beds by determining whether there was a significant correlation between the colonization pressure exerted by MRSA and the number of cases of acquired MRSA. This was then used as a tool to predict the number of patients contaminated with MRSA in hospitals with and without dedicated cohort facilities. We found that the relative risk of MRSA acquisition increased with the colonization pressure exerted by MRSA imported cases. This statistical model enabled us to predict that the risk of MRSA acquisition would increase by 160% per year in the absence of a dedicated cohort facility. We conclude that these units are useful to control the spread of MRSA in hospitals.