Methicillin-resistant Staphylococcus aureus in a trauma population: does colonization predict infection?

Methicillin-resistant Staphylococcus aureus (MRSA) is increasingly responsible for infections in hospitalized patients. Patients colonized with MRSA appear to be at higher risk for subsequent MRSA infections than those who are not colonized. In this study, we determined MRSA colonization status of trauma patients at hospital admission and compared the incidence of subsequent MRSA infections between MRSA colonized and noncolonized patients. Collected data were entered into databases at a single, Level I trauma center over a 13-month period. Three hundred fifty-five adult trauma patients were screened for MRSA on admission to the trauma intensive care unit. The patients were categorized into two groups, those colonized with MRSA at admission and those who were not. Thirty-six of 355 patients (10.1%) were colonized. Of the 319 patients not colonized, 21 (6.6%) developed MRSA infections. Twelve of 36 (33.3%) colonized patients developed MRSA infections (P < 0.001). No differences in types of MRSA infections were found between the two groups. Colonized patients who developed MRSA infections had higher death rates, 22.2 versus 5.0 per cent (P < 0.001). Patients colonized with MRSA on admission may be at higher risk for developing MRSA infections during hospitalization. MRSA screening protocols should be used to identify these at-risk patients.