The incidence and complications of methicillin-resistant Staphylococcus aureus in a community Level I trauma center.

BACKGROUND Methicillin-resistant Staphylococcus aureus (MRSA) is a growing cause of infections among hospitalized trauma patients. We examined the incidence and infectious consequences of MRSA among trauma patients admitted to our Level I Trauma Center during 24 months. METHODS Nasal swab cultures were obtained at admission and on hospital day 5. Patient demographics and infectious complications were recorded and compared. Differences with p values less than 0.05 were considered significant. RESULTS Admission MRSA screening was positive in 71 patients, yielding a carrier prevalence rate of 5.8% (95% CI 4.5-7.1%). No admission characteristic was associated with positive MRSA screening. Twelve patients (1.7%, 95% CI 0.7-2.6%) who were MRSA negative at admission tested positive for MRSA on hospital day 5. The clinical MRSA infection incidence rate was 1.4% (95% CI 0.7-2.0%). The screening test for MRSA at admission demonstrated a sensitivity of 23.5% (95% CI 6.8-49.9%) and specificity of 94.5% (95% CI 93-95.7%) for predicting MRSA infection. MRSA infections were associated with increased lengths of stay: intensive care unit 17.7 versus 5.1 days, p < 0.001, hospital 23.1 versus 8.6 days, p < 0.001. CONCLUSIONS MRSA infections affect a minority of our trauma patients yet prolong length of stay. Admission MRSA screening of trauma patients does not sufficiently identify patients at risk for infectious complications and should not be practiced.