We sought to estimate the period prevalence of methicillin-resistant Staphylococcus aureus (MRSA) skin and soft tissue infection (SSTI) and evaluate risk factors for MRSA SSTI in an emergency department (ED) population.
We carried out a cohort study with a nested case-control design. Patients presenting to our ED with a wound culture and a discharge diagnosis of SSTI between January 2003 and September 2004 were dichotomized as MRSA positive or negative. Fifty patients with MRSA SSTI matched by calendar time to 100 controls with MRSA-negative SSTI had risk factors assessed using multivariate conditional logistic regression.
Period prevalence of MRSA SSTI was 54.8% (95% confidence interval [CI] 50.2%-59.4%). The monthly period prevalence increased from 21% in January 2003 to 68% in September 2004 (p