Prevalence of methicillin-resistant Staphylococcus aureus (MRSA) among patients visiting the emergency room at a tertiary hospital in Brazil

We surveyed patients seen at the emergency room at a tertiary hospital in Brazil from August to November 1997. All patients' (n = 600) anterior nares were cultured for MRSA; the results were confirmed by oxacillin disk diffusion methods and by detection of the mecA gene with PCR. Bacteria were found in 93.3% (560) of the patients and MRSA in 0.7% (n = 4). One patient had community-acquired MRSA. We concluded that MRSA is uncommon among patients visiting the emergency room. The presence of community-acquired MRSA can lead to serious medical and epidemiological issues, although initial clinical presentation may not differ from that of infections with other staphylococci. The empirical use of vancomycin for suspected community-acquired infections is seldom warranted