Unexpected absence of meticillin-resistant Staphylococcus aureus nasal carriage by healthcare workers in a tertiary hospital in Kenya.

Healthcare workers (HCWs) are a major reservoir of meticillin-resistant Staphylococcus aureus (MRSA). A cross-sectional study was conducted between July and December 2010 to determine the prevalence of nasal carriage of MRSA at the Aga Khan University Hospital Nairobi. Nasal swabs were taken from 246 randomly selected HCWs. MRSA was identified using both phenotypic and genotypic methods. The prevalence of MRSA carriage was 0% [95% confidence interval (CI): 0-1.5%] whereas that of meticillin-susceptible Staphylococcus aureus was 18.3% (95% CI: 14.0-23.6%). Given the absence of MRSA in our hospital, screening HCWs should be limited to an outbreak setting.