Consider Using MRSA Nares for CAP, DFIs — Otherwise Avoid!

Background: Anti–methicillin-resistant Staphylococcus aureus (MRSA) therapy is commonly suboptimal. There is heterogeneity in the use of MRSA nares swab for antibiotic stewardship. Objective: To review the data supporting MRSA nares swab for antibiotic stewardship in various common infections. Design: Narrative review. Discussion: The negative predictive value (NPV) and positive predictive value (PPV) vary with associated MRSA prevalence in different infectious syndromes. In community-acquired pneumonia (CAP), the estimated MRSA prevalence is 7% to 13% and the associated NPV is >98% and PPV is variable and <50%. In diabetic foot infection (DFI), there is significant local variability in MRSA prevalence. When local MRSA prevalence is <15%, the NPV of MRSA nares swab is >90%. When local MRSA prevalence is =30%, the NPV of MRSA nares swab is =80%. For other infectious syndromes, neither the NPV nor PPV of MRSA nares swabs are generally adequate to change empiric antibiotic r more...