Prevalence and risk factors for methicillin-resistant Staphylococcus aureus in an HIV-positive cohort

Background: Persons living with HIV (PLWH) are disproportionately burdened with methicillin-resistant Staphylococcus aureus (MRSA). Our objective was to evaluate prevalence and risks for MRSA colonization in PLWH. Methods: Adults were recruited from Johns Hopkins University AIDS Service in Baltimore, Maryland. A risk questionnaire and specimen collection from anatomic sites with culture susceptibility and genotyping were completed. Generalized estimating equation modeling identified MRSA colonization risk factors. Results: Of 500 participants,mostwere black (69%), on antiretroviral therapy (ART) (87%),with undetectable viral loads (73.4%). Median CD4 count was 487 cells/mm³ (interquartile range, 316-676.5 cells/mm³). MRSA prevalence was 15.4%, predominantly from the nares (59.7%). Forty percent were nares negative but were colonized elsewhere. Lower odds for colonizationwere associatedwith recent sexual activity (adjusted odds ratio [AOR]=0.84, P<.001) andART (AOR=0.85, P=.011). Increasedoddswere associatedwithlower income (<$25,000 vs >$75,000; AOR = 2.68, P <.001), recent hospitalization (AOR = 1.54, P <.001), incarceration (AOR = 1.55, P <.001), use of street drugs (AOR = 1.43, P <.001), and skin abscess (AOR = 1.19, P <.001). Conclusions: Even with high MRSA prevalence, the proportion identified through nares surveillance alone was low, indicating the importance of screening multiple anatomic sites. Associations were not found with same-sex coupling or black race. MRSA prevention might be a benefit of ART in PLWH.