Staphylococcus aureus skin infection recurrences among household members: an examination of host, behavioral, and pathogen-level predictors.

BACKGROUND Many patients suffer from recurrent Staphylococcus aureus infections, but there are few data examining recurrence predictors. METHODS We followed adults and children after treatment for S. aureus skin infections and their household contacts in Los Angeles and Chicago. We surveyed subjects for S. aureus body colonization, household fomite contamination, and behavioral and clinical factors at baseline and 3 and 6 months later. Using repeated measures modeling, we examined host, pathogen, behavioral, and clinical factors associated with recurrence. RESULTS Among 330 index subjects, 182 (55%) were infected with an isolate of the USA300 methicillin-resistant S. aureus (MRSA) genetic background. Recurrences occurred in 39% by month 3 and 51% by month 6. Among 588 household contacts, 10% reported a skin infection by month 3 and 13% by month 6. Among index subjects, recurrence was associated with (P < .05) Los Angeles site, diabetes, recent hospitalization, recent skin infection, recent cephalexin use, and household S. aureus or MRSA fomite contamination; recurrence was inversely associated with recent contact sports participation. In the multivariate model, independent predictors of recurrence in index patients were recent hospitalization, household MRSA fomite contamination, and lack of recent contact sports participation. Among household contacts, independent predictors of subsequent skin infection were Chicago site, antibiotic use in the prior year, and skin infection in the prior 3 months. CONCLUSIONS In our longitudinal study, patients with a S. aureus skin infection were more likely to suffer a recurrence if household fomites were MRSA contaminated. Interventions to prevent recurrence may be enhanced by decontamination of household fomites.