Prevalence and behavioural risk factors ofStaphylococcus aureusnasal colonization in community-based injection drug users

Abstract

SUMMARYThe aims of this study were to identifyStaphylococcus aureusnasal colonization prevalence, behavioural risk factors, and to determine staphylococcal protein A (spa) types in community-based injection drug users (IDUs). Nasal swabs were collected and methicillin susceptibility testing andspa/SCCmectyping were performed onS. aureusisolates. Generalized estimating equations were used to report adjusted odds ratios and 95% confidence intervals. Of the 440 participants, 24·1% were colonized and 5·7% had methicillin-resistantS. aureus(MRSA). Colonization was associated with age, employment/marital status, and the presence of scabs but not with sexually transmitted disease co-infection, HIV status, antibiotic use, hospitalization, or drug treatment programme participation. The USA300 MRSA clonespatypes were most common, but 15/49spatypes were new to one of the international databases. Community-based IDUs appear to have different risk factors compared to IDUs from clinical studies. In addition, the number of newly identifiedspatypes indicates a diverse, understudied population.