HIV infection among men who have sex with men and women (MSMW): A systematic review and comprehensive meta-analysis

INTRODUCTION: Some public health researchers have suggested that men who have sex with men and women (MSMW) are responsible for significant HIV transmission or "bridging." However, few studies have estimated MSMW-specific HIV risks. We conducted a systematic review and comprehensive meta-analysis to assess a) differences in HIV prevalence and risk behavior between MSMW and men who have sex with men only (MSMO); and b) population sizes of MSMW and HIV-positive MSMW. METHODS: We conducted systematic searches of PubMed and PsycINFO. Articles were included if they were peer-reviewed, published in English, and presented HIV prevalence data for U.S. MSMW. Meta-analyses were conducted with NIH-supported software using random-effects models. RESULTS: 3474 articles were identified; 31 met inclusion criteria. MSMW were less likely than MSMO to be HIV-positive (OR=0.4, 95% CI: 0.3, 0.5) and to report URAI (OR=0.4, 95% CI: 0.3, 0.5). Among MSM, 33.8% (95% CI: 23.7%, 45.6%) were past-year MSMW. Among confirmed HIV-positive MSM, 21.0% (95% CI: 14.7%, 28.9%) were past-year MSMW. We estimate that 1,204,204 U.S. males are past-year MSMW, of whom 121,800 are HIV-positive. DISCUSSION: This represents the first meta-analysis of HIV prevalence between MSMW and MSMO in the U.S. Lower URAI engagement among MSMW may explain commensurately reduced HIV prevalence. Our HIV-positive MSMW estimate aligns with CDC estimates for HIV-positive male heterosexuals and IDU; thus, we propose that MSMW risk to female partners has been relatively overstated. MSMW-specific data collection, research, and HIV prevention and care delivery are necessary to better quantify and ameliorate this population's HIV burden.