Sexual Behavior Among Men Who Have Sex With Men: The Need for More Targeted Outreach to Men Who Also Have Sex With Cisgender Women.

Background: In Peru, as in the Americas overall, men who have sex with men (MSM) are disproportionately affected by HIV. Most research focuses on practices between cisgender men, whereas many MSM report male and female partners, cisgender, transgender, or both.

Methods: Data for these analyses were from a treatment-as-prevention study in Lima (the Sabes study). We compared demographics and behaviors of MSM who reported cisgender women partners in the past 3 months (MSMW) and MSM who reported both cisgender and transgender women partners (MSMW-T) to MSM who reported only male partners (MSMO). We calculated HIV incidence in each group during 2-year follow-up.

Results: Compared with MSMO, MSMW and MSMW-T more often self-identify as heterosexual or bisexual and report insertive sex practices. MSMW reported condomless sex with cisgender women: vaginal (72%), anal sex (18%). One-third of MSMW reported condomless receptive anal sex with men in the past 3 months, with 24% of MSMW overall who reported both condomless receptive sex with men and condomless insertive vaginal or anal sex with cisgender women. Of these, 17% were HIV infected. HIV incidence did not differ significantly between groups.

Conclusion: Most MSMW and MSMW-T report bisexual or heterosexual orientation and prefer insertive sex. MSMW and MSMW-T (47% and 29%, respectively) engage in receptive anal intercourse. In both groups, the majority who engaged in condomless receptive sex with men (76% MSMW, 85% MSMW-T) also engaged in condomless vaginal and/or anal sex with women, indicating need for intervention.