We surveyed 122 trans men using a hybrid sampling method that included randomly selected physical and online venues and peer referral to measure HIV prevalence and risk behaviors. HIV prevalence was 0% (one-sided 97.5% confidence interval 0-3.3%). Of 366 partnerships described, 44.8% were with cisgender women, 23.8% with cisgender men, 20.8% with trans men, and 10.7% with trans women. Condomless receptive anal and front hole/vaginal sex averaged one to three episodes per six months. HIV prevalence in trans men is likely closer to heterosexual cisgender men and women in San Francisco than trans women or MSM. Prevention prioritizing trans women and MSM, coupled with individualized and relevant sexual health education for trans men with partners from these populations, may best address the HIV prevention needs of trans men. Systematic collection of transgender status in Census and health data is needed to understand other health disparities among trans men.
Keywords: HIV prevalence; Sexual behavior; Trans men.