PrEP and PEP for HIV Prevention Among Gay, Bisexual, and MSM in Brazil: Findings from the SMESH Study.

The HIV epidemic remains a global concern, particularly among vulnerable populations. Effective strategies, such as pre-exposure prophylaxis (PrEP) and post-exposure prophylaxis (PEP), are crucial to reducing HIV transmission. This study assessed HIV prophylaxis use among men who have sex with men (MSM) in Brazil, examined associated factors, and evaluated perceptions regarding access through the public healthcare system (SUS). A cross-sectional study (2019-2023) was conducted using respondent-driven sampling (RDS) in ten state capitals across five Brazilian regions. Eligible participants were men aged ≥ 18 years, identifying as MSM, who reported oral or anal sex with another man in the past 12 months. Data were collected via structured questionnaires on socio-behavioral characteristics. Descriptive analyses used RDS-II estimators, and associations with prophylaxis use were examined using survey-weighted Poisson regression. Among 1,139 participants, 21.4% reported PrEP use and 20.5% reported PEP use. PrEP uptake was significantly lower among individuals identifying as pardo (PR = 0.58 [95% CI 0.36-0.92]), with no significant associations found for education or social class. Both PrEP and PEP use were positively associated with having more than five sexual partners in the past six months and with having a partner living with HIV. Notably, 86.3% of participants (95% CI 81.1-91.6) expressed willingness to access PrEP through SUS. Despite high willingness, PrEP uptake remains suboptimal, particularly among pardo MSM. These findings underscore the urgency of targeted public policies to expand equitable access to HIV prevention services in Brazil.