UCLA

BACKGROUND: Gay, bisexual, and other men who have sex with men (GBMSM) are often considered a homogenous "high-risk" group. We aimed to differentiate subgroups based on participants' last sexual partner and explore associations with HIV transmission risk factors. SETTING: We utilized cross-sectional data (06/2022 to 03/2023) from "high-risk" GBMSM in Lima, Perú. METHODS: Participants included cisgender men and gender nonconforming adults assigned male at birth reporting condomless anal sex with ≥1 serodiscordant or unknown serostatus cisgender man or transgender woman in the past 6 months. Latent class analysis was performed using the last sexual partner characteristics, including partner type, sexual role, and condomless anal sex position. Multinomial logistic regression examined HIV risk factors associated with latent classes, including drug use, transactional sex, sexually transmitted infection diagnosis, sexual identity, hazardous alcohol use, and number of anonymous partners. RESULTS: From 2119 participants (47.1% living with HIV), 5 latent classes were identified: "pasivo partner" (26.1%); " one-time activo partner" (20.2%); " recurring activo partner" (16.6%); " one-time moderno partner" (13.3%); and "recurring moderno partner" (23.8%). Class memberships were each associated with different groupings of HIV transmission risk factors. Certain moderno partner classes were associated with substance use and larger anonymous sexual networks, particularly among GBMSM not living with HIV, compared with the "pasivo partner" class. CONCLUSIONS: Our findings demonstrate that GBMSM in Lima represent a behaviorally diverse population whose HIV risk is shaped by sexual roles, partnership types, and network structures. Culturally informed prevention strategies that incorporate these dynamics-such as role-specific partner-notification methods-are essential to more effectively address HIV transmission in the region.