Introduction Anthropologists use qualitative methods to elicit cultural frameworks which structure patterns of behaviour and social organisation. These resultant “emic” models offer a window on the world of meaning for social actors in their engagement with others. We employed ethnographic approaches to investigate how men who have sex with men (MSM) identify potential sex partners, determine partner risk profiles, and adopt specific seroadaptive behaviours and strategies to minimise risk of STI/HIV transmission.

Methods Sexually-active MSM in St. Louis, MO USA were recruited from online advertisements on a variety of social networking sites, as well as flyers posted at bars, clubs, and other venues. Participants completed extended, in-depth qualitative interviews about sex partner selection, sexual practices, and seroadaptive approaches for STI/HIV prevention, including knowledge and use of pre-exposure prophylaxis (PrEP).

Results As of 13 March 2015, 11 subjects were enrolled in the study, with median age 30 (IQR 27 – 35). Participants reported increasingly nuanced categories of partner risk perception, including “HIV-negative plus PrEP,” “HIV-negative,” “HIV-positive, undetectable,” “HIV-positive, detectable,” “HIV-positive, unknown viral load” and “HIV-unknown.” Serosorting was observed. Seropositioning was universal for HIV prevention – subjects reporting active engagement to minimise risk of HIV transmission (but not syphilis or other STIs) to negative or status-unknown partners. Knowledge of PrEP was variable. Emic conceptions of risk invoked existential models of concern for self and others. Adoption and performance of specific behaviours validated and confirmed perceptions of benevolence toward self and others.

Conclusion HIV prevention was highly valued and actively sought by sexually-active MSM. Risk conceptions were mediated through complex understandings of partner risk profiles, and performance of seroadaptive behaviours served to validate perceptions of well-being and benevolence. The need for syphilis prevention was under-appreciated. These findings have implications for improving STI/HIV prevention approaches among MSM.

Disclosure of interest statement Supported with funding from the US Centres for Disease Control and Prevention (CDC).