Brief Report: Seroadaptive Behaviors Varied Among Geographically Diverse iPrEx Participants

Seroadaptive behaviors refer to a wide range of harm reduction practices to decrease HIV transmission risk. Effective implementation of seroadaptive behaviors is dependent on knowledge of one's own serostatus and that of one's sexual partners. Partner-level and environmental-level attributes may affect seroadaptation practices. We assessed factors associated with seroadaptive behaviors.

Men who have sex with men and transgender women were recruited from an HIV pre-exposure prophylaxis clinical trial (iPrEx) with study sites in the US, Peru, Ecuador, Brazil, Thailand, and South Africa. Partnership-level data were collected at the baseline visit for the 3 most recent partners. Participants were considered to have practiced seroadaptive behaviors if: (1) they believed their partner to be HIV-negative, that is, serosorting; or (2) no condomless receptive sex occurred with an HIV-positive or unknown status partner, that is, seropositioning.

Of 2331 participants, 41% always practiced seroadaptive behaviors, 36% sometimes did, and 23% never did. Participants enrolled at study sites in the US (P < 0.001) and Peru/Ecuador (P < 0.001) were more likely to practice seroadaptive behaviors, whereas transgender women were less likely to do so (P < 0.001). Seroadaptive behaviors were more likely to occur in relationships with steady partners (P = 0.005) and emotionally close relationships (P = 0.013).

Seroadaptive behaviors were more frequently observed among iPrEx participants from the US, Peru, and Ecuador study sites and among participants in relationships with partners who they were more committed to and felt emotionally close to. Our findings suggest that seroadaptive behaviors may be influenced by social norms that vary geographically and culturally.