From May 2015 to June 2018, we conducted a PrEP demonstration project at two hospitals and four community-led clinics in Bangkok and Pattaya. HIV-negative, MSM and TGW aged ≥18 years old, reporting sex without a condom, were offered daily PrEP. Participants received HIV testing and completed a computer-based questionnaire at enrollment, 6 and 12 months. We collected self-reported PrEP adherence at months 1, 3, 6, 9, and 12. We used logistic regression to determine factors associated with the decision to take PrEP and calculated HIV incidence among baseline HIV-negative participants. Of 803 participants enrolled, 349 (43.5%) started PrEP. Participants were more likely to start PrEP if they were sex workers, had moderate or high self-perceived risk of HIV, or a high PrEP-knowledge score. Participants used PrEP for a median of 6.1 months. Reported condom use increased and the number of sex partners decreased during follow-up regardless of PrEP use. Six participants not-taking PrEP acquired HIV (HIV incidence 2.2 per 100 person-years), and five taking PrEP acquired HIV (HIV incidence 2.1 per 100 person-years). All five reported taking <4 pills the weeks before study visits.
Keywords: HIV incidence; MSM; Pre-exposure prophylaxis; Thailand; transgender women.