Men who have sex with men (MSM) in Thailand have high HIV prevalence. This analysis used three years of data from the Behavioral Surveillance Survey (BSS) to examine the behaviors and biomedical interventions among MSM in Bangkok. Percent MSM with an HIV or STI test in the past 12 months decreased from 50.8% to 29.8%, and 42.2% to 33.0%, respectively. The frequency of HIV/STI testing was higher among those who had university-level education, as well as among those who reported higher AIDS knowledge, and had utilized prevention services. Additionally, awareness of PrEP peaked in 2017 (74.1%). The study found an increasing trend of men who had sex without a condom the last time they had anal sex with a man, and/or with multiple partners. Nearly two-thirds of the sample were reached by HIV prevention interventions. One-third had correct AIDS knowledge. These findings suggest that, after an increase of sex behavior risk, a decrease in PrEP awareness, and unknown HIV status, HIV prevalence among MSM in Bangkok may have begun to increase again. Intensified prevention interventions are urgently needed to reduce HIV behavioral risk for MSM since that is a major driver of the HIV epidemic in Thailand.
