Time trends in the risk of HIV infection among men who have sex with men in Chiang Mai, Thailand: an observational study.

A cross-sectional study on men who have sex with men (MSM) for the HIV prevention project was conducted to assess the prevalence of HIV infection-related behaviors among 551 MSM recruited in 2008-2009 and 1910 MSM in 2014-2018 for voluntary counseling and testing at a HIV clinic in Chiang Mai. Overall, the study found that the prevalence of HIV infection was significantly decreased from 12.9% (71/551) in the earlier study (2008-2009) to 8.2% (157/1910) in the recent study (2014-2018) (p = 0.001). By comparison, in 2008-2009 and 2014-2018, there was no statistically significant difference in consistent condom use (39.0% [186/477] vs. 38.9% [591/1512], p = 0.969), while unprotected anal sex with casual partners significantly increased (44.5% [159/357] vs. 51.9% [645/1242], p = 0.014) and receptive anal sex significantly increased (37.7% [180/477] vs. 45.1% [860/1905], p = 0.004). However, previous HIV testing within 1 year increased significantly from 64.6% (197/305) to 74.7% (677/906, p = 0.001). In exploratory multivariate analysis, the factors associated with HIV infection included gay men, age below 20 years, being self-employed, being an employee, having only receptive anal sex, having both receptive/insertive anal sex, being a former substance user, using online dating, having a history of sexually transmitted infection symptoms, self-perception as being at high risk for HIV, last HIV testing >1 year, and never previously testing for HIV. The data represent the trend of health-seeking behavior improvements. The findings demonstrated the need for a novel sexual health service in an endemic setting and health promotion for online partner-seeking.