Chemsex and Beyond: A Study of Factors Associated with Substance Use Among Men Who Have Sex with Men and Transgender Women in Southern Vietnam to Develop Informed HIV and STI Prevention and Intervention Programs

Background: Amphetamine-type stimulant (ATS) use is a major public health concern among men who have sex with men (MSM) and transgender women (TGW) in communities worldwide and in Vietnam.

Methods: A cross-sectional study was conducted on 1000 adult MSM and TGW from 9 community-based organizations in southern Vietnam from March to August 2019. Data on demographics, sexual behaviors, STIs, HIV infection, and substance use were collected with a self-administered questionnaire including the ASSIST tool. Blood and urine samples were collected for HIV and ATS testing.

Results: The prevalence of lifetime ATS use in the previous three months was 50.5% and 49.4%, respectively. Multivariable analyses showed that ATS use was significantly associated with sex with a transactional partner (aOR [29] = 3.06, 95% CI = 2.13-4.39) who engaged in sex and got paid for it (aOR = 2.78, 95% CI = 1.64-4.73), and purchasing sex (aOR = 2.34, 95% CI = 1.06-5.16). The role in sex with a partner with significant association was 'insertive and receptive equally vs. insertive only' (aOR = 1.78, 95% CI = 1.14-2.76).

Conclusion: ATS use is associated with many sexual behaviors that could be associated with an increased risk of HIV transmission among MSM and TGW populations.