Sexualized drug use and STD and HIV incidence among men who have sex with men in Amsterdam, the Netherlands

Background: We assessed the association between sexualized drug use (SDU), and incident sexually transmitted diseases (STDs) and human immunodeficiency virus (HIV) infections among men who have sex with men (MSM). Methods: We used data from the MS2 cohort study, conducted at the STI Outpatient Clinic of the Public Health Service of Amsterdam, the Netherlands, in 2014–2019. Eligible participants were adult HIV-negative MSM with ≥2 STDs in the preceding year and MSM living with HIV and ≥1 STD. Participation encompassed 3-monthly visits including STD screening and questionnaires on drug use. Primary outcomes were incident HIV, anal chlamydia/gonorrhoea, and syphilis. We studied the association between SDU of individual drugs and incident HIV and STDs, using Poisson regression. Analyses were adjusted for age and HIV-status. Results: 131 HIV-negative MSM and 173 MSM living with HIV were included for analysis. SDU with GHB/GBL (aIRR = 7.2, 95% CI = 1.4–35.5) in the 3 months before testing was associated with incident HIV. SDU with GHB/GBL (aIRR = 1.2, 95% CI = 1.0–1.4), ketamine (aIRR = 1.3, 95% CI = 1.0–1.6) or methamphetamine (aIRR = 1.3, 95% CI = 1.0–1.6) was associated with incident anal chlamydia/gonorrhoea. We found no association between SDU with specific drug types and syphilis incidence. Conclusions: SDU with GHB/GBL, ketamine and methamphetamine among MSM was associated with incident HIV and anal chlamydia/gonorrhoea. HIV-negative MSM engaging in SDU should be advised to use HIV pre-exposure prophylaxis, and all MSM engaging in SDU should be advised to have STD screening regularly. We suggest counselling on STDs among MSM engaging in SDU.