Men who have Sex with Men and Chemsex: A Clinic-Based Cross-sectional Study in South Australia

Background Chemsex, the intentional combining of sex with the use of particular psychoactive substances typically crystal methamphetamine, gamma-hydroxybutyrate(GHB)/gamma butyrolactone(GBL), mephedrone, and ketamine has been reported among men who have sex with men (MSM). Chemsex is more common among MSM than in the general population. We aimed to determine the prevalence and factors associated with chemsex in a sample of MSM attending three clinical settings in South Australia (SA). Methods MSM attending three urban clinics in South Australia between 1 February 2017 and 31 August 2017 were invited to complete questionnaires reporting socio-demographic information, sexual practices, drug use, and HIV/STI status. We determined the proportion of respondents reporting chemsex and evaluated factors associated with this practice using unadjusted and adjusted logistic regression. Results Chemsex was reported by 29% of this sample and was associated with being Australian-born (APR = 1.45; 95%CI: 1.02–2.06), engaging in group sex once/a few times (APR = 1.86; 95%CI 1.35–2.57) or at least monthly (APR = 2.30; 95%CI 1.23–4.29), hooking-up for sex online and on mobile phone applications (APR = 1.70; 95%CI 1.19–2.43), being HIV positive (APR = 2.46; 95%CI 1.62–3.73) and taking PrEP (APR = 1.85; 95%CI 1.06–3.23). Condom-less anal sex (CAS) was significantly associated with chemsex (APR = 1.44; 95%CI 1.04–1.99). Conclusion The practice of chemsex in MSM in our clinical settings was associated with HIV-positive status and with certain sexual practices. This practice by HIV-negative and HIV-positive men may play a role in STI and HIV transmission. There is a need to better understand this practice and our findings may inform the development of clinically based STI/HIV prevention and health promotion interventions for MSM in similar settings.