Background Recreational drug use (RDU), particularly during sex, may contribute to human immunodeficiency virus (HIV) and sexually transmitted infections (STI) transmission by increasing sexual risk behaviour. We studied changes in RDU, including chemsex, and associations with condomless anal sex (CAS), HIV and STI among HIV-negative men who have sex with men (MSM).

Methods MSM enrolled in the Amsterdam Cohort Studies with ≥1 study visit between 2008–2017 (n=887) were asked questions on behaviors in the preceding 6 months and underwent HIV/STI testing (chlamydia, gonorrhea, syphilis) biannually. Changes in RDU (overall/during sex) and chemsex (GHB/GBL, mephedrone, methamphetamine, ketamine, amphetamine, cocaine and/or XTC during sex), and their associations with CAS, HIV and any STI (<6 months), were tested across calendar years using logistic regression with generalized estimating equations, while adjusting for age, calendar year, country of birth and education level.

Results Of 884 included MSM, 83.5% were born in the Netherlands and 75.3% had a college degree. Median age on 1-January-2008 was 32.4 (IQR=24.9–38.9) years. Median number of visits with RDU data was 11 (IQR=5–18). RDU increased from 66.8% in 2008 to 70.0% in 2017 (2017 vs 2008: aOR=1.23, 95%CI=1.03–1.48). RDU during sex increased from 52.4% in 2008 to 58.7% in 2013 (2013 vs 2008: aOR=1.22, 95%CI=1.05–1.42) and remained stable afterwards. Chemsex increased from 19.3% in 2008 to 23.6% in 2017 (2017 vs 2008: aOR=1.52, 95%CI=1.21–1.90). Among those with a reported sex partner, RDU during sex was associated with CAS (aOR=1.33, 95%CI=1.17–1.52), HIV (aOR=7.92, 95%CI=2.75–22.8), and STI (aOR=2.31, 95%CI=1.92–2.77). Chemsex was associated with CAS (aOR=1.54, 95%CI=1.32–1.79), HIV (aOR=6.46, 95%CI=3.48–12.0), and STI (aOR=2.29, 95%CI=1.88–2.76).

Conclusion Slight increases in RDU and chemsex were found over time among HIV-negative MSM in Amsterdam and were strongly associated with CAS, HIV and STI. Effective interventions to reverse these trends in RDU are needed.

Disclosure No significant relationships.