Cross-sectional analysis of chemsex drug use and gonorrhoea diagnosis among men who have sex with men in the UK.

Background: Illicit drug use among men who have sex with men (MSM) has been associated with sexual risk and HIV. Less is documented about associations with other sexually transmissible infections (STIs). The aim of the present study was to determine whether the use of drugs commonly associated with chemsex is associated with increased risk of gonorrhoea among MSM. Methods: Using data from 16065 UK-based respondents to the European MSM Internet Survey (2010), we examined associations between a recent diagnosis of gonorrhoea and three chemsex drugs (crystal methamphetamine, γ-hydroxybutyric acid (GHB)/γ-butyrolactone (GBL) and mephedrone). Univariate logistic regression identified determinants of gonorrhoea diagnosis and multivariate logistic regression models calculated adjusted odds ratios (aORs) for independent associations between chemsex drugs and gonorrhoea. Results: MSM who reported using crystal methamphetamine and GHB/GBL in the previous year had 1.92- and 2.23-fold higher odds of gonorrhoea respectively over the same period (P=0.0001 and P<0.0001; n=15137) after adjusting for age, recruitment website, HIV status, residence and use of other chemsex drugs. MSM reporting the use of all three chemsex drugs had the highest increased odds (aOR 3.58; P<0.0001; n=15174). Mephedrone alone was not associated with gonorrhoea in multivariate models. Conclusions: Use of chemsex drugs is associated with a higher risk of gonorrhoea. The results of this study complement existing research about crystal methamphetamine and indicate a role for GHB/GBL in adverse sexual health outcomes. The use of mephedrone alongside other chemsex drugs may account for its lack of association with gonorrhoea in multivariate models. Future research should use encounter-level data, examine other STIs and attribute pathways through which chemsex leads to infection.