METHODS: A total of 179 MSM using PrEP were followed up for 18 months and were screened quarterly for chlamydia, gonorrhoea, and syphilis from 2015-2018 in Belgium. Participants were stratified into three different groups (no STI; one STI episode; recurrent STI episodes during the study). Socio-demographic and sexual behavioural characteristics were compared between the three groups and significant associations with recurrent STI were explored using multivariate logistic regression models.
RESULTS: A total of 62.0% (n=111/179) of participants experienced at least one STI during the study, and more than one in three became reinfected with an STI at another visit (n=66/179; 36.9%). Participants experiencing recurrent STIs reported the highest frequency of sexualized drug use (86.4%) compared to participants experiencing one (60.0%) or no STI (47.1%). Therefore, sexualized drug use was highly associated with recurrent STIs (adjusted odds ratio (aOR): 4.35). Other factors associated with recurrent STIs were being younger than 40 years old (aOR: 3.29), had a high number (>4) of non-steady partners with whom receptive (aOR: 1.17) or insertive (aOR:1.12) condomless anal intercourse occurred in the last three months CONCLUSIONS: Sexualised drug use was the greatest risk factor for having recurrent STIs. Tailoring prevention and care, including specialised services tackling problematic drug use in a sexual context, may help to curb the STI epidemic among MSM.