Abstract Body

In the ANRS IPERGAY trial, on demand pre-exposure prophylaxis (PrEP) has been demonstrated to be highly effective in preventing HIV infection among men who have sex with men (MSM). We aimed to identify MSM who would benefit the most from PrEP by assessing baseline risk factors for HIV infection in this population.

We analyzed baseline data from participants enrolled in the placebo arm of the ANRS IPERGAY trial or infected between pre-enrollment and baseline, and who completed the online questionnaire. We analyzed socio-demographic characteristics, past use of psychoactive substances and sexual behavior as risk factors for HIV infection. HIV incidence rate ratios (RR) were estimated with their 95% Confidence Intervals (CI). Results are reported in the table.

203 MSM were included in this analysis, with a median age of 34 years (IQR: 29-42). Overall, 16 HIV infections occurred during a median follow-up of 9 months (IQR: 5-20). The number of sexual partners in prior 2 months (≥10 vs. <10) and the number of condomless receptive anal sex episodes in prior 12 months (≥6 vs. <6) were associated with a significantly increased risk for HIV infection (RR: 3.1; 95%CI [1.1-9.9] and RR: 3.3; 95%CI [1.2-10.2] respectively), whereas those with mostly insertive sexual practices were at lower risk (RR: 0.1, 95%CI: 0-0.6). A diagnosis of bacterial STI at baseline was not significantly associated with an increased risk. Participants who met casual partners in backrooms/sex-clubs or in private sex-parties were also at increased risk for HIV infection (RR: 3.9; 95%CI [1.1-26.8] and RR: 2.9; 95%CI [1.1-9.5] respectively). The use of ketamine, MDMA, GHB/GBL or drugs for erectile dysfunction in prior 12 months was associated with a significantly increased risk of HIV infection. We found no association with age, education level, having a steady partner, or tobacco, alcohol and cannabis consumption in prior 12 months, but being enrolled in Paris was associated with a significant increased risk of HIV infection (RR: 4.1; 95%CI [1.1-28.3]).

MSM who have frequent condomless receptive anal sex, multiple partners met in backrooms/sex-clubs or in private sex-parties, or use drugs for sex should be particularly targeted in prevention programs in particular if they live in an area with a high prevalence of HIV infection.