This study explores sexual HIV preventive behaviors of men who have sex with men (MSM), including the use of treatment as prevention (TasP) and PrEP, during their most recent anal intercourse (MRAI) with a casual partner. We especially look at factors associated with the non-use of these prevention tools during MRAI with a casual partner.

Data were extracted from the cross-sectional online survey called ‘Rapport au sexe 2019’, conducted in France among MSM. We performed univariate analyses to describe respondents’ characteristics, and simple and multiple logistic regression models to investigate the associations between unprotected MRAI with a casual partner and personal characteristics and situational determinants. Statistical analyses were performed using Stata software version 15.

Among participants, 76.2% self-reported they were HIV-negative, 9.7% HIV-positive, and 14.1% were unaware of their HIV status. Condoms were the most common prevention tool used during MRAI. The use of TasP was reported by 29.1% of HIV-positive respondents and PrEP by 17.8% of HIV-negative respondents. The proportion of MSM who declared no prevention practice was significant (24.7%). A high level of social vulnerability was associated with unprotected anal intercourse in HIV-negative and unknown HIV status respondents.

Our findings underline the existence of specific vulnerable groups at great risk of HIV infection. Prevention programs must be adapted to the entire MSM population in all its diversity by promoting the whole range of current prevention tools.