Sialon II aimed to carry out and promote combined and targeted prevention complemented by a meaningful surveillance among MSM in a number of European cities. Data were collected through peer data-collectors using time-location sampling community (night) venues in Brussels, Belgium through a bio-behavioural self-administered survey. Oral fluid samples were used to estimate HIV prevalence.
Data were analysed in a sample of 391 (mean age 35y) MSM. The estimated HIV prevalence by oral samples was 12.3% (CI 7.9-18.6) with knowledge of status for 69.9% as compared to 10.4% (CI 6.0-17.6) for self-declared HIV-positive status. Previous HIV testing behaviour was high with 69.3% been tested in the past 12 months and 98.9% receiving HIV results. The median number of sex partners in the last six months was 9.4 with over half of MSM having steady as well as casual partners. Anal intercourse with non-steady partners was common with 46.3% reporting 2-6 partners in the last 6 months. Condom use during last anal sex was 40% with steady partners and 75% with non-steady partners. Age, country of birth or residence, and diagnosis of a sexually transmitted infection (STI) were not associated with self-report of HIV-positive status. Being HIV positive was associated with having been tested for an STI in the past 12 months (OR 5.4, p=0.074) and the use of drugs (poppers, ecstasy, Viagra, cocaine, amphetamine, GHB) (AOR 7.0 (CI: 1.5-33.2); P=0.017). Having anal intercourse with two or more non-steady partners in the past six months (compared to no partners) was significantly associated with HIV-positive self-report (AOR 2-10 partners 7.7 (CI 1.0-59.0) and >10 partners 7.0 (CI 1.5-33.2); p=0.002).
Specific patterns of sexual behaviour, a high number of partners and low rates of condom use were found among MSM in Brussels, Belgium. A strong association with STI testing and drug use during sexual intercourse was demonstrated. Future prevention messages should adopt a syndemic framework and include information on drug use, most pressingly in the age of PreP.