In post-industrialised countries, since the turn of the millennium we have witnessed outbreaks of hepatitis C among HIV-diagnosed gay men, and cohort studies of HIV-diagnosed men-who-have-sex-with-men (MSM) have shown high incidence of HCV infection, or re-infection after clearance. Clinicians and health promotion specialists have repeatedly expressed concerns that the HCV epidemic will jump to HIV-negative MSM. For the last two decades there has been a widespread perception that HCV will inevitably affect the whole population of MSM. For many years, studies of HIV-negative MSM have provided no strong evidence for an HCV sero-prevalence higher than among other adult men, and no outbreaks had been observed among HIV-negative MSM. It has hence been conceptualised that HIV infection itself might be a major risk factor for HCV acquisition, due to alterations of cellular immunity, but the risk attributable to immune dysfunction is still unclear. Some have argued that sero-adaptive sexual networks might better explain the observed differences between HIV-diagnosed and other MSM. As for behavioural factors, while the role of condomless anal sex for HCV transmission is controversial, there is consensus that mucosal disruption and sexual exposure to blood are major risk factors. With the recent advent of oral HIV pre-exposure prophylaxis, shifts in sexual networks have been observed as well as rising HCV incidence in PrEP-using HIV-negative MSM. This reignites previous fears about the imminence of an HCV epidemic among HIV-negative MSM. While intravenous drug use with shared equipment has been known for decades to be a leading risk factor for HCV transmission –regardless of HIV infection or sexual orientation– its impact on HCV transmission in MSM is understudied. This talk aims at (1) summarising the available literature on HCV transmission, focussing on HIV-negative MSM, and (2) providing a conceptual framework of sexual and sex-associated HCV transmission in gay men.

Disclosure No significant relationships.