New cases of hepatitis C have fallen among gay and bisexual men with HIV in France

The rate of new hepatitis C infections halved among gay and bisexual men with HIV in France between 2014 and 2017 following the introduction of direct-acting antivirals, a French cohort study has reported.

However, Dr Mathieu Castry and colleagues say that additional risk reduction measures will be needed to drive down hepatitis C transmission and achieve micro-elimination of the virus among gay and bisexual men living with HIV in France.

Hepatitis C transmission began to rise among gay and bisexual men with HIV in Europe and North America after 2000. A previous French study found that hepatitis C prevalence doubled in this population between 2012 and 2018. The increase in hepatitis C transmission in this population is due to unprotected anal intercourse, fisting, group sex and sexualised use of injected drugs, which may involve the sharing of injecting equipment.

Several modelling studies have projected that hepatitis C incidence could be greatly reduced in gay and bisexual men through high levels of treatment and cure of chronic infection, as well as treatment of acute infection.

To assess the possible impact of direct-acting antiviral treatment on hepatitis C incidence in France, the researchers looked at hepatitis C incidence in the French hospital database on HIV, a nationally representative cohort of people living with HIV receiving care at 175 hospitals in France between 2014 and 2017.

Hepatitis C treatment using second-generation direct-acting antivirals was available without restriction to people living with HIV throughout the study period.

The researchers identified 14,273 gay or bisexual men in the cohort who attended a clinic between 2014 and 2017, had a negative hepatitis C antibody test in the two years before inclusion in the analysis and a subsequent hepatitis C antibody test between 2014 and 2017. From this cohort they calculated hepatitis C incidence between 2014 and 2017, assuming that all selected participants were tested every six months according to French guidelines.

Those included in the analysis had a median age of 44 years, 83% were taking antiretroviral treatment at the beginning of the follow-up period and 99% by the end of follow-up, and 71% had an undetectable viral load (<50 copies/ml) at the beginning of follow-up. Study participants were followed for a median of four years (45,866 person-years of follow-up). Between 2014 and 2017, they received a median of three hepatitis C antibody tests, at a median testing interval of 11 months.

During the follow-up period, 330 new hepatitis C infections were diagnosed, an overall incidence of 0.76 cases per 100 person-years of follow-up. The number of infections declined each year, from 101 in 2014 to 54 in 2017, and the incidence rate fell by 54% between 2014 and 2017. Incidence fell by 33% between 2016 and 2017.

Although incidence declined in all age groups, the decline in men under 30 at study entry was not statistically significant and the rate of infection was almost twice as high in men under 30 compared to the 30-45 age group (incidence rate ratio 1.96, p<0.0001).

Incidence also remained higher in those living in the Paris region than in those living elsewhere (IRR 1.51, p=0.0003).

The researchers say that the decline in incidence is unlikely to be attributable to reductions in risk behaviours, as condomless sex continued to increase up to 2017 in the ANRS PRIMO cohort of gay and bisexual men with HIV enrolled soon after acquiring HIV.

Castry and colleagues say their findings match observations in the Netherlands and the United Kingdom after the introduction of direct-acting antivirals. But they warn that although further scale-up of treatment would lead to greater reductions in hepatitis C incidence, increases in hepatitis C transmission among HIV-negative gay and bisexual men in France could halt progress towards hepatitis elimination, due to shared sexual networks. They say that risk reduction strategies for gay and bisexual men living with HIV and for HIV-negative men are also needed to limit the incidence of hepatitis C.