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, the French research group who carried out the study
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 and 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, researchers looked at hepatitis C
incidence in the ANRS-CO4-FHDH cohort, 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 within two years prior to 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) and
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
(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 PRMO cohort of gay and bisexual
men with HIV enrolled soon after acquiring HIV.
The French group 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 HCV incidence.