Changes in incidence of hepatitis C virus reinfection and access to direct-acting antiviral therapies in people with HIV from six countries, 2010-19: an analysis of data from a consortium of prospective cohort studies.

BACKGROUND

Reinfection after successful treatment with direct-acting antivirals is hypothesised to undermine efforts to eliminate hepatitis C virus (HCV) infection among people with HIV. We aimed to assess changes in incidence of HCV reinfection among people with HIV following the introduction of direct-acting antivirals, and the proportion of all incident cases attributable to reinfection.

METHODS

We pooled individual-level data on HCV reinfection in people with HIV after spontaneous or treatment-induced clearance of HCV from six cohorts contributing data to the International Collaboration on Hepatitis C Elimination in HIV Cohorts (InCHEHC) in Australia, Canada, France, the Netherlands, Spain, and Switzerland between Jan 1, 2010, and Dec 31, 2019. Participants were eligible if they had evidence of an HCV infection (HCV antibody or RNA positive test) followed by spontaneous clearance or treatment-induced clearance, with at least one HCV RNA test after clearance enabling measurement of reinfection. We assessed differences in first reinfection incidence between direct-acting antiviral access periods (pre-direct-acting antiviral, limited access [access restricted to people with moderate or severe liver disease and other priority groups], and broad access [access for all patients with chronic HCV]) using Poisson regression. We estimated changes in combined HCV incidence (primary and reinfection) and the relative contribution of infection type by calendar year.

FINDINGS: Overall, 6144 people with HIV who were at risk of HCV reinfection (median age 49 years [IQR 42-54]; 4989 [81%] male; 2836 [46%] men who have sex with men; 2360 [38%] people who inject drugs) were followed up for 17 303 person-years and were included in this analysis. The incidence of first HCV reinfection was stable during the period before the introduction of direct-acting antivirals (pre-introduction period; 4·1 cases per 100 person-years, 95% CI 2·8-6·0). Compared with the pre-introduction period, the average incidence of reinfection was 4% lower during the period of limited access (incidence rate ratio [IRR] 0·96, 95% CI 0·78-1·19), and 28% lower during the period of broad access (0·72, 0·60-0·86). Between 2015 and 2019, the proportion of incident HCV infections due to reinfection increased, but combined incidence declined by 34%, from 1·02 cases per 100 person-years (95% CI 0·96-1·07) in 2015 to 0·67 cases per 100 person-years (95% CI 0·59-0·75) in 2019.

INTERPRETATION: HCV reinfection incidence and combined incidence declined in people with HIV following direct-acting antiviral introduction, suggesting reinfection has not affected elimination efforts among people with HIV in InCHEHC countries. The proportion of incident HCV cases due to reinfection was highest during periods of broad access to direct-acting antivirals, highlighting the importance of reducing ongoing risks and continuing testing in people at risk.

FUNDING: Australian National Health and Medical Research Council.