HCV microelimination in harm reduction centres has benefits beyond HCV cure but is hampered by high reinfection rates.

Background & Aims: Significant scale-up of treatment among people who inject drugs (PWID) is crucial to achieve WHO HCV elimination targets. We explored the impact of on-site HCV diagnosis and treatment on PWID in an externalised hepatology clinic at the biggest harm reduction centre (HRC) in Barcelona attending to a marginalised PWID population with ongoing high-risk practices. Methods: On-site HCV point-of-care testing was performed for diagnosis and treatment delivery. HCV-RNA was assessed at SVR12 (sustained virologic response at 12 weeks) and every 6 months. The programme included behavioural questionnaires at baseline and after treatment. Results: Between 2018 and 2020, 919 individuals were prospectively enrolled. Of these, only 46% accepted HCV screening. HCV-RNA+ prevalence was 55.7% (n = 234). Of the 168 (72%) individuals starting treatment, 48% were foreigners, 32% homeless, 73% unemployed, and 62% had a history of incarceration. At enrolment, 70% injected drugs daily and 30% reported sharing needles or paraphernalia. Intention-to-treat SVR12 was 60%; only 4% were virological failures, the remaining were either early reinfections (20%) or losses to follow-up (16%). The overall reinfection rate during follow-up was 31/100 persons/year. HIV coinfection and daily injection were associated with a higher risk of reinfection. Nonetheless, beyond viral clearance, antiviral therapy was associated with a significant reduction in injection frequency, risk practices, and homelessness. Conclusions: HCV treatment can be successfully delivered to active PWID with high-risk practices and has a significant benefit beyond HCV elimination. However, approaching this difficult spectrum of the PWID population implies significant barriers such as low rate of screening acceptance and high dropout and reinfection rates. Lay summary: People who inject drugs attending harm reduction centres represent the most difficult population to treat for hepatitis C. We show that hepatitis C treatment has a significant benefit beyond viral cure, including improving quality of life, and decreasing injection frequency and risk practices. However, intrinsic barriers and the high reinfection rates hamper the achievement of viral microelimination in this setting.