The impact of direct-acting antivirals on hepatitis C viraemia among people who inject drugs in England; real-world data 2011-2018.

Direct-acting antiviral (DAA) therapy for anybody with viraemic HCV infection has been scaled-up in England since 2017. To assess early impacts, we investigated trends in, and factors associated with, HCV viraemia among people who inject drugs (PWID). We also examined trends in self-reported treatment access. Bio-behavioural data from an annual, national surveillance survey of PWID (2011-2018) estimated trends in viraemic prevalence among HCV antibody-positive PWID. Multivariable logistic regression identified characteristics independently associated with viraemia. Trends in treatment access were examined for PWID with known infection. Between 2011 and 2016, viraemic prevalence among antibody-positive PWID remained stable (2011, 57.7%; 2016, 55.8%) but decreased in 2017 (49.4%) and 2018 (50.4%) (both p < 0.001). After adjustment for demographic and behavioural characteristics, there remained significant reduction in viraemia in 2017 (adjusted odds ratio [aOR] 0.79, 95% CI 0.65-0.94) and 2018 (aOR 0.79, 95% CI 0.66-0.93) compared to 2016. Other factors associated with viraemia were male gender (aOR 1.68, 95% CI 1.53-1.86), geographical region, injecting in past year (aOR 1.26, 95% CI 1.13-1.41), imprisonment (aOR 1.14, 95% CI 1.04-1.31) and homelessness (aOR 1.17, 95% CI 1.04-1.31). Among non-viraemic PWID with known infection, the proportion reporting ever receiving treatment increased in 2017 (28.7%, p < 0.001) and 2018 (38.9%, p < 0.001) compared to 2016 (14.5%). In conclusion, there has been a small reduction in HCV viraemia among antibody-positive PWID in England since 2016, alongside DAA scale-up, and some indication that treatment access has improved in the same period. Population-level monitoring and focus on harm reduction is critical for achieving and evaluating elimination.