Uptake of testing, linkage to care, and treatment for hepatitis C infection among people who inject drugs in Australia: the ETHOS Engage Study

Background: People who inject drugs (PWID) are at high risk of hepatitis C virus (HCV) infection but have poor access to HCV treatment in most settings. Unrestricted direct-acting antiviral (DAA) therapy has been available in Australia since March 2016. Our objective was to evaluate burden of HCV and the extent of, and factors associated with, engagement with the HCV cascade of care among PWID in an era of unrestricted DAA therapy access.

Methods: ETHOS Engage is an observational cohort study collecting demographic, behavioural and clinical data among PWID attending drug treatment clinics and needle and syringe programs in Australia. All PWID underwent point-of-care (POC) HCV RNA testing via Xpert® HCV Viral Load Finger-Stick assay. Multivariate logistic regression models were used to identify demographic and behavioural factors associated with treatment uptake.

Results: Between May and November 2018, 507 PWID were enrolled. Overall, 70% had injected drugs in the last month, and 70% were currently receiving opioid substitution therapy (OST). Of all enrolled, 73% (n=370) were ever HCV-infected (Ab positive), and 58% (n=296) were ever chronic HCV-infected (RNA positive or prior treatment). Among those Ab positive (n=370), 76% had previously been tested for HCV RNA. Among those with evidence of current or past chronic HCV (n=296), 86% had ever been linked to care and 68% had ever received treatment for HCV. Uptake of HCV therapy was high across sub-populations, including those with current and no OST (71%, 59%) recent injecting (last month) (70%), and heroin (68%), other opioid (57%) and amphetamine (70%) injecting in the last month. In adjusted analysis, no factors were associated with treatment uptake. Among those with a POC HCV RNA result at enrolment, 26% had current HCV infection (HCV RNA+ve), 33% had treatment-induced clearance, 17% spontaneous clearance, and 23% were uninfected (HCV Ab-ve). The proportion with current HCV infection was similar across demographic and behavioural sub-populations.

Conclusion: The DAA era in Australia has produced high treatment uptake and lowered HCV viraemia among PWID attending drug treatment and needle syringe programs. To reach elimination targets, subgroups of PWID may require additional support to encourage further screening and engagement with HCV care.