Elimination of hepatitis C virus among people who inject drugs in Australia

Abstract

Background: Hepatitis C virus (HCV) is a global public health threat contributing to morbidity and mortality worldwide—particularly among people who inject drugs (PWID). Aims: The aim of this research was to assess progress towards HCV elimination among PWID during the direct-acting antiviral therapy (DAA) era. Specific aims included assessing (1) current HCV prevalence among PWID and associated factors (2), treatment uptake among PWID and associated factors, and (3) inpatient hospitalisation as a setting to enhance DAA uptake. Methods: In Chapter Two, current HCV and treatment uptake are analysed among PWID attending drug treatment and needle and syringe programs throughout Australia in an observational cohort (the ETHOS Engage Study). Factors associated with current HCV infection and HCV treatment uptake were assessed using logistic regression. In Chapter Three, DAA uptake data from a population-based linkage study covering all people in New South Wales with HCV notification were analysed using logistic regression. In Chapter Four, survival analysis was used to assess population-level DAA uptake by history and characteristics of hospitalisation. In Chapter Five, the change in HCV viremia and treatment uptake among PWID between two recruitment waves was assessed in the ETHOS Engage Study. Logistic regression was used to assess the factors associated with current HCV infection and treatment uptake in the second recruitment wave. Key Findings: HCV viraemic prevalence has declined considerably following high DAA uptake among PWID populations in recent years. Despite this success, there remain populations requiring enhanced support. Indicators of higher marginalisation—including homelessness, frequent injection drug use, and frequent hospitalisation—were associated with lower treatment uptake. Among PWID who were hospitalised, treatment uptake was lower among those who had been hospitalised for drug use, injection-related infectious diseases, and mental health disorders. Current HCV infection was associated with markers of higher marginalisation. Between the two ETHOS Engage recruitment waves, we observed a decline in HCV viremia and an increase in treatment; however, gaps remain. Conclusion: Public health action is needed to enhance HCV care among marginalised groups of PWID. Innovative and novel interventions—including the utilisation of inpatient hospitalisation—are needed to enhance care. Contribution from multidisciplinary stakeholders is necessary to ensure HCV elimination is equitably reached across all PWID.