Disease Elimination Program, Burnet Institute, Melbourne, Victoria, Australia.
Department of Epidemiology and Preventive Medicine, Monash University, Clayton, Victoria, Australia.
Department of Infectious Diseases, The Alfred and Monash University, Melbourne, Victoria, Australia.
Department of Gastroenterology, St Vincent's Hospital Melbourne, Melbourne, Victoria, Australia.
Department of Medicine, The University of Melbourne, Parkville, Victoria, Australia.
Modelling suggests that more frequent screening of people who inject drugs (PWID) and an improved care cascade are required to achieve the WHO hepatitis C virus (HCV) elimination target of an 80% reduction in incidence by 2030. We determined the testing frequencies (2-yearly, annually, 6-monthly and 3-monthly) and retention in care required among PWID to achieve the HCV incidence reduction target through treatment as prevention in low (25%), medium (50%) and high (75%) chronic HCV prevalence settings. Mathematical modelling of HCV transmission among PWID, capturing testing, treatment and other features of the care cascade were employed. In low-prevalence settings, 2-yearly antibody testing of PWID was estimated to reach the elimination target by 2027-2030 depending on retention in care, with annual testing reducing the time by up to 3 years. In medium-prevalence settings, if close to 90% testing coverage were achieved, then annual antibody testing of PWID would be sufficient. If testing coverage were lower (80%), 6-monthly antibody testing with at least 70% retention in care or annual HCV RNA/cAg testing would be required. In high-prevalence settings, even 3-monthly HCV RNA/cAg testing of PWID was unable to achieve the incidence reduction target. Thus, for geographical areas or subpopulations with high prevalence, WHO incidence targets are unlikely to be met without 3-monthly RNA/cAg testing accompanied by other prevention measures. Novel testing strategies, such as rapid point-of-care antibody testing or replacing antibody testing with RNA/cAg tests as a screening tool, can provide additional population-level impacts to compensate for imperfect follow-up or testing coverage.