Simplifying Hepatitis C Pathways for People Who Inject Drugs in Armenia, Georgia, and Tanzania

The goal of this non-randomised, quasi-experimental, prospective comparative trial is to trial simplified care pathways for hepatitis C testing and treatment for people who inject drugs in Armenia, Georgia, and Tanzania. The main questions it aims to answer are: 1. What is the feasibility of implementing a hepatitis C simplified care and same-day treatment care model in community and harm reduction settings in the three study countries? 2. Does a same-day treatment initiation model involving only POC antibody tests (with a shortened read-time) increase hepatitis C treatment uptake and SVR12 outcome (cure) among people who inject drugs compared with a simplified care model involving POC antibody followed by a confirmatory RNA test? 3. What is the comparative cost-effectiveness between a same-day antibody only hepatitis C testing and treatment model and the simplified care model (POC antibody/confirmatory RNA test) model? Participants will: * be enrolled in a new simplified model of care in each country (Arm 1). After the enrolment target is met for Arm 1 (approx. 3-9 months into implementation) new participants will be enrolled into a same-day treatment trial, using presumptive treatment after a reactive POC test result at shortened read-time (5minutes) (Arm 2) * if in Arm 1, participants will commence SOF-VEL DAA treatment after receiving an RNA test to confirm current hepatitis C infection. They will then continue along the treatment pathway, returning for RNA testing 4-16 weeks after SVR12 to determine cure. * if in Arm 2, participants will begin SOF-VEL DAA treatment on the same day as the 5 minute RDT testing. They will then continue along the treatment pathway, returning for RNA testing 4-16 weeks after SVR12 to determine cure. Researchers will compare cure and participant retention rates between the two groups.