Fig. 2

Study Flow Diagram. The four separate study groups of participants (see Additional file 1: Appendix 1 for full details). The known HCV-positive subjects that have not started treatment have a confirmatory RNA test before treatment commences and then are tested for SVR12 weeks after the completion of the SOF/DAC treatment regime, to assess first-line treatment response. After 12-months, these subjects are re-tested for HCV RNA to establish re-infection rates. HCV Ab-positive subjects at the screening stage (diagnosed HCV positives), follow a similar study pathway to assess first-line treatment response and then assess re-infection rates after 12-months. HCV Ab negative participants at screening (diagnosed HCV negatives) are re-tested 12 months later to establish HCV incidence rates. Finally, known HCV-negative subjects have previously been tested 12–18 months prior to recruitment and are tested to assess HCV incidence