ABSTRACT Background: Intravenous drug use remains the single biggest risk factor for the acquisition of Hepatitis C. The majority of centres in the UK will not treat those who are actively injecting drugs or have only very recently stopped. The main barrier to treatment is a perception that the patient will simply become reinfected. There is no firm data to support this and it is this gap in knowledge that this project will address. Aims and Objectives: Firstly, to determine the reinfection rate in a cohort of drug users (current and past) with Hepatitis C who have been previously treated and cured. Secondly, to determine long term outcomes in those who injected drugs at the time of treatment and compare this to past injecting drug users. Methods: This is a prospective study looking at reinfection rates based on a cohort of intravenous drug users that have been previously treated and achieved a sustained virological response (SVR). The HCV database at North Manchester Hospital of all patients started on treatment since 2004 was accessed. Those who were injecting drugs in the 6 months prior to treatment including those who continued to inject during treatment were identified. These are the âcurrentâ drug using group. The other group of patients that stopped injecting drugs at least 6 months prior to commencing treatment were also identified. These are the âpastâ drug using group. The sample size was 60. The patients were followed up for at least 2 years to collect data on outcomes including reinfection rates using annual HCV RNA (with subsequent genotyping if positive) and liver disease progression using standard liver function blood tests and a Fibroscan (a non-invasive method to assess liver fibrosis and cirrhosis). Quality of life data was also collected at each visit. Results: The total duration of follow up post SVR in this study was 248.6 years. There were two cases of reinfection. The rate of reinfection in all participants was 0.80 cases per 100 person years (95% confidence interval [CI], 0.10 to 2.88). The mean MCS scores were found to significantly decline (p=0.001) in those who were non cirrhotic, not reinfected and not consuming alcohol in excess. Further research is needed in this area.