This protocol is an adapted version of the protocol 'Hepatitis C reinfection after successful directly acting antiviral treatment: A North-Atlantic multicenter interventional study'. The investigators will plan this study so that the data are similar to this protocol and results can be compared within this alliance of hepatologists with special interest in care for substance users.
Study schedule: Data collection will be performed according to the study schedule shown in Table 1. Following assessment for SVR12, participants will be followed for 2 years at 6 months' intervals at the discretion of each study site.

