O21 HCV reinfection and injecting risk behaviour following elbasvir/grazoprevir treatment in patients on opioid agonist therapy: Co-STAR three year follow-up study oleh G. Dore, J. Grebely, F. Altice, A.H. Litwin, O. Dalgard, E.J. Gane, O. Shibolet, A. Luetkemeyer, R. Nahass, C.Y. Peng, B. Conway, D.M. Iser, H.C. Huang, I.N. Gendrano, M. Kelly, P. Hwang, M. Robertson, J. Wahl, E. Barr, H.L. Platt