hiv infected patients, age >18 years, meet vietnam guideline to begin art (cd4 count < 350 cells/mm3 and/or who stage iii or iv disease)

hepatitis c infection as documented by positive hcv antibodies and a detectable serum hcv rna level

ast and alt ≤ 2 x uln (≤ 80 u/l)

estimated creatinine clearance ≥ 60 ml/min

any prior art

positive hepatitis b surface antigen

clinical evidence of de-compensated cirrhosis (ascites, encephalopathy, esophageal bleeding)

requirement for acute therapy for other aids-defining illness within 14 days prior to study entry

currently on rifampicin therapy

in the first trimester of pregnancy, intent to become pregnant, or breast feeding during the study period