GPT and hepatitis B virus infection: In addition, patients with clinical jaundice, abnormal liver function tests (bilirubin > 3.5 mg/dL or alanine aminotransferase (ALT) >200 IU/L), known chronic liver disease, active hepatitis B infection (defined as hepatitis B surface antigen positive) or presenting with a clinical syndrome which in the opinion of the attending clinician, puts the patient at significant risk if he/she were to participate in the 1HP trial will be excluded from the trial.