Efficacy of Polyethylene Glycol-Interferon Alfa-2B (PEG-Intron, SCH 54031) Compared to Interferon Alfa-2B in Participants With Chronic Hepatitis C (MK-4031-016)

Inclusion Criteria: * Be serum positive for hepatitis C virus. * Have liver biopsy within 1 year prior to entry, with a pathology report confirming a histological diagnosis consistent with chronic hepatitis. * Have one abnormal historic ALT at least 6 months prior to screening, with elevated ALT at entry. * Have compensated liver disease, testing negative for HIV and serum hepatitis B surface antigen (HBsAg) at entry. * If male or female of childbearing potential, be practicing adequate contraception during treatment. Exclusion Criteria: * Be female who is currently pregnant or nursing. * Have prior treatment with any interferon. * Have suspected hypersensitivity to alpha interferon. * Have participated in any other clinical trial within 30 days of entry * Have received treatment with any investigational drug within 30 days of entry. * Have received prior treatment for hepatitis with any other antiviral or immunomodulatory drug within the previous 2 years. * Have any other cause for the liver disease other than chronic hepatitis C including but not limited to: co-infection with hepatitis B virus; Hemochromatosis; alpha-1 antitrypsin deficiency; Wilson's disease; autoimmune hepatitis; alcoholic liver disease; obesity-induced liver disease; and drug-related liver disease. * Have hemophilia or any other condition that would prevent the participant from having a liver biopsy, including anticoagulant therapy. * Have hemoglobinopathies (e.g., Thalassemia) * Have evidence of advanced liver disease such as history or presence of ascites, bleeding varices, spontaneous encephalopathy. * Have received organ transplants. * Have a preexisting psychiatric condition, especially severe depression, or a history of severe psychiatric disorder, such as major psychoses, suicidal ideation and/or attempt. * Have central nervous system trauma or active seizure disorders requiring medication. * Have significant cardiovascular dysfunction within the past 6 months (e.g., angina, congestive heart failure, recent myocardial infarction, severe hypertension or significant arrhythmia). * Have poorly controlled diabetes mellitus. * Have chronic pulmonary disease (e.g., chronic obstructive pulmonary disease). * Have immunologically mediated disease (e.g., inflammatory bowel disease \[Crohn's disease, ulcerative colitis\], rheumatoid arthritis, idiopathic thrombocytopenia purpura, systemic lupus erythematosus, autoimmune hemolytic anemia, scleroderma, severe psoriasis, clinical cryoglobulinemia with vasculitis). * Have any medical condition requiring, or likely to require during the course of the study, chronic systemic administration of steroids. * Have history of substance abuse, such as alcohol, intravenous drugs and inhaled drugs. * Have clinically significant retinal abnormalities. * Be unable to abstain from the consumption of alcohol. * Have any other condition which in the opinion of the investigator would make the patient unsuitable for enrollment, or could interfere with the patient participating in and completing the protocol.