Rate and Predictors of Relapse in the Treatment of Hepatitis C (Study P05181)

Inclusion Criteria: * Participants with chronic hepatitis C virus (HCV)\[any genotype\] who received pegylated interferon alfa-2b plus ribavirin as first treatment for hepatitis C. * Negative HCV RNA at the end of treatment (24 or 48 weeks according to the product labeling as appropriate), measured by the assay used at each institution. Only institutions using an assay with a limit of detection of 50 IU/mL or less will be eligible. Exclusion Criteria: * Women of childbearing potential (i.e., premenopausal women and women who are less than 6 months postmenopausal) who will not use an appropriate contraceptive method during the course of the clinical study. Appropriate contraceptives include double barrier methods (eg, diaphragm or condom plus spermicide), intrauterine device, oral, injectable or subcutaneous hormonal contraceptive, or surgically sterilized partner. * Completed treatment with pegylated interferon alfa-2b plus ribavirin more than 4 weeks before study entry. * Positive HCV RNA at the end of treatment (24 or 48 weeks according to the product labeling as appropriate). * Participants treated for a period shorter than the enrollment period. * Co-infection with Human Immumodeficiency Virus (HIV). * Co-infected with Hepatitis B Virus (HBV).