This study will determine the minimal rate of transfusion-induced HCV and HGV infection and will allow for an annualized incidence estimate and a determination of the national burden of transfusion-induced hepatitis virus infection in children, a value that is currently unknown. In addition, by use of archival samples and the interval from transfusion to testing, the study will determine the duration of infection and rate of viral persistence. Finally, prospective followup with liver biopsy will establish the extent of disease in those chronically infected. If persistent infection and chronic liver disease are as common in children as in adults, this would have major implications for anti-viral therapy programs and might shift treatment emphasis to pediatric populations where response rates might be higher and where long-term benefit would be greater.