The FDA have issued a Guidance for Industry entitled: “Lookback” for Hepatitis C Virus (HCV): Product Quarantine, Consignee Notification, Further Testing, Product Disposition, and Notification of Transfusion Recipients Based on Donor Test Results Indicating Infection with HCV.
According to the FDA: "Chronic hepatitis due to HCV is a major health problem in the U.S. The infection is usually clinically silent until the liver is seriously damaged. As a result, infected people usually are unaware of their disease. Although transfusion-transmitted infections account for only a very small proportion of HCV infections, it is possible to identify and “lookback” at prior donations that might have been collected during the “window period.”"
To review the document, go to: http://www.fda.gov/downloads/BiologicsBloodVaccines/GuidanceComplianceRegulatoryInformation/Guidances/Blood/ucm078828.pdf