[Transfusion-induced virus infections: how great is the risk?]

The risk of infection by blood transfusions contaminated with the human immunodeficiency virus (HIV) and/or the hepatitis C virus (HCV) was dramatically reduced after the introduction of blood donor screening using specific and sensitive 2nd- or 3rd-generation enzyme immunoassays for virus antibody detection. In addition, donors selection provides the greatest safety. The strategy for safe blood supply includes medical examination and self-exclusion of donors. For example, in German blood donors, the current detection rate of HIV is between 1.36 and 1.82 confirmed positive results per 100,000 blood donations. For hepatitis C the rate of anti-HCV-positive donors is between 0.27 and 0.49%. The overall risk of HIV infection ranges from 1 in 500,000 to 1 in 3 million and that of a transfusion-associated HCV infection from 1 in 20,000 to 1 in 40,000 per transfused blood unit. From the observed virus load among German blood donors, the transfusion-associated mortality was calculated to be 1 in 260,000 per transfused blood unit. Implications are discussed resulting from this low risk of HIV and/or HCV infection by blood transfusions.