Viral risks associated with blood transfusion

Great strides have been made within the last decade to help ensure the safety of the blood supply. Additional tests to detect infectious agents, as well as development of improved donor screening and deferral techniques have helped make the risk of transfusion-transmitted disease very low. Currently, blood banks perform seven tests to detect infectious agents. Prospective donors are carefully questioned about factors that place them at risk for transfusion-transmitted disease and donors known to test positive for certain viruses are permanently deferred. The risks of receiving a human immunodeficiency virus (HIV)-infected unit is now estimated to be 1 in 493,000, while the risk of hepatitis B is 1 in 63,000. However, changes in prevalence within the blood donor population brought about by changes in the factors that place an individual at risk for a transfusion-transmitted disease could significantly alter these risks. The American public continues to be concerned about the safety of blood transfusion. These concerns coupled with the fears that new viruses or new strains of viruses will be identified that escape detection has created the impetus for development of methods that will remove or inactivate viruses in cellular blood products.