Summary: The U.S. blood supply is safer today than at any time in recent history, with risks from blood transfusions quite small compared with the benefits of transfusion in saving lives. Improved donor screening and education have removed from the donor many persons who are at high risk for disease, and tests used to screen blood for viruses are considerably more sensitive than earlier versions. However, risks remain. Eight of every 10,000 donated units of blood carry a serious risk to the recipient, including allergic reactions, bacteria, reactions to incompatible blood transfusions, and viruses. GAO estimates that four out of 1,000 patients who receive the average transfusion of five units of blood are at risk of being exposed to contaminated blood that could sicken or even kill them. On the other hand, as many as half of the 1,000 recipients would be at serious risk of dying immediately unless they receive a transfusion. The risk that a surgery patient will require blood and develop a chronic disease or die as a result of that blood is estimated at five in 100,000. For the average person with no foreseeable plans for surgery, the annual risk of developing a chronic disease or dying from the transfusion is five in 1 million.
