Blood transfusion and residual risk
Evaluation of the residual risks of blood transfusion in France is based on the permanent collection of the accidents declared by the hemovigilance correspondents of the hospitals and the Blood French Institution. The viral risk is based on a statistical estimation to establish the probability of a blood collection occurring during a viral incubation period in a blood donor. Besides the risk of volemic overload, tranfusional risks are classified into immunologic risks (allergy, blood group incompatibility), infectious risks (bacteria, virus, parasites and prion), and transfusion-related acute lung injury (TRALI). In 2008, 2,850,812 blood products (BP) were distributed and 7,494 side effects were notified (2.63‰). Among these side effects, 3,613 (48.2%) were considered as highly imputable to BP (13 per 10,000 BP). Viral residual risk in 2006-2008 was of 1 per 2,400,000 blood donations for HIV, 1 per 8,200,000 blood donations for HCV, 1 per 1,000,000 blood donations for HBV, and 1 per 3,500,000 for HTLV. In parallel, the risk of bacterial contamination was of 1 per 1,500,000 red blood cells concentrates (RBCC) and 1 per 37,000 platelet concentrates by apheresis. ABO blood group incompatibilities were of 1 per 183 000 RBCC. In 2008, 30 TRALI were associated to blood tranfusion. Four deaths were recorded, representing 1 death per 712,703 delivered BP. With a high level of safety achieved, blood transfusion remains a therapeutic act requiring high vigilance.