Approaches to minimize infection risk in blood banking and transfusion practice

The use of blood donor history and state-of-the-art FDA-licensed serological and nucleic acid testing (NAT) assays have greatly reduced the "infectious window" for several transfusion-transmitted pathogens. Currently transmission of human immunodeficiency virus (HIV), Human T-cell Lymphotropic Virus (HTLV), hepatitis viruses and West Nile Virus are rare events. The seroprevalence of cytomegalovirus in the donor population is high and cytomegalovirus infection can cause significant complications for immunocompromised recipients of blood transfusion. Careful use of CMV seronegative blood resources and leukoreduction of blood products are able to prevent most CMV infections in these patients. Currently, bacterial contamination of platelet concentrates is the greatest remaining infectious disease risk in blood transfusion. Specialized donor collection procedures reduce the risk of bacterial contamination of blood products; blood culture and surrogate testing procedures are used to detect potential bacterially contaminated platelet products prior to transfusion. A rapid quantitative immunoassay is now available to test for the presence of lipotechoic acid and lipopolysaccharide bacterial products prior to platelet transfusion. Attention has now turned to emerging infectious diseases including variant Creutzfeldt-Jakob disease, dengue, babesiosis, Chagas' disease and malaria. Challenges are presented to identify and prevent transmission of these agents. Several methods are being used or in development to reduce infectivity of blood products, including solvent-detergent processing of plasma and nucleic acid cross-linking via photochemical reactions with methylene blue, riboflavin, psoralen and alkylating agents. Several opportunities exist to further improve blood safety through advances in infectious disease screening and pathogen inactivation methods.