The CDC and the FDA are responsible for monitoring the blood supply for infectious agents that threaten its safety, while the NHLBI supports research to improve the safety and availability of blood and blood products. Although the United States blood supply is safer than ever, concerns continue to arise about new infectious agents such as human herpes virus-8 (HHV-8, associated with Kaposi's sarcoma), Borna virus, variants of HIV-1, a new variant of the CJD agent, and a virus called TTV that may be associated with hepatitis. Wide-ranging travel from one continent to another, from rainforests to industrial cities, has made the world a "global village" in which an emerging infectious disease anywhere can represent a potential threat to the blood supply of the United States.
Three major questions arise when an agent is suspected of being transmitted by transfusion:
To answer these questions, reliable screening and confirmatory tests of donor-recipient paired specimens, or at least pre-and post-transfusion recipient specimens, are needed.
The NHLBI Retroviral Epidemiology Donor Study (REDS), initiated in 1989, includes a sample repository and database that have facilitated investigations of human retroviruses in volunteer blood donors. The repository and database allow a rapid analysis of critical questions about the safety of the blood supply. For example, prevalence and incidence of newly discovered infectious agents can be estimated rapidly, the characteristics of populations at risk can be evaluated, and the impact of new screening methods can be assessed. The REDS program includes epidemiological, laboratory, and clinical investigations, and thus provides a comprehensive framework for monitoring blood donations for new or known infectious agents. REDS is recognized widely for its important contributions to blood banking and transfusion safety. The program was extended recently for another five years to enlarge the donor-recipient repository.