Screening Volunteer Blood Donations for Transmissible Infectious Diseases

Abstract

labmedicine.com November 2005 Volume 36 Number 11 LABMEDICINE 717 Blood transfusion has provided life-saving support for the last 80 years. Transfusions are necessary in a variety of circumstances, which include medical care, surgical treatment, and acute trauma cases. It is estimated that annual need for transfusions exceeds 20 million blood products annually in the United States. There are little long-term effects on recipients, and the risk of infection is low for currently screened infectious agents.1,2 However, there remains an unknown risk of new emerging blood borne pathogens for which donor screening is currently not available. Since the early days of blood transfusion there has been a steady progression in the identification of transmissible infectious diseases, with consequent improvement in blood safety. Historically, blood donor screening used health histories, a self-deferral process and pre-selected donor groups to enhance safety. The number of transfusion-transmitted infectious diseases (TTIDs) has increased since the beginning of routine blood transfusion in the late 1930s.3 Syphilis was the first TTID for which prospective blood donors were tested in the 1950s.4 Although post-transfusion hepatitis was recognized in the 1940s, it was thought to be transient and a minor infection. Awareness of TTIDs became more significant, along with the public demand for increased blood safety, with the introduction of human immunodeficiency virus (HIV) into the blood donor pool. The first acquired immunodeficiency syndrome (AIDs) case was reported in 1981, with the first reported AIDS transfusion related case in 1982.5,6 It was not until 1985 that blood banks had a test available to screen blood for the AIDS virus. For the 4-year interim period, volunteer blood donors were screened based on high-risk behavior and self-exclusion. Hepatitis was the second most feared transfusion associated chronic infection, caused by hepatitis B and hepatitis C (previously known as non A/non B). The transfusion risk for contracting hepatitis was 25% before 1965.2 Immunoassays were first developed for the hepatitis B virus in the 1970s.7 Since that time, there have been unprecedented efforts by the transfusion medicine industry to make the blood supply safer. As a result, chronic post-transfusion infections have diminished significantly (Table 1). Reasons for improved blood safety include2: • Discontinued paying donors (moved to an all volunteer donor pool). • Development of an antibody test for hepatitis B surface antigen (HBsAg) in 1976-1977. • Instituted better donor screening methods including health history and demographics. • Added surrogate testing for non-A-non-B hepatitis, including alanine aminotransferase in the late 1980s. Screening Volunteer Blood Donations for Transmissible Infectious Diseases