The effectiveness of donor selection for reducing the risk of HCV, HBV and HIV in new blood donors

Reducing the risk of transfusion-transmissible viral infection through blood donor selection: the Australian experience 2000 through 2006

BACKGROUND

Selection of voluntary donors who are at low risk of transfusion-transmissible viral infection (TTVI) is central in maintaining the safety of the blood supply. Evaluation of its effectiveness and the dynamics of the process may offer opportunities to further improve transfusion safety.

STUDY DESIGN AND METHODS

The impact of donor selection on prevalence of TTVI was analyzed in all allogeneic donations in Australia between July 2000 and June 2006 by interviewing donors found to have a TTVI. The presence and disclosure of infective risks was reassessed.

RESULTS

A total of 6.3 million donations were tested; of these, 1,449 (0.02%) were repeat-reactive for a TTVI and were discarded. This comprised 605 (42%) positive for the presence of hepatitis B, 818 (56%) positive for the presence of hepatitis C, 18 (1%) positive for the presence of human immunodeficiency virus, and 20 (1%) positive for the presence of human T-cell lymphotropic virus-I and/or -II (HTLV-I/II). This prevalence was 50 to 350 times lower than in the Australian population. In 1,158 cases (80%), an infective risk was identified; 509 donors (44%) had more than one. The most common identified were country of birth and parental ethnicity (n = 682, 26% of risks), tattoos and/or piercings (n = 448, 18%), and intravenous drug use (n = 302, 12%). In 302 cases (21%) disclosure at predonation screening would have resulted in deferral. Factors influencing nondisclosure included temporal remoteness and perceptions that laboratory testing rendered disclosure unnecessary.

CONCLUSION

These findings affirm the effectiveness of current stringent donor selection criteria in reducing the residual risk of TTVI. Ongoing donor education regarding the importance of risk disclosure is required.

Risk management in blood transfusion services

Risk is usually simplistically defined as the probability of an adverse outcome, under-recognising the importance of perception. The intuitive centre of the risk structure is 1 in a million (10(-6)), the background risk of death in developed countries. In Australia, current risks of transmission of HIV and HCV by blood transfusion are about 10(-6), the risk is higher for HBV and lower for HTLV1, but the risk of death from the infections is much less, particularly for HTLV1. When blood service professionals take risk related actions, their judgement must be tempered by contemporary political and social realities and the public's real and disproportionate horror of catastrophe.