Impact of individual-donation nucleic acid testing on risk of human immunodeficiency virus, hepatitis B virus, and hepatitis C virus transmission by blood transfusion in South Africa
South African National Blood Service, 2 Constantia Boulevard, Roodepoort 1709, South Africa; South African National Blood Service, Roodepoort, South Africa
Background: In 2005, the South African National Blood Service introduced individual-donation (ID) nucleic acid test (NAT) screening for human immunodeficiency virus (HIV) RNA, hepatitis C virus (HCV) RNA, and hepatitis B virus (HBV) DNA. At the same time the use of ethnic origin to prioritize the transfusion of blood according to a hierarchy of residual risk was discontinued. Study design and methods: ID-NAT (Ultrio on Procleix Tigris, Chiron) and serology (PRISM, Abbott) repeat test and confirmation testing algorithms were designed to enable differentiation between false-positive and true-NAT and -serology yields. After 1 year, the NAT and serology yield rates in first-time, lapsed, and repeat donors were analyzed and used to estimate the residual risk of HIV, HBV, and HCV infections by blood transfusion. Results: The HIV, HBV, and HCV ID-NAT window phase yield rates in 732,250 blood donations were 1:45,765, 1:11,810, and 1:732,200, respectively. Seven of 16 HIV window phase donations with viral loads above 16,000 copies/mL were HIV p24 antigen enzyme-linked immunosorbent assay positive. PRISM detected anti-HIV and hepatitis B surface antigen (HBsAg) in 89.4 and 73.9% of early infections in repeat donors. The Procleix assay detected viremia in 99.7 and 95.5% of anti-HIV- and HBsAg-positive first-time donors. In these donors, the occult HBV DNA carrier rate was 1:5200. The residual transmission risk of ID-NAT HIV, HBV, and HCV window phase donations was estimated at 1:479,000, 1:61,500, and 1:21,000,000 respectively. Conclusion: One-year ID-NAT screening of 732,250 donations interdicted 16 HIV, 20 HBV, and 1 HCV window phase donations and 42 anti-hepatitis B core antigen-reactive infections during an early recovery or a later stage of occult HBV infection. © 2009 American Association of Blood Banks.
antigen p24; hepatitis B surface antigen; article; blood donor; blood transfusion; controlled study; enzyme linked immunosorbent assay; ethnic difference; false positive result; hepatitis B; Hepatitis B virus; hepatitis C; Hepatitis C virus; human; Human immunodeficiency virus; Human immunodeficiency virus infection; infection risk; major clinical study; serodiagnosis; South Africa; viremia; virus transmission; Blood Donors; Blood Transfusion; DNA, Viral; Hepatitis B; Hepatitis B Surface Antigens; Hepatitis C; HIV Infections; Humans; Prevalence; Risk; RNA, Viral; South Africa