Comparing specificity and seroconversion sensitivity among major blood screening assays for human immunodeficiency virus and viral hepatitis

BACKGROUND AND OBJECTIVES: Accurate detection of transfusion-transmissible infections, such as human immunodeficiency virus (HIV) and hepatitis C and B viruses (HCV/HBV), is critical to ensure blood safety, and screening assays must demonstrate high specificity and sensitivity. In this study, we compared the performances of Elecsys® HIV Duo, HCV Duo, Anti-HCV II and HBsAg II immunoassays with those of comparator assays HIV Ag/Ab Combo, Anti-HCV II and HBsAg on the Alinity® s platform and HIV Ag/Ab Combo, Anti-HCV and HBsAg Qualitative II on the Alinity i platform. MATERIALS AND METHODS: Approximately 2050 plasma samples from first-time blood donors and commercial seroconversion panels were used. Specificity was assessed as the proportion of true non-reactive samples identified by each assay. Seroconversion sensitivity was evaluated based on the detection time and average interval from nucleic acid testing (NAT)-positivity to assay reactivity. RESULTS: Overall, all Elecsys assays evaluated had similar specificities as the corresponding Alinity s/i assays, although the absolute difference in specificity between Alinity i Anti-HCV assay and the other HCV assays was statistically significant. The seroconversion sensitivities of Elecsys HIV Duo and HBsAg II assays were similar to the corresponding Alinity s/i assays. For HCV, Elecsys HCV Duo assay detected infection earlier than Alinity s/i assays for most panels (87.0% and 91.8%, respectively), with an average detection time from NAT positivity for HCV RNA of 1.5 days versus 21.4 and 23.8 days, respectively. CONCLUSION: The robust specificities and early detection capabilities of the evaluated Elecsys assays support their routine use in blood donor screening and diagnosis.