Head-to-head comparison of Enzyme Linked Immunosorbent Assay (ELISA) and Enhanced Chemiluminescence Immunoassay (ECLIA) for the detection of Transfusion Transmitted Disease (TTD) Markers; HIV, HCV and HBV in blood donors, in India.

Safe blood transfusion being the cornerstone of any Blood Transfusion Services requires meticulous testing for Transfusion Transmitted Disease (TTD) markers in donated blood. We performed head-to-head comparison of ELISA and ECLIA for detection of TTD markers for Human Immunodeficiency Virus (HIV), Hepatitis C Virus (HCV) and Hepatitis B Virus (HBV) in 10,164 Indian blood donors. All concordant reactive, discordant reactive and concordant non-reactive samples were re-confirmed using Individual Donor-Nucleic Acid Amplification Test (ID-NAT) as the 'gold standard' test. 223 samples were found reactive; out of which 93 (four HIV, 34 HCV and 55 HBV) samples were concordant reactive and tested positive by both methods while 130 discordant reactive samples were reactive either by ELISA or ECLIA. Out of 130 discordant reactive samples ELISA-reactive and ECLIA-non-reactive samples for HIV, HCV and HBV were 15, eight, and 29 respectively while ECLIA-reactive ELISA-non-reactive samples for HIV, HCV and HBV were 39, 36 and three respectively. Sensitivity of ECLIA and ELISA was 100 % for all three TTD markers, while specificity was 99.62 % and 99.85 % for HIV; 99.64 % and 99.84 % for HCV and 99.97 % and 99.70 % for HBV respectively. Strength of agreement and Kappa Statistics for ECLIA and ELISA compared to the gold standard test was poor and fair for HIV (k = 0.169 and 0.347), moderate and good for HCV (k = 0.539 and 0.763), and very good and good for HBV (k = 0.973 and 0.783). According to this study, it can be concluded both the testing techniques; ELISA and ECLIA have 100 % sensitivity for the detection for HBV, HCV and HIV in blood donors and therefore, either can be used for TTD screening in blood banks in India.