Fourth-Generation ELISA Screening of Blood Donors: A Reliable Alternative to Nucleic Acid Testing

Abstract

The gold standard for HIV screening of blood donors is individual nucleic acid amplification testing (NAT). However, individual NAT testing is cost-prohibitive, especially in a resource-limited setting. The fourth-generation ELISA that detects both p24 antigen and antibody to HIV-1 and 2 has been recommended as the minimum test for HIV to enhance blood transfusion safety and can be an alternative to NAT testing in resource-limited settings. The aim was to assess the performance of a fourth-generation ELISA in use at a regional blood transfusion service using nucleic acid amplification testing on units of screened blood negative to HIV. The study was a cross-sectional study conducted at the National Blood Transfusion Service center and the Plateau State Virology Research Centre, both in Jos, Nigeria. Between August and October 2016, one thousand and eighteen voluntary blood donors were recruited consecutively and had their samples tested using fourth-generation ELISA. One thousand p24 antigen-negative samples were pooled for NAT in an aliquot of 50 samples. All the pools of fifty samples of 1,000 HIV p24 antigen-antibody negative donor blood screened by the fourth-generation ELISA tested negative for HIV RNA on nucleic acid amplification. The yield of pooled NAT for HIV after a fourth-generation ELISA screening of blood donors was found to be zero in this study, thus establishing the fourth-generation ELISA's reliability. Therefore, we recommend adopting the fourth-generation ELISA test as a minimum requirement for blood donor screening.