Usefulness of nucleic acid testing among negative HBs Ag blood donors in Egypt.

Introduction Hepatitis B viral infection has been transmitted from donors with HBV infections who have negative HBs Ag. Many countries have implemented nucleic acid testing (NAT) to screen donors with non- reactive HBs Ag for detection of HBV DNA and enhance safety of blood transfusion, while it is restricted to limited blood banks in Egypt. Objective: To evaluate the significance of NAT technology in detection of HBV DNA in the Egyptian blood donors with HBs Ag non- reactivity. Methods: The study included 36,584 collected blood samples from volunteer blood donors at the blood bank of Zagazig University Hospitals. Each specimen was tested for HBs Ag; non- reactive sera were further tested for qualitative detection of HBV-DNA by NAT testing. All positive HBV-DNA donors were tested for anti- HBc and anti- HBs by electro-chemiluminescence immunoassay and confirmed by quantitative RT-PCR. Results: Among 34,671 donors non-reactive to HBs Ag, 34,657 (99.96%) were tested negative for HBV- DNA and 14 specimens (0.04%) were positive for HBV via NAT testing. Among HBV NAT positive donors, HBs Ab reactive only in (2); HBc Ab reactive only in (3); HBs and HBc Abs reactive in (3) while HBs and HBc Ab non-reactive in (6). All tested sera 14 (100%) showed low viral load for HBV (< 50 IU/ml) confirmed by RT- qPCR. Conclusion Our results highlighted the significance of the HBV NAT technique to reduce the potential risk of HBV transfusion-transmission and the critical need to enforce the usage of NAT technology in all blood banks in Egypt.