Anti-HBc antibodies and occult hepatitis B infection (OBI) among blood donors in Lomé, Togo

Abstract

Aims: Among the progressive forms of hepatitis B virus (HBV) infections, the HBs antigen (HBsAg) remains undetectable in 25% of cases. There is also a form of HBV infection called occult HBV infection (OBI) characterized by the presence of viral DNA in the blood and tissues with no detectable levels of HBsAg associated with or without anti-HBc Ab, or anti-HBs Ab out of the pre-seroconversion period, which constitutes an infectious risk in blood transfusion. Methods: To determine the prevalence of anti-HBc Abs and the HBV DNA in the blood of donors recruited at the blood transfusion center (CNTS) of Lomé. This is a cross-sectional study including 967 blood donations which were seronegative to HBs antigen during the biological qualification of the donation (BQD) from July 28 to August 19, 2022. The detection of total anti-HBc Abs (IgM and IgG) was performed by BIORAD enzyme-linked immunosorbent assay (ELISA) method; the viral load measurement was carried out according to the polymerase chain reaction method by amplification of COBAS AmpliPrep/TaqMan 4800 (Roche diagnostics). Data processing and analysis were performed using EXCEL 2013 software and SPSS software. Concerning the ethical aspect, we have obtained written consent from the donors and the agreement of the bioethics committee for health research No. 052/2022/CBRS. Results: The prevalence of anti-HBc Abs was 33.82% (CI: 30.83–36.80). Viral DNA was detected in 10 cases. The prevalence of occult hepatitis B was 3.05% (10/327) in blood donors carrying anti-HBc antibodies, and 1.03% (10/967) in the blood donors population that does not carry HBsAg. Conclusion: The presence of occult hepatitis B within the population of blood donors at the blood transfusion center of Lomé constitutes a real threat to transfusion safety. The association of the viral DNA detection by PCR to the serological tests that are currently carried out during the biological qualification of the donations could be a better approach to reduce the risk of transmission of HBV by blood transfusion at the CNTS of Lomé.