Occult hepatitis B infection among chronic liver disease patients in Tamil Nadu: Is screening mandatory?

Background: Occult hepatitis B infection (OBI) is characterised by the presence of hepatitis B virus deoxyribonucleic acid (HBV DNA) in the liver, but negative for Hepatitis B surface antigen (HBsAg), irrespective of the presence of HBV DNA in blood. Chronic liver disease (CLD) is a significant contributor to mortality. Globally, OBI prevalence varies from 1% to 87%. This study aims to determine OBI prevalence among chronic liver disease patients in Tamil Nadu by screening for anti-HB total core antibodies (anti-HBc) and HBV DNA among HBsAg-negative patients.
Methods: One hundred and sixty serum samples were obtained from CLD patients and tested using an enzyme-linked immunosorbent assay (ELISA) for HBsAg. The negative samples were tested for anti-HBc antibodies. The anti-HBc positive samples were tested for HBV DNA using real-time polymerase chain reaction (PCR).
Results: Among the 160 samples tested by HBsAg ELISA, 98 were negative for surface antigen. These samples underwent anti-HBc testing, of which eight samples were positive. HBV DNA tested positive in five of the eight anti-HBc positive samples. The prevalence of OBI in the present study was 3.13%.
Conclusion: In this study, 5% of CLD patients were diagnosed as OBI by anti-HBc assay and 3.13% by HBV DNA PCR, suggesting evidence of past exposure to HBV. To conclude, it is mandatory to diagnose OBI to prevent early progression to cirrhosis or hepatocellular carcinoma.