Prevalence of hepatitis delta virus infection among hepatitis B virus-infected and exposed patients

Background: Hepatitis delta virus (HDV) infection is a cause of coinfection and superinfection among hepatitis B virus (HBV)-infected patients. The global prevalence of HDV may vary drastically depending on the geographical location. In India, serological techniques form the basis for the determination of HDV prevalence in majority of the studies with very limited literature based on molecular techniques. In addition, sparse data on HDV infection among HBV-exposed group, i.e., patients with total antibodies to core antigen (anti-hepatitis B core [HBc]) positive and negative hepatitis B surface antigen (HBsAg), are available. Objective: This study was aimed to determine the prevalence of HDV in both HBV-infected and HBV-exposed groups, utilizing both serological and molecular methods. Settings and Design: This was a retrospective cross-sectional study conducted from January till June 2018 where samples of 142 patients were retrieved and were categorized into two groups: Group A included patients with both HBsAg and anti-HBc positivity (n = 120/142 [85%]), i.e., confirmed HBV infection, and Group B included patients with anti-HBc positivity and HBsAg negativity (n = 22/142 [15%]), i.e., exposed to HBV. Materials and Methods: All the specimens were retrieved from −80°C and were tested for anti-HDV immunoglobulin (Ig) M (IgM), anti-HDV IgG, and HDV RNA. Results: HDV infection was observed in only one patient in Group A and none in Group B, making an overall prevalence of 0.78% (95% confidence interval = 0.02%–3.9%). The infected patient was reactive for both IgM and IgG with a viral load of 2log10IU/ml. Conclusion: The present study provides evidence that HDV infection is very low(0.78%) in this part of India. However further prospective studies with larger sample size are warranted.