Seroprevalence of Hepatitis B Virus Infection in a Tertiary Care Hospital in Northeastern Karnataka, India: A 12-Month Retrospective Study

Abstract

Background & Objectives: Viral hepatitis B remains a major global public health concern and a significant cause of chronic liver disease, cirrhosis, and hepatocellular carcinoma. India falls within the intermediate endemicity zone for Hepatitis B virus (HBV) infection, accounting for 10–15% of the worldwide carrier pool. This study evaluated the seroprevalence of Hepatitis B surface antigen (HBsAg) across diverse clinical populations, including antenatal women, voluntary blood donors, and HIV-infected individuals, at a tertiary care center in Northeastern Karnataka, India.

Methods: A hospital-based retrospective observational study was conducted at the Department of Microbiology, Gulbarga Institute of Medical Sciences and Hospital, Kalaburagi, spanning 12 months from March 2023 to February 2024. Serum samples from 39,869 patients (comprising outpatient, inpatient, antenatal, blood bank, and pre-operative cohorts) were screened for HBsAg using immunochromatographic rapid assays (Hepacard, J. Mitra & Co. Pvt. Ltd.; reported sensitivity >99%, specificity >99%). Seroprevalence was analyzed in relation to gender, seasonal patterns, and targeted clinical subgroups. Statistical analyses were performed using Pearson's Chi-square (χ²) test and 95% confidence intervals (CI).

Results: Out of 39,869 individuals screened, 574 tested positive for HBsAg, establishing an overall seroprevalence of 1.44% (95% CI: 1.32%–1.56%). Male seroprevalence was significantly higher than female seroprevalence (1.58% [355/22,401] vs. 1.25% [219/17,468]; χ² = 7.39, p = 0.0066; Odds Ratio = 1.26, 95% CI: 1.07–1.49). Subgroup analysis revealed the highest positivity rate among voluntary blood donors (1.79%, 88/4,906; 95% CI: 1.44%–2.21%), followed by HIV-co-infected individuals (1.51%, 23/1,520; 95% CI: 0.96%–2.26%) and antenatal care (ANC) patients (1.21%, 149/12,260; 95% CI: 1.03%–1.42%).

Conclusion: The HBsAg seroprevalence of 1.44% places this region in the lower spectrum of intermediate HBV endemicity. The elevated prevalence among voluntary blood donors underscores the critical importance of rigorous pre-transfusion screening and stringent infection control practices. Routine antenatal screening and universal neonatal birth-dose vaccination remain essential to disrupt vertical transmission.