‘EVOLVE-HBV’: A retrospective cross-sectional study to quantify and characterise HBV infection, exposure, immunity and susceptibility in a rural population in KwaZulu-Natal, South Africa

Abstract

Abstract Introduction International goals aim to eliminate Hepatitis B Virus (HBV) as a public health threat by 2030, but data representing African populations remain limited. We therefore investigated the population prevalence of HBV and treatment eligibility in a rural South African setting. Methods We tested archived plasma samples from 2200 participants in a population-based study in KwaZuku Natal for HBV surface antigen (HBsAg), HBV core antibody (anti-HBc), and HBV surface antibody (anti-HBs). For samples testing HBsAg-positive, we quantified alanine transferase (ALT) and HBV DNA viral load. We evaluated demographic and clinical correlates of HBV biomarkers, explored the geographical distribution of HBsAg, and assessed HBV treatment eligibility. Results Weighted HBV infection prevalence was 10.4% (95% CI: 9.0%-12.1%). Evidence of HBV exposure and clearance was found in 34.9% (95% CI: 32.4 - 37.5). Overall prevalence of vaccine-mediated HBV immunity was 8.9% (95% CI: 7.5%-10.4%) but for the sub-group born between 2000-2005 (after the HBV vaccine was implemented) this increased to 20.2% (95% CI 15.8-25.4). Infection prevalence was highest in the South of the region. Over 60% of individuals testing HBsAg-positive met treatment eligibility criteria. Conclusion Prevalence of HBV infection and exposure in this setting is high, while vaccine-mediated immunity is low. These data highlight a pressing need for scale-up of interventions to support progress towards global elimination targets. Funding The Francis Crick Institute (ref. CC2223), the Africa Oxford Initiative (Research Development Award) and Wellcome Strategic Core Award (227167/A/23/z). Ethics University of KZN (UKZN) ref. 00004495/2022; University College London ref. 23221/001.