EVOLVE-HBV: A cross-sectional study of HBV seroepidemiology in a rural population in South Africa.

OBJECTIVES

The "EVOLVE" study set out to investigate the population prevalence of hepatitis B virus (HBV) infection, immunity, and treatment eligibility in a rural South African setting.

METHODS

We tested plasma samples from 2200 participants in a population-based study in KwaZulu-Natal, of whom 50% were living with human immunodeficiency virus, for HBV surface antigen (HBsAg), HBV core antibody, and HBV surface antibody. For samples testing HBsAg-positive, we quantified alanine aminotransferase (ALT) and HBV deoxyribonucleic acid (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% confidence interval [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 among the subgroup born between 2000 and 2005 (after the HBV vaccine was implemented), this increased to 20.2% (95% CI 15.8-25.4). Infection prevalence was highest in the southern part of the region. Over 60% of individuals testing HBsAg-positive met treatment eligibility criteria.

CONCLUSION

Prevalence of HBV in this setting is high, while vaccine-mediated immunity is low. These data highlight a pressing need for the scale-up of interventions to support progress toward elimination targets.