Seroprevalence and Risk Factors for Hepatitis E Virus in a Metropolis of Northeastern Brazil: A Population‐Based Survey

INTRODUCTION: Hepatitis E virus (HEV) is a leading cause of acute hepatitis worldwide. While traditionally linked to poor sanitation in endemic areas, evidence shows increasing circulation in developed settings. In Brazil, however, population-based data remain limited. Therefore, this study aimed to estimate HEV seroprevalence and identify associated risk factors in the general population of a metropolis in Northeastern Brazil. METHODS: Serum samples from a population-based survey using stratified cluster sampling and multistage selection were tested for anti-HEV (IgG) by ELISA. IgG-positive cases were further tested for IgM. Risk factors were analysed by odds ratio (OR) through bivariate logistic regression, considering p < 0.05 significant. Estimates were weighted by sample design effect using the 'survey' package (v4.1-1). Analyses were performed in Stata 15. RESULTS: Among 2,070 samples, 74 were positive for anti-HEV IgG (3.6%; 95% CI: 2.9-4.3), with no IgM reactivity. Seroprevalence by socioeconomic stratum was 3.3% (95% CI: 1.7-5.0) in the high stratum, 3.8% (95% CI: 2.6-4.6) in the intermediate and 3.5% (95% CI: 2.4-4.6) in the deprived stratum. Adults aged 55-65 years had higher odds of previous HEV exposure (adjusted OR = 6.02; 95% CI: 2.59-13.99; p < 0.001) compared to the 5-24 year group. Residents in households with alternative sewage systems showed higher odds of HEV positivity than those with public sewage access (OR = 1.58; 95% CI: 1.08-2.31; p = 0.021). CONCLUSION: Our findings demonstrate HEV circulation in metropolitan Northeast Brazil. Exposure was primarily associated with older age and precarious sanitary infrastructure, highlighting the need for targeted public health surveillance and improved basic sanitation.