Geospatial distribution of Hepatitis E seroprevalence in Nepal, 2021
Abstract
BACKGROUND: Hepatitis E virus (HEV) causes acute jaundice and poses an important public health problem in low- and middle-income countries. Limited surveillance capacity and suboptimal access to diagnostics leads to under-reporting of HEV infections in affected countries, including Nepal. Serum antibodies against HEV are indicative of past infection. We analyzed existing samples from a nationally representative serosurvey to describe the geospatial distribution and factors associated with HEV seroprevalence in Nepal, as a proxy for infection. METHODOLOGY/PRINCIPLE FINDINGS: A nationally representative cross-sectional serosurvey of 3,922 individuals ≥2 years old from 975 households spread across 65 wards throughout Nepal was conducted between November 2021 and January 2022. Bio-banked samples were tested for anti-HEV IgG. Seroprevalence and its 95% confidence interval were estimated by age, sex, ecological region, municipality type, and other waterborne-disease related risk factors. Bayesian geostatistical models were fitted to observed seroprevalence data and used to generate high-resolution maps of seroprevalence across Nepal. Available samples from 3,707 participants were tested for anti-HEV IgG, and 3,703 were used for final analysis. We found 20.8% (95% CI: 19.5-22.2) of participants had evidence of prior HEV infection. HEV seroprevalence increased with age, and was higher in males (23.5%, 95% CI: 21.5-25.5) than in females (18.6%, 95% CI: 16.9-20.3). Seroprevalence in hilly (28.9%, 95% CI: 26.6-31.2) and mountain (24.6%, 95% CI: 18.8-30.5) regions were significantly higher than in terai (14.2%, 95% CI: 12.7-15.8). While there was no significant difference between urban and rural populations, the predicted seroprevalence was highest in Kathmandu, the capital of Nepal, reaching seroprevalence of 50% in some selected area. No statistically significant differences were found for wealth quintile, water source, and toilet facility. CONCLUSIONS: This study provides population-based serologic evidence that HEV is endemic in Nepal, with the greatest risk of infection in Kathmandu.
Amy Dighe
Research Associate
My research interests include the emergence of infectious disease across species boundaries, and how we can better detect zoonotic spillover and early human to human transmission using integrated surveillance systems.
