Hepatitis E virus in the Kathmandu Valley: Insights from a representative longitudinal serosurvey

by Nishan Katuwal, Melina Thapa, Sony Shrestha, Krista Vaidya, Isaac I. Bogoch, Rajeev Shrestha, Jason R. Andrews, Dipesh Tamrakar, Kristen Aiemjoy

Background

Hepatitis-E virus (HEV), an etiologic agent of acute inflammatory liver disease, is a significant cause of morbidity and mortality in South Asia. HEV is considered endemic in Nepal; but data on population-level infection transmission is sparse.

Methods

We conducted a longitudinal serosurvey in central Nepal to assess HEV exposure. At each visit, capillary blood samples were collected and analyzed for the presence of anti-HEV IgG antibodies. The study took place between February 2019 and April 2021, with up to 4 visits per participant approximately 6 months apart.

Results

We collected 2513 samples from 923 participants aged 0–25 years, finding a seroprevalence of 4.8% and a seroincidence rate of 10.9 per 1000 person-years. Young adults and individuals consuming surface water faced the highest incidence of infection. Geospatial analysis identified potential HEV clusters, suggesting a need for targeted interventions.

Significance

Our findings demonstrate that HEV is endemic in Nepal and that the risk of infection increases with age.