1. Geospatial distribution of Hepatitis E seroprevalence in Nepal, 2021.
- Author
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Rhee, Chulwoo, Dighe, Amy, Katuwal, Nishan, Cho, Haeun, Mraidi, Ramzi, Tamrakar, Dipesh, Lim, Jacqueline KyungAh, Poudyal, Nimesh, Park, Il-Yeon, Kim, Deok Ryun, Amatya, Ritu, Shrestha, Rajeev, Azman, Andrew S., and Lynch, Julia
- Subjects
HEPATITIS E virus ,HEPATITIS E ,ECOLOGICAL regions ,VIRAL transmission ,RURAL-urban differences - 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. Author summary: Hepatitis E virus spreads through fecal to oral transmission, primarily via contaminated water. The virus can impair liver function and causes frequent outbreaks of acute jaundice in Nepal. Diagnostic tests are often not accessible, meaning many cases of hepatitis E go undetected and it is difficult to know how many people are affected or where to target interventions to protect those most at risk. However, infections can be detected retrospectively by looking for long-lasting antibodies produced by the body in response to the virus. We looked for these antibodies in blood specimens collected from a population representative sample of individuals across Nepal and found that, overall, around 1 in 5 people had likely been infected previously. Risk of past infection varied across the three ecological regions of Nepal and was higher in Hilly and Mountain regions than in the southern Terai. We fitted a geospatial model to our data to map the predicted risk across the country and found it to be highest in Kathmandu, with up to half the population previously infected. This research demonstrates the scale of hepatitis E virus infections in Nepal and identified parts of the Hilly region–particularly Kathmandu–as areas where people are most at risk. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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