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, Lynch Julia
International Vaccine Institute, Seoul, Republic of Korea.
Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America.
PLoS Negl Trop Dis. 2024 Dec 23;18(12):e0012746. doi: 10.1371/journal.pntd.0012746. eCollection 2024 Dec.
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.
This study provides population-based serologic evidence that HEV is endemic in Nepal, with the greatest risk of infection in Kathmandu.
戊型肝炎病毒（HEV）可导致急性黄疸，在低收入和中等收入国家构成重要的公共卫生问题。监测能力有限以及诊断手段欠佳，导致包括尼泊尔在内的受影响国家对戊型肝炎病毒感染的报告不足。抗戊型肝炎病毒血清抗体可指示既往感染情况。我们分析了一项具有全国代表性的血清学调查中的现有样本，以描述尼泊尔戊型肝炎病毒血清流行率的地理空间分布及其相关因素，作为感染情况的替代指标。
方法/主要发现：2021年11月至2022年1月期间，对尼泊尔全国65个行政区975户家庭中3922名2岁及以上个体进行了具有全国代表性的横断面血清学调查。对生物样本库中的样本进行抗戊型肝炎病毒IgG检测。按年龄、性别、生态区域、市政类型以及其他与水传播疾病相关的风险因素估算血清流行率及其95%置信区间。对观察到的血清流行率数据拟合贝叶斯地理统计模型，并用于生成尼泊尔全国血清流行率的高分辨率地图。对3707名参与者的可用样本进行了抗戊型肝炎病毒IgG检测，3703份样本用于最终分析。我们发现20.8%（95%置信区间：19.5 - 22.2）的参与者有既往戊型肝炎病毒感染的证据。戊型肝炎病毒血清流行率随年龄增长而升高，男性（23.5%，95%置信区间：21.5 - 25.5）高于女性（18.6%，95%置信区间：16.9 - 20.3）。丘陵地区（28.9%，95%置信区间：26.6 - 31.2）和山区（24.6%，95%置信区间：18.8 - 30.5）的血清流行率显著高于特赖地区（14.2%，95%置信区间：12.7 - 15.8）。虽然城乡人口之间没有显著差异，但预测血清流行率在尼泊尔首都加德满都最高，在一些选定地区达到50%。在财富五分位数、水源和卫生设施方面未发现统计学上的显著差异。
本研究提供了基于人群的血清学证据，表明戊型肝炎病毒在尼泊尔呈地方性流行，加德满都感染风险最高。
