The combination of natural disasters and inadequate infrastructure introduce unique challenges in providing safe drinking water in low-income countries. For example, Nepal faces several challenges in managing sporadic diarrheal outbreaks across the country, given its complex geographic terrain, and its susceptibility to extreme natural events like earthquakes, floods, and landslides. To assess the risks of diarrheal diseases caused by fecal contamination in several water sources in different geographical regions of Nepal, we conducted a two months cross-sectional study throughout 37 out of 75 districts in Nepal, including the ones affected by Nepal 2015 earthquake. Quantitative Microbial Risk Assessment (QMRA) was applied to estimate the human health risk based on Escherichia coli (E. coli) count for 2,822 water samples collected at source and households. Disease burden calculations suggested that Hilly and Terai (low-land) regions are at the highest risk with 0.27 and 0.16 DALYs per person per year (DALYpppy), respectively, whereas mountain region disease burden was 0.02 DALYpppy. The risk comparison among exposure pathways indicated that the water used in households, including drinking water and water for washing, posed higher risks than from source water, reservoir water or tap water, suggesting deteriorated sanitation conditions in households. These findings suggest that the combination of QMRA and spatial analysis can help to prioritize intervention activities after a major natural disaster.

自然灾害和基础设施不足的结合给低收入国家提供安全饮用水带来了独特的挑战。例如，鉴于尼泊尔复杂的地理地形以及对地震，洪水和山体滑坡等极端自然事件的敏感性，尼泊尔在处理该国零星的腹泻暴发方面面临若干挑战。为了评估在尼泊尔不同地理区域的几种水源中因粪便污染而引起的腹泻病风险，我们在尼泊尔75个地区中的37个地区（包括受2015年尼泊尔地震影响的地区）中进行了为期两个月的横断面研究。定量微生物风险评估（QMRA）用于评估基于大肠杆菌（E. coli）的人类健康风险）计数从来源和家庭收集的2,822个水样。疾病负担的计算表明，丘陵和特莱（低地）地区的人均每年最高危险分别为0.27和0.16 DALYs（DALYpppy），而山区疾病负担为0.02 DALYpppy。暴露途径之间的风险比较表明，家庭用水（包括饮用水和洗涤用水）带来的风险要高于自来水，水库水或自来水，这表明家庭卫生条件恶化。这些发现表明，将QMRA与空间分析相结合可以帮助在发生重大自然灾害后确定干预活动的优先级。