Soil-transmitted helminth (STH) infections caused 4.98 million years live with disability globally in 2014, mostly affecting the poor. When farmers handle excreta for reuse in agriculture, involuntary ingestion of excreta particles is an important infection pathway for STH infections. The aim of this study was to quantify farmers' ingestion of human excreta during common agricultural practices in Vietnam. The weight of excreta that remained on farmers' hands, the weight of excreta that would remain on a farmer' mouth after contact with hand, and the frequency of contact between hand to the mouth by observing farmers while they handled excreta were simulated and quantified. Our findings revealed that farmers are on average exposed 5.16 h to excreta handling per year. Based on this average exposure time, it was estimated that farmers ingest 91 mg of excreta per year (95% CI: 73–110 mg). Our study presents for the first time a robust quantitative estimation of excreta ingestion by farmers during excreta handling in agricultural practices. Hence, this paper makes an important contribution to more robust quantitative microbial risk assessment and health impact assessment related to STH infections and diarrhea in Vietnam and other similar settings where excreta is used as fertilizer.

2014年，土壤传播的蠕虫（STH）感染在全球造成498万人的残疾，其中大部分影响了穷人。当农民处理排泄物以重新用于农业时，排泄物颗粒的非自愿摄入是STH感染的重要感染途径。这项研究的目的是量化越南农民在普通农业实践中摄入的人体排泄物。模拟并量化了残留在农民手上的粪便重量，接触手后残留在农民口中的粪便重量以及观察农民处理粪便时手与嘴之间的接触频率。我们的研究结果表明，农民平均每年需要处理粪便5.16小时。根据此平均曝光时间，据估计，农民每年摄入91毫克的粪便（95％CI：73-110毫克）。我们的研究首次提出了一种可靠的定量估计方法，用于估计农民在农业实践中处理粪便时的粪便摄入量。因此，本文为越南和其他以排泄物为肥料的类似环境中与STH感染和腹泻有关的更健壮的定量微生物风险评估和健康影响评估做出了重要贡献。