Urban Water Systems, Enteric Pathogen Distribution & Gut Microbiome Development in Children: A Natural Experiment in Mozambique

这项研究在评估世界银行(WB)资助的四个城市的一个主要项目时发挥了我们的领导作用 莫桑比克的一些地区。我们将测试供水的改善是否以及如何减少或延迟肠道致病菌。 感染和冲击相关的急性和慢性胃肠道相关疾病。我们利用的是 随机分配进入新的自来水系统，增加了新的微生物和健康 终端。这将是使用实验设计和 首先，检查新的家庭供水连接对这些健康结果的影响。在改进的同时 近几十年来，病例治疗降低了腹泻的死亡率，发病率持续存在， 据估计，全球每年有40亿腹泻病例。反复、累积的有害健康影响 肠道病原体感染和腹泻发作在前两次发生时尤其相关。 生命中的岁月。越来越多的证据表明，早期感染肠道病原体，即使在没有 腹泻症状，与长期的慢性后遗症有关，包括环境肠道功能障碍 (EED)、发育迟缓和认知障碍。对洗涤干预措施的研究往往集中在减少 腹泻，很少有检查过特定的肠道病原体，也没有长期与胃肠道相关的后遗症。 研究宿主水平的胃肠道状况，如肠道微生物群组成和EED，可能会有所帮助。 解释对肠道感染的不同急性反应，以及这些反应的下游后果 感染。虽然有证据表明不同文化的肠道微生物群组成存在差异， 地区和人口，到目前为止，这些差异的环境决定因素，如是否获得管道 水，还没有用明确的反事实进行实验评估。需要更多的研究来 了解这些关系以及社区干预措施(如水)对它们的影响 供应供应。我们建议测试向低收入城市家庭提供自来水对以下方面的影响： (SA1)急性胃肠道疾病(肠道病原体流行、腹泻流行)；(SA2)慢性 胃肠道状况(EED、肠道微生物群组成、生长迟缓)；和(SA3)时机 肠道病原体血清转换及其与慢性胃肠道疾病的关系 条件。我们的多学科团队在影响评估、肠道疾病、饮用水方面拥有专业知识 质量，和元基因组学，以及在低收入人群中研究肠道疾病的丰富经验 世界各地的环境。这项研究将为如何最好地投资资源以提供 应对全球城市增长和改善儿童健康的基本基础设施，特别是对 据估计，全世界有11亿人缺乏安全饮用水供应。

This study leverages our leadership in the evaluation of a major World Bank (WB)-funded project in four urban areas of Mozambique. We will test if and how improvements in water supply reduce or delay enteropathogen infection, and impact associated acute and chronic gastrointestinal-related disorders. We take advantage of the randomized allocation of access to a new piped water system, adding novel microbial and health endpoints. This will be the largest water system improvement evaluated using an experimental design and the first to examine the impact of new household water connections on these health outcomes. While improved case treatment has reduced mortality from diarrhea in recent decades, morbidity has persisted, with an estimated four billion diarrhea cases annually worldwide. The deleterious health effects of repeated, cumulative enteric pathogen infections and diarrhea episodes are especially relevant when they occur during the first two years of life. Increasing evidence suggests that early infection with enteric pathogens, even in the absence of diarrhea symptoms, is associated with long-term chronic sequelae, including environmental enteric dysfunction (EED), growth faltering, and cognitive impairment. Studies of WASH interventions often focus on reducing diarrhea, and few have examined specific enteric pathogens, nor long-term gastrointestinal-related sequelae. The study of host-level gastrointestinal conditions, such as gut microbiome composition and EED, may help explain differential acute responses to enteric infections, as well as the downstream consequences of these infections. While there is evidence of differences in gut microbiome composition across different cultures, regions, and populations, to date the environmental determinants of these differences, such as access to piped water, have not been evaluated experimentally, using explicit counterfactuals. More research is needed to understand these relationships and how they are affected by community-level interventions such as water supply provision. We propose to test how provision of piped water to low-income, urban households impacts: (SA1) acute gastrointestinal conditions (enteric pathogen prevalence, diarrhea prevalence); (SA2) chronic gastrointestinal conditions (EED, gut microbiome composition, growth faltering); and (SA3) timing of enteropathogen seroconversion and the association between seroconversion and chronic gastrointestinal conditions. Our multi-disciplinary team has expertise in impact evaluation, enteric diseases, drinking water quality, and metagenomics, as well as extensive experience researching enteric diseases in low-income settings throughout the world. This research will inform decisions on how best to invest resources to provide essential infrastructure to cope with urban growth globally and improve child health, especially for the estimated 1.1 billion people worldwide who lack safe drinking water supplies.