Effect of drinking water treatment on bacterial strain sharing among Kenyan children

摘要 在腹泻和肠道感染率较高的社区，细菌菌株共享的空间尺度 年幼的孩子没有得到很好的研究。然而，了解这些传播模式是至关重要的知识 选择和实施干预措施，在资源有限的环境中保护儿童健康。 水处理干预措施通常是针对家庭一级的，但最近的大规模试验 家庭一级的干预措施并没有始终显示儿童腹泻患病率的下降。一 解释是，家庭层面的饮用水干预未能阻断社区传播 途径，导致儿童持续接触细菌病原体。在这里，我们将研究菌株共享 在多个空间尺度上的儿童对之间，包括在家庭内部和家庭之间 城乡环境。我们将利用之前(由我们的团队)收集的240套粪便样本 兄弟姐妹(n=480名儿童)，包括来自120户城市家庭和120户农村家庭的兄弟姐妹。在这两个地方 在城市和农村的研究地点，我们将有独特的机会从相同数量的家庭中进行抽样 来自有或不能获得社区饮用水氯化处理的村庄。我们将1)比较 肯尼亚农村和城市社区细菌菌株共享的规模；以及2)评估 在城市和农村社区共享细菌菌株的社区范围内获得氯化消毒的机会。我们的 研究种群还将使我们能够调查细菌菌株的共享模式和社区范围的水 对于年龄较小的学龄儿童和年龄较大的学龄儿童，治疗效果不同。我们将使用短读元基因组学 测序和我们团队开发的一套创新的计算细菌菌株跟踪工具 来实现这些目标。我们的发现将告诉我们未来饮用水和其他 应实施环境干预措施，如果提供旨在保护的干预措施 农村和城市社区的幼儿接触细菌病原体的情况应该不同。

SUMMARY In communities with high rates of diarrhea and enteric infections, the spatial scale of bacterial strain sharing in young children has not been well studied. Yet, understanding these transmission patterns is critical knowledge for selecting and implementing interventions to protect child health in resource-constrained environments. Water treatment interventions are often targeted at the household level, yet recent large-scale trials of household-level interventions have not consistently shown reductions in child diarrhea prevalence. One explanation is that household-level drinking water interventions fail to disrupt community transmission pathways, resulting in continued child exposure to bacterial pathogens. Here, we will investigate strain sharing between child pairs at multiple spatial scales, including within households and between households across urban and rural settings. We will leverage previously collected (by our team) fecal samples from 240 sets of siblings (n=480 children), including siblings from 120 urban households and 120 rural households. In both urban and rural study sites, we will have the unique opportunity to sample from equal numbers of households from villages with and without access to community-wide drinking water chlorination. We will 1) compare the scale of bacterial strain sharing in rural versus urban communities in Kenya; and 2) evaluate the effect of access to community-wide chlorination on bacterial strain sharing in both urban and rural communities. Our study population will also allow us to investigate if bacterial strain sharing patterns and community-wide water treatment effects differ for younger versus older school-aged children. We will use short-read metagenomic sequencing and a new innovative suite of computational bacterial strain tracking tools developed by our team to achieve these aims. Our findings will inform the scope and scale at which future drinking water and other environmental interventions should be implemented, and if the delivery of interventions designed to protect young children from exposure to bacterial pathogens should be different for rural versus urban communities.