Environmental change and diarrheal disease

描述（由申请人提供）：当粪口病原体遇到人类的贫困和错位时，腹泻疾病是可预测的结果。腹泻病是社会经济水平、资源可得性和人类社会接触变化的敏感指标吗？像这样的过程很难以受控的方式进行研究。在厄瓜多尔沿海地区修建一条新公路是为此目的进行的一次宝贵的自然试验。这条公路将把一些以前偏远的村庄与地方、区域和国家的货物、服务和人员网络连接起来，在他们之间建立新的联系。我们假设：(1)村庄之间的联系水平和类型与肠道病原体感染相关；(2)村庄内社会关系、新资源、个人卫生和卫生行为的变化与肠道病原菌感染相关。这些假设使用村庄作为分析单位。在估计各种暴露风险对疾病发病率的贡献时，探索这些途径之间相互依赖的含义也很重要。这是我们研究的第三个目的：利用疾病传播模型分析这些接触模式变化的联合效应。采用准实验设计，将对20个村庄进行为期4年的跟踪调查，以便充分代表农村-城市连续体。这个连续体将通过几个因素来衡量，这些因素将一个特定的村庄与Borbon联系起来，Borbon位于两条河流的交汇处，这两条河流支撑着该地区的村庄。数据将从三个层面收集。首先，居住在被研究村庄的健康促进者将实施一项积极的监测方案。他们将管理一种新的调查工具，以测量某一村庄所有腹泻疾病的发病率，并监测疾病的近端和远端决定因素。第二，我们的实地小组将对每个社区进行一年两次的访问，该小组最近在这些村庄完成了一项横断面可行性研究。每次访问将持续两周。在这些访问中，将从所有有症状的个体和随机选择的对照中收集粪便样本。此外，在这些访问期间，将使用调查工具收集有关用水行为、环境卫生、个人卫生、食品消费模式以及旅行和移徙的信息。第三，厄瓜多尔当地人类学家将每半年对每个村庄进行一次访问。这些访问将包括开放式访谈以及关于社会网络形成和变化的附加问题。访问还将允许村庄发展和道路。

DESCRIPTION (provided by applicant): Diarrheal diseases are predictable outcomes when fecal-oral pathogens meet human poverty and-dislocation. Are diarrheal diseases sensitive indicators of change in socioeconomic level, resource availability, and human social contacts? Processes like these are extremely difficult to study in a controlled fashion. The construction of a new road in coastal Ecuador provides a valuable natural experiment for this purpose. This road will link some previously remote villages to local, regional, and national networks of goods, services, and people, creating new connections among them. We hypothesize that: (1) the level and type of connections between villages are correlated with infection of enteric pathogens; and (2) the changing social connections, new resources, and sanitary and hygienic behaviors of individuals within villages are correlated with infection of enteric pathogens. These hypotheses use the village as their unit of analysis. When estimating the contribution of various exposure risks to disease incidence, it is also important to explore the implications of interdependence between these pathways. This is the third aim of our study: analyzing the joint effects of changes in these contact patterns using disease transmission models. Using a quasi-experimental design, twenty villages will be followed for 4 years, selected so that a rural-urban continuum is fully represented. This continuum will be measured by several factors that relate a given village to Borbon, the town located at the confluence of two rivers that support the villages within the region. Data will be collected at three levels. First, health promoters who live in the villages under study will implement an active surveillance program. They will administer a new survey tool to measure the incidence of all the diarrheal illnesses and monitor both proximal and distal determinants of disease, in a given village. Second, a biannual visit to each community will be conducted by our field team, which has recently completed a cross sectional feasibility study in these villages. Each visit will last two weeks. In these visits, stool samples will be collected from all symptomatic individuals and a random selection of controls. In addition, during these visits, survey tools will be used to collect information on water-use behavior sanitation, hygiene, food consumption patterns, and travel and migration. Third, semi-annual visits to each village will be undertaken by the local Ecuadorian anthropologist. These visits will include open-ended interviews as well as additional questions about social network formation and change. The visits will also allow village development and road.