Effects of sanitation on pathogen transmission and child health in Bangladesh

孟加拉国卫生设施对病原体传播和儿童健康的影响

• 批准号: 9085114
• 负责人: JOHN M COLFORD
• 金额: $ 53.01万
• 依托单位: UNIVERSITY OF CALIFORNIA BERKELEY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-16 至 2018-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9085114
• 关键词: Accounting; Address; Adoption; Animals; Area; Bacteria; Bangladesh; Behavior; Behavior monitoring; Behavioral; Birth; Centers for Disease Control and Prevention (U.S.); Cessation of life; Child; Child health care; Complex; Data; Data Collection; Developing Countries; Diarrhea; Disease; Effectiveness; Enrollment; Enteral; Environment; Feces; Field Workers; Foundations; Funding; Future; Hand; Health; Helminths; Household; Human; Hygiene; Individual; Infection; Intention; Intervention; Intervention Trial; Intestinal parasite; Latrine; Lead; Life; Measurement; Measures; Mediating; Methods; Molecular; Monitor; Mouth Diseases; Organism; Outcome; Outcome Measure; Parasites; Parasitic infection; Pathway Analysis; Pathway interactions; Play; Prevalence; Protocols documentation; Protozoa; Protozoan Infections; Randomized; Randomized Controlled Trials; Research Infrastructure; Risk; Rural; Sampling; Sanitation; Sewage; Soil; Source; Spottings; System; Testing; United States National Institutes of Health; Visit; Water; arm; base; behavior change; behavior measurement; burden of illness; cohort; contaminated drinking water; contaminated water; cost efficient; design; disease transmission; experience; follow-up; gastrointestinal; gastrointestinal infection; improved; insight; low income country; microbial; mortality; novel; oral pathogen; pathogen; prevent; programs; randomized trial; sensor; tool; transmission process; uptake

DESCRIPTION (provided by applicant): Diarrheal illness creates a large and persistent disease burden among children in low-income countries; mortality estimates attribute 10% of global deaths among children < 5 to diarrhea. Fecal-oral pathogens (believed to be the most important causes of diarrhea) are transmitted from feces to new hosts through a variety of complex, environmentally mediated pathways that interact with each other and are also influenced by human behavior. Sanitation interventions that prevent the spread of pathogens from feces into the environment (e.g. provision of latrines) could block these transmission pathways and reduce the burden of diarrheal disease. Despite the potential importance of sanitation in reducing diarrhea, all studies to date of sanitation interventions on child gastrointestinal infections in rural settings have used non-randomized designs. Additionally, few studies have included detailed monitoring of sanitation-related behaviors and microbiological assessment of the complex pathogen transmission pathways that lead from feces to child illness. Aims: The principal aims of this study are to assess the impact of improvements in sanitation infrastructure and household sanitation practices on fecal contamination along pathogen transmission pathways in rural Bangladesh, and to assess how these pathways mediate the impact of sanitation improvements on diarrhea and parasitic infections in children < 24 months old. We hypothesize that improved sanitation will reduce contamination of drinking water, household soil, and children's hands; we also posit that these pathways will mediate any reductions in diarrhea prevalence and parasitic infections caused by the intervention. Methods: We will test our hypotheses by nesting microbiological and behavioral measurements within WASH Benefits, a randomized controlled trial currently underway in rural Bangladesh funded by the Gates Foundation and led by our team. We will visit a total of 720 households from the trial's sanitation and control arms quarterly for 2 years, starting 12 months after intervention. At each visit, we will collect samples from tubewells, ponds, stored water, soil from the child play area, soil near tubewells and from children's hands for analysis of fecal indicator bacteria. During the last two sampling rounds, we will analyze samples for prominent fecal pathogens and perform source tracking to distinguish fecal contamination from humans versus animals. We will monitor sanitation practices through spot checks and passive infrared sensor measurements. These data will leverage the health outcomes measured in the existing trial protocol (diarrhea and helminth and protozoan infections in stool). We will compare fecal contamination between the study arms using intention to treat and complier average causal effect estimators. We will estimate the contribution of contamination to health outcomes through individual pathways by analysis of direct and indirect effects. Our team (UC Berkeley, Stanford, ICDDR,B) has extensive experience collaborating on studies of water, sanitation and hygiene in Bangladesh and other low-income countries on projects funded by the NIH, CDC, DFID, USEPA and the Gates Foundation.

描述（由申请人提供）：腹泻病在低收入国家的儿童中造成了巨大而持续的疾病负担；死亡率估计将<5的儿童全球死亡的10％归因于腹泻。粪便 - 口腔病原体（认为是腹泻最重要的原因）是通过各种相互相互作用的复杂，环境介导的途径从粪便传播到新宿主的，并且也受到人类行为的影响。防止病原体从粪便传播到环境的卫生干预措施（例如提供厕所）可能会阻止这些传播途径并减轻腹泻病的负担。尽管卫生在减少腹泻方面具有潜在的重要性，但在农村环境中对儿童胃肠道感染的卫生干预措施的所有研究都使用了非随机设计。此外，很少有研究包括对卫生相关行为的详细监测以及对从粪便到儿童疾病导致的复杂病原体传播途径的微生物评估。目的：这项研究的主要目的是评估卫生基础设施和家庭卫生实践改善对孟加拉国农村病原体传播途径沿粪便污染的影响，并评估这些途径如何介导卫生率改善对腹泻和寄生虫感染的影响。我们假设改善的卫生能力将减少饮用水，家用土壤和儿童手的污染；我们还认为，这些途径将介导腹泻患病率和由干预措施引起的寄生感染的任何降低。方法：我们将通过将微生物学和行为测量值嵌套在WASH福利范围内测试我们的假设，这是一项由盖茨基金会资助并由我们的团队领导的孟加拉国目前正在进行的随机对照试验。从干预后12个月开始，我们将在试验的卫生和控制武器季刊中总共参观720个家庭。每次访问时，我们都会从小管，池塘，储存的水，儿童游乐区的土壤，小管道附近的土壤和儿童手中收集样品，以分析粪便指标细菌。在最近的两个采样回合中，我们将分析样品中突出的粪便病原体，并执行来源跟踪，以区分粪便污染与人类与动物的污染。我们将通过点检查和被动红外传感器测量来监视卫生实践。这些数据将利用现有试验方案中测量的健康结果（腹泻和蠕动和原生动物感染粪便）。我们将使用对治疗和平均因果效应估计量的意图进行研究臂之间的粪便污染。我们将通过分析直接和间接效应来估算污染对健康结果的贡献。我们的团队（UC Berkeley，Stanford，ICDDR，B）在孟加拉国的水，卫生和卫生研究方面和其他低收入国家在NIH，CDC，DFID，USEPA，USEPA和GATES FOUNDATD的项目上都有丰富的合作经验。