Solar Water Disinfection: Randomized Intervention Trial

描述（由申请人提供）：发展中国家农村和城市周边地区三分之一以上的人口无法获得不含病原体的充足或清洁饮用水。因此，水媒胃肠炎仍然是一个主要的基础设施和公共卫生问题，特别是因为有效的治疗（过滤，氯化，处理厂）往往超出财政手段或用于水净化（火煮，燃烧碳基燃料）的环境资源变得稀缺，在这些社区。在这种情况下，饮用水的太阳能消毒是特别有吸引力的，使用直接阳光照射和太阳能加热的组合来杀死受污染的饮用水中的水传播病原体。到目前为止，SODIS技术作为一种在低收入国家提供安全饮用水的家庭低成本干预措施的效力已经得到充分证实，目前正在七个拉丁美洲国家开展大规模的推广和传播方案。本研究的主要目的是评估家庭太阳能水消毒（SODIS）在减少参与玻利维亚全国SODIS计划的农村5岁以下儿童胃肠道疾病负担方面的有效性。我们将在每个社区的5岁以下儿童队列中进行社区（群集）随机对照试验。将从国家方案指定的地区中选出总共22个社区接受SODIS干预。将采用配对设计，首先根据社区的疟疾基线发病率对社区进行排名，然后在11对连续社区中的每一对内随机分配干预措施。每个群组将招募30名儿童（共660名），并随访12个月。有关产后疾病的数据将从母亲的发病日记中获得，并通过每周家访进行验证。将在基线发病率调查期间和随访期间儿童腹泻发作时采集粪便样本。将对饮用水的原水源和经SODIS装置处理后的水样进行系统的水质监测。参与儿童的母亲将在基线和试验期间接受采访，了解其儿童在家中和社区内的当前用水情况、行为和环境暴露情况。本研究将具体评估：（1）在实验室实验和两项严格控制的III期试验中建立的SODIS技术的有效性有多少可以保留为有效性，即，在程序条件下;（2）可归因于SODIS的全因儿童腹泻的预防分数;和（3）病原体特异性归因于腹泻疾病的风险和SODIS的成本效益将被计算。该项目由加州大学伯克利分校组织，该大学在美国水干预试验方面具有丰富的经验，并受益于瑞士巴塞尔瑞士热带研究所在公共卫生研究方面的南北合作传统。它是与圣西门大学的玻利维亚合作伙伴和协调玻利维亚SODIS方案的SODIS基金会联合运作的。

DESCRIPTION (provided by applicant): More than one third of the population in rural and in peri-urban areas of developing countries have no access to sufficient or clean drinking water free of pathogens. Thus, waterborne gastroenteritis remains a major infrastructural and public health problem particularly, as effective treatment (filtration, chlorination, treatments plants) is often beyond financial means or environmental resources used for water purification (fire-boiling, burning carbon-based fuels) become scarce in those communities. In this context solar disinfection of drinking water is especially appealing using a combination of irradiation by direct sunlight and solar heating to kill the water-borne pathogens in contaminated drinking water. To date, the efficacy of the SODIS technology as a home-based, low-cost intervention to provide safe drinking water in low income countries is well established, and a large-scale promotion and dissemination program is under way in seven Latin American countries. The principal objective of this study is to evaluate the effectiveness of home-based solar water disinfection (SODIS) in reducing the burden of gastrointestinal illness in children under 5 years in rural villages participating in a country-wide Bolivian SODIS program. We will conduct a community (cluster)-randomized controlled trial following a cohort of children under age 5 in each community. Totally, 22 communities will be selected from among those districts designated by the country-program to receive the SODIS intervention. A pair-matched design will be employed where communities are first ranked according to their baseline incidence of diarrheal disease and the intervention then assigned within each of the 11 consecutive pairs of communities randomly to one of them. In each cluster, 30 children (660 in total) will be enrolled and followed up for 12 months. Data on diarrheal illness will be obtained from morbidity diaries kept by mothers and validated through weekly home visits. Stool samples will be collected during the baseline morbidity surveys and at times of a diarrheal episode in a child during follow-up. Water quality monitoring of raw water sources used for drinking water and of water samples after treatment with the SODIS device will be conducted systematically. Mothers of participating children will be interviewed at baseline and during the trial with regard to current water use, behavioral and environmental exposures of their child in the home and within the community. This study will specifically estimate: (1) how much of the efficacy of the SODIS technology established in laboratory experiments and in two tightly controlled phase-Ill trials can be retained as effectiveness, i.e., under program conditions; (2) the preventive fraction of all-cause child-diarrhea attributable to SODIS; and (3) pathogen-specific attributable risks of diarrheal illness and the cost-effectiveness of SODIS will be calculated. The project is organized by the University of California, Berkeley, with its substantial experience in water intervention trials in U.S. and it benefits from the tradition of North-South collaboration in public health research of the Swiss Tropical Institute, Basel, Switzerland. It is run jointly with the Bolivian partners at the Universidad Mayor de San Simon and the Fondazion SODIS that coordinates the Bolivian SODIS program.