Solar Water Disinfection Intervention Trial in Bolivia
Condition: Diarrhea
MeSH terms: Diarrhea
Study type: Interventional
Phase: Phase 3

Summary: 
      The importance of waterborne gastrointestinal illness throughout the developing world, the
      existence of a cheap and effective intervention (SODIS), the concurrent limited dissemination
      program for SODIS, the need for a controlled evaluation of the effectiveness of SODIS under
      actual field conditions, and the experience of our tri-national collaborative research team
      in successfully conducting large scale drinking water intervention and observational studies
      in both the United States and the developing world encourage us to propose the following
      randomized controlled trial in which our specific aims are to:

        -  Evaluate the hypothesis that SODIS reduces the incidence of gastrointestinal illness in
           660 children under the age of five years in rural Bolivia that are randomly selected
           from 22 villages ;

        -  Define, through an extensive microbiologic testing component, the baseline rates of
           pathogen-specific diarrheal illnesses and the pathogens responsible for the differences
           in diarrheal illness between active and control groups;

        -  Document the actual use and acceptance of SODIS by participants in the study;

        -  Assess the cost-effectiveness of SODIS and the social and economic impact of SODIS at
           household level;

        -  Examine through mathematical disease modelling the effects of the presence of multiple
           transmission pathways within a village on the preventable fraction estimate due to the
           introduction of SODIS.
    

Detailed description: 
      More than one third of the population in rural and in peri-urban areas of developing
      countries has 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 patho¬gens 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 <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; i.) how
      much of the efficacy of the SODIS technology established in laboratory experiments and in two
      tightly control¬led phase-III trials can be retained as effectiveness i.e. under program
      conditions, ii.) the preventive fraction of all-cause child-diarrhea attributable to SODIS.
      In addition, pathogen-specific attributable risks of diarrheal illness will be calculated.
      The project is organised by the University of California, Berkeley, with its substantial
      experience in water intervention trials in US 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 Universidad Mayor de San Simon which coordinates the
      Bolivian SODIS program.
    

Intervention name(s): Solar Water Disinfection (SODIS)
Intervention type(s): Device
Intervention description(s): Intervention group has SODIS implemented at the household level as a way to disinfect drinking water
Other intervention name(s): SODIS
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Prevention
Keywords: SODIS; Drinking Water; Disinfection; Intervention Trial