The magnitude of diarrhoeal disease is high in developing countries where an estimated 801,000 children under five die due to diarrhea each year. Consumption of water from unimproved sources is a potential contributor of diarrhoeal diseases and their transmission. In sub-Saharan Africa, safe water coverage is less than 50% where about 319 million people lack access to improved water sources and an estimated 1.9 billion people rely on faecally contaminated drinking-water.

 In Ethiopia, nearly 40 million people, most of them in rural areas, didn’t have access to safe drinking water. Even water safe at the source can be easily contaminated during collection, transport, and storage. However; more than 90% of households do not treat their drinking water at home.  Such a situation would pose high public health risks of diarrhea to unsafe water users unless prompt intervention is implemented. Evidences revealed in different parts of Ethiopia indicated that the two-week period prevalence of diarrhea among under-five children ranged from 22.5 to 30.5%. 

   Installation of large scale water treatment plants in rural Ethiopia is difficult due to the scarcity of resources including poor infrastructure Therefore, the situation demands implementation of alternative strategies such as easily applicable low-cost and environmental friendly household water treatment such as solar water disinfection (SODIS). Solar water disinfection (SODIS) where raw water is filled in polyethylene terephthalate (PET) bottles is one of the potential alternative household water treatment technologies that rely on the germicidal effects of sunlight and heat. However, SODIS is still largely unknown as a method of household water treatment technology in rural Ethiopia. So, evidence based health effect of SODIS intervention at household level is limited.  The main purpose of this study is to examine the   effect of SODIS intervention in reducing the burden of diarrhoeal disease among under-five children in rural community of northwest Ethiopia. 

 A community based clustered randomized controlled trial was conducted among children under five years of age in each community from January 10 to July 7, 2016. The SODIS intervention was designed according to the Swiss Federal Institute for Environmental Science and Technology (EWAG) published guideline.  Initially, the study area was divided into two blocks (“block A” and “block B”) with an adequate buffering zone between them.   Potential clusters in the study area were exhaustively listed and sorted out the eligible clusters based on the preset selection criteria within the two blocks.  Intervention and control blocks/arms were randomly assigned through lottery systems. Clusters were also selected in each block based on lottery methods. In the eligible 28 clusters (villages), households with under-five children were randomly allocated to the intervention and control groups and then assigned within each of the 14 pairs of communities randomly to one of them. In each cluster, 28-30 children (778 in total) were enrolled within 568 households and followed up for 6 consecutive months.   Nineteen data collectors with 6 supervisors approached the mother-child pairs in the selected households and completed the baseline survey with regard to socio-demographic, environmental, and   behavioral characteristics of each household in the community and follow up study.

The primary outcome of the study is childhood diarrhea   which is defined by WHO as “three or more loose or watery stools over the past 24 hours (or more frequently than it is normal for the individual).    It was computed as the number of under five children (U5C) who are new cases of a diarrhoeal disease over a six months of follow up period divided into person-weeks observation at risk during the similar period of time.  Data were collected biweekly bases.     

This research is operated under the aegis of Institute of Public Health, College of Medicine and Health Sciences, University of Gondar, Ethiopia.