Accessibility to Safe Drinking Water and Diarrheal Diseases: A Quasi-Experiment on a Case of Water Well Drilling in the Village of Kassouala, Municipality of Tchaourou, Benin, January 2018-July 2019

Background: In 2017, 900 million people in the world did not have sustainable access to safe drinking water (SDW). In addition, between 2016 and 2020, the global population with safely managed drinking water at home increased from 70 percent to 74 percent. Drinking water insecurity is the daily situation of people in developing countries. The lack of SDW supply is at the root of many diseases, including diarrheal diseases. Kassouala is a village in the municipality of Tchaourou without access to SDW, but having benefited from the drilling of a well in September 2018. The objective of this study was to study the effect of access to safe drinking water on the frequency of diarrheal diseases in Kassouala between January 2018 and July 2019. Methods: We conducted a quasi-experimental study in Kassouala using the natural experiments of the village of Bérétou as a control group for estimating the effect of a causal nature. There were double temporal (January 2018-July 2019) and geographical (Kassouala-Bérétou) comparisons based on data collected from health care registers. A population-based comparability survey of the two villages was conducted among 170 households in each village (experimental village, control village). A two-stage cluster sampling procedure was used to select the survey participants. Data were collected from heads of household by semi-structured questionnaire. We used Pearson or Mantel-Haenszel chi-square tests, as appropriate, and the “difference-in-difference” method to assess the effect. Results: In Kassouala, the proportion of households with access to safe drinking water had increased to 78.88%, whereas it was nil in 2018 before the well drilling, and the frequency of diarrheal diseases decreased significantly from January 2018 before drilling to July 2019 after drilling (57.11% to 44.64%; p < 0.0001). In Bétérou, on the other hand, a control village, used as counterfactual village, a significant increase was noted (31.48% vs. 50%; p < 0.0001). The difference-in-difference was estimated at -30.99% with a degree of statistical significance estimated at p < 0.0001 accounting for the decrease in the frequency of diarrhea in Kassoula relates to SDW accessibility to the population due to the drilling of the well. Conclusion: Access to safe drinking water in Kassouala has a causal effect on the reduction of diarrheal diseases. However, for the supply of drinking water to be integrated into the community development plan of Tchaourou, it is necessary to support the