Evaluation of a community-led total sanitation intervention in a rural area of the Southern Nations, Nationalities, and Peoples' Region, Ethiopia

Sanitation has historically been regarded as an effective tool to interrupt the transmission of faecal pathogens. Until 2016, however, there has been just one trial investigating effect of a community-led total sanitation (CLTS) intervention on child diarrhea. Most cost-benefit analyses of sanitation interventions have been either theoretical estimations or based on observational studies. The thesis aims to assess the effect of a CLTS intervention on child diarrhea, explore the existence of a sanitation externality, and investigate its economic efficiency. The trial was conducted in a rural area of Ethiopia from 2015 to 2017, enrolling 906 children in 24 intervention and 24 control clusters. There were decreases in both the incidence and longitudinal prevalence of child diarrhoea. After adjusting for clustering and stratification, the incidence ratio and longitudinal prevalence ratio were 0.66 (95% confidence interval [CI], 0.45–0.97; p=0.03) and 0.70 (95% CI, 0.52–0.95; p=0.02), respectively. There was, however, inconclusive evidence regarding the effect on the 7-day period prevalence at 10 months (relative risk=0.75; 95% CI, 0.35–1.60; p=0.45) post-triggering. Higher-quality latrines were associated with a reduction in child diarrhoea compared to those not meeting these criteria (Odds Ratio [OR]=0.46; 95% CI, 0.27–0.81; p=0.006). Children living in households with an unimproved latrine, those in high-coverage villages had a lower risk of diarrhoea than those in low-coverage villages (adjusted OR=0.55; 95% CI, 0.35–0.86, p=0.008). The base case benefit–cost ratio was determined to be 3.7 (95% Credible Interval, 1.9–5.4), and the net present value was calculated to be Int’l$1,193,786 (95% Credible Interval, 406,017–1,977,960). This CLTS intervention has the potential to reduce child diarrroea in a cost-effective way. There was evidence for substantial sanitation externalities. However, the quality and design of latrines should receive more attention in sanitation interventions, as low-quality latrines offered little protection.