Performance of Pit Latrines and Their Herd Protection Against Diarrhea: A Longitudinal Cohort Study in Rural Ethiopia.

In sanitation policies, "improved sanitation" is often broadly described as a goal with little rationale for the minimum standard required. We conducted a secondary analysis of data collected as part of a cluster randomized controlled trial in rural Ethiopia. We compared the performance of well-constructed and poorly constructed pit latrines in reducing child diarrhea. In addition, we explored whether having a well-constructed household latrine provides indirect protection to neighbors if cluster-level coverage reaches a certain threshold. We followed up children aged younger than 5 years (U5C) of 906 households in rural areas of the Gurage zone, Ethiopia, for 10 months after community-led total sanitation interventions. A study-improved latrine was defined as having all the following: pit of ≥2 m depth, slab of any material, drop-hole cover, wall, roof, door, and handwashing facilities (water and soap observed). U5C in households with a study-improved latrine had 54% lower odds of contracting diarrhea than those living in households with a latrine missing 1 or more of the characteristics (adjusted odds ratio [aOR]=0.46; 95% confidence interval [CI]=0.27, 0.81; P=.006). Analyses were adjusted for child age and sex, presence of improved water for drinking, and self-reported handwashing at 4 critical times. The odds of having diarrhea among those with an improved latrine based on the World Health Organization/UNICEF Joint Monitoring Program (JMP) definition (i.e., pit latrines with slabs) were not substantially different from those with a JMP-unimproved latrine (aOR=0.99; 95% CI=0.56, 1.79; P=.99). Of U5C living in households without a latrine or with a study-unimproved latrine, those in the high-coverage villages were less likely to contract diarrhea than those in low-coverage villages (aOR=0.55; 95% CI=0.35, 0.86; P=.008). We recommend that academic studies and routine program monitoring and evaluation should measure more latrine characteristics and evaluate multiple latrine categories instead of making binary comparisons only.

Effect of a Community-led Total Sanitation Intervention on the Incidence and Prevalence of Diarrhea in Children in Rural Ethiopia: A Cluster-randomized Controlled Trial.

We conducted a cluster-randomized trial in 48 rural villages of Ethiopia to assess the effect of community-led total sanitation (CLTS) on the diarrhea incidence of children. Twenty-four villages were randomly assigned to the intervention group and the other 24 were assigned to the control group. A CLTS intervention was implemented from January 2016 through January 2017. Baseline data collection was conducted during October and November 2015. At baseline, 906 children were recruited and followed-up until January 2017. These 906 children were randomly selected among all children in the 48 villages. To determine the 7-day period prevalence of diarrhea, four household-based surveys were conducted by independent data collectors at 3, 5, 9, and 10 months after the CLTS was initiated. To determine the incidence and longitudinal prevalence, the presence of daily diarrhea presence was recorded for 140 days using diary methods. The loss to follow-up rates were 95% for period prevalence and 93% for incidence and longitudinal prevalence. 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) after adjusting for clustering and stratification. The relative risk of period prevalence was 0.66 (95% CI, 0.45-0.98; P = 0.04) at 3 months after initiation. Improved toilet coverage increased from 0.0% at baseline to 35.0% at 10 months in the intervention villages, whereas it increased from 0.7% to 2.8% in the control villages. Adherence to the intervention was comparable with that of previous studies; therefore, we suggest that the findings of this study are replicable.

Benefits and Costs of a Community-Led Total Sanitation Intervention in Rural Ethiopia-A Trial-Based ex post Economic Evaluation.

We estimated the costs and benefits of a community-led total sanitation (CLTS) intervention using the empirical results from a cluster-randomized controlled trial in rural Ethiopia. We modelled benefits and costs of the intervention over 10 years, as compared to an existing local government program. Health benefits were estimated as the value of averted mortality due to diarrheal disease and the cost of illness arising from averted diarrheal morbidity. We also estimated the value of time savings from avoided open defecation and use of neighbours' latrines. Intervention delivery costs were estimated top-down based on financial records, while recurrent costs were estimated bottom-up from trial data. We explored methodological and parameter uncertainty using one-way and probabilistic sensitivity analyses. Avoided mortality accounted for 58% of total benefits, followed by time savings from increased access to household latrines. The base case benefit-cost ratio was 3.7 (95% CI: 1.9-5.4) and the net present value was Int'l $1,193,786 (95% CI: 406,017-1,977,960). The sources of the largest uncertainty in one-way sensitivity analyses were the effect of the CLTS intervention and the assumed lifespan of an improved latrine. Our results suggest that CLTS interventions can yield favourable economic returns, particularly if follow-up after the triggering is implemented intensively and uptake of improved latrines is achieved (as opposed to unimproved).