Effect of a community-led sanitation intervention on child diarrhoea and child growth in rural Mali: a cluster-randomised controlled trial

BACKGROUND

Community-led total sanitation (CLTS) uses participatory approaches to mobilise communities to build their own toilets and stop open defecation. Our aim was to undertake the first randomised trial of CLTS to assess its effect on child health in Koulikoro, Mali.

METHODS

We did a cluster-randomised trial to assess a CLTS programme implemented by the Government of Mali. The study population included households in rural villages (clusters) from the Koulikoro district of Mali; every household had to have at least one child aged younger than 10 years. Villages were randomly assigned (1:1) with a computer-generated sequence by a study investigator to receive CLTS or no programme. Health outcomes included diarrhoea (primary outcome), height for age, weight for age, stunting, and underweight. Outcomes were measured 1·5 years after intervention delivery (2 years after enrolment) among children younger than 5 years. Participants were not masked to intervention assignment. The trial is registered with ClinicalTrials.gov, number NCT01900912.

FINDINGS

We recruited participants between April 12, and June 23, 2011. We assigned 60 villages (2365 households) to receive the CLTS intervention and 61 villages (2167 households) to the control group. No differences were observed in terms of diarrhoeal prevalence among children in CLTS and control villages (706 [22%] of 3140 CLTS children vs 693 [24%] of 2872 control children; prevalence ratio [PR] 0·93, 95% CI 0·76-1·14). Access to private latrines was almost twice as high in intervention villages (1373 [65%] of 2120 vs 661 [35%] of 1911 households) and reported open defecation was reduced in female (198 [9%] of 2086 vs 608 [33%] of 1869 households) and in male (195 [10%] of 2004 vs 602 [33%] of 1813 households) adults. Children in CLTS villages were taller (0·18 increase in height-for-age Z score, 95% CI 0·03-0·32; 2415 children) and less likely to be stunted (35% vs 41%, PR 0·86, 95% CI 0·74-1·0) than children in control villages. 22% of children were underweight in CLTS compared with 26% in control villages (PR 0·88, 95% CI 0·71-1·08), and the difference in mean weight-for-age Z score was 0·09 (95% CI -0·04 to 0·22) between groups. In CLTS villages, younger children at enrolment (<2 years) showed greater improvements in height and weight than older children.

INTERPRETATION

In villages that received a behavioural sanitation intervention with no monetary subsidies, diarrhoeal prevalence remained similar to control villages. However, access to toilets substantially increased and child growth improved, particularly in children <2 years. CLTS might have prevented growth faltering through pathways other than reducing diarrhoea.

FUNDING

Bill & Melinda Gates Foundation.

Community-Level Sanitation Coverage More Strongly Associated with Child Growth and Household Drinking Water Quality than Access to a Private Toilet in Rural Mali

Sanitation access can provide positive externalities; for example, safe disposal of feces by one household prevents disease transmission to households nearby. However, little empirical evidence exists to characterize the potential health benefits from sanitation externalities. This study investigated the effect of community sanitation coverage versus individual household sanitation access on child health and drinking water quality. Using a census of 121 villages in rural Mali, we analyzed the association of community latrine coverage (defined by a 200 m radius surrounding a household) and individual household latrine ownership with child growth and household stored water quality. Child height-for-age had a significant and positive linear relationship with community latrine coverage, while child weight-for-age and household water quality had nonlinear relationships that leveled off above 60% coverage (p < 0.01; generalized additive models). Child growth and water quality were not associated with individual household latrine ownership. The relationship between community latrine coverage and child height was strongest among households without a latrine; for these households, each 10% increase in latrine coverage was associated with a 0.031 (p-value = 0.040) increase in height-for-age z-score. In this study, the level of sanitation access of surrounding households was more important than private latrine access for protecting water quality and child health.

The dirty business of eliminating open defecation: The effect of village sanitation on child height from field experiments in four countries

We examine the impacts of a sanitation program designed to eliminate open defecation in at-scale randomized field experiments in four countries: India, Indonesia, Mali, and Tanzania. The programs - all variants of the widely-used Community-Led Total Sanitation (CLTS) approach - increase village private sanitation coverage in all four locations by 7-39 percentage points. We use the experimentally-induced variation in access to sanitation to identify the causal relationship between village sanitation coverage and child height. We find evidence of threshold effects where increases in child health of 0.3 standard deviations are realized once village sanitation coverage reaches 50-75%. There do not appear to be further gains beyond this threshold. These results suggest that there are large health benefits to achieving coverage levels well below the 100% coverage pushed by the CLTS movement. Open defecation decreased in all countries through improved access to private sanitation facilities, and additionally through increased use of sanitation facilities in Mali who implemented the most intensive behavior change intervention.