Herd Protection from Drinking Water, Sanitation, and Hygiene Interventions

Progress in Water, Sanitation and Hygiene (WASH) coverage and potential contribution to the decline in diarrhea and stunting in Ethiopia

Inadequate safe water supply and poor sanitation and hygiene continue to be important risk factors for diarrhoea and stunting globally. We used data from the four rounds of the Ethiopian Demographic and Health Survey and applied the new World Health Organization (WHO)/UNICEF Joint Monitoring Program (JMP) service standards to assess progress in water, sanitation and hygiene (WASH) coverage between 2000 and 2016. We also performed an age-disaggregated pooled linear probability regression analysis followed by a decomposition analysis to determine whether changes in WASH practices have contributed to the changing prevalence of diarrhoea and stunting in children under 5 years of age. We observed a significant increase in the coverage of safe drinking water and adequate sanitation facilities over the period. At the national level, the use of a basic water source increased from 18% in 2000 to 50% in 2016. Open defecation declined from 82% to 32% over the same period. However, in 2016, only 6% of households had access to a basic sanitation facility, and 40% of households had no handwashing facilities. The reduction in surface water use between 2000 and 2016 explained 6% of the decline in diarrhoea observed among children aged 0-5 months. In children aged 6-59 months, between 7% and 9% of the reduction in stunting were attributable to the reduction in open defecation over this period. Despite progress, improvements are still needed to increase basic WASH coverage in Ethiopia. Our findings showed that improvements in water and sanitation only modestly explained reductions in diarrhoea and stunting.

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.

"People are now working together for a common good": The effect on social capital of participatory design for community-level sanitation infrastructure in urban informal settlements

Communities with higher levels of social capital perform better than communities with lower social capital in community-level water and sanitation interventions and have better health outcomes. Although research recommends bolstering social capital to improve intervention outcomes, few studies provide empirical evidence on the effect of intervention activities on social capital. This study aimed to evaluate the effect of participatory design and community engagement activities on social capital among urban informal settlements in Suva, Fiji and Makassar, Indonesia enrolled in the Revitalizing Informal Settlements and their Environments trial using the Short Adapted Social Capital Assessment Tool. We performed confirmatory factor analyses (CFA) to test tool performance and built structural equation models to assess intervention effect on CFA-informed, sub-scale scores for cognitive and structural social capital. Qualitative in-depth interviews in Fiji and Indonesia and focus group discussions in Fiji provided nuanced understanding of intervention effects on social capital from residents' perspectives. Results confirmed the hypothesized two-factor solution but revealed differences by country and by gender in Indonesia. The intervention appeared positively related to cognitive social capital among men and women in Indonesia and negatively related to cognitive and structural social capital among men and women in Fiji. While effect sizes were small and cluster-adjustment for a small number of settlements yielded non-significant effects, trends were consistent across models and bivariate analyses and were corroborated by qualitative findings. Several contextual factors may explain these results, including timing and duration of intervention activities and influence of COVID-19. Qualitative data suggested that the relationship between participatory design and social capital may be bidirectional, helping to explain why certain settlements appeared to be better equipped to benefit from intervention activities. Practitioners and program designers should carefully consider the social pre-conditions of communities in which they intend to work to optimize program outcomes and avoid unintended consequences.

Evidence of waste management impacting severe diarrhea prevalence more than WASH: An exhaustive analysis with Brazilian municipal-level data

Adequate housing protects from diarrhea, which is a substantial health concern in low- and middle-income countries. The purpose of this study was to quantify the relationship between severe diarrhea and housing features at the municipal level to help in public health planning. Regression analyses were performed on annual (2000-2012) datasets on Brazilian municipalities (5570) in six household feature categories (e.g., waste management) and four severe diarrhea outcomes (e.g., diarrhea deaths of under-5 children). Household data were not available elsewhere of this magnitude and granularity, highlighting the scientific value-add of this study. Municipalities were clustered prior to regression analysis because of data heterogeneity. The compositional household feature data were also subjected to principal component analysis to diminish feature variable multicollinearity. The highest explanatory power was found for diarrhea deaths of under-5 children (R2 = 10-22 %), while those in the over-5 population were the least best explained (R2 = 0.3-7 %). Household features predicted diarrhea outcomes more accurately in the "advanced" housing municipality cluster (R2 = 16-22 %) than in the "mid-level" (R2 = 7-20 %) and "basic" (R2 = 6-12 %) ones (over-5 diarrhea deaths excluded). Under-5 children's diarrhea death prevalence was three times higher in the "basic" cluster than in the "advanced" cluster. Importantly, the impact of waste management was overall the largest of all household features, even larger than those of WASH, i.e., water supply, sanitation, and household drinking water treatment. This is surprising in the context of existing literature because WASH is generally regarded as the most important household factor affecting gastrointestinal health. In conclusion, public health interventions could benefit from customizing interventions for diarrhea outcomes, municipality types, and household features. Waste management's identified stronger association with diarrhea compared to WASH may have important implications beyond the water field and Brazil.

The effect of a health extension program on improving water, sanitation, and hygiene practices in rural Ethiopia

BACKGROUND

To make basic primary health care services accessible, especially to the rural community, the government of Ethiopia launched the Health Extension Program (HEP) in 2004. Most of components of HEP are dedicated to hygiene and sanitation. Few studies have assessed the role of the Health Extension Program in improving water, hygiene, and sanitation (WASH) practices in Ethiopia. This study explored the role of health extension workers (HEWs) in influencing household water treatment practices, latrine ownership, latrine use and ownership, and the use of hand-washing facilities on the incidence of diarrheal diseases among the children under five years of age in rural Ethiopia.

METHODS

Using a cross sectional design, we conducted a national assessment that covered all nine regions of Ethiopia. We conducted face-to-face interviews among a sample of 6430 rural households using a structured questionnaire and an observation checklist to collect data from March 2018 to May 2019. Multilevel logistic regressions models were used to determine the relationships between the exposure of households to HEWs and WASH practice outcomes such as the use of water from an improved water source, household water treatment practices, availability of hand-washing and hand-washing with soap and water, availability of latrines, and use of latrines as well as the incidence of diarrheal diseases among children age 5 and younger. Our models were adjusted for covariates and confounders and P-values less than 5% were set to determine statistical significance.

RESULTS

We found that 72.7% of rural households had some type of latrine and 27.3% reported practicing open defecation. A total of 71.5% of rural households had access to drinking water from improved water sources, but only 9.4% reported practicing household water treatment. Exposure to HEWs was positively associated with household water treatment practices (AOR: 1.46; 95% CI = 1.01-2.10) and latrine availability (AOR: 1.44; 95% CI = 1.15-1.80). Among the households who were either visited by HEWs at their home or the that visited health posts to meet with the HEWs, being exposed to WASH health education by HEWs was significantly associated with the availability of a hand-washing facility (AOR: 5.14; 95% CI = 4.11-6.42) and latrine availability (AOR: 1.48; 95% CI = 1.10-2.01). However, we did not find a relationship between the incidence of diarrhea among children age 5 and under and exposure to HEWs (AOR: 2.09; 95% CI = 0.73- 6.62).

CONCLUSION

Our results show a significant association between exposure to the Health Extension Program/ HEWs and improved household water treatment practices, latrine construction, and the availability of hand-washing facilities in rural Ethiopia, suggesting the need to strengthen efforts to change WASH behavior through the Heath Extension Program. On the other hand, further investigation is needed regarding the spillover effect of latrine use practices and the reduction of the incidence of diarrheal diseases.

Exploring Survey-Based Water, Sanitation, and Animal Associations With Enteric Pathogen Carriage: Comparing Results in a Cohort of Cases With Moderate-to-Severe Diarrhea to Those in Controls in the Vaccine Impact on Diarrhea in Africa (VIDA) Study, 2015-2018

BACKGROUND

The magnitude of pediatric enteric pathogen exposures in low-income settings necessitates substantive water and sanitation interventions, including animal feces management. We assessed associations between pediatric enteric pathogen detection and survey-based water, sanitation, and animal characteristics within the Vaccine Impact on Diarrhea in Africa case-control study.

METHODS

In The Gambia, Kenya, and Mali, we assessed enteric pathogens in stool of children aged <5 years with moderate-to-severe diarrhea and their matched controls (diarrhea-free in prior 7 days) via the TaqMan Array Card and surveyed caregivers about household drinking water and sanitation conditions and animals living in the compound. Risk ratios (RRs) and 95% confidence intervals (CIs) were calculated using modified Poisson regression models, stratified for cases and controls and adjusted for age, sex, site, and demographics.

RESULTS

Bacterial (cases, 93%; controls, 72%), viral (63%, 56%), and protozoal (50%, 38%) pathogens were commonly detected (cycle threshold <35) in the 4840 cases and 6213 controls. In cases, unimproved sanitation (RR, 1.56; 95% CI, 1.12-2.17), as well as cows (RR, 1.61; 95% CI, 1.16-2.24) and sheep (RR, 1.48; 95% CI, 1.11-1.96) living in the compound, were associated with Shiga toxin-producing Escherichia coli. In controls, fowl (RR, 1.30; 95% CI, 1.15-1.47) were associated with Campylobacter spp. In controls, surface water sources were associated with Cryptosporidium spp., Shigella spp., heat-stable toxin-producing enterotoxigenic E. coli, and Giardia spp.

CONCLUSIONS

Findings underscore the importance of enteric pathogen exposure risks from animals alongside more broadly recognized water and sanitation risk factors in children.

Leveraging infectious disease models to interpret randomized controlled trials: Controlling enteric pathogen transmission through water, sanitation, and hygiene interventions

Randomized controlled trials (RCTs) evaluate hypotheses in specific contexts and are often considered the gold standard of evidence for infectious disease interventions, but their results cannot immediately generalize to other contexts (e.g., different populations, interventions, or disease burdens). Mechanistic models are one approach to generalizing findings between contexts, but infectious disease transmission models (IDTMs) are not immediately suited for analyzing RCTs, since they often rely on time-series surveillance data. We developed an IDTM framework to explain relative risk outcomes of an infectious disease RCT and applied it to a water, sanitation, and hygiene (WASH) RCT. This model can generalize the RCT results to other contexts and conditions. We developed this compartmental IDTM framework to account for key WASH RCT factors: i) transmission across multiple environmental pathways, ii) multiple interventions applied individually and in combination, iii) adherence to interventions or preexisting conditions, and iv) the impact of individuals not enrolled in the study. We employed a hybrid sampling and estimation framework to obtain posterior estimates of mechanistic parameter sets consistent with empirical outcomes. We illustrated our model using WASH Benefits Bangladesh RCT data (n = 17,187). Our model reproduced reported diarrheal prevalence in this RCT. The baseline estimate of the basic reproduction number R 0 for the control arm (1.10, 95% CrI: 1.07, 1.16) corresponded to an endemic prevalence of 9.5% (95% CrI: 7.4, 13.7%) in the absence of interventions or preexisting WASH conditions. No single pathway was likely able to sustain transmission: pathway-specific R 0 s for water, fomites, and all other pathways were 0.42 (95% CrI: 0.03, 0.97), 0.20 (95% CrI: 0.02, 0.59), and 0.48 (95% CrI: 0.02, 0.94), respectively. An IDTM approach to evaluating RCTs can complement RCT analysis by providing a rigorous framework for generating data-driven hypotheses that explain trial findings, particularly unexpected null results, opening up existing data to deeper epidemiological understanding.

Influence of community-level sanitation coverage and population density on environmental fecal contamination and child health in a longitudinal cohort in rural Bangladesh

BACKGROUND

Household-level sanitation interventions have had limited effects on child health or environmental contamination, potentially due to low community coverage. Higher community-level coverage with safely managed sanitation can reduce opportunities for disease transmission.

METHODS

We estimated associations between community sanitation coverage, environmental fecal contamination, and child health among 360 compounds in the control arm of the WASH Benefits trial in rural Bangladesh (NCT01590095). In each compound, we enumerated E. coli in environmental samples and recorded the 7-day prevalence of caregiver-reported diarrheal disease and acute respiratory infections (ARI) in children under five. We observed indicators of latrine access and quality among all neighboring compounds within 100 m of study compounds. We defined community coverage as the proportion of neighboring compounds with (1) at least one latrine, and (2) exclusively hygienic latrines (improved facility observed to safely contain feces), within both 50 m and 100 m of study compounds. We assessed effect modification by population density and season.

RESULTS

Adjusted for confounders, study compounds surrounded by 100% coverage of at least one latrine per compound within 50 m had slightly lower log10E. coli counts in stored water (Δlog = -0.13, 95% CI -0.26, -0.01), child hand rinses (Δlog = -0.13, 95% CI -0.24, -0.02), and caregiver hand rinses (Δlog = -0.16, 95% CI -0.29, -0.03) and marginally lower prevalence of diarrheal disease (prevalence ratio [PR] = 0.82, 95% CI 0.64, 1.04) and ARI (PR = 0.84, 95% CI 0.69, 1.03) compared to compounds surrounded by <100% coverage. Effects were similar but less pronounced at 100 m. At higher population densities, community latrine coverage was associated with larger reductions in E. coli on child and caregiver hands and prevalence of diarrheal disease. Coverage with exclusively hygienic latrines was not associated with any outcome.

CONCLUSION

Higher community sanitation coverage was associated with reduced fecal contamination and improved child health, with stronger effects at highly local scales (50m) and at high population densities. Our findings indicate that the relationship between community sanitation coverage, environmental contamination, and child health varies by definition of coverage, distance, and population density. This work highlights significant uncertainty around how to best measure sanitation coverage and the expected health effects of increasing sanitation coverage using a specific metric. Better understanding of community-level sanitation access is needed to inform policy for implementing sanitation systems that effectively protect community health.

Strategic complements: Poverty-targeted subsidy programs show additive benefits on household toilet purchases in rural Cambodia when coupled with sanitation marketing

While poverty-targeted subsidies have shown promise as a means of reducing financial constraints on low-income populations to invest in new latrines, concerns have been raised about whether they may reduce demand for new latrines among non-eligible, non-poor populations, especially in geographically limited or closed markets. Using quasi experimental methods, we investigate the interaction effects of the "CHOBA" subsidy, a partial poverty-targeted monetary incentive to build a toilet, and a sanitation marketing program (SanMark) on new latrine uptake among households from different income segments in 110 rural villages across six Cambodian provinces. These programs were implemented either jointly with or independently. Overall, we find strong complementarity of the CHOBA subsidy with SanMark where the coupled implementation of the programs increased latrine uptake across all households as compared to exclusive deployment of the programs independently. Additionally, the CHOBA subsidy alone resulted in higher gains among the poor compared to SanMark suggesting that financial constraint is indeed a significant demand barrier for new latrines. The presence of the poverty-targeted subsidies did not reduce demand for new latrine purchases among ineligible households. Instead, we find some evidence for a positive spillover effect of subsidies on uptake of latrines among ineligible households in villages where both programs were implemented indicating that the presence of sanitation subsidies and the decision to purchase latrines among non-beneficiaries can be viewed as complements. We employ multivariate logistic regressions as well as further robustness checks to estimate the effects of the different interventions, with qualitatively consistent results.

Improved Yet Unsafe: At the Light of NFHS-V

Following UNICEF’s analysis of National Family Health Survey-III Data (NFHS-III), it was opined that households with access to better sanitation and better access to improved water sources have much better infant survival rates than the others. Sahu et al. (2015, The Indian journal of medical research, 141(5), 709), Arun et al. (2017, International Conference on Cognitive Computing and Information Processing (pp. 81–92), Springer) and Tripathy and Mishra (2017, Journal of Tropical Pediatrics, 63(6), 431–439) supported these findings. However, Banerjee (2020a , Journal of Health Management, 22(1), 57–66), analysing NFHS-IV data, has vehemently criticised such findings and showed using regression with robust standard errors that improved access to better water sources leads to higher infant mortality. In another article published in the same year, Banerjee (2020b , Journal of Health Management, 22(3), 466–471) explained this paradox. Now with NFHS-V data coming out, time is apt to test the robustness of Banerjee’s findings (2002a). However, owing to the incomplete NFHS-V data published so far, unlike Banerjee (2002a) that has used data of 29 states, the present analysis is based on only 17 states. The findings support that the findings of Banerjee (2002a) were robust.

Neighbors' use of water and sanitation facilities can affect children's health: a cohort study in Mozambique using a spatial approach

BACKGROUND

Impact evaluation of most water, sanitation and hygiene (WASH) interventions in health are user-centered. However, recent research discussed WASH herd protection - community WASH coverage could protect neighboring households. We evaluated the effect of water and sanitation used in the household and by household neighbors in children's morbidity and mortality using recorded health data.

METHODS

We conducted a retrospective cohort including 61,333 children from a district in Mozambique during 2012-2015. We obtained water and sanitation household data and morbidity data from Manhiça Health Research Centre surveillance system. To evaluate herd protection, we estimated the density of household neighbors with improved facilities using a Kernel Density Estimator. We fitted negative binomial adjusted regression models to assess the minimum children-based incidence rates for every morbidity indicator, and Cox regression models for mortality.

RESULTS

Household use of unimproved water and sanitation displayed a higher rate of outpatient visit, diarrhea, malaria, and anemia. Households with unimproved water and sanitation surrounded by neighbors with improved water and sanitation high coverage were associated with a lower rate of outpatient visit, malaria, anemia, and malnutrition.

CONCLUSION

Household and neighbors' access to improve water and sanitation can affect children's health. Accounting for household WASH and herd protection in interventions' evaluation could foster stakeholders' investment and improve WASH related diseases control. Distribution of main water and sanitation facilities used during study period.

Risk factors for early childhood growth faltering in rural Cambodia: a cross-sectional study

OBJECTIVE

This study aimed to determine risk factors of growth faltering by assessing childhood nutrition and household water, sanitation, and hygiene (WASH) variables and their association with nutritional status of children under 24 months in rural Cambodia.

DESIGN

We conducted surveys in 491 villages (clusters) randomised across 55 rural communes in Cambodia in September 2016 to measure associations between child, household and community-level risk factors for stunting and length-for-age z-score (LAZ). We measured 4036 children under 24 months of age from 3877 households (491 clusters). We analysed associations between nutrition/WASH practices and child growth (LAZ, stunting) using generalised estimating equations (GEEs) to fit linear regression models with robust SEs in a pooled analysis and in age-stratified analyses; child-level and household-level variables were modelled separately from community-level variables.

RESULTS

After adjustment for potential confounding, we found household-level and community-level water, sanitation and hygiene factors to be associated with child growth among children under 24 months: presence of water and soap at a household's handwashing station was positively associated with child growth (adjusted mean difference in LAZ +0.10, 95% CI 0.03 to 0.16); household-level use of an improved drinking water source and adequate child stool disposal practices were protective against stunting (adjusted prevalence ratio (aPR) 0.80, 95% CI 0.67 to 0.97; aPR 0.82, 95% CI 0.64 to 1.03). In our age-stratified analysis, we found associations between child growth and community-level factors among children 1-6 months of age: shared sanitation was negatively associated with growth (-0.47 LAZ, 95% CI -0.90 to -0.05 compared with children in communities with no shared facilities); improved sanitation facilities were protective against stunting (aPR 0.43, 95% CI 0.21 to 0.88 compared with children in communities with no improved sanitation facilities); and open defecation was associated with more stunting (aPR 2.13, 95% CI 1.10 to 4.11 compared with children in communities with no open defecation). These sanitation risk factors were only measured in the youngest age strata (1-6 months). Presence of water and soap at the household level were associated with taller children in the 1-6 month and 6-12 month age strata (+0.10 LAZ, 95% CI -0.02 to 0.22 among children 1-6 months of age; +0.11 LAZ, 95% CI -0.02 to 0.25 among children 6-12 months of age compared with children in households with no water and soap). Household use of improved drinking water source was positively associated with growth among older children (+0.13 LAZ, 95% CI -0.01 to 0.28 among children 12-24 months of age).

CONCLUSION

In rural Cambodia, water, sanitation and hygiene behaviours were associated with growth faltering among children under 24 months of age. Community-level sanitation factors were positively associated with growth, particularly for infants under 6 months of age. We should continue to make effort to: investigate the relationships between water, sanitation, hygiene and human health and expand WASH access for young children.

Acquisition of carbapenem-resistant gram-negative bacilli among intensive care unit (ICU) patients with no previous use of carbapenems: Indirect population impact of antimicrobial use

Objective:

To measure the impact of exposure to patients using carbapenem on the acquisition of carbapenem-resistant gram-negative bacilli (CR-GNB) among patients not using carbapenems.

Design:

An ecological study and a cohort study.

Setting:

Two medical surgical intensive care units (ICUs) in inner Brazil.

Participants:

Patients admitted to 2 ICUs from 2013 through 2018 to whom carbapenem was not prescribed.

Methods:

In the ecologic study, the monthly use of carbapenems (days of therapy [DOT] per 1,000 patient days) was tested for linear correlation with the 2-month moving average of incidence CR-GNB among patients to whom carbapenem was not prescribed. In the cohort study, those patients were addressed individually for risk factors (demographics, invasive interventions, use of antimicrobials) for acquisition of CR-GNB, including time at risk and the “carbapenem pressure,” described as the aggregate DOT among other ICU patients during time at risk. The analysis was performed in univariate and multivariable Poisson regression models.

Results:

The linear regression model revealed an association of total carbapenem use and incidence of CR-GNB (coefficient, 0.04; 95% confidence interval [CI], 0.02–0.06; P = .001). In the cohort model, the adjusted rate ratio (RR) for carbapenem DOT was 1.009 (95% CI, 1.001–1.018; P = .03). Other significant risk factors were mechanical ventilation and the previous use of ceftazidime (with or without avibactam).

Conclusions:

Every additional DOT of total carbapenem use increased the risk of CR-GNB acquisition by patients not using carbapenems by nearly 1%. We found evidence for a population (“herd effect”-like) impact of antimicrobial use in the ICUs.

Adaptation of Water, Sanitation, and Hygiene Interventions: A Model and Scoping Review of Key Concepts and Tools

Background

Safe water, sanitation, and hygiene (WaSH) is important for health, livelihoods, and economic development, but WaSH programs have often underdelivered on expected health benefits. Underperformance has been attributed partly to poor ability to retain effectiveness following adaptation to facilitate WaSH programs' implementation in diverse contexts. Adaptation of WaSH interventions is common but often not done systematically, leading to poor outcomes. Models and frameworks from the adaptation literature have potential to improve WaSH adaptation to facilitate implementation and retain effectiveness. However, these models and frameworks were designed in a healthcare context, and WaSH interventions are typically implemented outside traditional health system channels. The purpose of our work was to develop an adaptation model tailored specifically to the context of WaSH interventions.

Methods

We conducted a scoping review to identify key adaptation steps and identify tools to support systematic adaptation. To identify relevant literature, we conducted a citation search based on three recently published reviews on adaptation. We also conducted a systematic database search for examples of WaSH adaptation. We developed a preliminary model based on steps commonly identified across models in adaptation literature, and then tailored the model to the WaSH context using studies yielded by our systematic search. We compiled a list of tools to support systematic data collection and decision-making throughout adaptation from all included studies.

Results and Conclusions

Our model presents adaptation steps in five phases: intervention selection, assessment, preparation, implementation, and sustainment. Phases for assessment through sustainment are depicted as iterative, reflecting that once an intervention is selected, adaptation is a continual process. Our model reflects the specific context of WaSH by including steps to engage non-health and lay implementers and to build consensus among diverse stakeholders with potentially competing priorities. We build on prior adaptation literature by compiling tools to support systematic data collection and decision-making, and we describe how they can be used throughout adaptation steps. Our model is intended to improve program outcomes by systematizing adaptation processes and provides an example of how systematic adaptation can occur for interventions with health goals but that are implemented outside conventional health system channels.

Interventions promoting uptake of water, sanitation and hygiene (WASH) technologies in low- and middle-income countries: An evidence and gap map of effectiveness studies

Background

Lack of access to and use of water, sanitation and hygiene (WASH) cause 1.6 million deaths every year, of which 1.2 million are due to gastrointestinal illnesses like diarrhoea and acute respiratory infections like pneumonia. Poor WASH access and use also diminish nutrition and educational attainment, and cause danger and stress for vulnerable populations, especially for women and girls. The hardest hit regions are sub-Saharan Africa and South Asia. Sustainable Development Goal (SDG) 6 calls for the end of open defecation, and universal access to safely managed water and sanitation facilities, and basic hand hygiene, by 2030. WASH access and use also underpin progress in other areas such as SDG1 poverty targets, SDG3 health and SDG4 education targets. Meeting the SDG equity agenda to "leave none behind" will require WASH providers prioritise the hardest to reach including those living remotely and people who are disadvantaged.

Objectives

Decision makers need access to high-quality evidence on what works in WASH promotion in different contexts, and for different groups of people, to reach the most disadvantaged populations and thereby achieve universal targets. The WASH evidence map is envisioned as a tool for commissioners and researchers to identify existing studies to fill synthesis gaps, as well as helping to prioritise new studies where there are gaps in knowledge. It also supports policymakers and practitioners to navigate the evidence base, including presenting critically appraised findings from existing systematic reviews.

Methods

This evidence map presents impact evaluations and systematic reviews from the WASH sector, organised according to the types of intervention mechanisms, WASH technologies promoted, and outcomes measured. It is based on a framework of intervention mechanisms (e.g., behaviour change triggering or microloans) and outcomes along the causal pathway, specifically behavioural outcomes (e.g., handwashing and food hygiene practices), ill-health outcomes (e.g., diarrhoeal morbidity and mortality), nutrition and socioeconomic outcomes (e.g., school absenteeism and household income). The map also provides filters to examine the evidence for a particular WASH technology (e.g., latrines), place of use (e.g., home, school or health facility), location (e.g., global region, country, rural and urban) and group (e.g., people living with disability). Systematic searches for published and unpublished literature and trial registries were conducted of studies in low- and middle-income countries (LMICs). Searches were conducted in March 2018, and searches for completed trials were done in May 2020. Coding of information for the map was done by two authors working independently. Impact evaluations were critically appraised according to methods of conduct and reporting. Systematic reviews were critically appraised using a new approach to assess theory-based, mixed-methods evidence synthesis.

Results

There has been an enormous growth in impact evaluations and systematic reviews of WASH interventions since the International Year of Sanitation, 2008. There are now at least 367 completed or ongoing rigorous impact evaluations in LMICs, nearly three-quarters of which have been conducted since 2008, plus 43 systematic reviews. Studies have been done in 83 LMICs, with a high concentration in Bangladesh, India, and Kenya. WASH sector programming has increasingly shifted in focus from what technology to supply (e.g., a handwashing station or child's potty), to the best way in which to do so to promote demand. Research also covers a broader set of intervention mechanisms. For example, there has been increased interest in behaviour change communication using psychosocial "triggering", such as social marketing and community-led total sanitation. These studies report primarily on behavioural outcomes. With the advent of large-scale funding, in particular by the Bill & Melinda Gates Foundation, there has been a substantial increase in the number of studies on sanitation technologies, particularly latrines. Sustaining behaviour is fundamental for sustaining health and other quality of life improvements. However, few studies have been done of intervention mechanisms for, or measuring outcomes on sustained adoption of latrines to stop open defaecation. There has also been some increase in the number of studies looking at outcomes and interventions that disproportionately affect women and girls, who quite literally carry most of the burden of poor water and sanitation access. However, most studies do not report sex disaggregated outcomes, let alone integrate gender analysis into their framework. Other vulnerable populations are even less addressed; no studies eligible for inclusion in the map were done of interventions targeting, or reporting on outcomes for, people living with disabilities. We were only able to find a single controlled evaluation of WASH interventions in a health care facility, in spite of the importance of WASH in health facilities in global policy debates. The quality of impact evaluations has improved, such as the use of controlled designs as standard, attention to addressing reporting biases, and adequate cluster sample size. However, there remain important concerns about quality of reporting. The quality and usefulness of systematic reviews for policy is also improving, which draw clearer distinctions between intervention mechanisms and synthesise the evidence on outcomes along the causal pathway. Adopting mixed-methods approaches also provides information for programmes on barriers and enablers affecting implementation.

Conclusion

Ensuring everyone has access to appropriate water, sanitation, and hygiene facilities is one of the most fundamental of challenges for poverty elimination. Researchers and funders need to consider carefully where there is the need for new primary evidence, and new syntheses of that evidence. This study suggests the following priority areas:Impact evaluations incorporating understudied outcomes, such as sustainability and slippage, of WASH provision in understudied places of use, such as health care facilities, and of interventions targeting, or presenting disaggregated data for, vulnerable populations, particularly over the life-course and for people living with a disability;Improved reporting in impact evaluations, including presentation of participant flow diagrams; andSynthesis studies and updates in areas with sufficient existing and planned impact evaluations, such as for diarrhoea mortality, ARIs, WASH in schools and decentralisation. These studies will preferably be conducted as mixed-methods systematic reviews that are able to answer questions about programme targeting, implementation, effectiveness and cost-effectiveness, and compare alternative intervention mechanisms to achieve and sustain outcomes in particular contexts, preferably using network meta-analysis.

Community-level impacts of sanitation coverage on maternal and neonatal health: a retrospective cohort of survey data

Introduction

Access to sanitation facilities (toilets or latrines) greatly improves human health. Low community sanitation coverage may lead to increased exposure to pathogens for households both with and without a sanitation facility.

Methods

We created a retrospective cohort using Demographic and Health Surveys from 1990 through 2018. Using regression with matched women as a random intercept, we assessed the association between community-level sanitation coverage and neonatal mortality (Poisson model, n=1 254 862 live births, 187 datasets), small birth size (logit model, n=1 058 843 live births, 187 datasets) and anaemia (logit model, n=1 304 626 women, 75 datasets).

Results

Among women with household sanitation, the incidence of neonatal death (incidence rate ratio: 0.85, 95% CI 0.77 to 0.93), the odds of small birth size (OR: 0.81, 95% CI 0.76 to 0.87) and anaemia (OR: 0.82, 95% CI 0.79 to 0.85) were lower for women in communities with 100% sanitation coverage compared with 1%–30% (p≤0.001 for all). There was no difference in neonatal deaths between women in communities with 31%–99% sanitation coverage compared with 1%–30% (p≥0.05). Among women without household sanitation, there were no differences in neonatal mortality by community sanitation (p≥0.05). The odds of small birth size were decreased (OR: 0.91, 95% CI 0.87 to 0.97, p=0.003) for women in communities with 61%–99% sanitation coverage compared with 1%–30%; there was no association with the other community sanitation categories (p≥0.05). The odds of anaemia were increased (OR: 1.08, 95% CI 1.06 to 1.11, p<0.001) for women living in communities with 0% sanitation coverage compared with 1%–30%, but no association with the other community sanitation categories (p≥0.05).

Conclusion

Community sanitation coverage is associated with improved maternal and neonatal outcomes, particularly among women with household sanitation. This suggests that the impact of sanitation coverage on maternal and neonatal health is underestimated unless the community-level effects are considered.

Investment in drinking water and sanitation infrastructure and its impact on waterborne diseases dissemination: The Brazilian case

Investment in sanitation and drinking water infrastructure is essential for universal access to these services in developing countries. Universal coverage of water and sanitation services (WSS) can prevent the dissemination of waterborne diseases and mitigate their adverse effects. These diseases are responsible for many deaths worldwide, especially among the disadvantaged population and children. A causal effect can be established between WSS investment and hospital admissions due to waterborne diseases. Therefore, we considered an innovative network-DEA approach that models the link between serially connected subsystems (upstream investment and downstream hospitalizations). This approach allowed us: to measure the efficiency of both subsystems; estimate the amount of (efficient) investment necessary to universalize the access to proper WSS infrastructure; and mitigate hospital admissions due to waterborne diseases. We used the Brazil case study to test our model. On average, Brazilian states could increase the number of people not requiring hospitalizations due to waterborne diseases by 157 thousand per R$100 million invested in sanitation and 26 thousand per R$100 million invested in drinking water. Our results suggest that relatively small (efficient) investment in those two infrastructure types has a massive impact on hospitalizations. This impact would be more significant than the investment in WSS coverage. Therefore, if safely managed, WSS would cover all citizens, and Brazil would come closer to developed countries.

Longitudinal Effects of a Sanitation Intervention on Environmental Fecal Contamination in a Cluster-Randomized Controlled Trial in Rural Bangladesh

Household latrine access generally is not associated with reduced fecal contamination in the environment, but its long-term effectiveness has not been measured. We conducted an environmental assessment nested within the WASH Benefits Bangladesh randomized controlled trial (NCT01590095). We quantified E. coli and fecal coliforms in samples of stored drinking water, child hands, mother hands, soil, and food among a random sample of households from the sanitation and control arms of the trial. Samples were collected during eight quarterly visits approximately 1-3.5 years after intervention initiation. Overall, there were no substantial differences in environmental fecal contamination between households enrolled in the sanitation and control arms. Statistically significant reductions were found in stored water and child hands after pooling across sampling rounds, but the effects were small and not consistent across rounds. In addition, we assessed potential effect modification of intervention effects by follow-up time, season, wealth, community-level latrine density and coverage, population density, and domestic animal ownership. While the intervention had statistically significant effects within some subgroups, there were no consistent patterns of effect modification. Our findings support a growing consensus that on-site latrines are insufficient to prevent fecal contamination in the rural household environment.

Effects of an urban sanitation intervention on childhood enteric infection and diarrhea in Maputo, Mozambique: A controlled before-and-after trial

We conducted a controlled before-and-after trial to evaluate the impact of an onsite urban sanitation intervention on the prevalence of enteric infection, soil transmitted helminth re-infection, and diarrhea among children in Maputo, Mozambique. A non-governmental organization replaced existing poor-quality latrines with pour-flush toilets with septic tanks serving household clusters. We enrolled children aged 1-48 months at baseline and measured outcomes before and 12 and 24 months after the intervention, with concurrent measurement among children in a comparable control arm. Despite nearly exclusive use, we found no evidence that intervention affected the prevalence of any measured outcome after 12 or 24 months of exposure. Among children born into study sites after intervention, we observed a reduced prevalence of Trichuris and Shigella infection relative to the same age group at baseline (<2 years old). Protection from birth may be important to reduce exposure to and infection with enteric pathogens in this setting.

Cost effectiveness of community led total sanitation in Ethiopia and Ghana

We conducted cost effectiveness analyses of four different CLTS interventions implemented in Ethiopia and Ghana. In each country, a pilot approach in which additional local actors were trained in CLTS facilitation was compared to the conventional approach. Data were collected using bottom-up costing, household surveys, and observations. We assessed variability of cost effectiveness from a societal perspective for latrine ownership and latrine use outcomes in different contexts. Cost effectiveness ranged from $34–$1897 per household ($5.85–$563 per person) gaining access to a private latrine or stopping open defecation, depending on the intervention, context, and outcome considered. For three out of four interventions, CLTS appeared more cost effective at reducing open defecation than at increasing latrine ownership, although sensitivity analysis revealed considerable variation. The pilot approaches were more cost effective at reducing open defecation than conventional approaches in Ethiopia, but not in Ghana. CLTS has been promoted as a low-cost means of improving the ownership and use of sanitation facilities. In our study, the cost of CLTS per household gaining latrine access was slightly higher than in other studies, and the cost of CLTS per household stopping OD was slightly lower than in other studies. Our results show that aggregate measures mask considerable variability in costs and outcomes, and thus the importance of considering and reporting context and uncertainty in economic analysis of sanitation interventions.

Systems Science Approaches for Global Environmental Health Research: Enhancing Intervention Design and Implementation for Household Air Pollution (HAP) and Water, Sanitation, and Hygiene (WASH) Programs

BACKGROUND

Two of the most important causes of global disease fall in the realm of environmental health: household air pollution (HAP) and poor water, sanitation, and hygiene (WASH) conditions. Interventions, such as clean cookstoves, household water treatment, and improved sanitation facilities, have great potential to yield reductions in disease burden. However, in recent trials and implementation efforts, interventions to improve HAP and WASH conditions have shown few of the desired health gains, raising fundamental questions about current approaches.

OBJECTIVES

We describe how the failure to consider the complex systems that characterize diverse real-world conditions may doom promising new approaches prematurely. We provide examples of the application of systems approaches, including system dynamics, network analysis, and agent-based modeling, to the global environmental health priorities of HAP and WASH research and programs. Finally, we offer suggestions on how to approach systems science.

METHODS

Systems science applied to environmental health can address major challenges by a) enhancing understanding of existing system structures and behaviors that accelerate or impede aims; b) developing understanding and agreement on a problem among stakeholders; and c) guiding intervention and policy formulation. When employed in participatory processes that engage study populations, policy makers, and implementers, systems science helps ensure that research is responsive to local priorities and reflect real-world conditions. Systems approaches also help interpret unexpected outcomes by revealing emergent properties of the system due to interactions among variables, yielding complex behaviors and sometimes counterintuitive results.

DISCUSSION

Systems science offers powerful and underused tools to accelerate our ability to identify barriers and facilitators to success in environmental health interventions. This approach is especially useful in the context of implementation research because it explicitly accounts for the interaction of processes occurring at multiple scales, across social and environmental dimensions, with a particular emphasis on linkages and feedback among these processes. https://doi.org/10.1289/EHP7010.

Demystifying the Aquatic Paradox: The Infant Mortality in India

It is evident that better access to improved water sources will lead to the lessening of infant mortality rate (IMR). However, for India, such inference is ambiguous. There is a strong group of academicians such as Sahu et al. (2015) , Arun et al. (2017) and Tripathy and Mishra (2017) and organizations such as UNICEF that firmly believe that if access to the improved water sources can be improved, then there would be tremendous social welfare and much betterment to the IMR.

On the other hand, Banerjee et al. (2020) have refuted such claims and opined that access to improved water sources increases the IMR. The empirical validation of their claim has been flawless, but they are somewhat silent on why such a direct relationship between IMR and improved water source exists. They have made a comment based on assumptions that it might be complacency that develops with access to improved water sources that refrain the people to consider any type of water treatment before passing it to infants for drinking. Such a comment might be valid, but neither is it built upon a sound literature review nor does it stand on strong empirics. At this juncture, the present article tests the claim of Banerjee et al. (2020) based on pure empirics.

Improved sanitation is associated with reduced child stunting amongst Indonesian children under 3 years of age

Growing evidence suggests that household sanitation is associated with child nutritional status in low‐ and middle‐income countries. This paper examined whether household access to improved sanitation facilities and sources of drinking water was associated with stunting and anaemia amongst children aged 6–35 months of age in Indonesia. The sample for the analysis comprised 1,450 children aged 6–35 months who participated in the end‐line survey of the maternal and young child nutrition security project in Asia, conducted in three selected districts in Indonesia. Logistic regression models were used to determine the association between household sanitation and water source, and stunting and anaemia. Approximately 26% and 56% of children 6–35 months of age were stunted and anaemic, respectively. Children living in a household with improved sanitation facilities had 29% reduced odds of being stunted compared with those in a household with unimproved sanitation facilities, after adjusting for potential confounders including child's age and gender, maternal education, and iron–folic acid supplementation, as well as household wealth status and source of drinking water (OR = 0.68, 95% CI:0.48–0.96). No association between household sanitation and childhood anaemia was observed. Source of drinking water was not associated with stunting or anaemia amongst children. There were no synergistic effects of household sanitation and water supply on stunting and anaemia. This suggests that efforts to improve household sanitation condition may need to be considered an essential, integral part of the programmatic responses by governments and development partners for the prevention of childhood nutritional status. Further randomised research is necessary to determine the causal link.

Association between anemia and household water source or sanitation in preschool children: the Biomarkers Reflecting Inflammation and Nutritional Determinants of Anemia (BRINDA) project

BACKGROUND

The associations between anemia and household water source and sanitation remain unclear.

OBJECTIVES

We aimed to assess the associations between anemia and household water source or sanitation in preschool children (PSC; age 6-59 mo) using population-based surveys from the Biomarkers Reflecting Inflammation and Nutritional Determinants of Anemia (BRINDA) project.

METHODS

We analyzed national and subnational data from 21 surveys, representing 19 countries (n = 35,963). Observations with hemoglobin (Hb) and ≥1 variable reflecting household water source or sanitation were included. Anemia was defined as an altitude-adjusted Hb concentration <110 g/L. Household water source and sanitation variables were dichotomized as "improved" or "unimproved." Poisson regressions with robust variance estimates were conducted for each survey, adjusting for child sex, age, household socioeconomic status, maternal education, and type of residence.

RESULTS

Access to an improved water source and improved sanitation ranged from 29.9% (Burkina Faso) to 98.4% (Bangladesh, 2012), and from 0.2% (Kenya, 2007) to 97.4% (Philippines), respectively. Prevalence of anemia ranged from 20.1% (Nicaragua) to 83.5% (Bangladesh, 2010). Seven surveys showed negative associations between anemia and improved sanitation. Three surveys showed association between anemia and improved water, with mixed directions. Meta-analyses suggested a protective association between improved household sanitation and anemia [adjusted prevalence ratio (aPR) = 0.88; 95% CI: 0.79, 0.98], and no association between improved household water and anemia (aPR = 1.00; 95% CI: 0.91, 1.10). There was heterogeneity across surveys for sanitation (P < 0.01; I2 = 66.3%) and water (P < 0.01; I2 = 55.8%).

CONCLUSIONS

Although improved household sanitation was associated with reduced anemia prevalence in PSC in some surveys, this association was not consistent. Access to an improved water source in general had no association with anemia across surveys. Additional research could help clarify the heterogeneity between these conditions across countries to inform anemia reduction programs.

The WASH Benefits and SHINE trials: interpretation of WASH intervention effects on linear growth and diarrhoea

Child stunting is a global problem and is only modestly responsive to dietary interventions. Numerous observational studies have shown that water quality, sanitation, and handwashing (WASH) in a household are strongly associated with linear growth of children living in the same household. We have completed three randomised efficacy trials testing improved household-level WASH with and without improved infant and young child feeding (IYCF) on stunting and diarrhoea in Bangladesh, Kenya, and Zimbabwe. In all trials, improved IYCF had a statistically significant benefit, but WASH had no effect on linear growth. In observational analyses of data from the control groups of the three trials, baseline sanitation was a strong risk factor for stunting in the study populations, suggesting this frequently reported association might be confounded by unmeasured factors of household wellbeing. WASH interventions reduced diarrhoea in Bangladesh, but not in Kenya or Zimbabwe. Intervention promoters visited participants six times per month in Bangladesh compared with monthly in Kenya and Zimbabwe; a review of the literature shows that virtually all published studies that have reported an effect on diarrhoea through home-based water treatment and handwashing promotion achieved high adherence by visiting participants at daily to fortnightly intervals. Despite achieving substantial behavioural change and significant reduction in infection prevalence for some enteric pathogens, detection of enteropathogens among children in the WASH groups of the trials was typically at ten times higher prevalence compared with high-income countries. Considering these results, we recommend that future research in the WASH sector focus on developing and evaluating interventions that are radically more effective in reducing faecal contamination in the domestic environment than the interventions implemented in these trials.

Improved yet Unsafe: An Aquatic Perspective of Indian Infant Mortality

Infant mortality rate (IMR) is an important development indicator and a vital component of millennium development goals (MDGs) set by United Nations Development Programme (UNDP). According to UNDP, so far India has only fared moderately in reducing IMR (Goal 4 of MDGs). India (32) ranks 144th among 196 countries regarding IMR as per the 2017 data availed from World Development Indicators. Its adjacent countries such as Bhutan (25.6), Bangladesh (26.9) and Nepal (27.8) have fared much better regarding infant survival. Numbers within the parentheses indicate the IMR of the respective country. The United Nations Children’s Fund (UNICEF) has identified that IMR among families with better access to improved drinking water sources and toilet is much lower than those bereft of the same. This inference has been drawn from National Family Health Survey 3 data (NFHS III). The present study investigates into the aforementioned relation analysing NFHS IV data. The result depicts that contrary to UNICEF’s findings, IMR increases with better accessibility to improved water sources. Further to this, the article shows that an additional aqua-related practice together with improved drinking water sources might lead to the betterment of IMR for India.

Environmental and spatial determinants of enteric pathogen infection in rural Lao People's Democratic Republic: A cross-sectional study

TRIAL REGISTRATION

clinicaltrials.gov (NCT02342860).

Risk Factors for Undernutrition and Diarrhea Prevalence in an Urban Slum in Indonesia: Focus on Water, Sanitation, and Hygiene

Unsafe drinking water and poor sanitation and hygiene lead to deterioration of the child health condition in low- and middle-income countries. This study aimed to evaluate the nutritional and health status of children living in an urban slum and to clarify the factors contributing to undernutrition and diarrhea prevalence by focusing on water, sanitation, and hygiene from three viewpoints: household environments, child personal hygiene practices, and knowledge and awareness. The study was conducted at a preschool and two elementary schools in the densely populated area of Bandung, Indonesia. Participants were 228 pairs of children and their caretakers. The survey involved 1) anthropometric measurements (height and weight), 2) handwashing observation using a checklist, and 3) questionnaires. On multivariate logistic regression analysis, not using a towel for handwashing practices (adjusted odds ratio [AOR] = 2.37; 95% confidence interval [CI] = 1.13-4.96) was significantly associated with an increased risk of stunting. Regarding household environments, children from households using tap water as drinking water were significantly associated with an increased risk of stunting and thinness compared with households using tank water (AOR = 2.26; 95% CI = 1.03-4.93; and AOR = 2.88; 95% CI = 1.13-7.35, respectively). Moreover, children from households using open containers for water storage were significantly associated with an increased risk of diarrhea (AOR = 5.01; 95% CI = 1.08-23.15). Therefore, drinking water management at home and proper personal hygiene practices of children are important for maintaining and promoting child health in urban Indonesian slums.

Does Basic Sanitation Prevent Diarrhea? Contextualizing Recent Intervention Trials through a Historical Lens

Three of four recent major sanitation intervention trials found no effect on diarrhea. These results conflicted with longstanding beliefs from decades of literature. To understand this discordance, we placed recent trials into the historical context that preceded them in two ways. First, we evaluated the history of published literature reviews on sanitation and diarrhea. Second, we conducted meta-analyses on studies from the most recent systematic review to uncover features that predict effectiveness. We found that 13 literature reviews dating to 1983 consistently estimated a significant protective effect of sanitation against diarrhea. However, these were marred by flawed studies and inappropriately averaged effects across widely heterogeneous interventions and contexts. Our meta-analyses highlight that the overall effect of sanitation on diarrhea was largely driven by sewerage and interventions that improved more than sanitation alone. There is no true overall effect of sanitation because variability between intervention types and implementation contexts is too complex to average. Ultimately, the null effects of recent latrine interventions are not surprising. Instead, the one trial that found a strong relative reduction in diarrhea is the historical outlier. The development of transformative sanitation interventions requires a better understanding of the social and environmental contexts that determine intervention effectiveness.

Sanitation and Collective Efficacy in Rural Cambodia: The Value Added of Qualitative Formative Work for the Contextualization of Measurement Tools

Community-level action may be required to achieve the levels of sanitation uptake necessary for health gains. Evidence suggests that collective action is influenced by collective efficacy (CE)-a group's belief in its abilities to organize and execute action to achieve common goals. The extent to which it is necessary to fully contextualize existing CE measurement tools, in order to conduct meaningful assessments of the factors influencing CE perceptions, is not well understood. This study examines the value added of contextualizing an existing CE measurement tool using qualitative formative research. We employed a modified grounded theory approach to develop a contextualized CE framework based on qualitative data from rural Cambodian villages. The resulting framework included sub-constructs that were pertinent for the rural Cambodian context for which an existing, hypothesized framework did not account: perceived risks/benefits, action knowledge, shared needs/benefits, and external accountability. Complex confirmatory factor analyses indicated that contextualized models fit the data better than hypothesized models for women and men. This study demonstrates that inductive, qualitative research allows community-derived factors to enhance existing tools for context-specific CE measurement. Additional research is needed to determine which CE factors transcend contexts and could, thus, form the foundation of a general CE measurement tool.

Using structural equation modelling to untangle sanitation, water and hygiene pathways for intervention improvements in height-for-age in children <5 years old

BACKGROUND

Despite a strong theoretical rationale for combining water, sanitation and hygiene (WaSH) interventions to improve child health, study findings are heterogeneous with little understanding of the mechanisms for these effects. Our study objective was to demonstrate the utility of structural equation modeling (SEM) to assess intervention effects on height-for-age z score (HAZ) through the complex system of WaSH pathways.

METHODS

We used data from a matched cohort effectiveness evaluation of a combined on-premise piped water and improved sanitation intervention in rural Odisha, India. Height/length was measured in children 0-59 months old (n = 1826) from 90 matched villages in February-June 2016. WaSH behaviours and infrastructure were assessed through household surveys and observation, respectively. We used SEM to calculate the standardized path coefficients and the total contributions of WaSH pathways to HAZ.

RESULTS

Intervention improvements on HAZ were through the sanitation pathway (coverage → use β: 0.722; use → HAZ β: 0.116), with piped water coverage indirectly affecting HAZ through improved sanitation use (β: 0.148). Although the intervention had a positive association with handwashing station coverage, there was no evidence of a total hygiene pathway effect on HAZ or further direct effects through the water pathways.

CONCLUSIONS

This study demonstrates the utility of SEM to assess the mechanisms through which combined WaSH interventions impact HAZ as a system of pathways, providing a more nuanced assessment than estimation of the total intervention effect. Our finding, that water impacts HAZ through the sanitation pathway, is an important and actionable insight for WaSH programming.

A framework for targeting water, sanitation and hygiene interventions in pastoralist populations in the Afar region of Ethiopia

Globally, many populations face structural and environmental barriers to access safe water, sanitation and hygiene (WASH) services. Among these populations are many of the 200 million pastoralists whose livelihood patterns and extreme environmental settings challenge conventional WASH programming approaches. In this paper, we studied the Afar pastoralists in Ethiopia to identify WASH interventions that can mostly alleviate public health risks, within the population's structural and environmental living constraints. Surveys were carried out with 148 individuals and observational assessments made in 12 households as part of a Pastoralist Community WASH Risk Assessment. The results show that low levels of access to infrastructure are further compounded by risky behaviours related to water containment, storage and transportation. Additional behavioural risk factors were identified related to sanitation, hygiene and animal husbandry. The Pastoralist Community WASH Risk Assessment visually interprets the seriousness of the risks against the difficulty of addressing the problem. The assessment recommends interventions on household behaviours, environmental cleanliness, water storage, treatment and hand hygiene via small-scale educational interventions. The framework provides an approach for assessing risks in other marginal populations that are poorly understood and served through conventional approaches.

Burden of disease from inadequate water, sanitation and hygiene for selected adverse health outcomes: An updated analysis with a focus on low- and middle-income countries

BACKGROUND

To develop updated estimates in response to new exposure and exposure-response data of the burden of diarrhoea, respiratory infections, malnutrition, schistosomiasis, malaria, soil-transmitted helminth infections and trachoma from exposure to inadequate drinking-water, sanitation and hygiene behaviours (WASH) with a focus on low- and middle-income countries.

METHODS

For each of the analysed diseases, exposure levels with both sufficient global exposure data for 2016 and a matching exposure-response relationship were combined into population-attributable fractions. Attributable deaths and disability-adjusted life years (DALYs) were estimated for each disease and, for most of the diseases, by country, age and sex group separately for inadequate water, sanitation and hygiene behaviours and for the cluster of risk factors. Uncertainty estimates were computed on the basis of uncertainty surrounding exposure estimates and relative risks.

FINDINGS

An estimated 829,000 WASH-attributable deaths and 49.8 million DALYs occurred from diarrhoeal diseases in 2016, equivalent to 60% of all diarrhoeal deaths. In children under 5 years, 297,000 WASH-attributable diarrhoea deaths occurred, representing 5.3% of all deaths in this age group. If the global disease burden from different diseases and several counterfactual exposure distributions was combined it would amount to 1.6 million deaths, representing 2.8% of all deaths, and 104.6 million DALYs in 2016.

CONCLUSIONS

Despite recent declines in attributable mortality, inadequate WASH remains an important determinant of global disease burden, especially among young children. These estimates contribute to global monitoring such as for the Sustainable Development Goal indicator on mortality from inadequate WASH.

Role of Implementation Factors for the Success of Community-Led Total Sanitation on Latrine Coverage. A Case Study from Rural Ghana

Community-led total sanitation (CLTS) is an approach to improving sanitation to combat open defecation (OD). OD is a health threat to children under five. CLTS promotes the construction of latrines with the goal of declaring communities open defecation free. However, which factors of the implementation process are most important for the success has yet to be ascertained. The analysed sample comprised of 94 communities in rural Ghana, where CLTS was implemented and factors describing the implementation process of CLTS were assessed. Additionally, monitoring data from the implementation process were used. Multiple regression analysis revealed that latrine coverage was significantly related to attendance at the CLTS meeting, the number of supportive community leaders, the expectation of participants of receiving an incentive, and the number of follow-up visits. Implementers of CLTS should direct their attention to the processes following the community meeting. The success of CLTS can be improved by investing in follow-up visits, the support of local leaders, and the careful application of incentives.

A Faecal Contamination Index for interpreting heterogeneous diarrhoea impacts of water, sanitation and hygiene interventions and overall, regional and country estimates of community sanitation coverage with a focus on low- and middle-income countries

OBJECTIVES

The impact on diarrhoea of sanitation interventions has been heterogeneous. We hypothesize that this is due to the level of prevailing faecal environmental contamination and propose a Faecal Contamination Index (FAECI) of selected WASH indicators (objective 1). Additionally, we provide estimates of the proportion of the population living in communities above certain sanitation coverage levels (objective 2).

METHODS

Objective 1: Faecal contamination post-intervention was estimated from WASH intervention reports. WASH indicators composing the FAECI included eight water, sanitation and hygiene practice indicators, which were selected for their relevance for health and data availability at study- and country-level. The association between the estimated level of faecal environmental contamination and diarrhoea was examined using meta-regression. Objective 2: A literature search was conducted to identify health-relevant community sanitation coverage thresholds. To estimate total community coverage with basic sanitation in low- and middle-income countries, at relevant thresholds, household surveys with data available at primary sampling unit (PSU)-level were analysed according to the identified thresholds, at country-, regional- and overall level.

RESULTS

Objective 1: We found a non-linear association between estimated environmental faecal contamination and sanitation interventions' impact on diarrhoeal disease. Diarrhoea reductions were highest at lower faecal contamination levels, and no diarrhoea reduction was found when contamination increased above a certain level. Objective 2: Around 45% of the population lives in communities with more than 75% of coverage with basic sanitation and 24% of the population lives in communities above 95% coverage, respectively.

CONCLUSIONS

High prevailing faecal contamination might explain interventions' poor effectiveness in reducing diarrhoea. The here proposed Faecal Contamination Index is a first attempt to estimate the level of faecal contamination in communities. Much of the world's population currently lives in faecally contaminated environments as indicated by low community sanitation coverage.

The Sustainable Development Goal for Urban Sanitation: Africa's Statistical Tragedy Continues?

Sanitation delivery in the urban areas of sub-Saharan African countries has been a chronic issue, particularly difficult to tackle. Under the Millennium Development Goals, the sanitation target in urban sub-Saharan Africa was missed by a wide margin and witnessed almost no improvement. After 2 years of review, the WHO/UNICEF Joint Monitoring Programme published a new measure of access to sanitation as a baseline for the Sustainable Development Goals. There are a number of improvements in the new measure. However, despite the improvements, the new measure continues to be characterized by an important flaw: it continues to disregard how shared toilet facilities contribute towards the SDG sanitation target. As a result, the new measure does not indicate whether progress is being made in low-income urban areas where a large number of households rely on shared sanitation; nor does it provide a goal that can be achieved in cities of the poorest countries over the measurement period. But, its most egregious failing is that it directs resources towards investments which will often fail cost/benefit tests. In sum, it is not a surprise that a Working Group recommended that the measure should be changed to include some shared facilities. Following the Working Group's recommendation would have avoided the adverse consequences of continued reliance on a key component of the methodology used for monitoring sanitation improvements under the Millennium Development Goals. The paper discusses the limitations of this methodology in the context of urban sub-Saharan Africa, where current sanitation conditions are seriously lacking, and the significant future urban population growth will add more pressure for the delivery of vital sanitation services.

Implications of a complexity perspective for systematic reviews and guideline development in health decision making

There is growing interest in the potential for complex systems perspectives in evaluation. This reflects a move away from interest in linear chains of cause-and-effect, towards considering health as an outcome of interlinked elements within a connected whole. Although systems-based approaches have a long history, their concrete implications for health decisions are still being assessed. Similarly, the implications of systems perspectives for the conduct of systematic reviews require further consideration. Such reviews underpin decisions about the implementation of effective interventions, and are a crucial part of the development of guidelines. Although they are tried and tested as a means of synthesising evidence on the effectiveness of interventions, their applicability to the synthesis of evidence about complex interventions and complex systems requires further investigation. This paper, one of a series of papers commissioned by the WHO, sets out the concrete methodological implications of a complexity perspective for the conduct of systematic reviews. It focuses on how review questions can be framed within a complexity perspective, and on the implications for the evidence that is reviewed. It proposes criteria which can be used to determine whether or not a complexity perspective will add value to a review or an evidence-based guideline, and describes how to operationalise key aspects of complexity as concrete research questions. Finally, it shows how these questions map onto specific types of evidence, with a focus on the role of qualitative and quantitative evidence, and other types of information.

Latent variable modeling to develop a robust proxy for sensitive behaviors: application to latrine use behavior and its association with sanitation access in a middle-income country

BACKGROUND

Globally, diarrhea is a leading cause of child morbidity and mortality. Although latrines are integral for reducing enteric pathogen transmission, several studies have shown no evidence that latrine ownership improved child health. There are a number of explanations for these results. One explanation is that latrine access does not equate to latrine use. Latrine use, however, is difficult to accurately ascertain, as defecation behavior is often stigmatized. To address this measurement issue, we measure latrine use as a latent variable, indicated by a suite of psychosocial variables.

METHODS

We administered a survey of 16 defecation-related psychosocial questions to 251 individuals living in rural Ecuador. We applied latent class analysis (LCA) to these data to model the probability of latrine use as a latent variable. To account for uncertainty in predicted latent class membership, we used a pseudo-class approach to impute five different probabilities of latrine use for each respondent. Via regression modeling, we tested the association between household sanitation and each imputed latrine use variable.

RESULTS

The optimal model presented strong evidence of two latent classes (entropy = 0.86): consistent users (78%) and inconsistent users (22%), predicted by 5 of our 16 psychosocial variables. There was no evidence of an association between the probability of latrine use, predicted from the LCA, and household access to basic sanitation (OR = 1.1, 95% CI = 0.6-2.1). This suggests that home access to a sanitation facility may not ensure the use of the facility for every family member at all times.

CONCLUSION

Effective implementation and evaluation of sanitation programs requires accurate measurement of latrine use. Psychosocial variables, such as norms, perceptions, and attitudes may provide robust proxy-measures. Future longitudinal studies will help to strengthen the use of these surrogate measures, as many of these factors may be subject to secular trends. Additionally, subgroup analyses will elucidate how our  proxy indicators of latrine defecation vary by individual-level characteristics.

Collective Efficacy: Development and Validation of a Measurement Scale for Use in Public Health and Development Programmes

Impact evaluations of water, sanitation, and hygiene interventions have demonstrated lower than expected health gains, in some cases due to low uptake and sustained adoption of interventions at a community level. These findings represent common challenges for public health and development programmes relying on collective action. One possible explanation may be low collective efficacy (CE)-perceptions regarding a group's ability to execute actions related to a common goal. The purpose of this study was to develop and validate a metric to assess factors related to CE. We conducted this research within a cluster-randomised sanitation and hygiene trial in Amhara, Ethiopia. Exploratory and confirmatory factor analyses were carried out to examine underlying structures of CE for men and women in rural Ethiopia. We produced three CE scales: one each for men and women that allow for examinations of gender-specific mechanisms through which CE operates, and one 26-item CE scale that can be used across genders. All scales demonstrated high construct validity. CE factor scores were significantly higher for men than women, even among household-level male-female dyads. These CE scales will allow implementers to better design and target community-level interventions, and examine the role of CE in the effectiveness of community-based programming.

Who is the Woman in Women's Nutrition? A Narrative Review of Evidence and Actions to Support Women's Nutrition throughout Life

Nutrition interventions that target mothers alone inadequately address women's needs across their lives: during adolescence, preconception, and in later years of life. They also fail to capture nulliparous women. The extent to which nutrition interventions effectively reach women throughout the life course is not well documented. In this comprehensive narrative review, we summarized the impact and delivery platforms of nutrition-specific and nutrition-sensitive interventions targeting adolescent girls, women of reproductive age (nonpregnant, nonlactating), pregnant and lactating women, women with young children <5 y, and older women, with a focus on nutrition interventions delivered in low- and middle-income countries. We found that although there were many effective interventions that targeted women's nutrition, they largely targeted women who were pregnant and lactating or with young children. There were major gaps in the targeting of interventions to older women. For the delivery platforms, community-based settings, compared with facility-based settings, more equitably reached women across the life course, including adolescents, women of reproductive age, and older women. Nutrition-sensitive approaches were more often delivered in community-based settings; however, the evidence of their impact on women's nutritional outcomes was less clear. We also found major research and programming gaps relative to targeting overweight, obesity, and noncommunicable disease. We conclude that focused efforts on women during pregnancy and in the first couple of years postpartum fail to address the interrelation and compounding nature of nutritional disadvantages that are perpetuated across many women's lives. In order for policies and interventions to more effectively address inequities faced by women, and not only women as mothers, it is essential that they reflect on how, when, and where to engage with women across the life course.

Design, Intervention Fidelity, and Behavioral Outcomes of a School-Based Water, Sanitation, and Hygiene Cluster-Randomized Trial in Laos

Evidence of the impact of water, sanitation, and hygiene (WASH) in schools (WinS) interventions on pupil absence and health is mixed. Few WinS evaluations rigorously report on output and outcome measures that allow for comparisons of effectiveness between interventions to be made, or for an understanding of why programs succeed. The Water, Sanitation, and Hygiene for Health and Education in Laotian Primary Schools (WASH HELPS) study was a randomized controlled trial designed to measure the impact of the United Nations Children's Fund (UNICEF) Laos WinS project on child health and education. We also measured the sustainability of intervention outputs and outcomes, and analyzed the effectiveness of group hygiene activities on behavior change and habit formation. Here, we present the design and intermediate results from this study. We found the WinS project improved the WASH environment in intervention schools; 87.8% of schools received the intervention per design. School-level adherence to outputs was lower; on average, schools met 61.4% of adherence-related criteria. The WinS project produced positive changes in pupils' school WASH behaviors, specifically increasing toilet use and daily group handwashing. Daily group hygiene activities are effective strategies to improve school WASH behaviors, but a complementary strategy needs to be concurrently promoted for effective and sustained individual handwashing practice at critical times.

Sanitation and water supply coverage thresholds associated with active trachoma: Modeling cross-sectional data from 13 countries

BACKGROUND

Facial cleanliness and sanitation are postulated to reduce trachoma transmission, but there are no previous data on community-level herd protection thresholds. We characterize associations between active trachoma, access to improved sanitation facilities, and access to improved water sources for the purpose of face washing, with the aim of estimating community-level or herd protection thresholds.

METHODS AND FINDINGS

We used cluster-sampled Global Trachoma Mapping Project data on 884,850 children aged 1-9 years from 354,990 households in 13 countries. We employed multivariable mixed-effects modified Poisson regression models to assess the relationships between water and sanitation coverage and trachomatous inflammation-follicular (TF). We observed lower TF prevalence among those with household-level access to improved sanitation (prevalence ratio, PR = 0.87; 95%CI: 0.83-0.91), and household-level access to an improved washing water source in the residence/yard (PR = 0.81; 95%CI: 0.75-0.88). Controlling for household-level water and latrine access, we found evidence of community-level protection against TF for children living in communities with high sanitation coverage (PR80-90% = 0.87; 95%CI: 0.73-1.02; PR90-100% = 0.76; 95%CI: 0.67-0.85). Community sanitation coverage levels greater than 80% were associated with herd protection against TF (PR = 0.77; 95%CI: 0.62-0.97)-that is, lower TF in individuals whose households lacked individual sanitation but who lived in communities with high sanitation coverage. For community-level water coverage, there was no apparent threshold, although we observed lower TF among several of the higher deciles of community-level water coverage.

CONCLUSIONS

Our study provides insights into the community water and sanitation coverage levels that might be required to best control trachoma. Our results suggest access to adequate water and sanitation can be important components in working towards the 2020 target of eliminating trachoma as a public health problem.

Equity implications for sanitation from recent health and nutrition evidence

Recent evidence points to the possible underestimation of the health and nutrition impact of sanitation. Community sanitation coverage may first need to reach thresholds in the order of 60% or higher, to optimize health and nutrition gains. Increasing coverage of sanitation to levels below 60% of community coverage may not result in substantial gains. For example, moving Indonesia from 60% to 100% improved sanitation coverage could significantly reduce diarrhoea in children under 5 years old (by an estimated 24% reduction in odds ratio for child diarrhoea morbidity) with gains split equally by reaching underserved communities and the unserved within communities. We review the implications of these results across three levels of program implementation – from micro level approaches (that support communities to achieve open defecation-free status), to meso level (sub-national implementation) to macro level approaches for the national enabling environment and the global push to the Sustainable Development Goals. We found significant equity implications and recommend that future studies focus more extensively on community coverage levels and verified community open defecation free status rather than household access alone. Sanitation practitioners may consider developing phased approaches to improving water, sanitation and hygiene in communities while prioritizing the unserved or underserved.

Are there synergies from combining hygiene and sanitation promotion campaigns: Evidence from a large-scale cluster-randomized trial in rural Tanzania

SUMMARY

The current evidence on handwashing and sanitation programs suggests limited impacts on health when at-scale interventions have been tested in isolation. However, no published experimental evidence currently exists that tests the interaction effects between sanitation and handwashing. We present the results of two large-scale, government-led handwashing and sanitation promotion campaigns in rural Tanzania, with the objective of tracing the causal chain from hygiene and sanitation promotion to changes in child health outcomes and specifically testing for potential interaction effects of combining handwashing and sanitation interventions.

METHODS

The study is a factorial cluster-randomized control trial where 181 rural wards from 10 districts in Tanzania were randomly assigned to receive sanitation promotion, handwashing promotion, both interventions together or neither (control). Interventions were rolled out from February 2009 to June 2011 and the endline survey was conducted from May to November 2012, approximately one year after program completion. The sample was composed of households with children under 5 years old in the two largest villages in each ward. Masking was not possible due to the nature of the intervention, but enumerators played no part in the intervention and were blinded to treatment status. The primary outcome of interest was 7-day diarrhea prevalence for children under five. Intermediate outcomes of behavior change including improved latrine construction, levels of open defecation and handwashing with soap were also analyzed. Secondary health outcomes included anemia, height-for-age and weight-for-age of children under 5. An intention-to-treat analysis was used to assess the relationship between the interventions and outcomes of interest.

FINDINGS

One year after the end of the program, ownership of improved latrines increased from 49.7% to 64.8% (95% CI 57.9%-71.7%) and regular open defecation decreased from 23.1% to 11.1% (95% CI 3.5%-18.7%) in sanitation promotion-only wards. Households in handwashing promotion-only wards showed marginal improvements in handwashing behavior related to food preparation but not at other critical junctures. There were no detectable interaction effects for the combined intervention. The associated cost-per-household gaining access to improved sanitation is estimated to be USD $194. Final effects on child health measured through diarrhea, anemia, stunting and wasting were absent in all treatment groups.

INTERPRETATION

Although statistically significant, the changes in intermediate outcomes achieved through each intervention in isolation were not large enough to generate meaningful health impacts. With no observable signs of interaction, the combined intervention produced similar results. The study highlights the importance of focusing on intermediate outcomes of take up and behavior change as a critical first step in large-scale programs before realizing the changes in health that sanitation and hygiene interventions aim to deliver.

TRIAL REGISTRATION

Clinicaltrials.gov NCT01465204.

Sanitation marketing: A systematic review and theoretical critique using the capability approach

Sanitation is a human right that benefits health. As such, technical and behavioural interventions are widely implemented to increase the number of people using sanitation facilities. These include sanitation marketing interventions (SMIs), in which external support agencies (ESAs) use a hybrid of commercial and social marketing tools to increase supply of, and demand for, sanitation products and services. However, there is little critical discourse on SMIs, or independent rigorous analysis on whether they increase or reduce well-being. Most available information is from ESAs about their own SMI implementation. We systematically reviewed the grey and peer-reviewed literature on sanitation marketing, including qualitatively analysing and calculating descriptive statistics for the parameters measured, or intended to be measured, in publications reporting on 33 SMIs. Guided by the capability approach to development we identified that publications for most SMIs (n = 31, 94%) reported on commodities, whilst fewer reported on parameters related to impacts on well-being (i.e., functionings, n = 22, 67%, and capabilities, n = 20, 61%). When evaluating future SMIs, it may be useful to develop a list of contextualised well-being indicators for the particular SMI's location, taking into account local cultural norms, with this list ideally co-produced with local stakeholders. We identified two common practices in SMIs that can reduce well-being and widen well-being inequalities; namely, the promotion of conspicuous consumption and assaults on dignity, and we discuss the mechanisms by which such impacts occur. We recommend that ESAs understand sanitation marketing's potential to reduce well-being and design SMIs to minimize such detrimental impacts. Throughout the implementation phase ESAs should continuously monitor for well-being impacts and adapt practices to optimise well-being outcomes for all involved.

Effects of improved sanitation on diarrheal reduction for children under five in Idiofa, DR Congo: a cluster randomized trial

Background

The lack of safe water and sanitation contributes to the rampancy of diarrhea in many developing countries.

Methods

This study describes the design of a cluster-randomized trial in Idiofa, the Democratic Republic of the Congo, seeking evidence of the impact of improved sanitation on diarrhea for children under four. Of the 276 quartiers, 18 quartiers were randomly allocated to the intervention or control arm. Seven hundred and-twenty households were sampled and the youngest under-four child in each household was registered for this study. The primary endpoint of the study is diarrheal incidence, prevalence and duration in children under five.

Discussion

Material subsidies will be provided only to the households who complete pit digging plus superstructure and roof construction, regardless of their income level. This study employs a Sanitation Calendar so that the mother of each household can record the diarrheal episodes of her under-four child on a daily basis. The diary enables examination of the effect of the sanitation intervention on diarrhea duration and also resolves the limitation of the small number of clusters in the trial.

In addition, the project will be monitored through the ‘Sanitation Map’, on which all households in the study area, including both the control and intervention arms, are registered. To avoid information bias or courtesy bias, photos will be taken of the latrine during the household visit, and a supervisor will determine well-equipped latrine uptake based on the photos. This reduces the possibility of recall bias and under- or over-estimation of diarrhea, which was the main limitation of previous studies.

Trial registration

The study was approved by the Institutional Review Board of the School of Public Health, Kinshasa University (ESP/CE/040/15; April 13, 2015) and registered as an International Standard Randomized Controlled Trial (ISRCTN: 10,419,317) on March 13, 2015.

Electronic supplementary material

The online version of this article (doi:10.1186/s40249-017-0351-x) contains supplementary material, which is available to authorized users.

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.