Burden of disease attributable to unsafe drinking water, sanitation, and hygiene in domestic settings: a global analysis for selected adverse health outcomes.

BACKGROUND: Assessments of disease burden are important to inform national, regional, and global strategies and to guide investment. We aimed to estimate the drinking water, sanitation, and hygiene (WASH)-attributable burden of disease for diarrhoea, acute respiratory infections, undernutrition, and soil-transmitted helminthiasis, using the WASH service levels used to monitor the UN Sustainable Development Goals (SDGs) as counterfactual minimum risk-exposure levels. METHODS: We assessed the WASH-attributable disease burden of the four health outcomes overall and disaggregated by region, age, and sex for the year 2019. We calculated WASH-attributable fractions of diarrhoea and acute respiratory infections by country using modelled WASH exposures and exposure-response relationships from two updated meta-analyses. We used the WHO and UNICEF Joint Monitoring Programme for Water Supply, Sanitation and Hygiene public database to estimate population exposure to different WASH service levels. WASH-attributable undernutrition was estimated by combining the population attributable fractions (PAF) of diarrhoea caused by unsafe WASH and the PAF of undernutrition caused by diarrhoea. Soil-transmitted helminthiasis was fully attributed to unsafe WASH. FINDINGS: We estimate that 1·4 (95% CI 1·3-1·5) million deaths and 74 (68-80) million disability-adjusted life-years (DALYs) could have been prevented by safe WASH in 2019 across the four designated outcomes, representing 2·5% of global deaths and 2·9% of global DALYs from all causes. The proportion of diarrhoea that is attributable to unsafe WASH is 0·69 (0·65-0·72), 0·14 (0·13-0·17) for acute respiratory infections, and 0·10 (0·09-0·10) for undernutrition, and we assume that the entire disease burden from soil-transmitted helminthiasis was attributable to unsafe WASH. INTERPRETATION: WASH-attributable burden of disease estimates based on the levels of service established under the SDG framework show that progress towards the internationally agreed goal of safely managed WASH services for all would yield major public-health returns. FUNDING: WHO and Foreign, Commonwealth & Development Office.

Effectiveness of interventions to improve drinking water, sanitation, and handwashing with soap on risk of diarrhoeal disease in children in low-income and middle-income settings: a systematic review and meta-analysis.

BACKGROUND: Estimates of the effectiveness of water, sanitation, and hygiene (WASH) interventions that provide high levels of service on childhood diarrhoea are scarce. We aimed to provide up-to-date estimates on the burden of disease attributable to WASH and on the effects of different types of WASH interventions on childhood diarrhoea in low-income and middle-income countries (LMICs). METHODS: In this systematic review and meta-analysis, we updated previous reviews following their search strategy by searching MEDLINE, Embase, Scopus, Cochrane Library, and BIOSIS Citation Index for studies of basic WASH interventions and of WASH interventions providing a high level of service, published between Jan 1, 2016, and May 25, 2021. We included randomised and non-randomised controlled trials conducted at household or community level that matched exposure categories of the so-called service ladder approach of the Sustainable Development Goal (SDG) for WASH. Two reviewers independently extracted study-level data and assessed risk of bias using a modified Newcastle-Ottawa Scale and certainty of evidence using a modified Grading of Recommendations, Assessment, Development, and Evaluation approach. We analysed extracted relative risks (RRs) and 95% CIs using random-effects meta-analyses and meta-regression models. This study is registered with PROSPERO, CRD42016043164. FINDINGS: 19 837 records were identified from the search, of which 124 studies were included, providing 83 water (62 616 children), 20 sanitation (40 799 children), and 41 hygiene (98 416 children) comparisons. Compared with untreated water from an unimproved source, risk of diarrhoea was reduced by up to 50% with water treated at point of use (POU): filtration (n=23 studies; RR 0·50 [95% CI 0·41-0·60]), solar treatment (n=13; 0·63 [0·50-0·80]), and chlorination (n=25; 0·66 [0·56-0·77]). Compared with an unimproved source, provision of an improved drinking water supply on premises with higher water quality reduced diarrhoea risk by 52% (n=2; 0·48 [0·26-0·87]). Overall, sanitation interventions reduced diarrhoea risk by 24% (0·76 [0·61-0·94]). Compared with unimproved sanitation, providing sewer connection reduced diarrhoea risk by 47% (n=5; 0·53 [0·30-0·93]). Promotion of handwashing with soap reduced diarrhoea risk by 30% (0·70 [0·64-0·76]). INTERPRETATION: WASH interventions reduced risk of diarrhoea in children in LMICs. Interventions supplying either water filtered at POU, higher water quality from an improved source on premises, or basic sanitation services with sewer connection were associated with increased reductions. Our results support higher service levels called for under SDG 6. Notably, no studies evaluated interventions that delivered access to safely managed WASH services, the level of service to which universal coverage by 2030 is committed under the SDG. FUNDING: WHO, Foreign, Commonwealth & Development Office, and National Institute of Environmental Health Sciences.

Impact of drinking water, sanitation and handwashing with soap on childhood diarrhoeal disease: updated meta-analysis and meta-regression.

OBJECTIVES: Safe drinking water, sanitation and hygiene are protective against diarrhoeal disease; a leading cause of child mortality. The main objective was an updated assessment of the impact of unsafe water, sanitation and hygiene (WaSH) on childhood diarrhoeal disease. METHODS: We undertook a systematic review of articles published between 1970 and February 2016. Study results were combined and analysed using meta-analysis and meta-regression. RESULTS: A total of 135 studies met the inclusion criteria. Several water, sanitation and hygiene interventions were associated with lower risk of diarrhoeal morbidity. Point-of-use filter interventions with safe storage reduced diarrhoea risk by 61% (RR = 0.39; 95% CI: 0.32, 0.48); piped water to premises of higher quality and continuous availability by 75% and 36% (RR = 0.25 (0.09, 0.67) and 0.64 (0.42, 0.98)), respectively compared to a baseline of unimproved drinking water; sanitation interventions by 25% (RR = 0.75 (0.63, 0.88)) with evidence for greater reductions when high sanitation coverage is reached; and interventions promoting handwashing with soap by 30% (RR = 0.70 (0.64, 0.77)) vs. no intervention. Results of the analysis of sanitation and hygiene interventions are sensitive to certain differences in study methods and conditions. Correcting for non-blinding would reduce the associations with diarrhoea to some extent. CONCLUSIONS: Although evidence is limited, results suggest that household connections of water supply and higher levels of community coverage for sanitation appear particularly impactful which is in line with targets of the Sustainable Development Goals.

Child diarrhoea and nutritional status in rural Rwanda: a cross-sectional study to explore contributing environmental and demographic factors.

OBJECTIVE: To explore associations of environmental and demographic factors with diarrhoea and nutritional status among children in Rusizi district, Rwanda. METHODS: We obtained cross-sectional data from 8847 households in May-August 2013 from a baseline survey conducted for an evaluation of an integrated health intervention. We collected data on diarrhoea, water quality, and environmental and demographic factors from households with children <5, and anthropometry from children <2. We conducted log-binomial regression using diarrhoea, stunting and wasting as dependent variables. RESULTS: Among children <5, 8.7% reported diarrhoea in the previous 7 days. Among children <2, stunting prevalence was 34.9% and wasting prevalence was 2.1%. Drinking water treatment (any method) was inversely associated with caregiver-reported diarrhoea in the previous 7 days (PR = 0.79, 95% CI: 0.68-0.91). Improved source of drinking water (PR = 0.80, 95% CI: 0.73-0.87), appropriate treatment of drinking water (PR = 0.88, 95% CI: 0.80-0.96), improved sanitation facility (PR = 0.90, 95% CI: 0.82-0.97), and complete structure (having walls, floor and roof) of the sanitation facility (PR = 0.65, 95% CI: 0.50-0.84) were inversely associated with stunting. None of the exposure variables were associated with wasting. A microbiological indicator of water quality was not associated with diarrhoea or stunting. CONCLUSIONS: Our findings suggest that in Rusizi district, appropriate treatment of drinking water may be an important factor in diarrhoea in children <5, while improved source and appropriate treatment of drinking water as well as improved type and structure of sanitation facility may be important for linear growth in children <2. We did not detect an association with water quality.

Estimating Disease Duration in Cross-sectional Surveys.

BACKGROUND: In some common episodic conditions, such as diarrhea, respiratory infections, or fever, episode duration can reflect disease severity. The mean episode duration in a population can be estimated if both the incidence and prevalence of the condition are known. In this article, we discuss how an estimator of the average episode duration may be obtained based on prevalence alone if data are collected for two consecutive units of time (usually days) in the same person. METHODS: We derive a maximum likelihood estimator of episode duration, explore its behavior through a simulation study, and illustrate its use through a real example. RESULTS: We show that for two consecutive days, the estimator of the mean episode duration in a population equals one plus twice the ratio of the number of subjects with the condition on both days to the number of subjects with only 1 day ill. The estimator can be extended to account for 3 or 4 consecutive days. The estimator assumes nonoverlapping episodes and a time-constant incidence rate and is more precise for shorter than for longer average episode durations. CONCLUSION: The proposed method allows estimating the mean duration of disease episodes in cross-sectional studies and is applicable to large demographic and health surveys in low-income settings that routinely collect data on diarrhea and respiratory illness. The method may further be used for the calculation of the duration of infectiousness if test results are available for two consecutive days, such as paired throat swabs for influenza.

Development of A Multidimensional Scale to Assess Attitudinal Determinants of Sanitation Uptake and Use.

Over 1 billion people still practice open defecation. Low uptake and use of new sanitation technologies in a number of settings has underscored our current limited understanding of the complex attitudinal factors that influence a household's decision to adopt and use new sanitation technologies. Mokken scaling techniques were applied to series of population-based surveys in Odisha, India between September 2011 and October 2013 (sample sizes 120, 500, 2200). Surveys contained simple, agree/disagree statements about attitudes toward sanitation use and sanitation technologies. Analysis produced two scales-a 10-question General Scale, reflecting attitudes toward defecation and norms regarding latrine use for all respondents, and a 6-question Experiential Scale, reflecting personal experiences with and perceived convenience of sanitation technologies targeted at respondents with a latrine. Among all respondents, a one-point change in the General Scale was associated with a 5-percentage point change in the marginal probability of having access to a functioning latrine. Among respondents with a functional latrine at home, a one-point increase in the General and Experiential Scales were associated with a 4- and 8-percentage point decrease in the probability of engaging in any open defecation in the last 7 days, respectively.

Interventions to improve water quality for preventing diarrhoea.

BACKGROUND: Diarrhoea is a major cause of death and disease, especially among young children in low-income countries. In these settings, many infectious agents associated with diarrhoea are spread through water contaminated with faeces.In remote and low-income settings, source-based water quality improvement includes providing protected groundwater (springs, wells, and bore holes), or harvested rainwater as an alternative to surface sources (rivers and lakes). Point-of-use water quality improvement interventions include boiling, chlorination, flocculation, filtration, or solar disinfection, mainly conducted at home. OBJECTIVES: To assess the effectiveness of interventions to improve water quality for preventing diarrhoea. SEARCH METHODS: We searched the Cochrane Infectious Diseases Group Specialized Register (11 November 2014), CENTRAL (the Cochrane Library, 7 November 2014), MEDLINE (1966 to 10 November 2014), EMBASE (1974 to 10 November 2014), and LILACS (1982 to 7 November 2014). We also handsearched relevant conference proceedings, contacted researchers and organizations working in the field, and checked references from identified studies through 11 November 2014. SELECTION CRITERIA: Randomized controlled trials (RCTs), quasi-RCTs, and controlled before-and-after studies (CBA) comparing interventions aimed at improving the microbiological quality of drinking water with no intervention in children and adults. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trial quality and extracted data. We used meta-analyses to estimate pooled measures of effect, where appropriate, and investigated potential sources of heterogeneity using subgroup analyses. We assessed the quality of evidence using the GRADE approach. MAIN RESULTS: Forty-five cluster-RCTs, two quasi-RCTs, and eight CBA studies, including over 84,000 participants, met the inclusion criteria. Most included studies were conducted in low- or middle-income countries (LMICs) (50 studies) with unimproved water sources (30 studies) and unimproved or unclear sanitation (34 studies). The primary outcome in most studies was self-reported diarrhoea, which is at high risk of bias due to the lack of blinding in over 80% of the included studies. Source-based water quality improvementsThere is currently insufficient evidence to know if source-based improvements such as protected wells, communal tap stands, or chlorination/filtration of community sources consistently reduce diarrhoea (one cluster-RCT, five CBA studies, very low quality evidence). We found no studies evaluating reliable piped-in water supplies delivered to households. Point-of-use water quality interventionsOn average, distributing water disinfection products for use at the household level may reduce diarrhoea by around one quarter (Home chlorination products: RR 0.77, 95% CI 0.65 to 0.91; 14 trials, 30,746 participants, low quality evidence; flocculation and disinfection sachets: RR 0.69, 95% CI 0.58 to 0.82, four trials, 11,788 participants, moderate quality evidence). However, there was substantial heterogeneity in the size of the effect estimates between individual studies.Point-of-use filtration systems probably reduce diarrhoea by around a half (RR 0.48, 95% CI 0.38 to 0.59, 18 trials, 15,582 participants, moderate quality evidence). Important reductions in diarrhoea episodes were shown with ceramic filters, biosand systems and LifeStraw® filters; (Ceramic: RR 0.39, 95% CI 0.28 to 0.53; eight trials, 5763 participants, moderate quality evidence; Biosand: RR 0.47, 95% CI 0.39 to 0.57; four trials, 5504 participants, moderate quality evidence; LifeStraw®: RR 0.69, 95% CI 0.51 to 0.93; three trials, 3259 participants, low quality evidence). Plumbed in filters have only been evaluated in high-income settings (RR 0.81, 95% CI 0.71 to 0.94, three trials, 1056 participants, fixed effects model).In low-income settings, solar water disinfection (SODIS) by distribution of plastic bottles with instructions to leave filled bottles in direct sunlight for at least six hours before drinking probably reduces diarrhoea by around a third (RR 0.62, 95% CI 0.42 to 0.94; four trials, 3460 participants, moderate quality evidence).In subgroup analyses, larger effects were seen in trials with higher adherence, and trials that provided a safe storage container. In most cases, the reduction in diarrhoea shown in the studies was evident in settings with improved and unimproved water sources and sanitation. AUTHORS' CONCLUSIONS: Interventions that address the microbial contamination of water at the point-of-use may be important interim measures to improve drinking water quality until homes can be reached with safe, reliable, piped-in water connections. The average estimates of effect for each individual point-of-use intervention generally show important effects. Comparisons between these estimates do not provide evidence of superiority of one intervention over another, as such comparisons are confounded by the study setting, design, and population.Further studies assessing the effects of household connections and chlorination at the point of delivery will help improve our knowledge base. As evidence suggests effectiveness improves with adherence, studies assessing programmatic approaches to optimising coverage and long-term utilization of these interventions among vulnerable populations could also help strategies to improve health outcomes.

Socio-cultural and behavioural factors constraining latrine adoption in rural coastal Odisha: an exploratory qualitative study.

BACKGROUND: Open defecation is widely practiced in India. To improve sanitation and promote better health, the Government of India (GOI) has instituted large scale sanitation programmes supporting construction of public and institutional toilets and extending financial subsidies for poor families in rural areas for building individual household latrines. Nevertheless, many household latrines in rural India, built with government subsidies and the facilitation and support of non-government organizations (NGO), remain unused. Literature on social, cultural and behavioural aspects that constrain latrine adoption and use in rural India is limited. This paper examines defecation patterns of different groups of people in rural areas of Odisha state in India to identify causes and determinants of latrine non-use, with a special focus on government-subsidized latrine owners, and shortcomings in household sanitation infrastructure built with government subsidies. METHODS: An exploratory study using qualitative methods was conducted in rural communities in Odisha state. Methods used were focus group discussions (FGDs), and observations of latrines and interviews with their owners. FGDs were held with frontline NGO sanitation program staff, and with community members, separately by caste, gender, latrine type, and age group. Data were analysed using a thematic framework and approach. RESULTS: Government subsidized latrines were mostly found unfinished. Many counted as complete per government standards for disbursement of financial subsidies to contracted NGOs were not accepted by their owners and termed as 'incomplete'. These latrines lacked a roof, door, adequate walls and any provision for water supply in or near the cabin, whereas rural people had elaborate processes of cleansing with water post defecation, making presence of a nearby water source important. Habits, socialising, sanitation rituals and daily routines varying with caste, gender, marital status, age and lifestyle, also hindered the adoption of latrines. Interest in constructing latrines was observed among male heads for their female members especially a newlywed daughter-in-law, reflecting concerns for their privacy, security, and convenience. This paper elaborates on these different factors. CONCLUSIONS: Findings show that providing infrastructure does not ensure use when there are significant and culturally engrained behavioural barriers to using latrines. Future sanitation programmes in rural India need to focus on understanding and addressing these behavioural barriers.

From joint thinking to joint action: a call to action on improving water, sanitation, and hygiene for maternal and newborn health.

Yael Velleman and colleagues argue for stronger integration between the water, sanitation, and hygiene (WASH) and maternal and newborn health sectors. Please see later in the article for the Editors' Summary.

Effect of household-based drinking water chlorination on diarrhoea among children under five in Orissa, India: a double-blind randomised placebo-controlled trial.

BACKGROUND: Boiling, disinfecting, and filtering water within the home can improve the microbiological quality of drinking water among the hundreds of millions of people who rely on unsafe water supplies. However, the impact of these interventions on diarrhoea is unclear. Most studies using open trial designs have reported a protective effect on diarrhoea while blinded studies of household water treatment in low-income settings have found no such effect. However, none of those studies were powered to detect an impact among children under five and participants were followed-up over short periods of time. The aim of this study was to measure the effect of in-home water disinfection on diarrhoea among children under five. METHODS AND FINDINGS: We conducted a double-blind randomised controlled trial between November 2010 and December 2011. The study included 2,163 households and 2,986 children under five in rural and urban communities of Orissa, India. The intervention consisted of an intensive promotion campaign and free distribution of sodium dichloroisocyanurate (NaDCC) tablets during bi-monthly households visits. An independent evaluation team visited households monthly for one year to collect health data and water samples. The primary outcome was the longitudinal prevalence of diarrhoea (3-day point prevalence) among children aged under five. Weight-for-age was also measured at each visit to assess its potential as a proxy marker for diarrhoea. Adherence was monitored each month through caregiver's reports and the presence of residual free chlorine in the child's drinking water at the time of visit. On 20% of the total household visits, children's drinking water was assayed for thermotolerant coliforms (TTC), an indicator of faecal contamination. The primary analysis was on an intention-to-treat basis. Binomial regression with a log link function and robust standard errors was used to compare prevalence of diarrhoea between arms. We used generalised estimating equations to account for clustering at the household level. The impact of the intervention on weight-for-age z scores (WAZ) was analysed using random effect linear regression. Over the follow-up period, 84,391 child-days of observations were recorded, representing 88% of total possible child-days of observation. The longitudinal prevalence of diarrhoea among intervention children was 1.69% compared to 1.74% among controls. After adjusting for clustering within household, the prevalence ratio of the intervention to control was 0.95 (95% CI 0.79-1.13). The mean WAZ was similar among children of the intervention and control groups (-1.586 versus -1.589, respectively). Among intervention households, 51% reported their child's drinking water to be treated with the tablets at the time of visit, though only 32% of water samples tested positive for residual chlorine. Faecal contamination of drinking water was lower among intervention households than controls (geometric mean TTC count of 50 [95% CI 44-57] per 100 ml compared to 122 [95% CI 107-139] per 100 ml among controls [p<0.001] [n = 4,546]). CONCLUSIONS: Our study was designed to overcome the shortcomings of previous double-blinded trials of household water treatment in low-income settings. The sample size was larger, the follow-up period longer, both urban and rural populations were included, and adherence and water quality were monitored extensively over time. These results provide no evidence that the intervention was protective against diarrhoea. Low compliance and modest reduction in water contamination may have contributed to the lack of effect. However, our findings are consistent with other blinded studies of similar interventions and raise additional questions about the actual health impact of household water treatment under these conditions. TRIAL REGISTRATION: ClinicalTrials.govNCT01202383 Please see later in the article for the Editors' Summary.

Interventions to improve water quality and supply, sanitation and hygiene practices, and their effects on the nutritional status of children.

BACKGROUND: Water, sanitation and hygiene (WASH) interventions are frequently implemented to reduce infectious diseases, and may be linked to improved nutrition outcomes in children. OBJECTIVES: To evaluate the effect of interventions to improve water quality and supply (adequate quantity to maintain hygiene practices), provide adequate sanitation and promote handwashing with soap, on the nutritional status of children under the age of 18 years and to identify current research gaps. SEARCH METHODS: We searched 10 English-language (including MEDLINE and CENTRAL) and three Chinese-language databases for published studies in June 2012. We searched grey literature databases, conference proceedings and websites, reviewed reference lists and contacted experts and authors. SELECTION CRITERIA: Randomised (including cluster-randomised), quasi-randomised and non-randomised controlled trials, controlled cohort or cross-sectional studies and historically controlled studies, comparing WASH interventions among children aged under 18 years. DATA COLLECTION AND ANALYSIS: Two review authors independently sought and extracted data on childhood anthropometry, biochemical measures of micronutrient status, and adherence, attrition and costs either from published reports or through contact with study investigators. We calculated mean difference (MD) with 95% confidence intervals (CI). We conducted study-level and individual-level meta-analyses to estimate pooled measures of effect for randomised controlled trials only. MAIN RESULTS: Fourteen studies (five cluster-randomised controlled trials and nine non-randomised studies with comparison groups) from 10 low- and middle-income countries including 22,241 children at baseline and nutrition outcome data for 9,469 children provided relevant information. Study duration ranged from 6 to 60 months and all studies included children under five years of age at the time of the intervention. Studies included WASH interventions either singly or in combination. Measures of child anthropometry were collected in all 14 studies, and nine studies reported at least one of the following anthropometric indices: weight-for-height, weight-for-age or height-for-age. None of the included studies were of high methodological quality as none of the studies masked the nature of the intervention from participants.Weight-for-age, weight-for-height and height-for-age z-scores were available for five cluster-randomised controlled trials with a duration of between 9 and 12 months. Meta-analysis including 4,627 children identified no evidence of an effect of WASH interventions on weight-for-age z-score (MD 0.05; 95% CI -0.01 to 0.12). Meta-analysis including 4,622 children identified no evidence of an effect of WASH interventions on weight-for-height z-score (MD 0.02; 95% CI -0.07 to 0.11). Meta-analysis including 4,627 children identified a borderline statistically significant effect of WASH interventions on height-for-age z-score (MD 0.08; 95% CI 0.00 to 0.16). These findings were supported by individual participant data analysis including information on 5,375 to 5,386 children from five cluster-randomised controlled trials.No study reported adverse events. Adherence to study interventions was reported in only two studies (both cluster-randomised controlled trials) and ranged from low (< 35%) to high (> 90%). Study attrition was reported in seven studies and ranged from 4% to 16.5%. Intervention cost was reported in one study in which the total cost of the WASH interventions was USD 15/inhabitant. None of the studies reported differential impacts relevant to equity issues such as gender, socioeconomic status and religion. AUTHORS' CONCLUSIONS: The available evidence from meta-analysis of data from cluster-randomised controlled trials with an intervention period of 9-12 months is suggestive of a small benefit of WASH interventions (specifically solar disinfection of water, provision of soap, and improvement of water quality) on length growth in children under five years of age. The duration of the intervention studies was relatively short and none of the included studies is of high methodological quality. Very few studies provided information on intervention adherence, attrition and costs. There are several ongoing trials in low-income country settings that may provide robust evidence to inform these findings.

The effect of improved rural sanitation on diarrhoea and helminth infection: design of a cluster-randomized trial in Orissa, India.

BACKGROUND: Infectious diseases associated with poor sanitation such as diarrhoea, intestinal worms, trachoma and lymphatic filariasis continue to cause a large disease burden in low income settings and contribute substantially to child mortality and morbidity. Obtaining health impact data for rural sanitation campaigns poses a number of methodological challenges. Here we describe the design of a village-level cluster-randomised trial in the state of Orissa, India to evaluate the impact of an ongoing rural sanitation campaign conducted under the umbrella of India's Total Sanitation Campaign (TSC).We randomised 50 villages to the intervention and 50 villages to control. In the intervention villages the implementing non-governmental organisations conducted community mobilisation and latrine construction with subsidies given to poor families. Control villages receive no intervention. Outcome measures include (1) diarrhoea in children under 5 and in all ages, (2) soil-transmitted helminth infections, (3) anthropometric measures, (4) water quality, (5) number of insect vectors (flies, mosquitoes), (6) exposure to faecal pathogens in the environment. In addition we are conducting process documentation (latrine construction and use, intervention reach), cost and cost-effectiveness analyses, spatial analyses and qualitative research on gender and water use for sanitation. RESULTS: Randomisation resulted in an acceptable balance between trial arms. The sample size requirements appear to be met for the main study outcomes. Delays in intervention roll-out caused logistical problems especially for the planning of health outcome follow-up surveys. Latrine coverage at the end of the construction period (55%) remained below the target of 70%, a result that may, however, be in line with many other TSC intervention areas in India. CONCLUSION: We discuss a number of methodological problems encountered thus far in this study that may be typical for sanitation trials. Nevertheless, it is expected that the trial procedures will allow measuring the effectiveness of a typical rural sanitation campaign, with sufficient accuracy and validity.

Making sanitation count: developing and testing a device for assessing latrine use in low-income settings.

While efforts are underway to expand latrine coverage to an estimated 2.6 billion people who lack access to improved sanitation, there is evidence that actual use of latrines is suboptimal, limiting the potential health and environmental gains from containment of human excreta. We developed a passive latrine use monitor (PLUM) and compared its ability to measure latrine activity with structured observation. Each PLUM consisted of a passive infrared motion detector, microcontroller, data storage card, and batteries mounted in a small plastic housing that was positioned inside the latrine. During a field trial in Orissa, India, with ∼115 households, the number of latrine events measured by the PLUMs was in good agreement with that measured by trained observers during 5 h of structured observation per device per week. A significant finding was that the presence of a human observer was associated with a statistically significant increase in the number of latrine events, i.e., the users modified their behavior in response to the observer. Another advantage of the PLUM was the ability to measure activity continuously for an entire week. A shortcoming of the PLUM was the inability to separate latrine events that occurred in immediate succession, leading to possible undercounting during high-traffic periods. The PLUM is a promising technology that can provide detailed measures of latrine use to improve the understanding of sanitation behaviors and how to modify them and for assessing the intended health, livelihood, and environmental benefits of improved sanitation.

Occupational health outcomes among sanitation workers: A systematic review and meta-analysis.

BACKGROUND: Sanitation workers are essential to global public health and societal wellbeing. However, the health risks and outcomes associated with exposure to occupational risk factors among sanitation workers are neither well understood nor well quantified. We undertook a systematic review to (1) identify occupational risk factors among sanitation workers and (2) assess the effect of occupational exposure to human fecal sludge and wastewater on selected health outcomes among these workers. METHODS: We searched four databases (i.e., PubMED, MEDLINE, EMBASE, and LILACS) for eligible studies from inception through to January 01, 2020. The included population was workers ≥15 years engaged, formally or informally, in installing, operating, servicing, cleaning or emptying a sanitation technology at any step of the sanitation chain. The included comparator was workers in other occupations or the general population. Eligible outcomes were: mortality (any or all causes), gastroenteritis, occupational injuries, respiratory diseases, musculoskeletal disorders, and mental and social health conditions. Risk of bias was assessed separately on exposure assessment and health outcome using a modified Liverpool Quality Assessment Tool (LQAT). We pooled sufficiently homogenous studies using inverse variance meta-analysis with random effects. RESULTS: A total of 65 studies (9 cohort studies, 56 cross-sectional studies) met the inclusion criteria. One quarter of studies (n = 15) were from middle-income countries. Few studies assessed occupational risk factor exposures directly; most assigned exposure via proxy of occupation of sanitation worker. We judged nearly all studies to have "high risk of bias" in exposure and outcome assessment. Despite these limitations, the consistency of the overall evidence suggests that sanitation workers are at increased risk of gastroenteritis and respiratory conditions, and may be at increased risk of musculoskeletal disorders and mental/social health conditions. The pooled odds ratio for hepatitis A--the only outcome deemed suitable for meta-analysis--was 2.09 (95% Predicted Interval: 1.39-3.00, 12 studies). There was conflicting evidence from studies of increased risk of mortality; only one study reported on injuries. CONCLUSION: Despite a large number of studies, there is limited evidence to date of the health risks faced by sanitation workers, particularly among groups that may be at particular risk-- women, informal workers and those living in low-income countries. Nevertheless, the research to date provides suggestive evidence of elevated occupational risk among sanitation workers across a range of health condition. More research is needed to improve the current bodies of evidence for all included health outcomes to be able to quantify disease burden among this occupational group.

Building on a decade of progress in water, sanitation and hygiene to control, eliminate and eradicate neglected tropical diseases.

Water, sanitation and hygiene (WASH) are essential for the control and elimination of neglected tropical diseases (NTDs). The forthcoming NTD road map 'Ending the neglect to attain the Sustainable Development Goals: a road map for neglected tropical diseases 2021-2030' encourages cross-sectoral collaboration and includes cross-cutting targets on WASH. This commentary reflects on collaborative efforts between the NTD and WASH sectors over the past years and encourages strengthened partnerships to support the new road map and achieve the 2030 agenda ambition of leaving no one behind.

Interventions to improve disposal of human excreta for preventing diarrhoea.

BACKGROUND: Diarrhoeal diseases are a leading cause of mortality and morbidity, especially among young children in low-income countries, and are associated with exposure to human excreta. OBJECTIVES: To assess the effectiveness of interventions to improve the disposal of human excreta for preventing diarrhoeal diseases. SEARCH STRATEGY: We searched the Cochrane Infectious Disease Group Specialized Register; the Cochrane Central Register of Controlled Trials (CENTRAL), published in The Cochrane Library; MEDLINE; EMBASE; LILACS; the metaRegister of Controlled Trials (mRCT); and Chinese-language databases available under the Wan Fang portal, and the China National Knowledge Infrastructure (CNKI-CAJ). We also handsearched relevant conference proceedings, and contacted researchers and organizations working in the field, as well as checking references from identified studies. SELECTION CRITERIA: Randomized, quasi-randomized, and non-randomized controlled trials (RCTs) were selected, comparing interventions aimed at improving the disposal of human excreta to reduce direct or indirect human contact with no such intervention. Cluster (eg at the level of household or community) controlled trials were included. DATA COLLECTION AND ANALYSIS: We determined study eligibility, extracted data, and assessed methodological quality in accordance with the methods prescribed by the protocol. We described the results and summarized the information in tables. Due to substantial heterogeneity among the studies in terms of study design and type of intervention, no pooled effects were calculated. MAIN RESULTS: Thirteen studies from six countries covering over 33,400 children and adults in rural, urban, and school settings met the review's inclusion criteria. In all studies the intervention was allocated at the community level. While the studies reported a wide range of effects, 11 of the 13 studies found the intervention was protective against diarrhoea. Differences in study populations and settings, in baseline sanitation levels, water, and hygiene practices, in types of interventions, study methodologies, compliance and coverage levels, and in case definitions and outcome surveillance limit the comparability of results of the studies included in this review. The validity of most individual study results are further compromised by the non-random allocation of the intervention among study clusters, an insufficient number of clusters, the lack of adjustment for clustering, unclear loss to follow-up, potential for reporting bias and other methodological shortcomings. AUTHORS' CONCLUSIONS: This review provides some evidence that interventions to improve excreta disposal are effective in preventing diarrhoeal disease. However, this conclusion is based primarily on the consistency of the evidence of beneficial effects. The quality of the evidence is generally poor and does not allow for quantification of any such effect. The wide range of estimates of the effects of the intervention may be due to clinical and methodological heterogeneity among the studies, as well as to other important differences, including exposure levels, types of interventions, and different degrees of observer and respondent bias. Rigorous studies in multiple settings are needed to clarify the potential effectiveness of excreta disposal on diarrhoea.

Prevalence of Trachoma in Pakistan: Results of 42 Population-Based Prevalence Surveys from the Global Trachoma Mapping Project.

Purpose: Previous phases of trachoma mapping in Pakistan completed baseline surveys in 38 districts. To help guide national trachoma elimination planning, we set out to estimate trachoma prevalence in 43 suspected-endemic evaluation units (EUs) of 15 further districts.Methods: We planned a population-based trachoma prevalence survey in each EU. Two-stage cluster sampling was employed, using the systems and approaches of the Global Trachoma Mapping Project. In each EU, residents aged ≥1 year living in 30 households in each of 26 villages were invited to be examined by trained, certified trachoma graders. Questionnaires and direct observation were used to evaluate household-level access to water and sanitation.Results: One EU was not completed due to insecurity. Of the remaining 42, three EUs had trichiasis prevalence estimates in ≥15-year-olds ≥0.2%, and six (different) EUs had prevalence estimates of trachomatous inflammation-follicular (TF) in 1-9-year-olds ≥5%; each EU requires trichiasis and TF prevalence estimates below these thresholds to achieve elimination of trachoma as a public health problem. All six EUs with TF prevalences ≥5% were in Khyber Pakhtunkhwa Province. Household-level access to improved sanitation ranged by EU from 6% to 100%. Household-level access to an improved source of water for face and hand washing ranged by EU from 37% to 100%.Conclusion: Trachoma was a public health problem in 21% (9/42) of the EUs. Because the current outbreak of extremely drug-resistant typhoid in Pakistan limits domestic use of azithromycin mass drug administration, other interventions against active trachoma should be considered here.

Prevalence of Trachoma and Access to Water and Sanitation in Benue State, Nigeria: Results of 23 Population-Based Prevalence Surveys.

PURPOSE: We sought to determine the prevalence of trachoma in each local government area (LGA) of Benue State, Nigeria. METHODS: Two-stage cluster sampling was used to conduct a series of 23 population-based prevalence surveys. LGAs were the evaluation units surveyed. In each LGA, 25 households were selected in each of 25 clusters, and individuals aged 1 year and above resident in those households were invited to be examined for trachoma. Data on access to water and sanitation were also collected at household level. RESULTS: A total of 91,888 people were examined from among 93,636 registered residents across the 23 LGAs. The LGA-level prevalence of trachomatous inflammation-follicular (TF) in 1-9 year olds ranged from 0.3% to 5.3%. Two LGAs had TF prevalences of 5.0-9.9%. The LGA-level prevalence of trichiasis in ≥15-year-olds ranged from 0.0% to 0.35%. Access to improved drinking water sources ranged from 0% in Gwer West to 99% in Tarka, while access to improved sanitation ranged from 1% in Gwer West to 92% in Oturkpo. CONCLUSION: There is a need for public health-level interventions against trachoma in three LGAs of Benue State.

Prevalence of Trachoma in Kogi State, Nigeria: Results of four Local Government Area-Level Surveys from the Global Trachoma Mapping Project.

PURPOSE: To determine the prevalence of trachoma in four Local Government Areas (LGAs) of Kogi State, Nigeria. METHODS: In June 2014, we conducted population-based, cross-sectional surveys according to Global Trachoma Mapping Project (GTMP) protocols in selected LGAs of Kogi State. In each LGA, 25 clusters were selected with probability proportional to size. In each of these clusters, 25 households were enrolled for the survey. All residents of selected households aged ≥1 year were examined by GTMP-certified graders for trachomatous inflammation-follicular (TF) and trichiasis using the simplified trachoma grading scheme. Data on sources of household water and types of sanitation facilities were collected through questioning and direct observation. RESULTS: The age-adjusted TF prevalence in 1-9-year-olds ranged from 0.4% (95% CI 0.1-0.8%) in Bassa to 1.0% (95% CI 0.3-1.9%) in Omala. Across all four LGAs, only one case of trichiasis was found; this individual was in Omala, giving that LGA a trichiasis prevalence in individuals aged ≥15 years of 0.02% (95% CI 0.00-0.07%). Between 77 and 88% of households had access to water for hygiene purposes, while only 10-30% had access to improved sanitation facilities. CONCLUSION: Trachoma is not a public health problem in any of the 4 LGAs surveyed. There is, however, the need to increase access to adequate water and sanitation services to contribute to the health and social and economic well-being of these communities.