Fecal contamination of drinking-water in low- and middle-income countries: a systematic review and meta-analysis

Child feces disposal practices in humanitarian and non-humanitarian settings across 34 low- and middle-income countries

Globally, safe sanitation has improved significantly in the last two decades, but unsafe child feces disposal remains a growing challenge in many regions, exposing household members and communities to infectious pathogens. The drivers associated with child feces disposal in several contexts including humanitarian settings are not well understood. This study investigated child feces disposal (CFD) practices and associated factors in low- and middle-income countries, including in humanitarian settings. Data from 352,173 women in 34 countries, collected between 2012 and 2021 through Demographic and Health Surveys (DHS), were used. We utilized multivariate logistic regression to assess CFD practices among children under two years old and the factors linked to these practices. We incorporated data from the United Nations High Commissioner for Refugees (UNHCR) regarding refugee camps' locations in the analysis. Time series and local spatial autocorrelation analyses were run to examine changes in safe CFD practices over time and space, respectively. Results showed minimal improvement in safe child feces disposal over the past decade, with 55.6 % of respondents in non-humanitarian settings and 38.1 % in humanitarian settings improperly disposing of feces. Improper CFD significantly correlated with increased odds of diarrhea in non-humanitarian settings (OR 1.09 95 % CI: 1.05-1.13) but not in humanitarian settings (OR 1.14 95 % CI: 0.53-2.49). The most significant factors (p < 0.05) associated with safe CFD included being in the richest wealth quintile (OR 3.27 95 % CI: 3.06-3.49), having basic education (OR 1.28 95 % CI: 1.22-1.33), children eating solid food (OR 1.53 95 % CI: 1.48-1.57), improved sanitation access (OR 1.88 95 % CI: 1.81-1.96), and listening to radio at least weekly (OR 1.40 95 % CI: 135-1.46). Policymakers and development partners must include safe CFD guidelines in national policies and programs, as well as prioritize investments in household-level sanitation and educate caregivers about safe CFD practices.

Access to drinking safe water and its associated factors among households in East Africa: a mixed effect analysis using 12 East African countries recent national health survey

BACKGROUND

More than half of the population in Sub-Saharan Africa (SSA) faces limited access to safe drinking water. Unimproved water sources can pose risks to the health of entire households, particularly women and children. Despite the fact that East African countries have some of the poorest drinking water infrastructures globally, there is a lack of published data on this issue. Consequently, the objective of this study was to examine access to safe drinking water and its determinants among households in East Africa, utilizing recent nationally representative data.

METHODS

This study analyzed data from recent demographic and health surveys conducted in 12 East African nations between 2011 and 2022. Data were gathered from 204,275 households. A stratified two-stage cluster sampling method was employed, with enumeration areas serving as the main sampling units and households serving as the secondary sampling units. Binary and multiple multilevel logistic regression were used to examine the relevant factors associated with the use of different sources of drinking water in the region. In binary regression and multiple regression, P values of ≤ 0.2 and < 0.05, respectively, were used to determine the statistical significance of variables in the final model.

RESULTS

Approximately 72.62% (95% CI = 72.43, 72.83) of households have utilized improved sources of drinking water. Household heads aged 25-35 years (AOR = 1.09, 95% CI = 1.04, 1.14), 36-45 years (AOR = 1.09, 95% CI = 1.04, 1.14), and > 45 years (AOR = 1.08, 95% CI = 1.04, 1.14), those with secondary/higher education (AOR = 1.24, 95% CI = 1.20-1.29), and individuals in wealth index categories of poorest (AOR = 0.17, 95% CI = 0.16, 0.18), poorer (AOR = 0.21, 95% CI = 0.19, 0.22), middle (AOR = 0.25, 95% CI = 0.24, 0.27), and richer (AOR = 0.36, 95% CI = 0.34, 0.38) were associated with improved sources of drinking water. Additionally, female household leaders (AOR = 1.23, 95% CI = 1.20, 1.26), > 30 min of time taken to access the water source (AOR = 2.00, 95% CI = 1.95, 2.05), improved toilet facilities (AOR = 2.25, 95% CI = 2.19, 2.31), rural residence (AOR = 0.43, 95% CI = 0.42, 0.45), high community wealth (AOR = 1.31, 95% CI = 1.13-1.51), community media exposure (AOR = 1.32, 95% CI = 1.15, 1.51) were associated with improved sources of drinking water, respectively.

CONCLUSION

Approximately three-quarters of the population in East Africa has access to improved drinking water, although the quality of water in the region is still considered poor. It is important for relevant organizations to collaborate in order to improve the quality of drinking water, with special attention given to high-risk groups such as communities with high poverty and low literacy rates, poor households, and rural residents. Strengthening women's empowerment and increasing mass media exposure can also play a crucial role in accelerating the adoption of improved drinking water sources in East Africa.

Assessing the Influence of Hand-Dug Well Features and Management on Water Quality

Underground water quality can be affected by natural or human-made influences. This study investigates how the management and characteristics of hand-dug wells impact water quality in 3 suburbs of Kumasi, Ghana, using a combination of qualitative and quantitative research methods. Descriptive analysis, including frequency and percentages, depicted the demographic profiles of respondents. Box plot diagrams illustrated the distribution of physicochemical parameters (Total Dissolved Solid [TDS], Electrical Conductivity [EC], Turbidity, Dissolved Oxygen [DO], and Temperature). Factor analysis evaluated dominant factors among these parameters. Cluster analysis (hierarchical clustering) utilized sampling points as variables to establish spatial variations in water physicochemical parameters. Cramer's V correlation test explored relationships between demographic variables and individual perceptions of water management. One-way ANOVA verified significant mean differences among the physicochemical parameters. Logistic regression models assessed the influence of selected well features (e.g., cover and apron) on TDS, pH, Temperature, Turbidity, and DO. The findings revealed that proximity to human settlements affects water quality, and increasing turbidity is associated with unmaintained covers, significantly impacting water quality (P < .05). Over 80% of wells were located within 10 to 30 m of pollution sources, with 65.63% situated in lower ground and 87.5% being unmaintained. Other significant contamination sources included plastic bucket/rope usage (87.50%), defective linings (75%), and apron fissures (59.37%). Presence of E. coli, Total coliform, and Faecal coliform rendered the wells unpotable. Factor analysis attributed 90.85% of time-based and spatial differences to organic particle decomposition factors. However, Cramer's V correlation analysis found establishing association between demographic factor associations with individual perceptions of hand-dug well management difficult. It is encouraged to promote hand-dug well construction and maintenance standards to ensure that wells are properly built and protected from contamination sources.

Identifying predictors of E. coli in rural household water in sub-Saharan Africa using elimination regression

Exposure to fecally contaminated drinking water contributes to the global disease burden, especially in sub-Saharan Africa (SSA). We used cross-sectional data and elimination regression analysis to examine factors influencing E. coli contamination in household drinking water samples from 4,499 rural households in nine countries in SSA (Malawi, Mozambique, and Zambia in Southern Africa; Ghana, Mali, and Niger in Western Africa; and Kenya, Rwanda, and Tanzania in Eastern Africa). The proportion of household water samples containing E. coli was 71%, ranging from 45% (Malawi) to 89% (Tanzania). Pooled and multi-country predictive logistic regression models showed that using an unimproved-type water source, the absence of a community water committee, and domestic animal ownership were significantly associated with household drinking water contamination. Household water treatment and storage practices, sanitation and hygiene practices, and payment for drinking water were not significantly associated with E. coli contamination in any model. The season was a significant predictor of E. coli in the pooled model; samples collected in the rainy season were 2.3 [2.0, 2.7] times as likely to be contaminated with E. coli. Practitioners and policymakers should prioritize implementing piped on-plot water services, establishing effective local water source management structures, and incorporating animal husbandry practices into water, sanitation, and hygiene interventions.

Water Supply Interruptions Are Associated with More Frequent Stressful Behaviors and Emotions but Mitigated by Predictability: A Multisite Study

Water supply interruptions contribute to household water insecurity. Unpredictable interruptions may particularly exacerbate water insecurity, as uncertainty limits households' ability to optimize water collection and storage or to modify other coping behaviors. This study used regression models of survey data from 2873 households across 10 sites in 9 middle-income countries to assess whether water supply interruptions and the predictability of interruptions were related to composite indicators of stressful behaviors and emotional distress. More frequent water service interruptions were associated with more frequent emotional distress (β = 0.49, SE = 0.05, P < 0.001) and stressful behaviors (β = 0.39, SE = 0.06, P < 0.001). Among households that experienced interruptions, predictability mitigated these respective relationships by approximately 25 and 50%. Where the provision of continuous water supplies is challenged by climate change, population growth, and poor management, water service providers may be able to mitigate some psychosocial consequences of intermittency through scheduled intermittency and communication about water supply interruptions. Service providers unable to supply continuous water should optimize intermittent water delivery to reduce negative impacts on users, and global monitoring regimes should account for intermittency and predictability in post-2030 water service metrics to better reflect household water insecurity experiences.

Bacterial community assessment of drinking water and downstream distribution systems in highland localities of Ecuador

Bacterial communities in drinking water provide a gauge to measure quality and confer insights into public health. In contrast to urban systems, water treatment in rural areas is not adequately monitored and could become a health risk. We performed 16S rRNA amplicon sequencing to analyze the microbiome present in the water treatment plants at two rural communities, one city, and the downstream water for human consumption in schools and reservoirs in the Andean highlands of Ecuador. We tested the effect of water treatment on the diversity and composition of bacterial communities. A set of physicochemical variables in the sampled water was evaluated and correlated with the structure of the observed bacterial communities. Predominant bacteria in the analyzed communities belonged to Proteobacteria and Actinobacteria. The Sphingobium genus, a chlorine resistance group, was particularly abundant. Of health concern in drinking water reservoirs were Fusobacteriaceae, Lachnospiraceae, and Ruminococcaceae; these families are associated with human and poultry fecal contamination. We propose the latter families as relevant biomarkers for establishing local standards for the monitoring of potable water systems in highlands of Ecuador. Our assessment of bacterial community composition in water systems in the Ecuadorian highlands provides a technical background to inform management decisions.

The contribution of decentralized water systems on water quality in Maniema province, DRC

Decentralized water systems (DWS) distribute water in remote African areas. Throughout an intervention in Maniema, Congo, the influence of a DWS performing chlorination in the community's water quality was measured. Additionally, a socio-economic and WASH practices survey was conducted in the communities. Free residual chlorine (FRC) and microbiological contamination were measured; at the borehole, treatment site, distribution points, and households's water containers. In Big Five, water was collected from unimproved sources before DWS construction. Despite that, only 16,6% of households used efficient water treatment methods, resulting in 73% of water stored unsafe for consumption. After construction, household water quality drastically improved, regardless of FRC fluctuations; 93% of samples were classified as low health risk (safe). The renovation guaranteed continuous supply through electro-chlorinators in RVA, where chlorination was intermittent. Water from DWS with adequate chlorine levels prevented microbiological contamination in households for 12 hours. Although economically attractive, the system's sustainability will require future evaluation.

The Impact of Rapid Handpump Repairs on Diarrhea Morbidity in Children: Cross-Sectional Study in Kwale County, Kenya

BACKGROUND

Handpumps are used by millions of people as their main source of water. Although handpumps represent only a basic form of water provision, there have been continuous efforts to improve the performance of these systems as they are likely to remain in use for many years to come. The introduction of a professional maintenance service in southern Kenya has shown an order of magnitude improvement in operational performance over community-based management, with 90% of handpump faults repaired within 3 days of being reported. One driver behind these efforts is the assumption that a more reliable water supply will lead to a reduction in water-related disease. However, it is not clear if operational improvements lead to health gains. Despite limited empirical evidence, some modeling studies suggest that even short periods of drinking contaminated water can lead to disproportionate negative health impacts.

OBJECTIVE

The aim of this study was to assess whether the improvements in operational performance from the rapid professional maintenance of rural handpumps lead to improved household health outcomes.

METHODS

From a sample of households using handpumps as their primary water source in Kwale County, Kenya, we measured the 2-week prevalence of World Health Organization-defined diarrhea in children, reported by the adult respondent for each household. We compared the rates before and after a period during which the households' handpumps were being professionally maintained. We then conducted a cross-sectional analysis, fitting logistic regression models with reported diarrhea as the dependent variable and speed of repair as the independent exposure of interest, adjusting for household socioeconomic characteristics; dwelling construction; and Water, Sanitation, and Hygiene (WASH)-related factors. We fitted an additional model to examine select interactions between covariates.

RESULTS

Reported diarrhea in children was lower in households whose pumps had been repaired within 24 hours (adjusted odds ratio 0.35, 95% CI 0.24-0.51). This effect was robust to the inclusion of multiple categories of covariates. No reduction was seen in households whose pump repairs took more than 24 hours. Analysis of interaction terms showed that certain interventions associated with improved WASH outcomes were only associated with reductions in diarrhea in conjunction with socioeconomic improvements.

CONCLUSIONS

Only pump repairs consistently made within 24 hours of failure led to a reduction in diarrhea in the children of families using handpumps. While the efficacy of reduction in diarrhea is substantial, the operational challenges of guaranteeing same-day repairs limits the effectiveness of even best-in-class pump maintenance. Maintenance regimes that cannot bring handpump downtimes close to zero will struggle to generate health benefits. Other factors that reduce diarrhea prevalence have limited effect in isolation, suggesting that WASH interventions will be more effective when undertaken as part of more holistic poverty-reduction efforts.

Molecular detection of waterborne pathogens in infants' drinking water and their relationship with water quality determinants in eastern Ethiopia: loop-mediated isothermal amplification (LAMP)-based study

Cryptosporidium, Shigella, toxin-producing Escherichia coli, and rotavirus were reported to be the most responsible for severe and fatal diarrhea among infants. This study aimed to investigate the presence of these pathogens in infants' drinking water samples and analyzing using water quality determinants in eastern Ethiopia. A molecular (LAMP)-based cross-sectional study design was employed. A total of 410 and 37 water samples were tested from infant point-of-use at household and corresponding water source, respectively, from June 2020 to May, 2021. Cryptosporidium, Shigella, toxin-producing E. coli, and rotavirus were detected in 28.5, 30.0, 26.3, and 32.2%, of water samples tested from infant point-of-use, respectively. About 13.2% of the water samples were positive for all (four) pathogens together. Cryptosporidium, Shigella, toxin-producing E. coli, and rotavirus were detected in 27.0, 32.4, 29.7, and 37.8%, of water samples tested from water sources, respectively. Positive significant correlation was observed between infant point-of-consumption and water sources from which it is drawn toward the presence of each targeted pathogen. Unimproved water source showed a strong significant association with the presence of Cryptosporidium, Shigella and toxin-producing E. coli. Therefore, efforts should be made in development of improved water sources, source protection safety and health education to caretakers of infants.

E. coli contamination of drinking water sources in rural and urban settings: an analysis of 38 nationally representative household surveys (2014-2021)

The world is not on track to achieve universal access to safely managed water by 2030, and access is substantially lower in rural areas. This Sustainable Development Goal target and many other global indicators rely on the classification of improved water sources for monitoring access. We aimed to investigate contamination in drinking water sources, comparing improved and unimproved sources in urban and rural settings. We used data from Multiple Indicator Cluster Surveys, which tested samples from the household water source and a glass of water for Escherichia coli contamination across 38 countries. Contamination was widespread and alarmingly high in almost all countries, settings, and water sources, with substantial inequalities between and within countries. Water contamination was found in 51.7% of households at the source and 70.8% in the glass of water. Some improved sources (e.g., protected wells and rainwater) were as likely to be contaminated as unimproved sources. Some sources, like piped water, were considerably more likely to be contaminated in rural than urban areas, while no difference was observed for others. Monitoring water contamination along with further investigation in water collection, storage, and source classification is essential and must be expanded to achieve universal access to safely managed water.

Traditional and new proposals for environmental microbial indicators-a review

The continuous increment in world population coupled with the greatest natural resource consumption and waste generation has an enormous impact on the environment. To date, using biological indicators (bioindicators) to evaluate the biological quality of natural environments is very common. Nonetheless, selecting those suitable for each ecosystem or contaminant is one of the most important issues for environmental sciences. Bacteria and helminths are mainly related to fecal contamination, while antibiotic-resistant bacteria, fungi, viruses, and microalgae are organisms used to determine deteriorated ecosystems by diverse contaminants. Nowadays, each bioindicator is used as a specific agent of different contaminant types, but detecting and quantifying these bioindicator microorganisms can be performed from simple microscopy and culture methods up to a complex procedure based on omic sciences. Developing new techniques based on the metabolism and physiological responses of traditional bioindicators is shown in a fast environmental sensitivity analysis. Therefore, the present review focuses on analyzing different bioindicators to facilitate developing suitable monitoring environmental systems according to different pollutant agents. The traditional and new methods proposed to detect and quantify different bioindicators are also discussed. Their vital role is considered in implementing efficient ecosystem bioprospection, restoration, and conservation strategies directed to natural resource management.

Safe Today, Unsafe Tomorrow: Tanzanian Households Experience Variability in Drinking Water Quality

Measuring Escherichia coli in a single-grab sample of stored drinking water is often used to characterize drinking water quality. However, if water quality exhibits variability temporally, then one-time measurement schemes may be insufficient to adequately characterize the quality of water that people consume. This study uses longitudinal data collected from 193 households in peri-urban Tanzania to assess variability in stored water quality and to characterize uncertainty with different data collection schemes. Households were visited 5 times over the course of a year. At each visit, information was collected on water management practices, and a sample of stored drinking water was collected for E. coli enumeration. Water quality was poor for households, with 80% having highly contaminated (>100 CFU per 100 mL) water during at least one visit. There was substantial variability of water quality for households, with only 3% of households having the same category (low, medium, or high) of water quality for all five visits. These data suggest a single sample would inaccurately characterize a household's drinking water quality over the course of a year and lead to misestimates of population level access to safe drinking water.

Malaria and Typhoid Fever Coinfection among Febrile Patients in Ngaoundéré (Adamawa, Cameroon): A Cross-Sectional Study

Background

Malaria and typhoid fever remain the major cause of morbidity and mortality in tropical and subtropical countries. It is common today to see patients being concurrently infected or treated for the two diseases.

Objective

The aim of the present study was to determine the prevalence of malaria, typhoid fever, and their coinfection among febrile patients at Ngaoundéré Regional Hospital, Adamawa, Cameroon. Methodology. A cross-sectional and descriptive study was conducted on 208 febrile patients coming for medical consultation at Ngaoundéré Regional Hospital and suspected for malaria and/or typhoid fever from September to November 2019. After receiving the consent of each patient, clinical and sociodemographic information were collected using a pretested semistructured questionnaire. Thereafter, blood samples were collected and subjected to (i) blood film examination for malaria detection and (ii) qualitative and semiquantitative Widal assay for typhoid fever detection.

Results

Plasmodium falciparum was the only species identified, and the prevalence of malaria was 50.0% (n = 104). The seroprevalence of typhoid fever was 64.3% (n = 133). The malaria and typhoid fever coinfection was 30.3% (n = 63). The coinfection between S. paratyphi (A, B, and C) and malaria was also observed with the prevalence ranging from 32.2 to 63.9%. Female group and children from 2 to 10 years old were the most affected groups by the two infectious agents.

Conclusion

Typhoid fever and malaria were more prevalent in Ngaoundéré City, particularly in children and women. Further studies should be done on the risk factors of malaria and typhoid fever coinfection in different study areas.

Unimproved source of drinking water and its associated factors: a spatial and multilevel analysis of Ethiopian demographic and health survey

BACKGROUND

Drinking water quality has been a major public health concern in lower and middle income countries where access to improved water supplies is limited. Ethiopia is thought to have one of the worst drinking water infrastructures in the world. This study aimed to assess the spatial variation and determinants of using unimproved sources of drinking water in Ethiopia using recent nationally representative data.

METHODS

A population-based cross-sectional study was employed with the recent EDHS data of 2019. A total of 8663 households were sampled using a stratified two-stage cluster sampling method. Kuldorff's SaTScan version 9.6 software was used to generate spatial scan statistics. ArcGIS version 10.7 software was used to visualize the spatial patterns of unimproved drinking water sources. A multilevel multivariable mixed-effect logistic regression was used to identify factors associated with the use of an unimproved drinking water source. In the multivariable multilevel analysis, those variables with a p-value < 0.05 were considered to be significant predictors of using an unimproved source of drinking water.

RESULT

Around 31% (95% CI: 30%, 32%) of the population in Ethiopia uses unimproved sources of drinking water with significant spatial variation across the country. Households aged 41-60 [AOR = 0.69; 95%CI; 0.53, 0.89] as compared to the households aged 10-25, households having middle wealth index [AOR = 0.48; 95%CI; 0.40, 0.59], and households having a rich wealth index [AOR = 0.31; 95%CI; 0.25, 0.39] as compared to the poor households, living in high community literacy level [AOR = 0.36; 95%CI; 0.16, 0.80], living in high-level community poverty [AOR = 3.03; 95%CI; 1.32, 6.98], rural residence [AOR = 7.88; 95%CI; 2.74, 22.67] were significant predictors of use of unimproved source of drinking water. Hot spot areas of use of unimproved drinking water sources were observed in Amhara, Afar, and Somalia regions and some parts of SNNPR and Oromia regions in Ethiopia. The primary clusters were found in Ethiopia's Somalia and Oromia regions.

CONCLUSION

Around one third of the Ethiopian population utilizes unimproved source of drinking water and it was distributed non-randomly across regions of Ethiopia. The age of the household head, wealth status of the household, residence, community poverty level, and community literacy level were found to be significantly associated with utilizing unimproved drinking water source. State authorities, non-governmental organizations and local health administrators should work to improve the quality of drinking water particularly for high risk groups such as communities living in high poverty and low literacy, poor households, rural residents, and hot spot areas to decrease the adverse consequences of using unimproved drinking water source.

Latrine utilization and associated factors among districts implementing and not-implementing community-led total sanitation and hygiene in East Wollega, Western Ethiopia: A comparative cross-sectional study

INTRODUCTION

Discharge of excreta to the environment lead to surface and groundwater contamination and human exposure to disease-causing micro-organisms. There is limitation of evidences regarding the latrine utilization among community-led total sanitation and hygiene implemented and non-implemented districts of the East Wollega Zone. Hence, this study aimed to determine the magnitude and associated factors of latrine utilization among households in community-led total sanitation and hygiene implemented and non-implemented Districts in East Wollega Zone, Western Ethiopia.

METHODS

A cross-sectional study was conducted. A Multi-stage sampling technique was applied to select the 461 households. Data were collected using interviews and observations guided by a pre-structured questionnaire. Data were entered using Epi Data and exported to SPSS software version 25 for data recording, cleaning, and statistical analysis. Bivariable logistic regression was run to identify the candidate variables at p-value <0.25. Variables that had associations with latrine utilization in the bi-variable analysis were entered together into multivariable logistic regression. An Adjusted odds ratio with a 95% confidence interval was calculated and P-value< 0.05 was used to declare a statistically significant association.

RESULT

The overall prevalence of latrine utilization was found to be 52.7% (95%CI:48%, 57.3%). Religion (AOR = 0.149;95%CI:0.044,0.506), education (AOR = 3.861;95%CI:1.642,9.077), occupation, absence of children <5 years (AOR = 4.724;95%CI:2.313,9.648), toilet cleaning (AOR = 10.662;95%CI:5.571,20.403), frequency of latrine construction (AOR = 6.441;95%CI:2.203,18.826), maintenance need (AOR = 6.446; 95%CI:3.023,13.744), distance from health institution (AOR = 0.987; 95%CI:0.978, 0.996), distance from kebele office (AOR = 6.478; 95%CI:2.137,19.635), and latrine distance from dwelling (AOR = 11.656; 95%CI:2.108, 64.44) were the factors associated with latrine use.

CONCLUSION

The latrine utilization in this study is low as compared to other studies. Religion, education, occupation, absence of children <5 years, toilet cleaning, frequency of latrine construction, maintenance need of the toilet, distance from health institution, distance from kebele, and latrine distance from dwelling are the associated factors of latrine utilization. Both households and health workers have to work together to improve latrine utilization and the safe disposal of children's feces.

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.

Nowcasting of fecal coliform presence using an artificial neural network

At least 2 billion people worldwide use drinking water sources that are contaminated with feces, causing waterborne diseases; poor sanitation, poor hygiene, and unsafe drinking water result in a daily death rate of more than 800 children under 5 years of age from diarrheal diseases. This study shows the feasibility of a novel method to nowcast fecal coliforms' (FC) presence in drinking water sources by applying a multilayer perceptron artificial neuron network (MLP-ANN) model. The model gives a binary answer for FC presence or absence in drinking water sources using a minimum of water quality and geographical parameters, which can be monitored in real-time as predictors with low-cost and in-situ equipment. Using 51,400 samples to train, validate and test the model with temperature, pH, electrical conductivity, turbidity, dissolved oxygen, and total dissolved solids (TDS) as water-quality inputs and the water source type and location (as districts in India) as geographical inputs. The model achieved a total accuracy of 92.8% and a sensitivity of 98.2%, meaning that most FC-contaminated samples were classified correctly. In addition, precision reached 93.1%, meaning that most FC-contamination classifications were actually contaminated. The MLP-ANN performed better than the Linear Regression and K-Nearest Neighbors models, with lower accuracies of 90.2% and 91.0%, respectively. The MLP-ANN model could characterize the water quality geospatially, learn from the parameters whether the water is contaminated by FC, and predict with high accuracy on new testing data. This method can be used as a part of a sensor for FC monitoring and management in water, reducing the time gaps between routine lab testing and thus improving drinking water quality and addressing the SDG 6 targets.

Microbial source tracking to elucidate the impact of land-use and physiochemical water quality on fecal contamination in a mixed land-use watershed

Escherichia coli has been widely used as a fecal indicator bacterium (FIB) for monitoring water quality in drinking water sources and recreational water. However, fecal contamination sources remain difficult to identify and mitigate, as millions of cases of infectious diseases are reported yearly due to swimming and bathing in recreational water. The objective of this study was to apply molecular techniques for microbial source tracking (MST) to identify sources of fecal contamination in a representative mixed land-use watershed located in the Appalachian Mountains of the United States of America (USA). Monthly samples were collected over one year at 11 sites, including the confluence of key first-order streams in the study watershed representing distinct land-use types and anticipated fecal sources. Results indicated that coupled monitoring of host-specific MST markers with the FIB E. coli effectively identified sources and quantified fecal contamination in the study watershed. Human-associated MST markers were abundant primarily at developed sites, suggesting septic or sewer failure is a key source of fecal input to the watershed. Across the dataset, samples positive for E. coli and human MST markers were associated with a higher pH than those samples from which each target was not detected, thereby suggesting that acid mine drainage in the watershed likely contributed to inactivation or loss of culturability in E. coli. In addition, this research provides the first evidence that the BacCan-UCD marker is present in fox feces and can influence MST results in areas where substantial wildlife activity is present. Identifying the sources of fecal contamination and better understanding the impact of in-stream physiochemistry throughout this study will help to develop sustainable and effective watershed management plans to control fecal contamination to protect drinking water sources and recreational water.

Bacterial biofilm prevalence in dental unit waterlines: a systematic review and meta-analysis

BACKGROUNDS

Numerous studies have shown that dental unit water lines (DUWLs) are often contaminated by a wide range of micro-organisms (bacteria, fungi, protozoa) and various prevalence have been reported for it in previous studies. Therefore, this review study aims to describe the prevalence of bacterial biofilm contamination of DUWLs.

METHODS

This is a systematic review and meta-analysis in which the related keywords in different international databases, including Medline (via PubMed) and Scopus were searched. The retrieved studies were screened and the required data were extracted from the included studies. Three standard methods including American Dental Association (ADA), The Center for Disease Control and Prevention (CDC) and contaminated > 100 CFU/ml(C-100) standards were used to assess the bacterial biofilm contamination of DUWLs. All studies that calculated the prevalence of bacterial biofilm contamination of DUWLs, and English full-text studies were included in the meta-analysis. Studies that did not have relevant data or used unusual laboratory methods were excluded. Methodological risk of bias was assessed by a related checklist and finally, the data were pooled by fixed or random-effect models.

RESULTS

Seven hundred and thirty-six studies were identified and screened and 26 related studies were included in the meta-analysis. The oldest included study was published in 1976 and the most recent study was published in 2020. According to the ADA, CDC and C-100 standards, the prevalence of bacterial contamination was estimated to be 85.0% (95% confidence interval (CI): 66.0-94.0%), 77.0% (95%CI: 66.0-85.0%) and 69.0% (95%CI: 67.0-71.0%), respectively. The prevalence of Legionella Pneumophila and Pseudomonas Aeruginosa in DUWLs was estimated to be 12.0% (95%CI: 10.0-14.0%) and 8.0% (95%CI: 2.0-24.0%), respectively.

CONCLUSION

The results of this review study suggested a high prevalence of bacterial biofilm in DUWLs; therefore, the use of appropriate disinfecting protocol is recommended to reduce the prevalence of contamination and reduce the probable cross-infection.

Study design and rationale for the PAASIM project: a matched cohort study on urban water supply improvements and infant enteric pathogen infection, gut microbiome development and health in Mozambique

INTRODUCTION

Despite clear linkages between provision of clean water and improvements in child health, limited information exists about the health impacts of large water infrastructure improvements in low-income settings. Billions of dollars are spent annually to improve urban water supply, and rigorous evaluation of these improvements, especially targeting informal settlements, is critical to guide policy and investment strategies. Objective measures of infection and exposure to pathogens, and measures of gut function, are needed to understand the effectiveness and impact of water supply improvements.

METHODS AND ANALYSIS

In the PAASIM study, we examine the impact of water system improvements on acute and chronic health outcomes in children in a low-income urban area of Beira, Mozambique, comprising 62 sub-neighbourhoods and ~26 300 households. This prospective matched cohort study follows 548 mother-child dyads from late pregnancy through 12 months of age. Primary outcomes include measures of enteric pathogen infections, gut microbiome composition and source drinking water microbiological quality, measured at the child's 12-month visit. Additional outcomes include diarrhoea prevalence, child growth, previous enteric pathogen exposure, child mortality and various measures of water access and quality. Our analyses will compare (1) subjects living in sub-neighbourhoods with the improved water to those living in sub-neighbourhoods without these improvements; and (2) subjects with household water connections on their premises to those without such a connection. This study will provide critical information to understand how to optimise investments for improving child health, filling the information gap about the impact of piped water provision to low-income urban households, using novel gastrointestinal disease outcomes.

ETHICS AND DISSEMINATION

This study was approved by the Emory University Institutional Review Board and the National Bio-Ethics Committee for Health in Mozambique. The pre-analysis plan is published on the Open Science Framework platform (https://osf.io/4rkn6/). Results will be shared with relevant stakeholders locally, and through publications.

Unraveling the influence of human fecal pollution on antibiotic resistance gene levels in different receiving water bodies using crAssphage indicator gene

Discharged wastewater treatment plant (WWTP) effluents can contaminate receiving water bodies with human feces and alter the abundance of antibiotic resistance genes (ARGs). In this study, we examined the co-occurrence of ARGs, human fecal pollution indicator crAssphage, and antibiotics in human feces and a series of connected receiving water bodies affected by human feces, including water from different treatment units of a WWTP, river, lake, and tap waters. Results showed that crAssphage was detected in 68.2 % of the studied water bodies, confirming widespread human fecal contamination. Both ARG and crAssphage abundances exhibited a distance-decay effect from the emission source to the receiving environment. Interestingly, the detected ARG abundance in the water bodies was significantly correlated with crAssphage abundance but not with the residual antibiotic concentration, demonstrating that the presence of ARG could largely be explained by the extent of fecal pollution, with no clear signs of antibiotic selection. In addition, 14 ARGs co-shared by human feces and water bodies were significantly correlated with crAssphage. Furthermore, a close evolutionary relationship was observed between the bla_TEM-1 gene from human feces and aquatic environments. These results imply a potential ARG exchange between human feces and receiving water bodies. Overall, this study provides important insights into the distribution and sources of ARGs in water bodies affected by human fecal contamination.

Escherichia coli Contamination of Water for Human Consumption and Its Associated Factors in Peru: A Cross-Sectional Study

The objective of the study was to determine the factors associated with the presence of Escherichia coli contamination in water supplies for human consumption in Peru. A secondary analysis of the Food and Nutrition Surveillance by Life Stages survey (VIANEV) of 2017-2018 was performed. The presence of E. coli contamination in the water samples for human consumption of the households evaluated was defined as a dependent variable. A supply was considered contaminated when there was at least 1 colony-forming unit of E. coli in 100 mL of water for human consumption. Data from 886 participants were analyzed. It was found that 25.2% of household water supply sources for human consumption had E. coli at the time of sampling. Water reservoirs such as buckets or other containers (adjusted prevalence ratio [aPR]: 1.15; 95% confidence interval [CI]: 1.18-1.93), households belonging to a poor wealth quintile (aPR: 1.82; 95% CI: 1.01-3.25), residing in a rural area (aPR: 1.36; 95% CI: 1.01-1.83), and having a low human development index (aPR: 2.12; 95% CI: 1.15-3.91) were more likely to contain E. coli in water supplies for human consumption. However, households with chlorine concentrations of 0.5 mg/L or more in water (aPR: 0.20; 95% CI: 0.11-0.33) and with household members with a higher education (aPR: 0.67; 95% CI: 0.45-0.99) were less likely to contain E. coli in drinking-water supplies. From 2017 to 2018, one in four Peruvians had contamination by E. coli in the water supply to their homes, which was associated with sociodemographic factors, management, and water treatment.

Cefsulodin and Vancomycin: A Supplement for Chromogenic Coliform Agar for Detection of Escherichia coli and Coliform Bacteria from Different Water Sources

Background microorganism growth on Chromogenic Coliform Agar (CCA) can be challenging. For this reason, a new alternative method with a Cefsulodin/Vancomycin (CV)-supplemented CCA should be developed in this study. CCA supplemented with CV was validated according to ÖNORM EN ISO 16140-4:2021 using water from natural sources in Styria, Austria. Results show that the alternative method using the supplemented CCA has similar values in relation to sensitivity (82.2%), specificity (98.6%) and higher selectivity (59%) compared to the reference method. Repeatability and reproducibility were acceptable for the alternative method and showed similar results with the reference method. The alternative method shows a very low false positive rate and a low false negative rate paired with good performance regarding the inclusion study. The exclusion study shows the advantage of our method by suppressing background microorganisms and facilitating the process of enumeration of Escherichia coli and other coliform bacteria on CCA plates. Aeromonas hydrophila and Pseudomonas aeruginosa growth was inhibited using the supplement. To conclude, the coliform CV selective supplement combined with CCA is an appropriate tool for coliform bacteria detection in water samples.

Endotoxin as a Marker for Water Quality

BACKGROUND

Water quality testing is vital to protect human health. Current testing relies mainly on culture-based detection of faecal indicator organisms such as Escherichia coli (E.coli). However, bacterial cultures are a slow process, taking 24-48 h and requiring specialised laboratories and trained personnel. Access to such laboratories is often sparse in developing countries and there are many fatalities deriving from poor water quality. Endotoxin is a molecular component of Gram-negative bacterial cell walls and can be used to detect their presence in drinking water.

METHOD

The current study used a novel assay (BacterisK) to rapidly detect endotoxin in various water samples and correlate the results with E. coli content measured by culture methods. The data generated by the BacterisK assay are presented as an 'endotoxin risk' (ER).

RESULTS

The ER values correlate with E. coli and thus endotoxin can be used as a marker of faecal contamination in water. Moreover, the BacterisK assay provides data in near real-time and can be used in situ allowing water quality testing at different spatial and temporal locations.

CONCLUSION

We suggest that BacterisK can be used as a convenient risk assessment tool to assess water quality where results are required quickly or access to laboratories is lacking.

Identification of high nitrate concentration in shallow groundwater of an arid region: a case study of South Kuwait's Bay

Coastal aquifer is a fragile environment due to the interaction of groundwater with seawater, especially in arid environments. Groundwater along Kuwait's Bay is polluted due to discharge of waste from desalination plants, power plants, and other anthropogenic activities. Earlier studies on submarine groundwater discharge in Kuwait's Bay region have reported the transfer of nutrient flux from the groundwater to Kuwait's Bay. The current study focused on nitrate sources and processes governing their distribution in groundwater samples collected from the southern part of Kuwait's Bay. The concentration of nitrate in the samples ranged from 22.7 to 803.9 mg/L. Higher values were noted in the samples collected inland and a few samples adjacent to the Bay. Spearman's correlation analysis of the data indicated that NO₃- has a strong positive correlation with SO₄^2- and moderate positive correlation with Na ⁺ , TDS/EC. The PCA analysis and factor scores revealed the different sources for groundwater nitrate contamination as follows: leakage of sewer lines in the urban region has led to the infiltration of contaminated sewage, high saline environment due to seawater intrusion, chemical weathering, and influence of denitrifying bacteria. The health risk has resulted due to the NO_3- concentration being above the standard limit for adults. Furthermore, the nitrate concentration was higher in the region adjoining the landfills. In addition, the discharge of groundwater with higher nitrate to the adjacent open water in the Bay may lead to eutrophication. Hence, proper management strategies are to be adopted to control the nitrate pollution in groundwater.

Food, water, and sanitation insecurities: Complex linkages and implications for achieving WASH security

Food, water and sanitation insecurities are complex, multi-dimensional phenomena that entail more than availability and access; food, water, and sanitation resources must be safe and culturally appropriate. Researchers and implementers concerned with these insecurities have demonstrated that there are notable interactions between them resulting in significant psychological and biological outcomes. Recent randomised controlled trials (RCTs) in Bangladesh, Kenya (WASH Benefits) and Zimbabwe (SHINE) demonstrated no effect from water, sanitation and hygiene (WASH) interventions on linear growth, and mixed evidence on enteropathogen burden and risk of diarrhoea in young children. These data suggest a need for a more comprehensive understanding of WASH security. The risks posed by multiple resource insecurities shift depending on the individual, their movement throughout their day, their economically and socially prescribed roles, and ecological features such as seasonality and precipitation. By more fully integrating food, water and sanitation security in interventions and subsequent impact evaluations, we can achieve WASH security-one that addresses myriad transmission pathways and co-occurring diseases-that ultimately would improve health outcomes throughout the world. In this critical review, we outline the complexity of combined resource insecurities as a step towards transformative WASH.

Assessment of water, sanitation, and hygiene services in district health care facilities in rural area of Mekong Delta, Vietnam

Access to sufficient water, sanitation, and hygiene (WASH) services is a crucial requirement for patients during therapy and general well-being in the hospital. However, in low- and middle-income countries, these services are often inadequate, resulting in increased morbidity and mortality of patients. This study aimed at assessing the current situation of WASH services in six District Health Care Facilities (DHCFs) in rural areas of the Mekong Delta provinces, Vietnam. The results showed that these services were available with inappropriate quality, which did not compromise the stakeholders' needs. The revealed WASH infrastructures have raised concerns about the prolonged hospital stays for patients and push nosocomial infections to a high level. The safety of the water supply was doubted as the high E. coli (> 60%) and total coliform incidence (86%) was observed with very low residual chlorine concentration (< 0.1 mg/L) in water quality assessment. Moreover, water supply contained a high concentration of iron (up to 15.55 mg/L) in groundwater in one DHCF. Technical assessment tool analysis proved that the improper management and lack of knowledge by human resources were the primary roots of the observed status WASH services. Improvement of the perceptions of WASH should be done for the hospital staff with collaboration and support from the government to prevent incidents in the future.

High Prevalence of Chemical and Microbiological Drinking Water Contaminants in Households with Infants Enrolled in a Birth Cohort-Piura, Peru, 2016

Chemical and microbiological drinking water contaminants pose risks to child health but are not often evaluated concurrently. At two consecutive visits to 96 households in Piura, Peru, we collected drinking water samples, administered health and exposure questionnaires, and collected infant stool samples. Standard methods were used to quantify heavy metals/metalloids, pesticides, and Escherichia coli concentrations in water samples. Stool samples were assayed for bacterial, viral, and parasitic enteropathogens. The primary drinking water source was indoor piped water for 70 of 96 households (73%); 36 households (38%) stored drinking water from the primary source in containers in the home. We found high prevalence of chemical and microbiological contaminants in household drinking water samples: arsenic was detected in 50% of 96 samples, ≥ 1 pesticide was detected in 65% of 92 samples, and E. coli was detected in 37% of 319 samples. Drinking water samples that had been stored in containers had higher odds of E. coli detection (adjusted odds ratio [aOR]: 4.50; 95% CI: 2.04-9.95) and pesticide detection (OR: 6.55; 95% CI: 2.05-21.0) compared with samples collected directly from a tap. Most infants (68%) had ≥ 1 enteropathogen detected in their stool. Higher odds of enteropathogen infection at the second visit were observed among infants from households where pesticides were detected in drinking water at the first visit (aOR: 2.93; 95% CI: 1.13-7.61). Results show concurrent risks of exposure to microbiological and chemical contaminants in drinking water in a low-income setting, despite high access to piped drinking water.

Global occurrence of SARS-CoV-2 in environmental aquatic matrices and its implications for sanitation and vulnerabilities in Brazil and developing countries

This paper includes a systematic review of the SARS-CoV-2 occurrence in environmental aquatic matrices and a critical sanitation analysis. We discussed the interconnection of sanitation services (wastewater, water supply, solid waste, and stormwater drainage) functioning as an important network for controlling the spread of SARS-CoV-2 in waters. We collected 98 studies containing data of the SARS-CoV-2 occurrence in aquatic matrices around the world, of which 40% were from developing countries. Alongside a significant number of people infected by the virus, developing countries face socioeconomic deficiencies and insufficient public investment in infrastructure. Therefore, our study focused on highlighting solutions to provide sanitation in developing countries, considering the virus control in waters by disinfection techniques and sanitary measures, including alternatives for the vulnerable communities. The need for multilateral efforts to improve the universal coverage of sanitation services demands urgent attention in a pandemic scenario.

Virulence markers, adhesion and biofilm formation of Escherichia coli strains isolated from drinking water supplies of north Paraná State, Brazil

Waterborne diseases are a major public health problem responsible for a high number of deaths worldwide, of which Escherichia coli is a major agent of contamination. This study investigates the occurrence of different diarrheagenic E. coli (DEC) pathotypes and its relationship with adherence patterns and biofilm formation. Between 2012 and 2014, a total of 1,780 drinking water samples were collected from different rural communities and urban water systems of north Paraná State. A total of 14% were positive for E. coli and 250 non-duplicate E. coli isolates were obtained. Between the E. coli isolates, 28 (11.2%) harbored DEC-associated genes, 10.7% being classified as Shiga toxin-producing E. coli (STEC), 64.3% enteroaggregative E. coli (EAEC) and 25% atypical enteropathogenic E. coli (aEPEC). The aggregative adherence (AA) was the predominant adherence pattern (84%), significantly associated with biofilm formation (p < 0.0001). On the other hand, the AA pattern and biofilm formation were not significantly associated to DEC pathotypes (p > 0.05). Therefore, we proposed that the AA pattern and biofilm formation in E. coli isolated from drinking water supplies could be associated with adherence and colonization of abiotic surfaces, such as pipes, leading to persistence and resistance to treatment or disinfection.

Prevalence and Antimicrobial Resistance of Escherichia coli in Chicken Meat and Edible Poultry Organs Collected from Retail Shops and Supermarkets of North Western Province in Sri Lanka

Escherichia coli is a commensal bacterium that lives in human and animal intestines. Shiga toxin-producing strains of E. coli STECs are responsible for most food-related E. coli infections. Pathogenic E. coli transmits to human bodies due to the consumption of contaminated, raw, or undercooked food. This study was conducted to identify the prevalence of E. coli contamination in edible poultry meat and meat organs in the North Western Province of Sri Lanka. A total of 250 samples consisting of chicken meat (n = 144) and edible organs (n = 106) were collected from retail shops (n = 181) and supermarkets (n = 69), in both Kurunegala and Puttlam districts. The prevalence of E. coli from 250 chicken meat samples was 66.80% (167/250); E. coli prevalence at retail shops (66.85%) was higher than that at supermarkets (66.67%) and was not statistically significant. E. coli prevalence in chicken meat and edible organs was 65.73% and 69.16%, respectively. Molecular confirmation for the positive samples was done through polymerase chain reaction (PCR) using previously designed primers. An antibiotic susceptibility test was performed according to CLSI using nine antibiotics: ampicillin, amoxicillin, chloramphenicol, ceftazidime, ciprofloxacin, cephalexin, erythromycin, gentamicin, and tetracycline. Most isolates were resistant to erythromycin (80.84%) and amoxicillin (76.05%), while the least resistance was observed for gentamicin (4.79%). This study indicates the potential public health risk associated with chicken sold at retail and supermarket levels in the North Western Province of Sri Lanka.

A continuous, in-situ, near-time fluorescence sensor coupled with a machine learning model for detection of fecal contamination risk in drinking water: Design, characterization and field validation

We designed and validated a sensitive, continuous, in-situ, remotely reporting tryptophan-like fluorescence sensor and coupled it with a machine learning model to predict high-risk fecal contamination in water (>10 colony forming units (CFU)/100mL E. coli). We characterized the sensor's response to multiple fluorescence interferents with benchtop analysis. The sensor's minimum detection limit (MDL) of tryptophan dissolved in deionized water was 0.05 ppb (p <0.01) and its MDL of the correlation to E. coli present in wastewater effluent was 10 CFU/100 mL (p <0.01). Fluorescence response declined exponentially with increased water temperature and a correction factor was calculated. Inner filter effects, which cause signal attenuation at high concentrations, were shown to have negligible impact in an operational context. Biofouling was demonstrated to increase the fluorescence signal by approximately 82% in a certain context, while mineral scaling reduced the sensitivity of the sensor by approximately 5% after 24 hours with a scaling solution containing 8 times the mineral concentration of the Colorado River. A machine learning model was developed, with TLF measurements as the primary feature, to output fecal contamination risk levels established by the World Health Organization. A training and validation data set for the model was built by installing four sensors on Boulder Creek, Colorado for 88 days and enumerating 298 grab samples for E. coli with membrane filtration. The machine learning model incorporated a proxy feature for fouling (time since last cleaning) which improved model performance. A binary classification model was able to predict high risk fecal contamination with 83% accuracy (95% CI: 78% - 87%), sensitivity of 80%, and specificity of 86%. A model distinguishing between all World Health Organization established risk categories performed with an overall accuracy of 64%. Integrating TLF measurements into an ML model allows for anomaly detection and noise reduction, permitting contamination prediction despite biofilm or mineral scaling formation on the sensor's lenses. Real-time detection of high risk fecal contamination could contribute to a major step forward in terms of microbial water quality monitoring for human health.

Detection of Escherichia coli, rotavirus, and Cryptosporidium spp. from drinking water, kitchenware, and flies in a periurban community of Lusaka, Zambia

Fecal contamination with a poor water, sanitation and hygiene environment in urban informal settlements poses diarrhea risks. Little information is available on the contamination of environmental media with enteric pathogens in such settlements. We investigated the contamination of Escherichia coli, rotavirus, and Cryptosporidium spp. in water, on kitchenware, and on flies in urban informal settlements of Chawama and Kanyama, Lusaka, Zambia. These environmental media were examined by XM-G agar cultivation for E. coli and specific real-time RT-PCR assays to detect rotavirus and Cryptosporidium spp. E. coli; rotavirus, and Cryptosporidium spp. were detected in samples of household stored drinking water (6 of 10 samples, 3 of 10 samples, and 2 of 10 samples, respectively), cups (10 of 20 samples, 2 of 13 samples, 1 of 13 samples, respectively), and flies (35 of 55 samples, 5 of 17 samples, 1 of 17 samples, respectively). The ranges of rotavirus concentrations in household stored drinking water, on cups, and flies were 2.9 × 10²-2.2 × 10⁵ copies/L, 1.2 × 10²-4.3 × 10² copies/cup, and 5.0 × 10¹-2.0 × 10² copies/fly, respectively. These results indicate the contribution of drinking water and kitchenware to enteric pathogen exposure and potential role of flies in microbial transmission.

Associated factors of the co-occurrence of trachoma and soil-transmitted helminthiases in children 1 to 9 years old in rural communities of the Amazon basin in Loreto Department, Peru: Results from a population-based survey

BACKGROUND

There is evidence of the occurrence of trachoma in Peru, and studies have shown that soil-transmitted helminthiases (STH) are affecting rural communities in the Amazon basin in Loreto Department. This study was done to estimate trachoma prevalence, STH prevalence, and the associated factors for both diseases in children aged 1-9 years in rural communities of Peru.

METHODOLOGY

A population-based cross-sectional survey was carried out in rural communities of Loreto. A standardized survey questionnaire with individual and household risk factors related to both diseases was used. Ocular examination was done for all participants aged one year and above, and eye swab samples were collected from children with follicular trachoma (TF). Anthropometric measurements, stool samples for STH, and blood samples for hemoglobin measurement were taken from children.

PRINCIPAL FINDINGS

TF prevalence was 7.74% (95% CI 5.08-11.63%), STH prevalence was 49.49% (95% CI 25.00-52.43%), and prevalence of co-occurrence of both diseases was 5.06% (95% CI 2.80-8.98%) in children aged 1-9 years. Being at age 3-8 years old (AOR = 6.76; 95% CI 1.346-33.947), have an unclean face (AOR = 24.64; 95% CI 6.787-89.444), and having been dewormed in the last six months (AOR = 2.47; 95% CI 1.106-5.514), were risk factors of TF. Being a female (AOR = 0.22; 95% CI 0.103-0.457) was associated with decreased odds of TF. Having been dewormed in the last six months (AOR = 0.30; 95% CI 0.139-0.628) was a preventative factor for STH. Risk factors for children with both diseases mirrored the findings for risk factors for individual diseases.

CONCLUSIONS

Neglected tropical diseases and associated risk factors overlap in communities living in vulnerable conditions in the Amazon basin of Peru. These findings support the need to implement integrated interventions, including mass drug administration, water, sanitation, and hygiene for both diseases in the study area.

Engineering Biomimetic Extracellular Matrix with Silica Nanofibers: From 1D Material to 3D Network

Biomaterials at nanoscale is a fast-expanding research field with which extensive studies have been conducted on understanding the interactions between cells and their surrounding microenvironments as well as intracellular communications. Among many kinds of nanoscale biomaterials, mesoporous fibrous structures are especially attractive as a promising approach to mimic the natural extracellular matrix (ECM) for cell and tissue research. Silica is a well-studied biocompatible, natural inorganic material that can be synthesized as morpho-genetically active scaffolds by various methods. This review compares silica nanofibers (SNFs) to other ECM materials such as hydrogel, polymers, and decellularized natural ECM, summarizes fabrication techniques for SNFs, and discusses different strategies of constructing ECM using SNFs. In addition, the latest progress on SNFs synthesis and biomimetic ECM substrates fabrication is summarized and highlighted. Lastly, we look at the wide use of SNF-based ECM scaffolds in biological applications, including stem cell regulation, tissue engineering, drug release, and environmental applications.

Evaluation of Drinking Water Quality and Bacterial Antibiotic Sensitivity in Wells and Standpipes at Household Water Points in Freetown, Sierra Leone

Water quality surveillance can help to reduce waterborne diseases. Despite better access to safe drinking water in Sierra Leone, about a third of the population (3 million people) drink water from unimproved sources. In this cross-sectional study, we collected water samples from 15 standpipes and 5 wells and measured the physicochemical and bacteriological water quality, and the antimicrobial sensitivity of Escherichia coli (E. coli) in two communities in Freetown, Sierra Leone in the dry and wet seasons in 2021. All water sources were contaminated with E. coli, and all five wells and 25% of standpipes had at least an intermediate risk level of E. coli. There was no antimicrobial resistance detected in the E. coli tested. The nitrate level exceeded the WHO’s recommended standard (>10 parts per million) in 60% of the wells and in less than 20% of the standpipes. The proportion of samples from standpipes with high levels of total dissolved solids (>10 Nephelometric Turbidity Units) was much higher in the rainy season (73% vs. 7%). The level of water contamination is concerning. We suggest options to reduce E. coli contamination. Further research is required to identify where contamination of the water in standpipes is occurring.

Communicating Water, Sanitation, and Hygiene under Sustainable Development Goals 3, 4, and 6 as the Panacea for Epidemics and Pandemics Referencing the Succession of COVID-19 Surges

WASH (water, sanitation, and hygiene) has become the most crucial amenity in the past decade for every individual on the planet. In the UN agenda for 2030, which created 17 Sustainable Development Goals (SDGs), SDGs 3, 4, and 6 directly correlate with WASH practices and management for creating a good health hygiene environment for all. The dearth of WASH facilities has created barriers for averting the transmission of COVID-19, motivating the concept of WASH as the primary step of precaution and prevention, which includes WASH practices, communication for literacy, and positive behavioral changes primarily in developing and low-income countries. This Review deals with the complex concept of correlation of WASH and SDGs 3, 4, and 6 while defining elaborate WASH practices, including the prominence of clean water, the need for sanitation facilities, and health hygiene for good health and immunity for preparedness for and during epidemics and pandemics. Certain risk factors explain the sectors in which the gaps exist, creating a gap for implementation of WASH practices in epidemics and pandemics across the globe. Further, COVID-19 surge succession is presented along with data of different variants that have occurred. The need of WASH understanding is required using different tools (audio-visual, social media, print media, and mass media) and strategies (communication, advocacy, and positive behavioral changes) for every individual as an act to counter consequences during and after the COVID-19 pandemic and as a routine practice for future preparedness. This Review gives a detailed concept of WASH understanding for every sector from community to government agencies and research professionals to act immediately for the sustainable future of humanity.

Differences in levels of E. coli contamination of point of use drinking water in Bangladesh

This study aimed to quantify the inequalities and identify the associated factors of the UN sustainable development goal (SDG) targets in relation to safe drinking water. The concentration of the gut bacterium Escherichia coli in drinking water at the point of use (POU) and other information were extracted from the latest wave of the nationally representative Bangladesh Multiple Indicator Cluster Survey (MICS 2019). Bivariate and multivariable multinomial logistic regression models were used to identify potential predictors of contamination, whereas, classification trees were used to determine specific combinations of background characteristics with significantly higher rates of contamination. A higher risk of contamination from drinking water was observed for households categorized as middle or low wealth who collected water from sources with higher concentrations of E. coli. Treatment of drinking water significantly reduced the risk of higher levels of contamination, whereas owning a pet was significantly associated with recontamination. Regional differences in the concentrations of E. coli present in drinking water were also observed. Interventions in relation to water sources should emphasize reducing the level of E. coli contamination. Our results may help in developing effective policies for reducing diarrheal diseases by reducing water contamination risks.

Adapting sanitary inspections for the monitoring of small drinking water supplies in Iceland

Sanitary inspections (SIs) are checklists of questions used to identify actual and potential sources and pathways of drinking water contamination. Though the importance of SI adaptation to local contexts is widely acknowledged, there is currently limited guidance on how this should be undertaken in practice. During this research, World Health Organization (WHO) draft template SI forms for spring and borehole supplies were adapted for use in Iceland based on a series of desk reviews and field tests, an approach which may guide other future SI adaptation processes. SI results were collected from 25 spring supplies and nine borehole supplies in three regions of Iceland using adapted SI forms. These results were combined with 10-year historical water quality data from the same supplies to explore potential relationships between both data sets. Binary logistic regression test results indicated a statistically significant association (P = 0.025; odds ratio (OR) 1.864, 95% CI 1.080-3.220) between SI Question 3 (Does ponding from surface water occur around the spring/borehole?) receiving a 'High' risk level assignment and at least one historical incidence of water quality noncompliance for the parameters heterotrophic plate count 22 °C, total coliforms, Escherichia coli, and turbidity at the same supply. The significant modifications applied to the starting template during the testing and development of the Icelandic SI form emphasises the importance of a robust adaptation process to ensure SI forms are appropriate for the local context. Results from the analysis of SI and water quality test results demonstrated the potential for these data sets to identify the primary risks at a supply. This information may then be used to direct remedial actions, especially when the amount of relevant data increases over time.

Effect of School Water, Sanitation, and Hygiene on Health Status Among Basic Level Students' in Nepal

BACKGROUND

Access to drinking Water, Sanitation, and Hygiene (WASH) at schools are the basic determinants of a child's right to healthy and quality education. In Nepal, most of the schools had limited WASH facilities, including separate sanitation facilities for girls. The limited WASH facilities, unsafe drinking water, poor sanitation, and hygiene practices result in irresponsible behaviors that directly impede on students' health. This study examines the association between WASH services and health status of basic level students', ranging sixth to eighth grades. In Nepal, basic level education consists up to eighth standards from grade 1.

METHODS

The study applies causal-comparative research design within 2 groups; 1 having improved WASH and another without improved WASH services at the schools in Dhanusha and Chitwan districts of Nepal. Each group consists 2 schools, so altogether 4 schools were included in this study. Total 768, equal 384 respondents were selected from each improved and without improved WASH facilities. The study was conducted in between January and March 2021 at a single-phase time. The sample size was calculated using the standard statistical formula for the infinite population. The study applied quantitative research method, including 3 sorts of analysis; univariate, bivariate, and the multivariate. The univariate was applied to analyze the frequency and percentages of the respondents. Bivariate analysis was made applying chi² test in order to show the association between 2 variables, whereas the multivariate logistic regression was performed through multilevel modeling to show the effects of school WASH facilities on students' health status.

RESULTS

Out of 768 students', 384 (50%) were from improved and 384 (50%) were from unimproved WASH facilities at schools. More than two third (64%) of respondents from the unimproved and higher than two fifth (41%) from the improved schools got sickness (P <.001). Further, three fifth (59%) of respondents aged 15 to 19 and higher than half (51%) of respondents ages of 10 to 14 years got sickness (P <.05). Most (57%) of the female respondents had sickness compared to males (47%), (P <.05). More than two-thirds (67%) of respondents from Dalit and nearly two-thirds (62%) of respondents from Brahmin/Chhetri-Terai more often found being sick in unimproved schools compared to other castes (55%), Janajati (43%), and Brahmin/Chhetri-Hill (39%) (P <.001). The school WASH services has significant effect (cOR = 0.388, CI; 290-0.519, P <.001) on students health status, even adjusting other socio-covariates (aOR = .442, CI; 0.302-0.646, P <.001). The female respondents were more likely to fall sick (aOR = 678, CI; 0.502-0.915, P <.01) compared to the male respondents keeping all other variables constant in the model.

CONCLUSION

The study recommends to extend WASH awareness program to school families, particularly to the students as there is an evident need to increase preventive as well as the therapeutic efficacy of the potential infections.

Water, Sanitation, and Hygiene Service Ladders and Childhood Diarrhea in Haramaya Demographic and Health Surveillance Site, Eastern Ethiopia

BACKGROUND

The WHO/UNICEF Joint Monitoring Program (JMP) service ladders are worldwide indicators for monitoring drinking water, sanitation, and hygiene elements of the sustainable development goal targets. However, evidence on how the prevalence of childhood diarrhea looks across the service ladders is limited. This study aimed to assess the relationship between WASH service ladders and the prevalence of childhood diarrhea in Haramaya Demographic and Health Surveillance site, Eastern Ethiopia.

METHODS

A cross-sectional study using a structured questionnaire, observational checklist, and water quality analysis was conducted on 535 households with children under 5 years of age. Poisson regression with a robust error variance estimator was used to investigate the relationship between dependent and independent variables.

RESULTS

The prevalence of diarrhea among under-five children in the surveillance site was 24.8% (95% CI: 22.3-27.6). The regression model revealed that water and sanitation service ladders were associated with childhood diarrhea. Childhood diarrhea was found to be 73% (APR = 0.27; 95% CI: 0.12-0.57) less common in families with a basic water service ladder than in households with a surface water service ladder. In addition, children in households with basic sanitation services had 83% (APR = 0.17; 95% CI: 0.05-0.56) lower diarrhea prevalence than children in households where open defecation was practiced.

CONCLUSION

The present study found that childhood diarrhea differed considerably among WASH service levels and continues to be a serious health problem at the surveillance site. This study also shows that much work is needed to improve WASH services.

Spatial Distribution and Determinant Factors of Handwashing Practice With Essential Agents Among Households in Ethiopia

Objectives: This study aimed to assess the spatial distribution and determinant factors of handwashing practice using essential handwashing agents (soap and water) among households in Ethiopia.

Methods: A two-stage stratified cluster sampling technique was used. Mixed-effect logistic regression analysis was also used to identify determinants of handwashing practice with essential agents.

Results: In Ethiopia, household handwashing practices with essential agents had spatial variation (Moran’s Index 0.62, p < 0.001). The Amhara and Somali regions were identified as significant hotspots with low handwashing practice using essential agents.

Conclusion: In Ethiopia, handwashing practice with essential agents showed spatial variation across the country with a very low rate. Areas with low handwashing practice with essential agents need high priority in the allocation of resources to ensure communities’ access to fixed and portable handwashing facilities, soap, and reliable water supplies. Households with low access to improved sanitation facilities, low wealth status, and low educational status should be targeted for the intervention.

Water quality assessment and evaluation of human health risk of drinking water from source to point of use at Thulamela municipality, Limpopo Province

Water quality has been linked to health outcomes across the world. This study evaluated the physico-chemical and bacteriological quality of drinking water supplied by the municipality from source to the point of use at Thulamela municipality, Limpopo Province, South Africa; assessed the community practices regarding collection and storage of water and determined the human health risks associated with consumption of the water. Assessment of water quality was carried out on 114 samples. Questionnaires were used to determine the community’s practices of water transportation from source to the point-of-use and storage activities. Many of the households reported constant water supply interruptions and the majority (92.2%) do not treat their water before use. While E. coli and total coliform were not detected in the water samples at source (dam), most of the samples from the street taps and at the point of use (household storage containers) were found to be contaminated with high levels of E. coli and total coliform. The levels of E. coli and total coliform detected during the wet season were higher than the levels detected during the dry season. Trace metals’ levels in the drinking water samples were within permissible range of both the South African National Standards and World Health Organisation. The calculated non-carcinogenic effects using hazard quotient toxicity potential and cumulative hazard index of drinking water through ingestion and dermal pathways were less than unity, implying that consumption of the water could pose no significant non-carcinogenic health risk. Intermittent interruption in municipal water supply and certain water transportation and storage practices by community members increase the risk of water contamination. We recommend a more consistent supply of treated municipal water in Limpopo province and training of residents on hygienic practices of transportation and storage of drinking water from the source to the point of use.

Water Access and Adherence Intention Among HIV-Positive Pregnant Women and New Mothers Receiving Antiretroviral Therapy in Zambia

Background

Mother-to-infant transmission of HIV is a major problem in Sub-Saharan Africa despite free or subsidized antiretroviral treatment (ART), but is significantly reduced when mothers adhere to ART. Because potable water access is limited in low-resource countries, we investigated water access and ART adherence intention among HIV-positive pregnant women and new mothers in Zambia.

Methods

Our convenience sample consisted of 150 pregnant or postpartum women receiving ART. Descriptive statistics compared type of water access by low and high levels of ART adherence intention.

Results

Most (71%) had access to piped water, but 36% of the low-adherence intention group obtained water from a well, borehole, lake or stream, compared to only 22% of the high-adherence intention group. The low-adherence intention group was more rural (62%) than urban (38%) women but not statistically significant [unadjusted Prevalence Ratio (PR) 0.73, 95% CI: 0.52-1.02; adjusted PR 1.06, 95% CI: 0.78-1.45].

Conclusion

Providing potable water may improve ART adherence. Assessing available water sources in both rural and urban locations is critical when educating women initiating ART.

Prevalence and Correlates of Water, Sanitation, and Hygiene (WASH) and Spatial Distribution of Unimproved WASH in Nepal

This study aims to estimate the prevalence and correlation of household levels of water, sanitation, and hygiene (WASH), including the identification of areas where WASH facilities are unimproved in Nepal. The study population was 11,040 household heads, using the data collected in the Nepal Demographic and Health Survey 2016. Logistic regression analysis was performed and crude odds ratios (OR) with 95% confidence intervals (CI) using a 0.05 significance level are presented. Getis–Ord Gi* statistics were used to identify the hot and cold spot areas of unimproved WASH. GPS locations of WASH points were used for spatial analysis. Approximately 95% of households had an improved water source, 84% had improved sanitation facilities, 81% had a fixed place for handwashing, and 47% had soap and water. Education, wealth, and ecology were significantly associated with WASH. The people from the hills were less likely to have an improved water source (OR = 0.32; 95% CI: 0.16–0.64) than those from the plain. Households with a poor wealth index had 78% lower odds of having an improved water source compared to households with a rich wealth index. Respondents from Madhes Province had lower odds (OR = 0.15; 95% CI: 0.08–0.28) and Gandaki Pradesh had the highest odds (OR = 2.92; 95% CI: 1.52–5.61) of having improved sanitation facilities compared to Province 1. Respondents aged 35–44 years had higher odds (OR = 1.16; 95% CI: 1.04–1.29) of having soap and water available compared to those aged 45 years and older. Education and geographical disparities were the factors associated with having reduced access to WASH. These findings suggest the need to focus on advocacy, services, and policy approaches.

Modeling Exposure to Fecal Contamination in Drinking Water due to Multiple Water Source Use

The Joint Monitoring Programme estimated that 71% of people globally had access to "safely managed" drinking water in 2017. However, typical data collection practices focus only on a household's primary water source, yet some households in low- and middle-income countries (LMICs) engage in multiple water source use, including supplementing improved water supplies with unimproved water throughout the year. Monte Carlo simulations and previously published data were used to simulate exposure to fecal contamination (as measured by E. coli) along a range of supplemental unimproved source use rates (e.g., 0-100% improved water use, with the remainder made up with unimproved water). The model results revealed a statistically significant increase in annual exposure to E. coli when individuals supplement their improved water with unimproved water just 2 days annually. Additionally, our analysis identified scenarios-realistic for the data set study setting-where supplementing with unimproved water counterintuitively decreases exposure to E. coli. These results highlight the need for evaluating the temporal dynamics in water quality and availability of drinking water sources in LMICs as well as capturing the use of multiple water sources for monitoring global access to safe drinking water.

Hygiene in early childhood development centres in low-income areas of Blantyre, Malawi

Diarrhoeal disease remains a leading cause of death in children in sub-Saharan Africa, attributed to environmental health factors such as inadequate water, sanitation and hygiene (WASH) and food hygiene. This formative study in low-income areas of Blantyre focussed on the practices in Early Childhood Development Centre (ECDCs) environments where children spend a significant amount of time. A mixed-methods approach was applied to identify key hygiene behaviours in ECDCs through; checklist and structured observations (n = 849 children; n = 33 caregivers), focus group discussions (n = 25) and microbiological sampling (n = 261) of drinking water, food handler's hands, and eating utensils. ECDCs had inadequate WASH infrastructure; coupled with poor hygiene practices and unhygienic environments increased the risk of faecal-oral disease transmission. Presence of E. coli in drinking water confirmed observed poor water handling habits by staff and children. Addressing undesired hygiene practices in ECDCs has the potential to improve the health outcomes of children in low-income settings.

Mapping and Visualizing Global Knowledge on Intermittent Water Supply Systems

Intermittent water supply systems (IWSSs) are prevalent in most developing countries and some developed ones. Their usage is driven by necessity rather than as a principal objective, mostly due to technical and economic deficiencies. Major health risks and socio-economic inequities are associated with such systems. Their impacts are aggravated by climate changes and the COVID-19 crisis. These are likely to have profound implications on progress toward advancing sustainable development goals (SDGs). Motivated by providing a comprehensive overview of global knowledge on IWSSs, the present work proposed to track and analyze research works on IWSSs utilizing bibliometric techniques and visual mapping tools. This includes investigating the trends and growth trajectories of research works on IWSSs and analyzing the various approaches proposed to expand our understanding with respect to the management, modeling, optimization, and impacts of IWSSs. The national and international contributions and collaboration figures are further analyzed at country, institution, author, and source levels. This analysis indicates that research works conducted on IWSSs have certain expectations in terms of productivity (total global productivity; 197 documents). The United States was the best country in terms of productivity (58 documents; 29.4%), while the Water Switzerland journal was the most productive journal (19 documents; 9.6%). The impacts of IWSSs on health and well-being have attracted considerable attention. The outcomes showed deep and justified worries in relation to the transition from intermittent to continuous supply, equity, and mitigating the health risks associated with IWSSs in the foreseen future. The utilization of artificial intelligence techniques and expert systems will drive and shape future IWSS-related research activities. Therefore, investments in this regard are crucial.

Outbreak of acute gastroenteritis associated with drinking water in rural Kazakhstan: A matched case-control study

We conducted an outbreak investigation from June 3 to 15th in a rural village in northern Kazakhstan, after surveillance showed an increase in gastroenteritis. Cases were residents who presented for medical treatment for diarrhea, fever (>37.5 °C), vomiting, or weakness from May 14 to June 15, 2021. Controls were residents matched by age ±2 years at a ratio of two controls for every case. Cases and controls were interviewed using structured questionnaires. We abstracted clinical data from medical records. We mapped cases and assessed risk for disease using conditional multivariable logistic regression. We identified 154 cases of acute gastroenteritis (attack rate of ~26 per 1,000 inhabitants). Symptoms were diarrhea, fever, vomiting, weakness, and decreased appetite. Among cases that participated (n = 107), 74% reported having drank unboiled tap water vs 18% of controls (n = 219). This was the only risk factor associated with disease (adjusted odds ratio: 18; 95% CI 9-35). Drinking water from a dispenser or carbonated drinks was protective. The city has two water supply networks; cases were clustered (107 cases in 79 households) in one. The investigation found that monitoring of quality and safety of water according to national regulations had not been conducted since 2018. No fatalities occurred, and no associated cases were reported after our investigation. Results suggest that untreated tap water was the probable source of the outbreak. The water supply had been cleaned and disinfected twice by the facility 2 days before our investigation began. Recommendations were made for regular monitoring of water supply facilities with rapid public notification when issues are detected to reduce likelihood of future drinking water associated outbreaks.

Seasonal Variability Influence on the Prevalence of Diarrhoea among Under-Five-Year-old Children in Kersa District, Eastern Ethiopia: A Community-Based Longitudinal Study

BACKGROUND

The health effects of climate change have been found to be a global concern for the last 2 centuries. However, the effect of climate variability on diarrhoea among under-five-year-old children is perhaps undocumented or otherwise unknown. The aim of the present study was to determine the effect of climate variability on diarrhoea among children under 5 years of age.

METHODS

A community-based longitudinal study was conducted over 8 repeated visits from June 2016 to May 2018 at the Kersa Demographic Surveillance and Health Research Center. A total of 500 randomly selected households and their 48 improved water sources were included in the survey from 3 agro-ecological zones, the rural and urban areas of the study area. Data was collected on household characteristics, diarrhoea, WASH practices, water quality and quantity in households, and improved water sources. A structured pre-tested questionnaire, an observational check list and laboratory tests were used for data collection. The data was entered into Epi Data Version 3.01 and transferred to Stata Version 12 for analysis. Multilevel mixed-effect Poisson regression was used to determine the relationship between predictors and outcome variables. A P-value of less than .05 was the cut-off point for statistically significant.

RESULTS

The prevalence of diarrhoea in 2 weeks among children under 5 years of age was 17.2% (95% CI: 15.8-19.71). Rainfall, E. coli contamination of drinking water at the source and in the home, 20 L of water consumption per capita per day, sharing water sources with animals and home water treatment by residents of the mid- and lowlands were all predictors of diarrhoea. The space-time scan statistic confirmed that child diarrhoea had random variation in both space and time.

CONCLUSION

Climate variability has influenced the prevalence of diarrhoea among under-five-year-old children. Climate-resilient measures should be taken to reduce the burden of diarrhoea in the community.