Ingestion of Fecal Bacteria along Multiple Pathways by Young Children in Rural Bangladesh Participating in a Cluster-Randomized Trial of Water, Sanitation, and Hygiene Interventions (WASH Benefits)

Efficient disinfection of real toilet blackwater by ultraviolet/peracetic acid process: Selective intracellular biomolecular oxidation

Toilet blackwater (BW) disinfection is crucial for preventing microbial contamination but is hindered by its complex composition. This study explored the combined ultraviolet and peracetic acid (UV/PAA) process as a novel strategy for BW disinfection. The UV/PAA process effectively inactivated Fecal coliform (1.372 × 10-5 s-2) in real BW, despite presence of turbidity, suspended solids, and organic matter, which could hinder disinfection. The highly electrophilic PAA and acetoxy(peroxy) radicals were identified as crucial contributors to bacterial inactivation. Biochemical analysis and Density Functional Theory calculations revealed that the system primarily operates through selective intracellular biomolecular oxidation. Electrophilic species preferentially oxidized amino acids with highly local nucleophilicity index, particularly those containing sulfur or nitrogen moieties. This selective oxidation caused protein denaturation, inducing cells into a viable but non-culturable (VBNC) state. Meanwhile, the membrane integrity and metabolic activity was preserved, while oxidative stress and DNA disruption effectively limited bacterial regrowth, proving that this process selectively damages intracellular biomolecules, such as amino acids and DNA. Additionally, the process significantly reduced the abundance of gut microbiota and other pathogens in real BW, highlighting its broad-spectrum antimicrobial efficacy. The UV/PAA process represented a sustainable and eco-friendly advanced disinfection solution for BW treatment.

Assessing E. coli levels in surface soils of informal settlements using boot sock and standard grab methods

Rapid urbanization leads to the growth of informal settlements, where inadequate sanitation infrastructure is common, thus promoting environmental contamination and risk of gastrointestinal infection. Soil contamination contributes to the transmission of enteropathogens, but traditional sampling approaches may poorly indicate public health risks due to limited spatial representation. This study compares traditional grab sampling of soil with a boot sock method, a composite technique designed to better reflect human-pathogen interactions. The boot sock method provided more sensitive detection of E. coli and lower inter-replicate variation compared to grab samples. Post hoc power analyses indicated that the boot sock technique required fewer samples to achieve adequate spatial representation across a sampling area than grab samples, potentially improving time and cost efficiency in pathogen exposure risk estimation.

Effects of household concrete floors on maternal and child health: the CRADLE trial - a randomised controlled trial protocol

INTRODUCTION

Early life soil-transmitted helminth (STH) infection and diarrhoea are associated with growth faltering, anaemia, impaired child development and mortality. Exposure to faecally contaminated soil inside the home may be a key contributor to enteric infections, and a large fraction of rural homes in low-income countries have soil floors. The objective of this study is to measure the effect of installing concrete floors in homes with soil floors on child STH infection and other maternal and child health outcomes in rural Bangladesh.

METHODS AND ANALYSIS

The Cement-based flooRs AnD chiLd hEalth trial is an individually randomised trial in Sirajganj and Tangail districts, Bangladesh. Households with a pregnant woman, a soil floor, walls that are not made of mud and no plan to relocate for 3 years will be eligible. We will randomise 800 households to intervention or control (1:1) within geographical blocks of 10 households to account for strong geographical clustering of enteric infection. Laboratory staff and data analysts will be blinded; participants will be unblinded. We will instal concrete floors when the birth cohort is in utero and measure outcomes at child ages 3, 6, 12, 18 and 24 months. The primary outcome is prevalence of any STH infection (Ascaris lumbricoides, Necator americanus or Trichuris trichiura) detected by quantitative PCR at 6, 12, 18 or 24 months follow-up in the birth cohort. Secondary outcomes include household floor and child hand contamination with Escherichia coli, extended-spectrum beta-lactamase producing E. coli and STH DNA; child diarrhoea, growth and cognitive development; and maternal stress and depression.

ETHICS AND DISSEMINATION

Study protocols have been approved by institutional review boards at Stanford University and the International Centre for Diarrheal Disease Research, Bangladesh. We will report findings on ClinicalTrials.gov, in peer-reviewed publications and in stakeholder workshops in Bangladesh.

TRIAL REGISTRATION NUMBER

NCT05372068.

Dirt floors and domestic animals are associated with soilborne exposure to antimicrobial resistant E. coli in rural Bangladeshi households

Soil can harbor enteropathogens and antimicrobial-resistant organisms in settings with domestic animals. We enrolled 49 households with young children (28 soil floors, 21 concrete floors) in Bangladesh and recorded animal ownership/management. Staff swabbed the floor of children's sleeping area with a sterile sponge and collected floor dust and a child hand rinse. We used IDEXX QuantiTray/2000 with and without cefotaxime supplementation to enumerate cefotaxime-resistant and generic E. coli . There was 8.0 g/m 2 of dust on soil floors vs. 0.2 g/m 2 on concrete floors (p-value=0.005). We detected E. coli on 100% of soil vs. 86% of concrete floors and cefotaxime-resistant E. coli on 89% of soil vs. 43% of concrete floors (p-values<0.05). Cefotaxime-resistant E. coli prevalence on floors was 36% in compounds without animals, 79% in compounds with animals and 100% if animals stayed indoors overnight or the floor had animal feces; associations were strongest for chickens. In multivariable models, generic and cefotaxime-resistant E. coli counts were 1.5-2 log higher on soil vs. concrete floors, and counts on floors and child hands were 0.17-0.24 log higher for every 10 additional chickens owned (p-values<0.05). Efforts to mitigate infections and antimicrobial resistance in low-income countries should test flooring improvements and hygienic animal management.

Synopsis

In rural Bangladeshi households, generic and cefotaxime-resistant E. coli were more common on soil floors than concrete floors and among households with higher cohabitation intensity with domestic animals, especially chickens.

Associations between weather extremes and faecal contamination along pathogen transmission pathways in rural Bangladeshi households: a prospective observational study

BACKGROUND

Weather extremes are predicted to influence pathogen exposure but their effects on specific faecal-oral transmission pathways are not well investigated. We evaluated associations between extreme rain and temperature during different antecedent periods (0-14 days) and Escherichia coli along eight faecal-oral pathways in rural Bangladeshi households.

METHODS

We used data from the WASH Benefits Bangladesh cluster-randomised controlled trial (NCT01590095). E coli was enumerated in hand rinses from children younger than 5 years and their mothers, food, stored drinking water, tubewells, captured flies, ponds, and courtyard soil using IDEXX Quanti-Tray/2000 in nine rounds over 3·5 years and spatiotemporally matched to daily weather data. We used generalised linear models with robust standard errors to estimate E coli count ratios (ECRs) associated with extreme rain and temperature, defined as greater than the 90th percentile of daily values during the study period.

FINDINGS

A total of 26 659 samples were collected during the study period. Controlling for temperature, extreme rain on the sampling day was associated with increased E coli in food (ECR=3·13 [95% CI 1·63-5·99], p=0·0010), stored drinking water (ECR=1·98 [1·36-2·88], p=0·0004), and ponds (ECR=3·46 [2·34-5·11], p<0·0001), and reduced E coli in soil (ECR=0·36 [0·24-0·53], p<0·0001). Extreme rain the day before sampling was associated with reduced E coli in tubewells (ECR=0·10 [0·02-0·62], p=0·014). Associations were similar for rainfall 1-7 days before sampling and slightly attenuated for rainfall 14 days before sampling. Controlling for rainfall, extreme temperature on the sampling day was associated with increased E coli in stored drinking water (ECR=1·49 [1·05-2·12], p=0·025) and food (ECR=3·01 [1·51-6·01], p=0·0020). Associations with temperature were similar for all antecedent periods and particularly pronounced for food. Neither rainfall nor temperature were consistently associated with E coli on hands and flies.

INTERPRETATION

In rural Bangladesh, measures to control enteric infections following weather extremes should focus on water treatment and safe storage to reduce contamination of drinking water and food stored at home and on reducing exposure to surface waters.

FUNDING

Bill & Melinda Gates Foundation, National Institutes of Health, World Bank.

Pathogens and Antimicrobial Resistance Genes in Household Environments: A Study of Soil Floors and Cow Dung in Rural Bangladesh

In low- and middle-income countries, living in homes with soil floors and animal cohabitation may expose children to fecal organisms, increasing risk of enteric and antimicrobial-resistant infections. Our objective was to understand whether cow cohabitation in homes with soil floors in rural Bangladesh contributed to the presence and diversity of potential pathogens and antimicrobial resistance genes (ARGs) in the home. In 10 randomly selected households in rural Sirajganj District, we sampled floor soil and cow dung, which is commonly used as sealant in soil floors. We extracted DNA and performed shotgun metagenomic sequencing to explore potential pathogens and ARGs in each sample type. We detected 6 potential pathogens in soil only, 49 pathogens in cow dung only, and 167 pathogens in both soil and cow dung. Pathogen species with relative abundances >5% in both soil floors and cow dung from the same households included E. coli (N=8 households), Salmonella enterica (N=6), Klebsiella pneumoniae (N=2), and Pseudomonas aeruginosa (N=1). Cow dung exhibited modestly higher pathogen genus richness compared to soil floors (Wilcoxon signed-rank test p=0.002). Using Bray-Curtis dissimilarity, pathogen species community composition differed between floors and cow dung (PERMANOVA p<0.001). All soil floors and cow dung samples contained ARGs against antibiotic classes including sulfonamides, rifamycin, aminoglycosides, lincosamides, and tetracycline. Paired floor and cow dung samples shared ARGs against rifamycin. Our findings support the development of interventions to reduce soil and animal feces exposure in rural, low-income settings.

Impact of integrated WASH and maternal and child health interventions on diarrhea disease prevalence in a resource-constrained setting in Kenya

BACKGROUND

Water, sanitation and hygiene (WASH) and child health interventions are proven simple and cost-effective strategies for preventing diarrhea and minimizing excess mortality. Individually, they are able to prevent diarrhea though sub-optimally, and their effectiveness when combined may be higher. This study examined the effect of integrated WASH and maternal and child health (MCH) interventions on prevalence of diarrhea, in a resource-limited setting in Kenya.

METHODS

A controlled intervention was implemented in Narok County. The interventions included WASH interventions integrated with promotion of MCH. A structured questionnaire was used to collect data on targeted indicators before and after the interventions. Data were analyzed using descriptive statistics and Chi-square to establish the impact of the interventions.

RESULTS

A total of 431and 424 households and 491 and 487 households in intervention and control sites, respectively, participated in the baseline and endline surveys. Following implementation of the interventions, prevalence of diarrhea decreased by 69.1% (95% CI: 49.6-87.1%) and 58.6% (95% CI: 26.6-82.4%) in the intervention and control site, respectively. Treatment of drinking water and animal husbandry practices were significantly associated with diarrhea post-interventions.

CONCLUSIONS

Integrating WASH interventions with other diarrhea control strategies and contextualizing them to meet site-specific needs may effectively prevent diarrhea.

Effects of household concrete floors on maternal and child health - the CRADLE trial: a randomised controlled trial protocol

Introduction

Early life soil-transmitted helminth infection and diarrhea are associated with growth faltering, anemia, impaired child development, and mortality. Exposure to fecally contaminated soil inside the home may be a key contributor to enteric infections, and a large fraction of rural homes in low-income countries have soil floors. The objective of this study is to measure the effect of installing concrete floors in homes with soil floors on child soil-transmitted helminth infection and other maternal and child health outcomes in rural Bangladesh.

Methods and analysis

The Cement-based flooRs AnD chiLd hEalth (CRADLE) trial is an individually randomised trial in Sirajganj and Tangail districts, Bangladesh. Households with a pregnant woman, a soil floor, walls that are not made of mud will be eligible, and no plan to relocate for 3 years. We will randomise 800 households to intervention or control (1:1) within geographic blocks of 10 households to account for strong geographic clustering of enteric infection. Laboratory staff and data analysts will be blinded; participants will be unblinded. We will install concrete floors when the birth cohort is in utero and measure outcomes at child ages 3, 6, 12, 18, and 24 months. The primary outcome is prevalence of any soil-transmitted helminth infection (Ascaris lumbricoides, Necator americanus, or Trichuris trichiura) detected by qPCR at 6, 12, 18, or 24 months follow-up in the birth cohort. Secondary outcomes include household floor and child hand contamination with E. coli, extended-spectrum beta-lactamase producing E. coli, and soil-transmitted helminth DNA; child diarrhea, growth, and cognitive development; and maternal stress and depression.

Ethics and dissemination

Study protocols have been approved by institutional review boards at Stanford University and the International Centre for Diarrheal Disease Research, Bangladesh (icddr,b). We will report findings on ClinicalTrials.gov, in peer-reviewed publications, and in stakeholder workshops in Bangladesh.

Trial registration number

NCT05372068, pre-results.

Identifying Potential Determinants of Faecal Contamination on Domestic Floors in Three Settings in Rural Kenya: A Mixed Methods Analysis

Observational evidence suggests that household floors may be an important domain for the transmission of enteric and parasitic infections. However, little work has been done to investigate how household floors can become contaminated with human and animal faeces. This study uses a mixed methods approach to postulate the proximal and distal determinants of household floor contamination with faeces in groups of rural villages in 3 counties in Kenya (Bungoma, Kwale and Narok). Quantitative data was collected through a household census and analysed descriptively and using mixed effects logistic regression models. Qualitative data was collected through unstructured observations of daily routines and in-depth interviews. These data were analysed thematically with case memos produced for routine activities that were hypothesised to be determinants of floor contamination. Possible proximal determinants of floor contamination included; (1) animal contact with floors; (2) child faeces disposal, and; (3) floor cleaning routines. Distal determinants are suggested to be rooted in the socioeconomic, environmental, and cultural context in which households were located and included; (1) the type and number of animals owned by households; (2) presence/absence of dedicated shelters for housing animals at night, which impacted whether sleeping or cooking areas were exposed to animals; (3) Accessibility of inside spaces to poultry and other roaming animals; (4) ownership of an improved floor; (5) ability of animals to access neighbours compounds; (6) seasonal changes in weather. These results will be of use in identifying the contexts in which faecal contamination of domestic floors may be contributing towards transmission of enteric and parasitic infections and in designing effective interventions to prevent this exposure.

Animal Handling Practice Among Rural Households in Northwest Ethiopia Increases the Risk of Childhood Diarrhea and Exposure to Pathogens From Animal Sources

Background

In Ethiopia, domestic animals and their feces are not properly contained. However, the risk of exposure to zoonotic pathogens is not well documented. This study was conducted to assess animal handling practices and the risk of childhood diarrhea among rural households in northwest Ethiopia.

Methods

This study was done among 403 randomly selected households. Information on animal handling was collected using a questionnaire and spot-check observation. The occurrence of childhood diarrhea in 14 days prior to the survey was assessed based on the reports of female head of households. Multivariable binary logistic regression analysis was performed to identify the association between animal handling practices and childhood diarrhea.

Results

All the female head of households had contact with animal feces when preparing fuel disks and plastering the house components with animal dung. Domestic animals shared a corral within the living space of the humans in 20% of the households. Animals entered the human living quarters and accessed foods in 32% of the households. Moreover, 24% of the children aged 24 to 59 months had diarrhea in a 2-week period prior to the survey. Childhood diarrhea was associated with domestic animals sharing the same house as humans (AOR: 3.3, 95% CI: 1.3, 8.6), presence of animal excreta in child playing areas (AOR: 2.4, 95% CI: 1.2, 4.6), contact of domestic animals with stored foods (AOR: 3.5, 95% CI: 2.0, 5.9), trapped dirt under fingernails of female heads (AOR: 3.7, 95% CI: 1.9, 7.5), open defecation (AOR: 3.24, 95% CI: 1.8, 5.9), and unprotected sources (AOR: 4.2, 95% CI: 1.1, 15.3).

Conclusion

Domestic animals and their excreta are not hygienically contained in the area. Animal handling practices including their excreta and the hygiene behavior of female head of households (eg, handwashing and food handling practices) should be improved to prevent childhood diarrhea.

Trans-cinnamaldehyde fumigation inhibits Escherichia coli by affecting the mechanism of intracellular biological macromolecules

This study aimed to determine the antibacterial mechanism of cinnamaldehyde fumigation in Escherichia coli (E. coli). Through vapour fumigation, cinnamaldehyde was confirmed to exhibit effective antibacterial activity against E. coli. The minimum inhibitory concentration (MIC) and minimum bacterial concentration (MBC) were 0.25 μL/mL and 0.5 μL/mL, respectively. Based on transmission electron microscopy, the wrinkled bacterial cells observed after fumigation could be related to the leakage of intracellular substances. Laser tweezers Raman spectroscopy revealed changes in the main chain of proteins, the hydrogen bond system and spatial structure, and single- and double-stranded DNA breaks. In addition, breakage of the fatty acyl chain backbone was found to affect the vertical order degree of the lipid bilayer and cell membrane fluidity, thereby inhibiting the growth of E. coli. Overall, our findings indicate that cinnamaldehyde fumigation inhibits E. coli growth by inducing changes in intracellular biological macromolecules.

Assessment of water, hygiene, and sanitation practice and associated factors among Bihari refugee camp in Bangladesh: A cross-sectional study

Background and Aims

The global significance of water, sanitation, and hygiene (WASH) cannot be overstated, extending far beyond the confines of developing nations and encompassing even the most developed ones. This study, rooted in the Bihari refugee camp in Bangladesh, seeks to underscore the universality of WASH concerns.

Methods

Using a cross-sectional design and a structured questionnaire, we conducted a meticulous evaluation of WASH practices with 313 participants selected through random sampling.

Results

Findings shows the water practice, among all of them, only 4.8% of the respondents were very happy with the water supply system and 16.0% of the respondents were happy with this. A total of 29.7% of the respondents were satisfied with safe drinking water and only 4.8% of the respondents were very satisfied with safe drinking water. Regarding the hygiene practice, among all respondents, 10.2% of them were satisfied with using the same bathroom by multiple people. Only 5.4% respondents were happy in their living environment. Regarding sanitation practice, only 31.3% had private toilet facilities. Among all of the respondents, 13.7% of the respondents were satisfied with using the same toilet by multiple people. Respondents who were illiterate (p < 0.01) and self-employed (p < 0.04) were satisfied with the water supply. Similarly, respondents who were illiterate (p < 0.03) and self-employed (p < 0.00) were satisfied with safe drinking water. Respondents who were illiterate (p < 0.02) and whose monthly income was below 8000 BDT (p < 0.00) were satisfied using same bathroom by multiple people. Respondents who were self-employed (p < 0.01), whose monthly income 8000-12,000 BDT (p < 0.01) and having single room (p < 0.00) were satisfied using the same toilet by multiple people.

Conclusion

Enhanced access to safe WASH facilities, coupled with a comprehensive understanding of the study's findings, have the potential to serve as vital signposts for the development and implementation of policies and interventions.

Risk factors for extended-spectrum beta-lactamase (ESBL)-producing E. coli carriage among children in a food animal-producing region of Ecuador: A repeated measures observational study

BACKGROUND

The spread of antibiotic-resistant bacteria may be driven by human-animal-environment interactions, especially in regions with limited restrictions on antibiotic use, widespread food animal production, and free-roaming domestic animals. In this study, we aimed to identify risk factors related to commercial food animal production, small-scale or "backyard" food animal production, domestic animal ownership, and practices related to animal handling, waste disposal, and antibiotic use in Ecuadorian communities.

METHODS AND FINDINGS

We conducted a repeated measures study from 2018 to 2021 in 7 semirural parishes of Quito, Ecuador to identify determinants of third-generation cephalosporin-resistant E. coli (3GCR-EC) and extended-spectrum beta-lactamase E. coli (ESBL-EC) in children. We collected 1,699 fecal samples from 600 children and 1,871 domestic animal fecal samples from 376 of the same households at up to 5 time points per household over the 3-year study period. We used multivariable log-binomial regression models to estimate relative risks (RR) of 3GCR-EC and ESBL-EC carriage, adjusting for child sex and age, caregiver education, household wealth, and recent child antibiotic use. Risk factors for 3GCR-EC included living within 5 km of more than 5 commercial food animal operations (RR: 1.26; 95% confidence interval (CI): 1.10, 1.45; p-value: 0.001), household pig ownership (RR: 1.23; 95% CI: 1.02, 1.48; p-value: 0.030) and child pet contact (RR: 1.23; 95% CI: 1.09, 1.39; p-value: 0.001). Risk factors for ESBL-EC were dog ownership (RR: 1.35; 95% CI: 1.00, 1.83; p-value: 0.053), child pet contact (RR: 1.54; 95% CI: 1.10, 2.16; p-value: 0.012), and placing animal feces on household land/crops (RR: 1.63; 95% CI: 1.09, 2.46; p-value: 0.019). The primary limitations of this study are the use of proxy and self-reported exposure measures and the use of a single beta-lactamase drug (ceftazidime with clavulanic acid) in combination disk diffusion tests for ESBL confirmation, potentially underestimating phenotypic ESBL production among cephalosporin-resistant E. coli isolates. To improve ESBL determination, it is recommended to use 2 combination disk diffusion tests (ceftazidime with clavulanic acid and cefotaxime with clavulanic acid) for ESBL confirmatory testing. Future studies should also characterize transmission pathways by assessing antibiotic resistance in commercial food animals and environmental reservoirs.

CONCLUSIONS

In this study, we observed an increase in enteric colonization of antibiotic-resistant bacteria among children with exposures to domestic animals and their waste in the household environment and children living in areas with a higher density of commercial food animal production operations.

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

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

The effect of a large-scale water, sanitation and hygiene intervention in Bangladesh on knowledge, behaviour and health: Findings from an endline programme evaluation

OBJECTIVES

The Sanitation, Hygiene Education and Water Supply in Bangladesh Programme (SHEWA-B) was a 5-year intervention aiming to improve water, sanitation and hygiene (WASH) practices among 20 million rural residents through community hygiene promoters. This analysis evaluates the impact of SHEWA-B on knowledge, behaviour and childhood diarrhoea outcomes.

METHODS

The evaluation included repeated cross-sectional surveys and health surveillance in matched cohorts in intervention and control clusters. Cross-sectional surveys and structured observations at baseline, midline, and endline assessed the availability of WASH technology, caregiver knowledge and behaviour. Fieldworkers collected monthly health data in a subset of control and intervention households to determine the prevalence of diarrhoea.

RESULTS

Of 5091 households surveyed, participants residing in intervention clusters showed minimal improvements in knowledge, reported behaviour, or use of WASH technology compared to the control clusters. During structured observations, intervention households increased more than control households at handwashing before preparing food and after cleaning a baby's anus when comparing endline to baseline, but these changes were not seen when comparing endline to the midline. The prevalence of childhood diarrhoea remained similar in both groups before (10.2% in intervention, 10.0% in control) and after (8.8% in intervention, 11.7% in control) midline changes were made to improve the intervention. Intervention clusters showed no improvement in diarrhoea over time compared to control clusters.

CONCLUSIONS

SHEWA-B's community-based WASH promotion did not yield the intended impact on knowledge, behaviour or health. Greater priority should be given to approaches that have demonstrated effectiveness. Including rigorous evaluations would broaden the evidence base to support and improve large-scale programmes.

Exploring the determinants and indicators of poultry feces management behaviors in rural Western Uganda

Animal ownership has reported financial and nutritional benefits but has also been associated with enteric and respiratory infections, and inadequate sanitation and hygiene can lead to children touching and ingesting animal fecal matter. We identified key indicators for poultry feces management and investigated their social determinants using data from a baseline survey of a randomized-controlled trial of a poultry management training program in rural Western Uganda. The baseline survey was conducted in the Masindi and Kiryandongo districts of Uganda in September 2019, and data collected from 609 households were used. We evaluated indicators for poultry feces management behaviors using scale development methods, including descriptive statistics, bivariate correlation analyses, and Factor Analysis of Mixed Data. We also investigated social determinants of key poultry feces management behaviors using logistic and multinomial logistic regression models. A significant increase in odds of having free-roaming poultry was found for each additional poultry owned (OR = 1.18, P < 0.001). The odds of a household having an observed enclosure for poultry increased by 5% with each incremental poultry owned (OR = 1.05, P < 0.001), and by 4% with increasing wealth with each additional point on the poverty probability index score (OR = 1.04, P < 0.001). Our results also suggest enclosures are intermittently used and constructing them without further intervention likely will not be sufficient for effectively managing animal fecal contamination. We recommend that future studies on animal feces management measure indicators for corralling and feces disposal practices and evaluate their relationship to enteric pathogen exposure and health outcomes. Insights from this work can inform the development of robust indicators of poultry feces management behaviors that can be used for monitoring and evaluation purposes.

Characterizing Behaviors Associated with Enteric Pathogen Exposure among Infants in Rural Ecuador through Structured Observations

The relative importance of environmental pathways that results in enteropathogen transmission may vary by context. However, measurement of contact events between individuals and the environment remains a challenge, especially for infants and young children who may use their mouth and hands to explore their environment. Using a mixed-method approach, we combined 1) semistructured observations to characterize key behaviors associated with enteric pathogen exposure and 2) structured observations using Livetrak, a customized software application, to quantify the frequency and duration of contacts events among infants in rural Ecuador. After developing and iteratively piloting the structured observation instrument, we loaded the final list of prompts onto a LiveTrak pallet to assess environmental exposures of 6-month infants (N = 19) enrolled in a prospective cohort study of diarrheal disease. Here we provide a detailed account of the lessons learned. For example, in our field site, 1) most mothers reported washing their hands after diaper changes (14/18, 77.8%); however only a third (4/11, 36.4%) were observed washing their hands; 2) the observers noted that animal ownership differed from observed animal exposure because animals owned by neighboring households were reported during the observation; and 3) using Livetrak, we found that infants frequently mouthed their hands (median = 1.9 episodes/hour, median duration: 1.6 min) and mouthed surroundings objects (1.8 episodes/hour, 1.9 min). Structured observations that track events in real time, can complement environmental sampling, quantitative survey data and qualitative interviews. Customizing these observations enabled us to quantify enteric exposures most relevant to our rural Ecuadorian context.

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.

Narrative Review of Primary Preventive Interventions against Water-Borne Diseases: Scientific Evidence of Health-EDRM in Contexts with Inadequate Safe Drinking Water

Waterborne diseases account for 1.5 million deaths a year globally, particularly affecting children in low-income households in subtropical areas. It is one of the most enduring and economically devastating biological hazards in our society today. The World Health Organization Health Emergency and Disaster Risk Management (health-EDRM) Framework highlights the importance of primary prevention against biological hazards across all levels of society. The framework encourages multi-sectoral coordination and lessons sharing for community risk resilience. A narrative review, conducted in March 2021, identified 88 English-language articles published between January 2000 and March 2021 examining water, sanitation, and hygiene primary prevention interventions against waterborne diseases in resource-poor settings. The literature identified eight main interventions implemented at personal, household and community levels. The strength of evidence, the enabling factors, barriers, co-benefits, and alternative measures were reviewed for each intervention. There is an array of evidence available across each intervention, with strong evidence supporting the effectiveness of water treatment and safe household water storage. Studies show that at personal and household levels, interventions are effective when applied together. Furthermore, water and waste management will have a compounding impact on vector-borne diseases. Mitigation against waterborne diseases require coordinated, multi-sectoral governance, such as building sanitation infrastructure and streamlined waste management. The review showed research gaps relating to evidence-based alternative interventions for resource-poor settings and showed discrepancies in definitions of various interventions amongst research institutions, creating challenges in the direct comparison of results across studies.

Impact of an Urban Sanitation Intervention on Enteric Pathogen Detection in Soils

Environmental fecal contamination is common in many low-income cities, contributing to a high burden of enteric infections and associated negative sequelae. To evaluate the impact of a shared onsite sanitation intervention in Maputo, Mozambique on enteric pathogens in the domestic environment, we collected 179 soil samples at shared latrine entrances from intervention (n = 49) and control (n = 51) compounds during baseline (preintervention) and after 24 months (postintervention) as part of the Maputo Sanitation Trial. We tested soils for the presence of nucleic acids associated with 18 enteric pathogens using a multiplex reverse transcription qPCR platform. We detected at least one pathogen-associated gene target in 91% (163/179) of soils and a median of 3 (IQR = 1, 5) pathogens. Using a difference-in-difference analysis and adjusting for compound population, visibly wet soil, sun exposure, wealth, temperature, animal presence, and visible feces, we estimate the intervention reduced the probability of detecting ≥1 pathogen gene by 15% (adjusted prevalence ratio, aPR = 0.85; 95% CI: 0.70, 1.0) and the total number of pathogens by 35% (aPR = 0.65; 0.44, 0.95) in soil 24 months following the intervention. These results suggest that the intervention reduced the presence of some fecal contamination in the domestic environment, but pathogen detection remained prevalent 24 months following the introduction of new latrines.

Fecal Contamination on the Household Compound and in Water Sources are Associated with Subsequent Diarrhea in Young Children in Urban Bangladesh (CHoBI7 Program)

We investigated the environmental and individual-level risk factors for diarrheal disease among young children in slum areas of Dhaka, Bangladesh. A prospective cohort study was conducted among 884 children under 5 years of age. Caregiver reports were collected on sociodemographic factors and hygiene behaviors. Diarrhea surveillance data was collected monthly based on caregiver-reported diarrhea for children in the past 2 weeks during the 12-month study period. Unannounced spot checks of the household compound were performed at 1, 3, 6, 9, and 12 months after enrollment to check for the presence of feces (animal or human) and the presence of animals in the child's sleeping space, to assess child and caregiver hands for the presence of dirt, and to collect samples of the household's source and stored drinking water. Children with feces found on the household compound during spot checks had a significantly higher odds of diarrhea (odds ratio: 1.71; 95% confidence interval: 1.23-2.38). Children residing in households with > 100 colony forming units/100 mL Escherichia coli in source drinking water had a significantly higher odds of diarrhea (OR: 1.43; 95% CI: 1.06-1.92). The presence of feces on the household compound and source drinking water with > 100 colony forming units/100 mL E. coli were significant risk factors for diarrheal disease for children < 5 years of age in slum areas of Dhaka, Bangladesh. These findings demonstrate the urgent need for comprehensive interventions to reduce fecal contamination on the household compound to protect the health of susceptible pediatric populations.

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

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

Quantitative Microbial Risk Assessment of Pediatric Infections Attributable to Ingestion of Fecally Contaminated Domestic Soils in Low-Income Urban Maputo, Mozambique

Rigorous studies of water, sanitation, and hygiene interventions in low- and middle-income countries (LMICs) suggest that children are exposed to enteric pathogens via multiple interacting pathways, including soil ingestion. In 30 compounds (household clusters) in low-income urban Maputo, Mozambique, we cultured Escherichia coli and quantified gene targets from soils (E. coli: ybbW, Shigella/enteroinvasive E. coli (EIEC): ipaH, Giardia duodenalis: β-giardin) using droplet digital PCR at three compound locations (latrine entrance, solid waste area, dishwashing area). We found that 88% of samples were positive for culturable E. coli (mean = 3.2 log10 CFUs per gram of dry soil), 100% for molecular E. coli (mean = 5.9 log10 gene copies per gram of dry soil), 44% for ipaH (mean = 2.5 log10), and 41% for β-giardin (mean = 2.1 log10). Performing stochastic quantitative microbial risk assessment using soil ingestion parameters from an LMIC setting for children 12-23 months old, we estimated that the median annual infection risk by G. duodenalis was 7100-fold (71% annual infection risk) and by Shigella/EIEC was 4000-fold (40% annual infection risk) greater than the EPA's standard for drinking water. Compounds in Maputo, and similar settings, require contact and source control strategies to reduce the ingestion of contaminated soil and achieve acceptable levels of risk.

Antimicrobial Resistance in Escherichia coli Strains Isolated from Humans and Pet Animals

Throughout scientific literature, we can find evidence that antimicrobial resistance has become a big problem in the recent years on a global scale. Public healthcare systems all over the world are faced with a great challenge in this respect. Obviously, there are many bacteria that can cause infections in humans and animals alike, but somehow it seems that the greatest threat nowadays comes from the Enterobacteriaceae members, especially Escherichia coli. Namely, we are witnesses to the fact that the systems that these bacteria developed to fight off antibiotics are the strongest and most diverse in Enterobacteriaceae. Our great advantage is in understanding the systems that bacteria developed to fight off antibiotics, so these can help us understand the connection between these microorganisms and the occurrence of antibiotic-resistance both in humans and their pets. Furthermore, unfavorable conditions related to the ease of E. coli transmission via the fecal-oral route among humans, environmental sources, and animals only add to the problem. For all the above stated reasons, it is evident that the epidemiology of E. coli strains and resistance mechanisms they have developed over time are extremely significant topics and all scientific findings in this area will be of vital importance in the fight against infections caused by these bacteria.