Child Mouthing of Feces and Fomites and Animal Contact are Associated with Diarrhea and Impaired Growth Among Young Children in the Democratic Republic of the Congo: A Prospective Cohort Study (REDUCE Program)

Perspective: Connecting the dots between domestic livestock ownership and child linear growth in low- and middle-income countries

Child stunting due to linear growth faltering remains a pervasive issue in low- and middle-income countries. Two schools of thought have existed pertaining to the role of domestic livestock ownership (DLO) in child linear growth. On one hand, it is argued that DLO leads to greater income and financial security, resulting in better child-raising conditions, including greater animal-source food (ASF) consumption, having protective effects towards child stunting. On the other hand, researchers argue that DLO contributes to faecal contamination and transmission of zoonotic enteric infections from animals to children, thus having destructive effects on child growth. Reviews of this association have revealed ambiguous findings. In this perspective, we argue that measuring the association between exposures to domesticated animals and child stunting is difficult and the ambiguous associations revealed are a result of confounding and differences in the management of DLO. We also argue that the increasingly prominent area of research of environmental enteric dysfunction, a sub-clinical condition of the small intestine thought to be due to frequent faecal pathogen exposure and associated with stunting, will be a useful tool to measure the potential destructive effects of DLO on child growth. We present our argument and identify challenges and considerations and directions for future research.

Is detection of enteropathogens and human or animal faecal markers in the environment associated with subsequent child enteric infections and growth: an individual participant data meta-analysis

BACKGROUND

Quantifying contributions of environmental faecal contamination to child diarrhoea and growth faltering can illuminate causal mechanisms behind modest health benefits in recent water, sanitation, and hygiene (WASH) trials. We aimed to assess associations between environmental detection of enteropathogens and human or animal microbial source tracking markers (MSTM) and subsequent child health outcomes.

METHODS

In this individual participant data meta-analysis we searched we searched PubMed, Embase, CAB Direct Global Health, Agricultural and Environmental Science Database, Web of Science, and Scopus for WASH intervention studies with a prospective design and concurrent control that measured enteropathogens or MSTM in environmental samples, or both, and subsequently measured enteric infections, diarrhoea, or height-for-age Z-scores (HAZ) in children younger than 5 years. We excluded studies that only measured faecal indicator bacteria. The initial search was done on Jan 19, 2021, and updated on March 22, 2023. One reviewer (AM) screened abstracts, and two independent reviewers (AM and RT) examined the full texts of short-listed articles. All included studies include at least one author that also contributed as an author to the present Article. Our primary outcomes were the 7-day prevalence of caregiver-reported diarrhoea and HAZ in children. For specific enteropathogens in the environment, primary outcomes also included subsequent child infection with the same pathogen ascertained by stool testing. We estimated associations using covariate-adjusted regressions and pooled estimates across studies.

FINDINGS

Data from nine published reports from five interventions studies, which included 8603 children (4302 girls and 4301 boys), were included in the meta-analysis. Environmental pathogen detection was associated with increased infection prevalence with the same pathogen and lower HAZ (ΔHAZ -0·09 [95% CI -0·17 to -0·01]) but not diarrhoea (prevalence ratio 1·22 [95% CI 0·95 to 1·58]), except during wet seasons. Detection of MSTM was not associated with diarrhoea (no pooled estimate) or HAZ (ΔHAZ -0·01 [-0·13 to 0·11] for human markers and ΔHAZ -0·02 [-0·24 to 0·21] for animal markers). Soil, children's hands, and stored drinking water were major transmission pathways.

INTERPRETATION

Our findings support a causal chain from pathogens in the environment to infection to growth faltering, indicating that the lack of WASH intervention effects on child growth might stem from insufficient reductions in environmental pathogen prevalence. Studies measuring enteropathogens in the environment should subsequently measure the same pathogens in stool to further examine theories of change between WASH, faecal contamination, and health. Given that environmental pathogen detection was predictive of infection, programmes targeting specific pathogens (eg, vaccinations and elimination efforts) can environmentally monitor the pathogens of interest for population-level surveillance instead of collecting individual biospecimens.

FUNDING

The Bill & Melinda Gates Foundation and the UK Foreign and Commonwealth Development Office.

Prevention of human exposure to livestock faecal waste in the household: a scoping study of interventions conducted in sub-Saharan Africa

BACKGROUND

Poorly managed animal faecal waste can result in detrimental environmental and public health implications. Limiting human exposure to animal waste through Animal inclusive Water Sanitation and Hygiene (A-WASH) strategies is imperative to improve public health in livestock keeping households but has received little attention to date. A small number of A-WASH interventions have previously been identified through a systematic review by another research team, and published in 2017. To inform intervention design with the most up-to-date information, a scoping study was conducted to map the existing evidence for A-WASH in sub-Saharan Africa (SSA) emerging since the previous review.

METHODS

This review followed PRISMA guidelines to identify interventions in SSA published between January 2016 to October 2022. Databases searched included PubMed, PMC Europe, CabDirect and Web of Science. Studies were eligible for inclusion if they were written in English and documented interventions limiting human contact with animal faecal material in the SSA context. Key data extracted included: the intervention itself, its target population, cost, measure of effectiveness, quantification of effect, assessment of success, acceptability and limitations. These data were synthesized into a narrative, structured around the intervention type.

FINDINGS

Eight eligible articles were identified. Interventions to reduce human exposure to animal faecal matter were conducted in combination with 'standard' human-centric WASH practices. Identified interventions included the management of human-animal co-habitation, educational programs and the creation of child-safe spaces. No novel A-WASH interventions were identified in this review, beyond those identified by the review in 2017. Randomised Controlled Trials (RCTs) were used to evaluate six of the eight identified interventions, but as effect was evaluated through various measures, the ability to formally compare efficacy of interventions is lacking.

CONCLUSION

This study indicates that the number of A-WASH studies in SSA is increasing and the use of RCTs suggests a strong desire to create high-quality evidence within this field. There is a need for standardisation of effect measures to enable meta-analyses to be conducted to better understand intervention effectiveness. Evaluation of scalability and sustainability of interventions is still lacking in A - WASH research.

Measurement in the study of human exposure to animal feces: A systematic review and audit

BACKGROUND

Human exposure to animal feces is increasingly recognized as an important transmission route of enteric pathogens. Yet, there are no consistent or standardized approaches to measurement of this exposure, limiting assessment of the human health effects and scope of the issue.

OBJECTIVE

To inform and improve approaches to the measurement of human exposure to animal feces, we audited existing measurement in low- and middle-income countries.

METHODS

We systematically searched peer-reviewed and gray literature databases for studies with quantitative measures of human exposure to animal feces and we classified measures in two ways. First, using a novel conceptual model, we categorized measures into three 'Exposure Components' identified a priori (i.e., Animal, Environmental, Human Behavioral); one additional Component (Evidence of Exposure) inductively emerged. Second, using the exposure science conceptual framework, we determined where measures fell along the source-to-outcome continuum.

RESULTS

We identified 1,428 measures across 184 included studies. Although studies overwhelmingly included more than one single-item measure, the majority only captured one Exposure Component. For example, many studies used several single-item measures to capture the same attribute for different animals, all of which were classified as the same Component. Most measures captured information about the source (e.g. animal presence) and contaminant (e.g. animal-sourced pathogens), which are most distal from exposure on the source-to-outcome continuum.

DISCUSSION

We found that measurement of human exposure to animal feces is diverse and largely distal from exposure. To facilitate better assessment of the human health effects of exposure and scope of the issue, rigorous and consistent measures are needed. We recommend a list of key factors from the Animal, Environmental, and Human Behavioral Exposure Components to measure. We also propose using the exposure science conceptual framework to identify proximal measurement approaches.

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.

Identifying psychosocial determinants of water, sanitation, and hygiene (WASH) behaviors for the development of evidence-based Baby WASH interventions (REDUCE program)

Diarrheal disease remains a leading cause of child mortality, globally. In the Democratic Republic of the Congo (DRC), each year there are an estimated 45 million episodes of diarrhea in children under five years of age. The Reducing Enteropathy, Diarrhea, Undernutrition, and Contamination in the Environment (REDUCE) program seeks to develop theory-driven, evidence-based approaches to reduce diarrheal diseases among young children. The REDUCE prospective cohort study in Walungu Territory in Eastern DRC took guidance from the risks, attitudes, norms, abilities, and self-regulation model, the integrated behavioral model for water, sanitation, and hygiene (WASH), and other behavior change theories to identify psychosocial factors associated with WASH behaviors. Psychosocial factors were measured among 417 caregivers at baseline and caregiver responses to child mouthing of dirty fomites and handwashing with soap was assessed by 5-hour structured observation at the 6-month follow-up. Caregivers who agreed that their child could become sick if they put dirt in their mouth (perceived susceptibility) and caregivers that agreed they could prevent their child from playing with dirty things outside (self-efficacy) were significantly more likely to stop their child from mouthing a dirty fomite. Higher perceived susceptibility, self-efficacy, and disgust, and lower dirty reactivity, were associated with higher handwashing with soap behaviors. This study took a theory-driven and evidence-based approach to identify psychosocial factors to target for intervention development. The findings from this study informed the development of the REDUCE Baby WASH Modules that have been delivered to over 1 million people in eastern DRC.

Twenty years of waterborne and related disease reports in Florida, USA

Florida represents a unique challenge for preventing and responding to infectious disease associated with water. This study cataloged the prevalence of reportable waterborne and water-related disease within Florida residents over the last twenty years and identified relationships between confirmed cases by location and additional risk factors. Data was collected through FLHealthCHARTS for confirmed cases between January 1, 1999 and December 31, 2019. Case records were compiled and analyzed by year, county, pathogen name and disease category, patient age, and where the infection was acquired. During this time, 218,707 cases of water-related disease were recorded with 214,745 due to waterborne disease, 3255 cases of water-related vector-borne disease, and 707 cases caused by a water-based toxin. Children aged 0–4 and the elderly demonstrated a higher proportion of waterborne disease while 45–49 year olds had increased rates of water-based toxins and water-related vector-borne disease. Most cases were reported in the southeast region. Across the state, opportunities for water contact have led to high rates of water-related infectious disease. Public health initiatives and response efforts should target the pathogens of greatest impact for each region, largely zoonotic waterborne diseases, using a One Health approach.

•

Over 200,000 cases of water-related disease have been reported to the Florida Department of Health over the last 20 years

•

Most reported disease is due to waterborne pathogens followed by water-related vector-borne disease and water-based toxins

•

Salmonellosis makes up the largest reported water-related disease burden for Florida

•

Children and seniors have higher risk for waterborne disease; adults have higher risk for toxins and vector-borne disease

•

Water disease prevention and response must use a One Health model for collaboration with human and animal health providers

The role of chicken management practices in children's exposure to environmental contamination: a mixed-methods analysis

BACKGROUND

Household chicken production presents an opportunity to promote child nutrition, but the benefits might be offset by increased environmental contamination. Using household surveys, direct observations, and in-depth interviews with woman caregivers, we sought to describe the relationship between chicken management practices and household exposure to environmental contamination, and assess barriers to adopting improved husbandry practices.

METHODS

First, we analyzed baseline data from 973 households raising chickens in the two interventions arms from the Agriculture-to-Nutrition (ATONU) study in Ethiopia to assess the relationship between animal management practices and environmental exposures. Second, we conducted six-hour direct observations of children's environmental exposures in 18 households. Among these households, we analyzed in-depth interviews with child caregivers.

RESULTS

Quantitative analyses showed that households raised approximately 11 chickens, had animal feces visible on the property 67% of the time, and children's hands were visibly dirty 38% of the time. Households with more chickens had lower exposure to animal feces. Having a chicken coop increased the risk of observing animal feces on the property by 30%, but among those with a coop, having an enclosed coop reduced that risk by 83%. Coops that were enclosed, had fencing, and were located further from homes were associated with a reduced risk of observing animal feces and an increased likelihood of children having clean hands. Direct observations showed that chicken coops were often poorly designed or not used. On average, 3 to 5 chickens were inside homes at a time, and livestock and domestic animals were frequently inside of houses and interacting with young children. In-depth interviews revealed that protection of animals, maintenance of household cleanliness and health, type of chicken (local versus improved) and resource constraints influenced management decisions.

CONCLUSIONS

Improvements in chicken management practices could mitigate the exposure of household members to environmental contamination. Our findings highlight the need for training and resources to promote safe animal husbandry practices and optimal child health in nutrition-sensitive livestock projects.

TRIAL REGISTRATION

Clinical trials number: NCT03152227 ; Retrospectively registered at ClinicalTrials.gov on May 12, 2012.

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.

Formative research for the development of baby water, sanitation, and hygiene interventions for young children in the Democratic Republic of the Congo (REDUCE program)

BACKGROUND

Research exploring the unique exposure pathways to fecal pathogens for young children and innovative water, sanitation, and hygiene (WASH) interventions for susceptible pediatric populations is needed to reduce the burden of diarrheal diseases and stunting globally. The Reducing Enteropathy, Diarrhea, Undernutrition, and Contamination in the Environment (REDUCE) program seeks to 1) identify exposure pathways to fecal pathogens that are significant contributors to morbidity for young children in South Kivu, Democratic Republic of the Congo, and 2) develop and evaluate scalable interventions that reduce fecal contamination and exposure from these pathways. The formative research portion of the project sought to identify feasible and acceptable WASH interventions to modify behaviors found to be associated with diarrheal disease and impaired growth in our REDUCE cohort study.

METHODS

Ninety-one semi-structured interviews, 6 focus group discussions, and a pilot study of 102 households were conducted during 24 months of formative research. Thirty-one interviews and six focus group discussions were conducted with caregivers, community health workers, and village leaders to explore existing WASH practices and to identify barriers and facilitators to WASH behaviors. Findings were organized using the Integrated Behavioral Model for Water, Sanitation and Hygiene to facilitate interpretation and identify determinants to Baby WASH behaviors in this setting. Care Group modules and enabling technology were developed based on exploratory findings and then revised during a two-part, iterative pilot study. Sixty interviews were conducted with participants in a pilot study of the REDUCE Baby WASH Care Group modules to learn about their experiences with the intervention.

RESULTS

Six REDUCE Baby WASH Care Group modules were developed based on formative research findings and covered the following topics: 1) living with animals; 2) child mouthing of fomites and feces; 3) composting animal feces; 4) child feces disposal; 5) handwashing with soap; and 6) water treatment.

CONCLUSION

This study took a theory-driven and evidence-based approach to formative research and the development of the REDUCE Baby WASH Care Group modules. Intervention design focused on interrupting the exposure routes for infants and young children to fecal pathogens in the environment and promoting low-cost, low-burden Baby WASH behavioral recommendations and enabling technology. These developed REDUCE Baby WASH Care Group modules are currently being rolled out to over 1,000,000 beneficiaries in Democratic Republic of the Congo.