Soil Ingestion is Associated with Child Diarrhea in an Urban Slum of Nairobi, Kenya

Water, Sanitation, and Hygiene Risk Factors on the Prevalence of Diarrhea among Under-Five Children in the Rural Community of Dangila District, Northwest Ethiopia

Background

Under-five diarrhea is one of the major causes of morbidity and mortality in developing countries. Despite the tremendous achievement in reducing child mortality and morbidity in the last two decades, diarrhea is still the major causes of morbidity and mortality in resource-limited countries like Ethiopia due to the absence of clean water and poor sanitation and hygiene.

Objective

This study aimed to assess the association of water, sanitation, and hygiene on the prevalence of diarrhea among under-five children in the rural community of Ethiopia.

Methods

A cross-sectional study was conducted among randomly selected 419 under-five children from October to December 2021 in Dangila district, Northwest Ethiopia. A structured questionnaire was used to collect sociodemographic, environmental, and behavioral data. Data were entered into Epi Info and analyzed using SPSS software. Descriptive analysis was used to calculate the prevalence of diarrhea. Univariate and multivariate logistic regression were used to compute the association of water, sanitation, and hygiene with diarrhea. Statistical significance was considered if P < 0.05.

Results

Among 419 participants, the prevalence of diarrhea was 106 (25.3%). The absence of handwashing habit of children (AOR = 7.70; 95% CI: 2.71–21.79) and caregivers after toilet (AOR = 19.10; 95% CI: 5.46–66.52), absence of latrine (AOR = 3.87; 95% CI: 1.24–12.08), playing with soil (AOR = 8.40; 95% CI: 4.58–36.66), and eating soil (AOR = 6.24; 95% CI: 1.99–19.78) were significantly associated with under-five diarrhea. Children who drink unprotected water were 2.21 times (AOR = 2.21; 95% CI: 0.51–9.69) more exposed to under-five diarrhea than who drink protected water, but it is not statistically significant (P = 0.29).

Conclusion

The prevalence of under-five diarrhea is high in Dangila district. The absence of clean water and poor handwashing practice and the absence of latrine are the main factors associated with diarrhea. Therefore, strengthening water, sanitation, and hygiene strategy in the rural community should be prioritized.

Navigating Data Uncertainty and Modeling Assumptions in Quantitative Microbial Risk Assessment in an Informal Settlement in Kampala, Uganda

Decision-makers in developing communities often lack credible data to inform decisions related to water, sanitation, and hygiene. Quantitative microbial risk assessment (QMRA), which quantifies pathogen-related health risks across exposure routes, can be informative; however, the utility of QMRA for decision-making is often undermined by data gaps. This work integrates QMRA, uncertainty and sensitivity analyses, and household surveys in Bwaise, Kampala (Uganda) to characterize the implications of censored data management, identify sources of uncertainty, and incorporate risk perceptions to improve the suitability of QMRA for informal settlements or similar settings. In Bwaise, drinking water, hand rinse, and soil samples were collected from 45 households and supplemented with data from 844 surveys. Quantified pathogen (adenovirus, Campylobacter jejuni, and Shigella spp./EIEC) concentrations were used with QMRA to model infection risks from exposure through drinking water, hand-to-mouth contact, and soil ingestion. Health risks were most sensitive to pathogen data, hand-to-mouth contact frequency, and dose-response models (particularly C. jejuni). When managing censored data, results from upper limits of detection, half of limits of detection, and uniform distributions returned similar results, which deviated from lower limits of detection and maximum likelihood estimation imputation approaches. Finally, risk perceptions (e.g., it is unsafe to drink directly from a water source) were identified to inform risk management.

Carriage of antimicrobial-resistant bacteria in a high-density informal settlement in Kenya is associated with environmental risk-factors

BACKGROUND

The relationship between antibiotic use and antimicrobial resistance varies with cultural, socio-economic, and environmental factors. We examined these relationships in Kibera, an informal settlement in Nairobi-Kenya, characterized by high population density, high burden of respiratory disease and diarrhea.

METHODS

Two-hundred households were enrolled in a 5-month longitudinal study. One adult (≥ 18 years) and one child (≤ 5 years) participated per household. Biweekly interviews (n = 1516) that included questions on water, sanitation, hygiene, and antibiotic use in the previous two weeks were conducted, and 2341 stool, 2843 hand swabs and 1490 drinking water samples collected. Presumptive E. coli (n = 34,042) were isolated and tested for susceptibility to nine antibiotics.

RESULTS

Eighty percent of presumptive E. coli were resistant to ≥ 3 antibiotic classes. Stool isolates were resistant to trimethoprim (mean: 81%), sulfamethoxazole (80%), ampicillin (68%), streptomycin (60%) and tetracycline (55%). Ninety-seven households reported using an antibiotic in at least one visit over the study period for a total of 144 episodes and 190 antibiotic doses. Enrolled children had five times the number of episodes reported by enrolled adults (96 vs. 19). Multivariable linear mixed-effects models indicated that children eating soil from the household yard and the presence of informal hand-washing stations were associated with increased numbers of antimicrobial-resistant bacteria (counts increasing by 0·27-0·80 log₁₀ and 0·22-0·51 log₁₀ respectively, depending on the antibiotic tested). Rainy conditions were associated with reduced carriage of antimicrobial-resistant bacteria (1·19 to 3·26 log₁₀ depending on the antibiotic tested).

CONCLUSIONS

Antibiotic use provided little explanatory power for the prevalence of antimicrobial resistance. Transmission of resistant bacteria in this setting through unsanitary living conditions likely overwhelms incremental changes in antibiotic use. Under such circumstances, sanitation, hygiene, and disease transmission are the limiting factors for reducing the prevalence of resistant bacteria.

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)

Quantifying the contribution of individual exposure pathways to a child's total ingestion of fecal matter could help prioritize interventions to reduce environmental enteropathy and diarrhea. This study used data on fecal contamination of drinking water, food, soil, hands, and objects and second-by-second data on children's contacts with these environmental reservoirs in rural Bangladesh to assess the relative contribution of different pathways to children's ingestion of fecal indicator bacteria and if ingestion decreased with the water, sanitation, and hygiene interventions implemented in the WASH Benefits Trial. Our model estimated that rural Bangladeshi children <36 months old consume 3.6-4.9 log₁₀ most probable number E. coli/day. Among children <6 months, placing objects in the mouth accounted for 60% of E. coli ingested. For children 6-35 months old, mouthing their own hands, direct soil ingestion, and ingestion of contaminated food were the primary pathways of E. coli ingestion. The amount of E. coli ingested by children and the predominant pathways of E. coli ingestion were unchanged by the water, sanitation, and hygiene interventions. These results highlight contaminated soil, children's hands, food, and objects as primary pathways of E. coli ingestion and emphasize the value of intervening along these pathways.

Major enteropathogens in humans, domestic animals, and environmental soil samples from the same locality: prevalence and transmission considerations in coastal Odisha, India

OBJECTIVES

Regions with limited sanitation facilities have higher rates of infections with various enteric pathogens. It is therefore important to identify different hosts and their relative contribution to pathogen shedding into the environment, and to assess the subsequent health risks to humans.

METHODS

In this study, human faecal (n=310), animal faecal (n=150), and environmental (soil) samples (n=40) were collected from the same locality and screened for selected enteric pathogens by immunochromatography and/or polymerase chain reaction.

RESULTS

At least 1 microbial agent was detected in 49.0%, 44.7%, and 40.0% of the samples from human, animals, and soil, respectively. Among humans, rotavirus was predominantly detected (17.4%) followed by enteropathogenic Escherichia coli (EPEC) (15.4%), Shigella (13.8), and Shiga toxin-producing E. coli (STEC) (9.7%). Among animals, STEC was detected most frequently (28.0%), and EPEC was the major enteric pathogen detected in soil (30.0%). The detection rate of rotavirus was higher among younger children (≤2 years) than among older children. Single infections were more commonly detected than multiple infections in humans (p<0.01), unlike the observations in animal and soil samples. For diarrhoeagenic E. coli and Shigella, most of the human and animal isolates showed close relatedness, suggesting possible cross-infection between humans and domesticated animals in the area studied.

CONCLUSIONS

The present study provides an improved understanding of the distribution of major enteric pathogens coexisting in humans and animals in the region, thereby suggesting a high potential for possible transmission among livestock and communities residing in the studied locality.

Human fecal contamination of water, soil, and surfaces in households sharing poor-quality sanitation facilities in Maputo, Mozambique

Identifying the origin of fecal contamination can support more effective interventions to interrupt enteric pathogen transmission. Microbial source tracking (MST) assays may help to identify environmental routes of pathogen transmission although these assays have performed poorly in highly contaminated domestic settings, highlighting the importance of both diagnostic validation and understanding the context-specific ecological, physical, and sociodemographic factors driving the spread of fecal contamination. We assessed fecal contamination of compounds (clusters of 2-10 households that share sanitation facilities) in low-income neighborhoods of urban Maputo, Mozambique, using a set of MST assays that were validated with animal stool and latrine sludge from study compounds. We sampled five environmental compartments involved in fecal microbe transmission and exposure: compound water source, household stored water and food preparation surfaces, and soil from the entrance to the compound latrine and the entrances to each household. Each sample was analyzed by culture for the general fecal indicator Escherichia coli (cEC) and by real-time PCR for the E. coli molecular marker EC23S857, human-associated markers HF183/BacR287 and Mnif, and GFD, an avian-associated marker. We collected 366 samples from 94 households in 58 compounds. At least one microbial target (indicator organism or marker gene) was detected in 96% of samples (353/366), with both E. coli targets present in the majority of samples (78%). Human targets were frequently detected in soils (59%) and occasionally in stored water (17%) but seldom in source water or on food surfaces. The avian target GFD was rarely detected in any sample type but was most common in soils (4%). To identify risk factors of fecal contamination, we estimated associations with sociodemographic, meteorological, and physical sample characteristics for each microbial target and sample type combination using Bayesian censored regression for target concentration responses and Bayesian logistic regression for target detection status. Associations with risk factors were generally weak and often differed in direction between different targets and sample types, though relationships were somewhat more consistent for physical sample characteristics. Wet soils were associated with elevated concentrations of cEC and EC23S857 and odds of detecting HF183. Water storage container characteristics that expose the contents to potential contact with hands and other objects were weakly associated with human target detection. Our results describe a setting impacted by pervasive domestic fecal contamination, including from human sources, that was largely disconnected from the observed variation in socioeconomic and sanitary conditions. This pattern suggests that in such highly contaminated settings, transformational changes to the community environment may be required before meaningful impacts on fecal contamination can be realized.

Local Perceptions, Cultural Beliefs, Practices and Changing Perspectives of Handling Infant Feces: A Case Study in a Rural Geita District, North-Western Tanzania

We report on the management of infant feces in a rural village in Geita region, Tanzania. Findings discussed here emerged incidentally from a qualitative study aimed at investigating vulnerability and resilience to health challenges in rural settings. Data was gathered through semi-structured focus group discussions (FDGs) with women (n = 4; 32 participants), men (n = 2; 16 participants), and community leaders (n = 1; 8 participants). All FDGs were audio recorded, transcribed verbatim and thematically analyzed using Atlas.ti. Respondents reported feces of a child under the age of six months were considered pure compared to those of older children. Infant feces were seen as transitioning to harmful at the point when the child began to eat solid food, resulting in their stool visually changing in appearance. Caregivers reportedly used soft implements to handle infant feces due to the belief that tools with hard surfaces would physically harm the child. Infant feces were disposed in environments around the house due to the belief that disposal in latrines would prevent developmental milestones and result in other perceived negative health outcomes for the child. Changing views expressed by participants suggest a window of opportunity to implement evidence-based and culturally relevant interventions to encourage the safe disposal of infant feces.

Child feces management practices and fecal contamination: A cross-sectional study in rural Odisha, India

Safe child feces management (CFM) is likely critical for reducing exposure to fecal pathogens in and around the home, but the effectiveness of different CFM practices in reducing fecal contamination is not well understood. We conducted a cross-sectional study of households with children <6 years in rural Odisha, India, using household surveys (188 households), environmental sample analysis (373 samples for 80 child defecation events), and unstructured observation (33 households) to characterize practices and measure fecal contamination resulting from CFM-related practices, including defecation, feces handling and disposal, defecation area or tool cleaning, anal cleansing, and handwashing. For environmental sampling, we developed a sampling strategy that involved collecting samples at the time and place of child defecation to capture activity-level fecal contamination for CFM practices. Defecating on the floor or ground, which was practiced by 63.7% of children <6 years, was found to increase E. coli contamination on finished floors (p < 0.001) or earthen ground surfaces (p = 0.008) after feces were removed, even if paper was laid down prior to defecation. Use of unsafe tools (e.g., paper, plastic bag, straw/hay) to pick up child feces increased E. coli contamination on caregiver hands after feces handling (p < 0.0001), whereas the use of safe tools (e.g., potty, hoe, scoop) did not increase hand contamination. Points of contamination from cleaning CFM hardware and anal cleansing were also identified. The most common disposal location for feces of children <6 years was to throw feces into an open field (41.6%), with only 32.3% disposed in a latrine. Several households owned scoops or potties, but use was low and we identified shortcomings of these CFM tools and proposed alternative interventions that may be more effective. Overall, our results demonstrate the need for CFM interventions that move beyond focusing solely on feces disposal to address CFM as a holistic set of practices.

Microbial Source Tracking Using 16S rRNA Amplicon Sequencing Identifies Evidence of Widespread Contamination from Young Children's Feces in an Urban Slum of Nairobi, Kenya

Child exposure to fecal contamination remains common in low- and middle-income countries after sanitation interventions. Unsafe disposal of children's feces may contribute to this continued exposure, but its relative importance to domestic fecal contamination is not well understood. To address this gap, we interviewed and collected environmental samples (drinking water, caregiver hands, child hands, surfaces, soil, open drainage ditches, standing water, streams) from 40 households in Kibera, an urban slum in Nairobi, Kenya. To track young children's feces (<3 years old) separately from other human-associated fecal sources, we validated distance-based and Bayesian (SourceTracker) microbial source tracking methods using amplicon-based sequencing of the 16S rRNA gene. Contamination by young children's feces could be identified and distinguished separately from older child/adult feces with high sensitivity and specificity in water and soil. Among environmental samples, young children's feces were almost always identified as the dominant source of human fecal contamination inside households (hands, surfaces) whereas older children/adult feces were often identified as the dominant source outside households (standing water, streams, soil). Markers for young children's feces were also detected in standing water and streams, and markers for both fecal sources were equally likely to be dominant in open ditches. These results establish motivation for sanitation interventions that directly address child feces management.

Child Defecation and Feces Disposal Practices and Determinants among Households after a Combined Household-Level Piped Water and Sanitation Intervention in Rural Odisha, India

Latrine access alone may be insufficient to encourage households to dispose of young children's feces safely in a latrine, and little is known about the determinants of improved child feces disposal. We used longitudinal data collected at up to three timepoints for children less than 5 years of age from households in Odisha, India, which received a combined household-level piped water supply and sanitation intervention, but did not specifically promote the safe disposal of child feces. Among the 85% of intervention households who reported access to improved sanitation, we characterized child defecation and feces disposal practices by age, across time, and season, and assessed determinants of improved disposal. Feces from children less than 3 years of age was commonly picked up by caregivers but disposed of unsafely with garbage into open areas (56.3% of households) or in a drain/ditch (6.2%). Although children 3 and 4 years were more likely to use a latrine than younger children, their feces was also more likely to be left in the open if they did not defecate in a latrine. For children less than 5 years of age, most (84.7%) children's feces that was safely disposed of in a latrine was because of the children defecating in the latrine directly. Significant predictors for disposing of child feces in an improved latrine were the primary female caregiver reporting using a latrine to defecate, the child's age, and water observed at place for handwashing. These findings suggest that child feces interventions should focus on encouraging children to begin using a toilet at a younger age and changing the common behavior of disposing of young child's feces into open areas.

Risk Factors for Detection, Survival, and Growth of Antibiotic-Resistant and Pathogenic Escherichia coli in Household Soils in Rural Bangladesh

Soils in household environments in low- and middle-income countries may play an important role in the persistence, proliferation, and transmission of Escherichia coli Our goal was to investigate the risk factors for detection, survival, and growth of E. coli in soils collected from household plots. E. coli was enumerated in soil and fecal samples from humans, chickens, and cattle from 52 households in rural Bangladesh. Associations between E. coli concentrations in soil, household-level risk factors, and soil physicochemical characteristics were investigated. Susceptibility to 16 antibiotics and the presence of intestinal pathotypes were evaluated for 175 E. coli isolates. The growth and survival of E. coli in microcosms using soil collected from the households were also assessed. E. coli was isolated from 44.2% of the soil samples, with an average of 1.95 log10 CFU/g dry soil. Soil moisture and clay content were associated with E. coli concentrations in soil, whereas no household-level risk factor was significantly correlated. Antibiotic resistance and pathogenicity were common among E. coli isolates, with 42.3% resistant to at least one antibiotic, 12.6% multidrug resistant (≥3 classes), and 10% potentially pathogenic. Soil microcosms demonstrate growth and/or survival of E. coli, including an enteropathogenic extended-spectrum beta-lactamase (ESBL)-producing isolate, in some, but not all, of the household soils tested. In rural Bangladesh, defined soil physicochemical characteristics appear more influential for E. coli detection in soils than household-level risk factors. Soils may act as reservoirs in the transmission of antibiotic-resistant and potentially pathogenic E. coli and therefore may impact the effectiveness of water, sanitation, and hygiene interventions.IMPORTANCE Soil may represent a direct source or act as an intermediary for the transmission of antibiotic-resistant and pathogenic Escherichia coli strains, particularly in low-income and rural settings. Thus, determining risk factors associated with detection, growth, and long-term survival of E. coli in soil environments is important for public health. Here, we demonstrate that household soils in rural Bangladesh are reservoirs for antibiotic-resistant and potentially pathogenic E. coli strains and can support E. coli growth and survival, and defined soil physicochemical characteristics are drivers of E. coli survival in this environment. In contrast, we found no evidence that household-level factors, including water, sanitation, and hygiene indicators, were associated with E. coli contamination of household soils.

Escherichia coli Contamination across Multiple Environmental Compartments (Soil, Hands, Drinking Water, and Handwashing Water) in Urban Harare: Correlations and Risk Factors

Escherichia coli pathotypes (i.e., enteropathogenic and enterotoxigenic) have been identified among the pathogens most responsible for moderate-to-severe diarrhea in low- and middle-income countries (LMICs). Pathogenic E. coli are transmitted from infected human or animal feces to new susceptible hosts via environmental reservoirs such as hands, water, and soil. Commensal E. coli, which includes nonpathogenic E. coli strains, are widely used as fecal bacteria indicator, with their presence associated with increased likelihood of enteric pathogens and/or diarrheal disease. In this study, we investigated E. coli contamination in environmental reservoirs within households (N = 142) in high-population density communities of Harare, Zimbabwe. We further assessed the interconnectedness of the environmental compartments by investigating associations between, and household-level risk factors for, E. coli contamination. From the data we collected, the source and risk factors for E. coli contamination are not readily apparent. One notable exception is the presence of running tap water on the household plot, which is associated with significantly less E. coli contamination of drinking water, handwashing water, and hands after handwashing. In addition, E. coli levels on hands after washing are significantly associated with handwashing water contamination, hand contamination before washing, and diarrhea incidence. Finally, we observed that animal ownership increases E. coli contamination in soil, and E. coli in soil are correlated with contamination on hands before washing. This study highlights the complexity of E. coli contamination in household environments within LMICs. More, larger, studies are needed to better identify sources and exposure pathways of E. coli-and enteric pathogens generally-to identify effective interventions.