Fecal Exposure Research Articles

Fecal SN-38 Content as a Surrogate Predictor of Intestinal SN-38 Exposure and Associated Irinotecan-induced Severe Delayed-Onset Diarrhea by a Novel Use of the Spectrofluorimetric Method.

Irinotecan administration can lead to severe delayed-onset diarrhea (SDOD) in clinical practice. Currently, there is no reliable surrogate predictor of intestinal exposure to SN-38 and subsequent diarrhea incidence. The relationship between fecal 7-ethyl-10-hydroxycamptothecin (SN-38) content and SDOD was investigated in Fisher 344 rats using a novel spectrofluorimetric method. Additionally, a pharmacokinetic study of irinotecan was performed to evaluate the biodistribution of SN-38 to establish the relationship between tissue and fecal SN-38 exposure. The spectrofluorimetric method was successfully employed to measure fecal SN-38 and CPT-11content from Day 3 to Day 6 post-irinotecan administration. Only fecal SN-38 content on Day 3 exhibited a significantly positive correlation with SDOD incidence on Days 4 and 5. A cutoff value of SN-38 ≥ 0.066mg/g in feces was identified, predicting severe diarrhea incidence with 81% accuracy and 80% specificity. The positive correlation between fecal SN-38 content and SN-38 exposure in the ileum on Day 3 was also reflected in the changes of indicators during intestinal injury, such as prostaglandin E2 level and antioxidant activity. Fecal SN-38 content proves to be representative of intestinal exposure to SN-38, indicative of intestinal injury, and predictive of SDOD incidence in rats, while the spectrofluorimetric method demonstrates the translational potential.

Behavioural faecal exposure pathways in a nomadic lifestyle :

Background: Water, sanitation and hygiene (WASH) is the cornerstone for health and growth at all stages of life in maintain health and increase in life span. Poor sanitation has led to disease increase in microorganisms such as Escherichia coli. Sanitation is influenced in a community by factors such as perception, behavioral practices such as open defecation and disposal of these waste. This study aimed to identify behavioral faecal exposure pathways in the nomadic community of Turbi ward. Methods: Mixed method approach using qualitative and quantitative research methods was applied in this study to assess exposure pathways and related behavior among the nomadic community of Turbi ward. Thematic data analysis was used to analyze data generated from behavioural observations. Data was presented using graphs and pie charts. Results: A total of 100 households were sampled and about 68% (n=100) of population use surface water for domestic. Turbi manyatta had the highest with 30% (n=100), followed by Kambi Nyoka at 16%(n=100) and the least was Shurr manyatta at 2% (n=100). Surface water was the dominant source of water for these community. About 76% (n=100) of the households did not treat their water before use for domestic purposes and due to scarcity of water the community store water in jerricans for more than one week. About 87% of the residents reported not washing hands before milking animals. Open defecation was the predominant method of waste disposal among the five selected Manyattas, accounting for 95% (n= 100). There was significant relationship between practicing open defecation and using surface water without treatment for domestic purpose at p-value 0.032 (95% CI), using Wilcoxon Signed-Rank test. Conclusion: The study revealed that the study community’s behavioral practices exposes them to faecal exposure due to habitual practice of open defecation, throwing waste to the bush, open burning, drinking untreated surface water and not washing hands before milking animals. There is need for advocacy on social behavior change, and strategies on health promotion targeting Water, Sanitation and Hygiene (WASH).

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 andidentify challenges and considerations and directions for future research.

Quantitative microbial risk assessment of the gastrointestinal risks to swimmers at Southeast Asian urban beaches using site-specific and combined autochthonous and fecal bacteria exposure data

Recreational exposure to microbial pollution at urban beaches poses a health risk to beachgoers. The accurate quantification of such risks is crucial in managing beaches effectively and establishing warning guidelines. In this study, we employed a quantitative microbial risk assessment (QMRA) framework to assess marine water quality and estimate the risks associated with Vibrio parahaemolyticus, an autochthonous pathogen that causes gastrointestinal illnesses, and enterococci, a traditional fecal bacteria indicator. The microbial contamination levels of V. parahaemolyticus and enterococci were determined from 48 water samples collected at two beaches in Thailand during dry and wet seasons. The accidentally ingested water volumes were obtained through a survey involving 438 respondents. The probability of illness (Pill) was estimated using dose–response models and Monte Carlo simulation. The results revealed that enterococci posed a higher risk of illness than V. parahaemolyticus at all seven study sites. The median combined gastrointestinal (GI) risk from both bacteria at all sites met the US EPA risk benchmark of 0.036 and the 0.05 benchmark set by the WHO, but the 95th percentile risk data at all sites exceeded the benchmarks. This emphasizes the need for the continuous monitoring and management of microbial pollution at these sites. The site-specific exposure data showed higher estimated risks with increased variations compared to the WHO-referenced values, which highlights the significance of locally measured microbial concentrations and survey exposure data to avoid underestimation. Estimating the risks from recreational exposure to waterborne bacteria can inform beach management policies aimed at reducing public health risks to swimmers. The study findings improve the understanding of the risks associated with water recreation activities at Southeast Asian beaches and offer valuable insights for the development of water quality guidelines, which are crucial for the sustainable development of the blue economy.

Quantification of microbial risk associated with fecal exposure in a nomadic lifestyle; case study of Turbi ward, Marsabit County

Background: Water, Sanitation and Hygiene (WASH) is the cornerstone for health and growth at all stages of life in helping to maintain health and increase in life span. Poor sanitation as lead to disease causing microorganisms such as E. coli to be on the rise. This study aimed to determine water and milk contamination of E. coli from nomadic community. Methods: A cross-sectional study was conducted on water and milk samples using most probable number method to determine contamination as a result of poor sanitation in this community. Results: The dominant exposure pathway in this study was water pathway with high E. coli positivity, 20% (n=50) for dam water sampled, 20% (n=50) for pan and borehole feed water tanks 20% (n=50). Dam water sources analyzed had presence of 1.05 x1107CFU/ml and pan water sources 1.93x104 CFU/ml, which is above acceptable E. coli level in water for consumption is (10-40 CFU/ml) Conclusions: Microbial contamination noted from this study indicates that there is poor sanitation in nomadic lifestyle. This study reaffirms the need for elaborate sanitation model tailored to the need of pastoralist community to reduce perennial faucal contamination of water sources for the community of Turbi ward. Elaborate sanitation model tailored to the need of pastoralist community to reduce perennial fecal contamination of water sources for the community of Turbi ward.

Multi-pathway assessment of fecal contamination in urban areas of Abidjan: The case of Abobo municipality

The presence of septic tank effluents in open spaces and roads due to poor fecal sludge management (FSM) in low-income cities represents a source of fecal contamination and potential risk of fecal-oral disease transmission. This study aimed at assessing fecal contamination exposure through six exposure pathways in Abobo, District of Abidjan in Côte d’Ivoire. The public health risk was evaluated in two clusters to identify the dominant exposure pathways and to compare which populations were most exposed. The SaniPath approach used included behavioral surveys (transect walk, household survey, school survey and community survey) and laboratory analysis. Surveys were conducted among 200 households, 6 schools and 4 community groups. In addition, 120 environmental samples were collected (in 2 clusters of 6 pathways with 10 samples per pathway per cluster). The colony forming unit (CFU) of E. coli was determined in samples using the surface plating technique on agar medium. Bayesian analyses were performed to estimate the distributions of fecal concentration and contact frequency, and exposure to fecal contamination was estimated using the Monte Carlo method with 1000 iterations. The highest concentrations of E. coli were observed in open drains (6.1 log CFU/ml), gullies (6 log CFU/ml) and soil (5.8 log CFU/ml) samples. The dominant exposure pathways were determined by multiplying the dose and the percentage of the population exposed, which was then log-transformed and denoted by (E). The study found that street food and gullies are the two dominant exposure pathways among the population living in Abobo. 100% of the children and between 73% and 91% of the adults are exposed to these dominant pathways in low and poor areas. In middle and high-income areas this concerns 75% to 95% of children and between 26% and 70% of adults. As well, the risk of exposure to the dominant pathways hits 9.2 in children and 8.6 for adults living in poor areas. While it reaches 8.1 and 7.1 respectively in children and adults living in middle and high-income areas. The study outcomes could help the authorities to structure how to target municipal wide interventions toward improving the sanitation conditions in the different neighborhoods.

Higher convergence of human-great ape enteric eukaryotic viromes in central African forest than in a European zoo: a One Health analysis

Human-animal pathogenic transmissions threaten both human and animal health, and the processes catalyzing zoonotic spillover and spillback are complex. Prior field studies offer partial insight into these processes but overlook animal ecologies and human perceptions and practices facilitating human-animal contact. Conducted in Cameroon and a European zoo, this integrative study elucidates these processes, incorporating metagenomic, historical, anthropological and great ape ecological analyses, and real-time evaluation of human-great ape contact types and frequencies. We find more enteric eukaryotic virome sharing between Cameroonian humans and great apes than in the zoo, virome convergence between Cameroonian humans and gorillas, and adenovirus and enterovirus taxa as most frequently shared between Cameroonian humans and great apes. Together with physical contact from hunting, meat handling and fecal exposure, overlapping human cultivation and gorilla pillaging in forest gardens help explain these findings. Our multidisciplinary study identifies environmental co-use as a complementary mechanism for viral sharing.

Infectious SARS-CoV-2 Particles from Rectal Swab Samples from COVID-19 Patients in Brazil.

The main objective of this study was to investigate the dynamic of SARS-CoV-2 viral excretion in rectal swab (RS), saliva, and nasopharyngeal swab (NS) samples from symptomatic patients and asymptomatic contacts. In addition, in order to evaluate the replication potential of SARS-CoV-2 in the gastrointestinal (GI) tract and the excretion of infectious SARS-CoV-2 from feces, we investigated the presence of subgenomic nucleoprotein gene (N) mRNA (sgN) in RS samples and cytopathic effects in Vero cell culture. A prospective cohort study was performed to collect samples from symptomatic patients and contacts in Rio de Janeiro, Brazil, from May to October 2020. One hundred and seventy-six patients had samples collected at home visits and/or during the follow up, resulting in a total of 1633 RS, saliva, or NS samples. SARS-CoV-2 RNA was detected in 130 (73.9%) patients who had at least one sample that tested positive for SARS-CoV-2. The presence of replicating SARS-CoV-2 in RS samples, measured by the detection of sgN mRNA, was successfully achieved in 19.4% (6/31) of samples, whilst infectious SARS-CoV-2, measured by the generation of cytopathic effects in cell culture, was identified in only one RS sample. Although rare, our results demonstrated the replication capacity of SARS-CoV-2 in the GI tract, and infectious viruses in one RS sample. There is still a gap in the knowledge regarding SARS-CoV-2 fecal-oral transmission. Additional studies are warranted to investigate fecal or wastewater exposure as a risk factor for transmission in human populations.

Characterization of the eukaryotic microbial communities in the chicken ileum in cage-free and conventional commercial housing systems

The current shift from conventional cage (CC) hen housing facilities towards cage-free (CF) hen housing in the egg industry has left many questions regarding how level of fecal exposure and exposure to other hens may influence the hen intestinal microbiota. In a previous publication we reported differences in the bacterial ileal communities and ileal morphology between hens in CC and CF production environments at a single commercial site. Here, we present the first 18S rRNA gene amplicon sequencing-based characterization of the eukaryotic ileal microbiota of adult layer hens, and their associations with intestinal health parameters and the bacterial microbiota. DNA was extracted from the ileal digesta of hens (n=32 CC, n=48 CF) using the Qiagen Powerlyzer Powersoil kit, followed by amplification of the V9 region of the 18S rRNA gene. Paired end sequencing was performed with the Illumina MiSeq platform, and the resulting reads were processed according to the Mothur MiSeq protocol in Mothur v1.43.0. De novo operational taxonomic unit (OTU) clustering was performed in mothur with a 99% similarity threshold, and OTUs were taxonomically classified with the SILVA SSU v138 reference database. OTUs classified as vertebrate, plant, or arthropod were removed, resulting in 3,136,400 high quality reads and 1,370 OTUs. Associations between OTUs and intestinal parameters were calculated using PROC GLIMMIX. PERMANOVA over Bray-Curtis distances revealed differences between CC and CF eukaryotic ileal microbiota at the whole community level, but no OTUs were differentially abundant after correcting for false discovery (P > 0.05; q > 0.1). Kazachstania and Saccharomyces, closely related genera of yeast, represented 77.1% and 9.7% of sequences respectively. Two Kazachstania OTUs and 1 Saccharomycetaceae OTU were positively correlated with intestinal permeability (r2 ≥ 0.35). Eimeria accounted for 7.6% of sequences across all samples. Intriguingly, 15 OTUs classified as Eimeria were inversely associated with intestinal permeability (r2 ≤ -0.35), suggesting Eimeria may play a more complex role in the microbiota of healthy birds than has been observed in disease challenges.

Identification techniques to prevent the current emerging disease hepatopancreatic microsporidiosis in white shrimp Penaeus vannamei: an overview

Aquaculture combines techniques for breeding and harvesting aquatic organisms used in shrimp production. It is important as a source of income and for generating foreign exchange in the regions where it is practiced. However, the timely detection of diseases continues to be a great challenge for aquaculture and fisheries production. In recent years, Enterocytozoon hepatopenaei (EHP) has emerged as a major pathogen of the Pacific white shrimp Penaeus vannamei in many Asian countries (Vietnam, China, Indonesia, Malaysia, Thailand, India, and Korea). In Latin America, only in Venezuela, and to date, there is no report of its presence in Mexico. It is transmitted directly from shrimp to shrimp by oral or fecal means, cannibalism, or exposure to contaminated water. Hepatopancreatic microsporidiosis (HPM) is mainly associated with stunted growth and severe infections that can cause a poor production cycle, mortality, and problems in larva-producing laboratories. This review aims to overview the main microsporidian parasites and diseases found in white shrimp, including the clinical signs, control and prevention measures for EHP infection, and the detection of HPM using different techniques. In order to offer timely detection tools, different techniques are available for the detection and study of microsporidia. Such as optical microscopy, transmission electron microscopy, and histology; however, for diagnostic purposes, molecular methods are preferred due to their sensitivity, specificity, and short-time analysis. Our review suggests that constant monitoring in shrimp hatcheries and farms is essential to avoid the entry or transference of infected organisms, affecting shrimp production and the ideal development of healthy shrimp.

Determinants of food preparation and hygiene practices among caregivers of children under two in Western Kenya: a formative research study

IntroductionDiarrhea is a leading cause of child morbidity and mortality worldwide and is linked to early childhood stunting. Food contamination from improper preparation and hygiene practices is an important transmission pathway for exposure to enteric pathogens. Understanding the barriers and facilitators to hygienic food preparation can inform interventions to improve food hygiene. We explored food preparation and hygiene determinants including food-related handwashing habits, meal preparation, cooking practices, and food storage among caregivers of children under age two in Western Kenya.MethodsWe used the Capabilities, Opportunities, and Motivations model for Behavior Change (COM-B) framework in tool development and analysis. We conducted 24 focus group discussions with mothers (N = 12), fathers (N = 6), and grandmothers (N = 6); 29 key informant interviews with community stakeholders including implementing partners and religious and community leaders; and 24 household observations. We mapped the qualitative and observational data onto the COM-B framework to understand caregivers’ facilitators and barriers to food preparation and hygiene practices.ResultsFacilitators and barriers to food hygiene and preparation practices were found across the COM-B domains. Caregivers had the capability to wash their hands at critical times; wash, cook, and cover food; and clean and dry utensils. Barriers to food hygiene and preparation practices included lack of psychological capability, for instance, caregivers’ lack of knowledge of critical times for handwashing, lack of perceived importance of washing some foods before eating, and not knowing the risks of storing food for more than four hours without refrigerating and reheating. Other barriers were opportunity-related, including lack of resources (soap, water, firewood) and an enabling environment (monetary decision-making power, social support). Competing priorities, socio-cultural norms, religion, and time constraints due to work hindered the practice of optimal food hygiene and preparation behaviors.ConclusionFood hygiene is an underexplored, but potentially critical, behavior to mitigate fecal pathogen exposure for young children. Our study revealed several knowledge and opportunity barriers that could be integrated into interventions to enhance food hygiene.

Contextual and psychosocial factors influencing caregiver safe disposal of child feces and child latrine training in rural Odisha, India.

Child feces are an important source of fecal exposure in household environments. Typically, one of two behaviors is necessary to mitigate this risk: either caregivers dispose of their children's feces into a latrine or children learn how to use a latrine. Although past studies have examined factors associated with these two behaviors collectively (i.e. "safe disposal"), there is a need to separately analyze these distinctive practices to better inform programming. This study aims to quantitatively examine contextual and psychosocial factors influencing caregiver safe disposal and, separately, child latrine training. We surveyed 791 primary female caregivers, who reported on 906 children <5 years old, across 74 villages in rural Odisha, India. At their last defecation event, 38% of children used the latrine and another 10% had their feces safely disposed of into the latrine. Since caregiver safe disposal was rare, we instead assessed safe disposal intention. We used linear regression and multilevel mixed effects models to examine contextual and psychosocial factors. For contextual factors, we found caregivers had stronger safe disposal intention when they came from wealthier households and had greater informational support, but weaker intention when their latrine was near the household. Caregivers more intensely practiced latrine training with their child when they themselves used the latrine for defecation, the latrine was fully intact, and they had greater instrumental support. For psychosocial factors, caregivers had stronger safe disposal intention when their households expected them to practice safe disposal, they felt strongly committed to the behavior, and had a plan for what to do when faced with a water shortage. Caregivers more intensely taught their child how to use the latrine when they believed their child was at risk of becoming sick if they practiced open defecation (OD); viewed child OD as unbeneficial; liked teaching their child; personally felt it was important for the child's father to help; felt confident in their ability to teach their child; and had greater action control over their training practice. Interestingly, caregivers put less effort into latrine training when they felt more concerned for their child's safety when the child defecated outside. These findings underscore the critical need to separately assess unique child feces management (CFM) practices and also provide a road map for practitioners on the types of behavior change strategies to consider in their CFM programming.

Tools for a comprehensive assessment of public health risks associated with limited sanitation services provision

Three water, sanitation and hygiene (WASH) support tools were applied to Kampala city, Uganda, to evaluate areas with the highest health hazard due to poor wastewater and faecal sludge management and to develop interventions to improve sanitation and reduce exposure. The Pathogen Flow and Mapping Tool (PFMT) assessed how different sanitation management interventions influence pathogen emissions to surface water using rotavirus as the indicator pathogen, while the HyCRISTAL health hazard tool evaluated how flooding and drainage infrastructure influence the presence of human excreta in the environment. The SaniPath tool identified common high-risk pathways of exposure to faecal contamination in food, open drains and floodwater. An overlap in high health hazard hotspot areas was identified by the PFMT and the HyCRISTAL tools. Across the city, the most important hazard sources were the indiscriminate disposal of faecal waste into open stormwater drains from onsite sanitation technologies, open defecation and the insufficient treatment of wastewater. The SaniPath tool identified drain water, floodwater, street food and uncooked produce as the dominant faecal exposure pathways for selected parishes in the city, demonstrating the presence of excreta in the environment. Together, the tools provide collective evidence guiding household, community, and city-wide sanitation, hygiene and infrastructure management interventions from a richer assessment than when a single tool is applied. For areas with high spatial risks, those practising open defecation, and for low-lying areas, these interventions include the provision of watertight pit latrines or septic tanks that are safely managed and regularly emptied. Faecal sludge should be emptied before flood events, direct connections of latrines to open storm drains should be prevented, and the safe handling of food and water promoted. The tools enhance decision making for local authorities, and the assessments can be replicated in other cities.

Assessment of the psychological dimension to open defecation in Ogun State

The possibility of faecal exposure increasing risk for COVID-19 infection makes imperative the need to interrogate current sanitation practices, as emerging studies indicate the possibility that the oral-faecal pathway could serve as an alternative to the respiratory and contact transmissions. This would help provide an analytical premise for planned improvement and greater precaution in ensuring human waste is safely contained, emptied, transported, and disposed or treated. This study adopts the RANT model (Risk, Attitude, Norm, and Toilet Management factors) in order to expatiate on the psychological determinants of open defecation by households who currently have toilets and either share them or use them separately. This is with a view to proffering suggestions on the sustainable measures for faecal waste management within Ogun state, Nigeria. Using a four-level multi-stage approach, questionnaires were administered to a total of 330 households within Ogun State, Nigeria. In the logistic modelling of the psychological factors explaining why households still defecate in the open, an indicator of the risk factor was more significant in the tendency of households, where toilets are shared, to still defecate in the open. Moreover, an indicator of the norm factor would explain why households who do not share toilets still defecate in the open. The study recommends the need to mainstream, and implement effectively, initiatives such as planning and landscaping of open spaces, bus terminals with adequate toilets, installations of signpost warning against open defecation, comprehensive water schemes in cities’ master plans of Ogun state, as a sustainable means of discouraging open defecation, and reducing the risk factors for COVID-19 infection and exposure to other infectious diseases.

A qualitative assessment of mothers' perceptions and behaviors in response to an intervention designed to encourage safe child feces management practices in rural Odisha, India

Abstract Child feces are not always safely disposed of into a latrine, potentially contributing to fecal exposure in the household environment. In India, safe disposal of child feces is a relatively uncommon practice despite gains in latrine coverage. This study took place after the delivery of a behavior change intervention that also included the provision of potties and scoops. The aims of this research were to (1) describe current child feces management (CFM) practices, (2) explore perceptions and behaviors of mothers who participated in intervention activities, and (3) assess the spillover of intervention activities in neighboring villages. Twenty-four in-depth interviews and four focus group discussions were conducted across six villages, three of which received the intervention. Using thematic analysis, we explored caregivers' descriptions of the different strategies to manage their child's feces. The study found (i) women's access to and perception of the intervention informed their knowledge, attitudes, perceived risk, and behaviors related to CFM, (ii) most women positively perceived the messages of the intervention with varying use of the tools provided for feces disposal, and (iii) there was no spillover in the neighboring villages. Our findings underscore that CFM practices must be addressed to reduce fecal contamination of the environment.

Transfer of Human Microbiome to Drosophila Gut Model.

Laboratory animals with human microbiome have increasingly been used to study the role of bacteria and host interaction. Drosophila melanogaster, as a model of microbiota-host interaction with high reproductive efficiency and high availability, has always been lacking studies of interaction with human gut microbiome. In this study, we attempted to use antibiotic therapy and human fecal exposure strategy to transfer the human microbiome to the drosophila. The method includes depleting the original intestinal bacteria using a broad-spectrum antibiotic and then introducing human microorganisms by a diet supplemented with donor’s fecal samples. The sequencing results showed that 80–87.5% of the OTUs (Operational Taxonomic Units) from donor feces were adopted by the recipient drosophila following 30 days of observation. In comparison to females, the male recipient drosophila inherited more microbiota from the donor feces and had significantly increased lifespan as well as improved vertical climbing ability. Furthermore, distinctly differential expression patterns for age and insulin-like signaling-related genes were obtained for the male vs. female recipients. Only the male drosophila offspring acquired the characteristics of the donor fecal microbiota.

Quantitative assessment of exposure to fecal contamination in urban environment across nine cities in low-income and lower-middle-income countries and a city in the United States

BackgroundDuring 2014 to 2019, the SaniPath Exposure Assessment Tool, a standardized set of methods to evaluate risk of exposure to fecal contamination in the urban environment through multiple exposure pathways, was deployed in 45 neighborhoods in ten cities, including Accra and Kumasi, Ghana; Vellore, India; Maputo, Mozambique; Siem Reap, Cambodia; Atlanta, United States; Dhaka, Bangladesh; Lusaka, Zambia; Kampala, Uganda; Dakar, Senegal. ObjectiveAssess and compare risk of exposure to fecal contamination via multiple pathways in ten cities. MethodsIn total, 4053 environmental samples, 4586 household surveys, 128 community surveys, and 124 school surveys were collected. E. coli concentrations were measured in environmental samples as an indicator of fecal contamination magnitude. Bayesian methods were used to estimate the distributions of fecal contamination concentration and contact frequency. Exposure to fecal contamination was estimated by the Monte Carlo method. The contamination levels of ten environmental compartments, frequency of contact with those compartments for adults and children, and estimated exposure to fecal contamination through any of the surveyed environmental pathways were compared across cities and neighborhoods. ResultsDistribution of fecal contamination in the environment and human contact behavior varied by city. Universally, food pathways were the most common dominant route of exposure to fecal contamination across cities in low-income and lower-middle-income countries. Risks of fecal exposure via water pathways, such as open drains, flood water, and municipal drinking water, were site-specific and often limited to smaller geographic areas (i.e., neighborhoods) instead of larger areas (i.e., cities). ConclusionsKnowledge of the relative contribution to fecal exposure from multiple pathways, and the environmental contamination level and frequency of contact for those “dominant pathways” could provide guidance for Water, Sanitation, and Hygiene (WASH) programming and investments and enable local governments and municipalities to improve intervention strategies to reduce the risk of exposure to fecal contamination.

Seasonal and gender impacts on fecal exposure trends in an urban slum

Seasonal and gender impacts have not been well considered in fecal exposure assessment, especially in low- and middle-income countries. This study examined the seasonal and gender impacts on fecal exposure trends in children through daily living activities in an urban slum in Bangladesh. We determined Escherichia coli concentrations in seven types of environmental samples (n = 232) and the activity data of children via diary recording, questionnaires, and interview surveys. Daily and monthly exposures were stochastically estimated for drinking, eating, pond bathing, well bathing, and hand-to-mouth contact. Of the five pathways, pond bathing and drinking contributed a large part of the daily and monthly exposure. Significant seasonal differences were observed in daily exposures for bathing, which were higher in the rainy season (2.59 × 102 CFU/day for boys and 6.19 × 10-1 CFU/day for girls) than in the dry season (1.69 × 102; 4.30 × 10-2), because of longer pond bathing time and more contaminated bathing water in the rainy season. In contrast, eating had significantly higher exposure in the dry season (3.71 × 10; 3.22 × 10) than the rainy season (1.50 × 10; 1.24 × 10) due to the higher dish contamination. Significantly higher daily exposure was observed in the bathing for boys than girls, as boys spent longer time for bathing at a heavily contaminated pond.

Safely Managed On-Site Sanitation: A National Assessment of Sanitation Services and Potential Fecal Exposure in Indonesia.

Sustainable Development Goal target 6.2 calls for universal access to adequate and equitable sanitation, setting a more ambitious standard for ‘safely managed sanitation services’. On-site sanitation systems (e.g., septic tanks) are widely used in low- and middle-income countries (LMICs). However, the lack of indicators for assessing fecal exposure risks presents a barrier to monitoring safely managed services. Furthermore, geographic diversity and frequency of disasters require a more nuanced approach to risk-informed decision-making. Taking Indonesia as an example, the purpose of this paper is to provide insights into current status and practices for on-site sanitation services in the contexts of LMICs. Using a dataset from a national socio-economic survey (n = 295,155) coupled with village census (n = 83,931), we assessed (1) household sanitation practices across Indonesia stratified by city-level population density and meteorological factors, (2) factors associated with septic tank emptying practice, and (3) inequalities in potential fecal exposure as measured by population density and WASH access by wealth quintile. We found a high reliance on on-site sanitation facilities (80.0%), almost half of which are assumed to be ‘uncontained’ septic tanks and one in ten facilities discharging untreated waste directly into the environment. The most densely populated areas had the highest rates of septic tank emptying, though emptying rates were just 17.0%, while in the lowest population density group, emptying was rarely reported. Multivariate regression analysis demonstrated an association between flooding and drought occurrence and septic tank emptying practice. Higher groundwater usage for drinking among poorer households suggests unsafe sanitation may disproportionally affect the poor. Our study underscores the urgent need to strengthen the monitoring of on-site sanitation in LMICs by developing contextualized standards. Furthermore, the inequalities in potential fecal exposure require greater attention and tailored support mechanisms to ensure the poorest gain access to safely managed sanitation services.

Associations between faecal pathogen detection, E.coli concentrations and youth exhibitor biosecurity practices at California county fairs.

Interactions with livestock in public settings such as county and state fairs can expose people and other livestock to faecal material capable of spreading zoonotic enteric pathogens. The goal of this study was to understand these risks by screening livestock faeces (n=245) and livestock bedding (n=155) for common zoonotic pathogens (Giardia, Cryptosporidium, Salmonella and Campylobacter spp.) and by measuring faecal indicator, Escherichia coli, concentrations in drinking water (n=153), feed containers (n=124) and bedding material (n=157) in four livestock species (cattle, sheep, goats and swine) from county fairs in California, USA. Results indicated that sheep were most likely to have pathogens detected in faeces and that Giardia was the most frequently detected pathogen in both faeces (11%) and bedding (21%) across all livestock species. Additionally, increasing the number of animals in a holding pen at fairs, increasing the stocking density of animals in transport trailers to fairs, and having access to water in transport trailers significantly increased the odds of detecting pathogens in livestock faeces of any animal species. Observing solid material in water, stale feed and soiled bedding was associated with detecting higher E.coli concentrations. These findings provide evidence of faecal pathogens present at county fairs and suggest that site observations can aid in assessing levels of faecal exposure. The findings also indicate that the use of biosecurity measures such as (a) routine changing of livestock drinking water, feed and bedding, (b) not overstocking animals in holding pens and trailers and (c) keeping species in separate holding areas may reduce the risk of humans and livestock being exposed to faecal pathogens.