Genetic sequence data evidence that human faecal-associated HF183 sequences are on human skin and in urine.

AIMS: The DNA marker HF183 is a partial 16S rRNA gene sequence highly specific to human-associated Bacteroides including Bacteroides dorei. While HF183 is used to assess human faecal contamination in aquatic environments worldwide, little is known about the existence of HF183 and B. dorei in human microbiomes outside of the human gastrointestinal tract and faeces. METHODS AND RESULTS: Previously published human skin and urine microbiome data sets from five independent human body skin studies, the Human Microbiome Project (HMP) and three independent human urine studies were analysed. The HF183 gene sequence was detected in all skin data sets, with the ratios of positive samples ranging from 0.5% to 36.3%. Popliteal fossa (knee), volar forearm and inguinal (groin) creases were identified as hot spots. HF183 was detected in two of three urine data sets, with ratios of positive samples ranging from 0% to 37.5%. All HF183-containing sequences from these data sets were classified as associated with B. dorei. CONCLUSIONS: HF183 is widespread on human skin and present in urine. SIGNIFICANCE AND IMPACT OF STUDY: Skin and urine microbiomes could be sources of HF183 to environmental waters. Such non-faecal sources of HF183 might explain low concentrations of HF183 in recreational waters when swimmers are present.

Child hand contamination is associated with subsequent pediatric diarrhea in rural Democratic Republic of the Congo (REDUCE Program).

OBJECTIVE: The Reducing Enteropathy, Undernutrition, and Contamination in the Environment (REDUCE) program focuses on identifying exposure pathways to faecal pathogens for young children in the Democratic Republic of the Congo (DRC) and on developing scalable interventions to reduce faecal contamination from these pathways. METHODS: A prospective cohort study of 690 participants was conducted to investigate the association between hand, food, and environmental faecal contamination and diarrhoeal disease prevalence among young children in Walungu Territory, South Kivu, DRC. A total of 1923 hand rinse, soil, food, object, surface, stored water and water source samples were collected during unannounced spot checks after baseline enrolment and analysed for Escherichia coli. Caregiver reports of diarrhoea were obtained from children < 5 years at a 6-month follow-up. RESULTS: E.coli was detected in 73% of child and caregiver hand-rinse samples, 69% of soil samples from child play spaces, 54% of child food samples, 38% of objects and surfaces children were observed putting in their mouths, 74% of stored water samples, and 40% of source water samples. Children < 5 years with E. coli on their hands had significantly higher odds of diarrhoea at the 6-month follow-up (odds ratio: 2.03 (95% confidence interval: 1.05, 3.92)). CONCLUSION: The cohort study findings from the REDUCE program have shown that child hand contamination is associated with diarrhoeal disease in rural DRC, and that there is high faecal contamination in child plays spaces and food. These findings provide evidence demonstrating the urgent need to provide clean play spaces for young children and interventions targeting hand hygiene to reduce paediatric exposure to faecal pathogens.

OBJECTIF: L'étude REDUCE (Réduire l'Entéropathie, la Dénutrition et la Contamination à partir de l'Environnement) se concentre sur l'identification des voies d'exposition aux pathogènes fécaux pour les jeunes enfants en République Démocratique du Congo (RDC) et sur le développement d'interventions évolutives pour réduire la contamination fécale par ces voies. MÉTHODES: Une étude de cohorte prospective de 690 participants a été menée pour étudier l'association entre la contamination fécale des mains, des aliments et de l'environnement et la prévalence des maladies diarrhéiques chez les jeunes enfants dans le Territoire de Walungu, dans le Sud-Kivu, en RDC. Un total de 1.923 échantillons de rinçages des mains, de sol, d'aliments, d'objets, de surfaces, d'eau stockée et de sources d'eau ont été collectés lors de contrôles ponctuels inopinés après l'inscription de base et analysés pour Escherichia coli. Les rapports des soignants concernant la diarrhée ont été obtenus pour les enfants de moins de 5 ans à un suivi de 6 mois. RÉSULTATS: E. coli a été détecté dans 73% des échantillons de rinçage des mains des enfants et des soignants, 69% des échantillons de sol des aires de jeux pour enfants, 54% des échantillons d'aliments pour enfants, 38% des objets et des surfaces que les enfants mettaient en bouche, 74 % des échantillons d'eau stockée et 40% des échantillons de sources d'eau. Les enfants de moins de 5 ans avec E. coli sur leurs mains avaient un risque de diarrhée significativement plus élevé au suivi de 6 mois (rapport de cotes: 2,03 (intervalle de confiance à 95%: 1,05, 3,92)). CONCLUSION: Les résultats de l'étude de cohorte du programme REDUCE ont montré que la contamination des mains des enfants est associée aux maladies diarrhéiques dans les régions rurales de la RDC et à une forte contamination fécale dans les aires de jeux et les aliments pour enfants. Ces résultats fournissent des données démontrant le besoin urgent de fournir des espaces de jeu propres aux jeunes enfants et des interventions ciblant l'hygiène des mains pour réduire l'exposition pédiatrique aux pathogènes fécaux.

Detection of canine parvovirus types 2b and 2c in canine faecal samples contaminating urban thoroughfares in Brazil.

Canine parvovirus type 2 (CPV-2) is a highly contagious virus that causes acute gastroenteritis in dogs all over the world. Because of its stability in the environment, CPV-2 can remain infective for a long time, especially if protected in organic matter. To demonstrate CPV-2's potential as an environmental hazard for nonimmunized susceptible hosts, we investigated 50 faecal samples collected from public areas in a municipality of Paraná state, Brazil. Seven samples tested positive for CPV by a PCR assay targeting the partial VP2 gene, with three strains being confirmed as CPV-2b variant and one as CPV-2c variant by sequence analysis. These findings were supported by phylogenetic analysis, and the species identity of faecal samples source was confirmed by canine mitochondrial DNA amplification and sequencing. Our results demonstrate the presence of CPV in canine faeces contaminating urban thoroughfares and reinforce the importance of environmental control to reduce the potential exposure risks to susceptible hosts.

Comprehensive assessment of handwashing and faecal contamination among elementary school children in an urban slum of Indonesia.

OBJECTIVE: Globally, the challenge of handwashing with soap (HWWS) still exists despite the importance of HWWS being shown previously. This study aimed to evaluate faecal contamination on the hands of children and to find factors related to faecal contamination from handwashing techniques, HWWS, knowledge and awareness of water, sanitation, and hygiene (WASH), and a comprehensive WASH index. METHODS: The study was conducted at two elementary schools with 169 children in a densely populated area of Bandung, Indonesia. The survey involved handwashing observation using a checklist, hand bacteria sampling and questionnaires. RESULTS: Most children (98.7%) had faecal contamination. Girls had significantly fewer Escherichia coli than boys (P < 0.05). Ability in handwashing techniques, HWWS, and knowledge and awareness of WASH were poor in the lower grades. Escherichia coli counts were negatively correlated with handwashing technique (r = -0.171, P < 0.05), HWWS (r = -0.225, P < 0.01) and the WASH index (r = -0.205, P < 0.05). CONCLUSIONS: Proper handwashing technique and HWWS at appropriate times can reduce faecal contamination. Moreover, it is important that both grade-based and gender-based handwashing education be considered in elementary school education.

OBJECTIF: A l'échelle mondiale, le défi du lavage des mains au savon (HWWS) existe toujours, en dépit de l'importance révélée de ce procédé. Cette étude visait à évaluer la contamination fécale sur les mains des enfants et à trouver des facteurs liés à la contamination fécale résultant des procédés de lavage des mains, du lavage des mains au savon, de la connaissance et de la sensibilisation à l'eau, aux sanitaires et à l'hygiène (WASH), ainsi qu'un indice WASH détaillé. MÉTHODES: L'étude a été menée dans deux écoles élémentaires avec 169 enfants dans une zone densément peuplée de Bandung, en Indonésie. L'enquête comprenait l'observation du lavage des mains à l'aide d'une liste de contrôle, un échantillonnage bactérien sur les mains et des questionnaires. RÉSULTATS: La plupart des enfants (98,7%) avaient une contamination fécale. Escherichia coli était nettement moins présent chez les filles que chez les garçons (p <0,05). L'aptitude dans les techniques de lavage des mains, le lavage des mains au savon, ainsi que la connaissance et la sensibilisation au WASH étaient faibles dans les classes inférieures. Les comptages d'E. Coli corrélaient négativement avec la technique de lavage des mains (r = -0,171 ; p <0,05), le lavage des mains au savon (r = 0,225 ; p <0,01) et l'indice WASH (r= - 0,205 ; p <0,05). CONCLUSIONS: Une technique de lavage des mains appropriée et un lavage des mains au savon à des moments opportuns peuvent réduire la contamination fécale. De plus, il est important de prendre en compte l'éducation au lavage des mains basée sur le niveau et le sexe dans l'enseignement primaire.

Detection of Escherichia coli in ready-to-eat fresh vegetables using broad-host-range recombinant phages.

AIM: To construct a simple method to detect Escherichia coli in ready-to-eat fresh vegetables using broad-host-range recombinant phages. METHODS AND RESULTS: Firstly, a gene encoding cytochrome c peroxidase (CCP) chromogenic enzyme was inserted into genomes of wild-type phages IP008 and IP052 to produce recombinant phages IP008BK and IP052BK. They were then used in the production of the chromogenic enzyme (CCP) through infection into E. coli. The method was then examined in the colorimetric detection of E. coli K12 in broth, and its appearance was confirmed by a significant change in absorbance after a few minutes of the enzyme assay. Secondly, the protocol using the recombinant phages for the detection of E. coli in vegetables, that is, lettuce and mustard greens, was investigated. A low E. coli concentration at 4 CFU per g vegetable was detected within 16·5 h that is of a shorter duration than agar plate methods and in some commonly known phage-based methods. CONCLUSION: The existence of E. coli as a faecal contamination indicator in two types of ready-to-eat fresh vegetables, that is, lettuce and mustard greens, can be identified by the broad-host-range recombinant phages. SIGNIFICANCE AND IMPACT OF STUDY: The method is simple and convenient since it enables the detection of E. coli without expensive apparatus. It is applicable to other types of food samples.

Comparison of an alcohol-based hand sanitation product with a traditional chlorhexidine hand scrub technique for hand hygiene preparation in an equine hospital.

AIMS: To investigate the efficacy of an alcohol gel-based hand antisepsis protocol compared with a traditional chlorhexidine-based protocol under conditions of routine clinical contamination, and following heavy faecal contamination. METHODS: Twelve adult participants were recruited and on four separate days completed a hand sanitation protocol using a chlorhexidine scrub or an alcohol-based gel, with hands that were grossly clean but contaminated or with faecal contamination. Bacterial samples were obtained from participants' hands before sanitation, immediately after and then 2 hours later. All samples were cultured on blood and MacConkey agar and bacterial colonies counted after 48 hours. RESULTS: for clean contaminated hands, the percentage reduction in bacterial colonies on blood agar immediately after hand sanitation was similar for both protocols (p=0.3), but was greater for the alcohol gel than chlorhexidine after 2 hours (p=0.005). For hands with faecal contamination, the percentage reduction in bacterial colonies on blood agar was similar for both protocols immediately and 2 hours after sanitation (p>0.2), but positive cultures were obtained on blood agar from samples collected after both protocols, for almost all participants. CONCLUSIONS: The results indicate equivalent efficacy of the alcohol-based gel and the pre-surgical chlorhexidine protocol. CLINICAL RELEVANCE: The alcohol-based gel protocol is an effective hand asepsis technique for grossly clean contaminated hands and those following faecal contamination, with comparable efficacy to chlorhexidine based scrub.

Development of a passive sampler based on a polymer inclusion membrane for total ammonia monitoring in freshwaters.

A passive sampler for determining the time-weighted average total ammonia (i.e. molecular ammonia and the ammonium cation) concentration (C TWA) in freshwaters, which incorporated a polymer inclusion membrane (PIM) as a semi-permeable barrier separating the aqueous source solution from the receiving solution (i.e. 0.8 mol L(-1) HCl), was developed for the first time. The PIM was composed of dinonylnaphthalene sulfonic acid (DNNS) as a carrier, poly (vinyl chloride) (PVC) as a base polymer and 1-tetradecanol as a modifier. Its optimal composition was found to be 35 wt% commercial DNNS, 55 wt% PVC and 10 wt% 1-tetradecanol. The effect of environmental variables such as the water matrix, pH and temperature were also studied using synthetic freshwaters. The passive sampler was calibrated under laboratory conditions using synthetic freshwaters and exhibited a linear response within the concentration range 0.59-2.8 mg L(-1) NH4(+) (0.46-2.1 mg N L(-1)) at 20 °C. The performance of the sampler was further investigated under field conditions over 7 days. A strong correlation between spot sampling and passive sampling was achieved, thus providing a proof-of-concept for the passive sampler for reliably measuring the C(TWA) of total ammonia in freshwaters, which can be used as an indicator in tracking sources of faecal contamination in stormwater drains.

Occurrence of enteric viruses in reclaimed and surface irrigation water: relationship with microbiological and physicochemical indicators.

AIMS: To assess the prevalence of enteric viruses in different irrigation water sources and in the irrigated produce, and the possible links with microbiological and physicochemical water characteristics. METHODS AND RESULTS: The prevalence and levels of Escherichia coli, Norovirus (NoV) genogroup I (GI) and II (GII), as well as Hepatitis A virus were assessed in three types of water: surface water (surface-W), reclaimed water subjected to secondary treatment (secondary-W) and reclaimed water subjected to tertiary treatment (tertiary-W), as well as in zucchini irrigated with these irrigation water sources. Chemical oxygen demand (COD), turbidity, total suspended solids, alkalinity and maximum filterable volume (MFV) were also measured in the water. Higher prevalence of NoV in secondary-W (GI 100%, GII 55·6%) and tertiary-W (GI 91·7%, GII 66·7%) compared with surface-W (GI 58·4%, GII 22·2%) was observed. Nov GI showed positive correlation with E. coli (Spearman's correlation coefficient = 0·68, P < 0·01), and with some physicochemical parameters such as COD (0·52, P < 0·01), turbidity (0·52, P < 0·01) and MFV (0·54, P < 0·01). Escherichia coli and enteric viruses were not detected in zucchini. CONCLUSION: There is a potential risk of contamination of crops with NoV when reclaimed water is used for irrigation. SIGNIFICANCE AND IMPACT OF THE STUDY: Increase the knowledge on the prevalence of enteric viruses in different irrigation water sources, and its consequences for fresh produce safety.

Investigation on the temporal variation and source tracking of faecal bacteria in a forest dominated watershed (Comox Lake), British Columbia, Canada.

AIMS: The aims of this study were to investigate the temporal variation in Escherichia coli density and its sources at the drinking water intake of Comox Lake for a period of 3 years (2011-2013). METHODS AND RESULTS: Density of E. coli was assessed by standard membrane filtration method. Source tracking of E. coli were done by using BOX-A1R-based rep-PCR DNA fingerprinting method. Over the years, the mean E. coli density ranged from nondetectable to 9·8 CFU 100 ml(-1) . The density of E. coli in each of the years did not show any significant difference (P > 0·05); however, a comparatively higher density was observed during the fall. Wildlife was (64·28%, 153/238) identified as the major contributing source of E. coli, followed by human (18·06%, 43/238) and unknown sources (17·64%, 42/238). Although the sources were varied by year and season, over all, the predominant contributing sources were black bear, human, unknown, elk, horse and gull. CONCLUSIONS: The findings of this investigation identified the multiple animal sources contributing faecal bacteria into the drinking water intake of Comox Lake and their varying temporal occurrence. SIGNIFICANCE AND IMPACT OF THE STUDY: The results of this study can reliably inform the authorities about the most vulnerable period (season) of faecal bacterial loading and their potential sources in the lake for improving risk assessment and pollution mitigation.

Virulence and antimicrobial resistance of Enterococcus faecium isolated from water samples.

UNLABELLED: The aim of this study was to determine the incidence of Enterococcus species and six virulence factors of Enterococcus faecium which were isolated from surface water and wells. Fifteen different water samples, which were used for drinking as well as agricultural irrigation, were collected from nine private wells and surface water from six rivers located at the east of Tehran. The Ent. faecium isolates were tested for their resistance to 10 antibiotics and their virulence factors were detected using multiplex PCR for esp, acm, gelE, asa1, cylA and hyl genes. The most predominant species in 315 isolates were Ent. faecium (n = 118) followed by Enterococcus galinarom (n = 110), Enterococcus mundeti (n = 18), Enterococcus hirea (n = 37) and Enterococcus casselifelavus (n = 32). The resistance rates were observed in 41·5, 27·1, 12·7, 6·8 and 1·7% isolates for tetracycline, erythromycin, ampicillin, ciprofloxacin and chloramphenicol respectively. None of the Ent. faecium isolates were resistant to vancomycin, teicoplanin, linezolid, gentamicin and quinuspristin-dalfopristin. Virulence determinant was found in 84·7, 33·9, 16·1 and 2·5% of isolates for acm, asa1, esp, cylA respectively. None of the isolates carried hyl and gelE gene. The presence of virulence factors and antibiotic resistance indicated that water might be an important source of dissemination of virulent enterococci. SIGNIFICANCE AND IMPACT OF THE STUDY: Contamination of drinking or recreational water by human or animal faecal waste is a major public health threat. In this study, we determine the incidence of Enterococcus species and six virulence factors of Enterococcus faecium which were isolated from surface water and wells. Results from this study suggest that the presence of Ent. faecium in natural and well waters was found to be significant in rural areas of Tehran. Resistant to erythromycin among Ent. faecium was relatively high and the incidence of acm and asa1 among our isolates was common overall.

Sewage-fed aquaculture: a sustainable approach for wastewater treatment and reuse.

This study assesses the long-term sustainability for operation and maintenance (O&M) of sewage-fed aquaculture-based sewage treatment system. The study focused on the integrated assessment of an engineered pond system of 8 million liters per day capacity in the city of Karnal, the State of Haryana, northern India. Major areas during the assessment included health, environmental, societal and institutional views aspects as well as the quality of treated effluent subjected for reuse. The treatment facility met the Indian regulatory standards (downstream reuse and discharge into the legally permitted water bodies) in terms of physical-chemical parameters. The total coliform and faecal coliform removal were up to 2-3 log units; nevertheless, it was not capable to come across the bacterial count requirement (<1,000 per 100 mL to minimise human health risk in aquaculture practices). The system was able to generate sufficient net income required for routine O&M. Annual revenue collected by the Municipal Corporation from the lease of the facility as well as selling of treated wastewater was $3,077 and $16,667-$25,000, respectively. The additional benefit from the facility for the farmers included the saving of fertilizers and cheapest source of water available for irrigation. Recycling of treated sewages for irrigation is also returned nutrients to the surrounding farms in Karnal. This exercise has saved significant quantities of chemical fertilizer (26-41 Ton of nitrogen, 10-18 Ton of phosphorous and 38-58 Ton of potassium per year) and the overall benefit for farmers during cultivation of one acre of crop was calculated to be approximately $133 per year.

Toys and toilets: cross-sectional study using children's toys to evaluate environmental faecal contamination in rural Bangladeshi households with different sanitation facilities and practices.

OBJECTIVE: To evaluate household faecal contamination using children's toys among 100 rural Bangladeshi households categorised as 'cleaner' (toilet that reliably separates faeces from the environment and no human faeces in/around living space) or 'less clean' (no toilet or toilet that does not reliably separate faeces from the environment and human faeces in/around living space). METHODS: We distributed toy balls to each household and rinsed each study toy and a toy already owned by the household in 200 ml of Ringer's solution. We enumerated faecal coliforms and faecal streptococci from each rinse using membrane filtration methods. RESULTS: Study toys from 39 cleaner households had lower mean faecal coliform contamination than toys from 61 less clean households (2.4 log10 colony-forming units (CFU)/200 ml vs. 3.2 log10 CFU/200 ml, P = 0.03). However, wealth measures explained a portion of this relationship. Repeat measures were moderately variable [coefficient of variation (CV) = 6.5 between two toys in the household at the same time, CV = 37.6 between toys in the household at two different times 3-4 days apart]. Too few households owned a non-porous toy to compare groups without risk of bias. CONCLUSION: In rural Bangladesh, improved sanitation facilities and practices were associated with less environmental contamination. Whether this association is independent of household wealth and whether the difference in contamination improves child health merit further study. The variation found was typical for measures of environmental contamination, and requires large sample sizes to ascertain differences between groups with statistical significance.

Faecal contamination in China: Trends, sources, and driving mechanisms.

Faecal contamination of surface waters is a global public health and economic burden. Here, we constructed a 30-year dataset to analyse the spatiotemporal trends and driving mechanisms of faecal coliforms (FCs) in China. We found that previous national policies to reduce water pollution have significantly improved the quality of surface water and, correspondingly, faecal contamination. However, the downward trend in FC levels has been more gradual than that for physico-chemical pollutants, and this trend may be exaggerated. Our results show that the driving mechanisms of faecal pollution were seasonal and complex. During the dry season, forests and grasslands were the source landscapes that exacerbated faecal pollution; during the wet season, urbanisation dominated, highlighting China's poorly designed drainage systems. Our projections revealed that faecal contamination will continue to worsen from 2022 to 2035, highlighting the need for pollution control. In the future, faecal indicators should be included in routine monitoring, evaluation, and assessment at the national level. Moreover, coordinated design of forest, grassland, and wetland landscapes is recommended for faecal pollution control at the regional level, whereas stormwater-related source control needs to be further strengthened at the urban level.

Agricultural and urban practices are correlated to changes in the resistome of riverine systems.

The objective of this study was to comprehensively characterise the resistome, the collective set of antimicrobial resistance genes in a given environment, of two rivers, from their source to discharge into the sea, as these flow through areas of different land use. Our findings reveal significant differences in the riverine resistome composition in areas of different land uses, with increased abundance and diversity of AMR in downstream agricultural and urban locations, with the resistome in urban areas more similar to the resistome in wastewater. The changes in resistome were accompanied by changes in microbial communities, with a reduction in microbial diversity in downstream agricultural and urban affected areas, driven mostly by increased relative abundance in the phyla, Bacteroidetes and Proteobacteria. These results provide insight into how pollution associated with agricultural and urban activities affects microbial communities and influences AMR in aquatic water bodies. These results add valuable insights to form effective strategies for mitigating and preserving aquatic ecosystems. Overall, our study highlights the critical role of the environment in the development and dissemination of AMR and underscores the importance of adopting a One Health approach to address this global public health threat.

Real-time karst groundwater monitoring and bacterial analysis as early warning strategies for drinking water supply contamination.

Karst aquifers have been globally exploited as a reliable source of drinking water but their intrinsic characteristics (concentrated recharge, high groundwater flow velocities, etc.) and the increase of anthropogenic pressures makes them highly vulnerable to pollution. Continuous monitoring of karst springs constitutes an effective approach for identifying episodic groundwater contamination and assuring safety conditions in drinking water supply systems. This study aims to improve groundwater protection insights through an integrated methodological approach based on real-time measurements of continuous water parameters coupled to bacterial analysis for the characterization of contamination events in a carbonate karst aquifer of a mountainous and rural area in S Spain. For this purpose, environmental, hydrodynamic and physico-chemical data in addition to bacterial activity (Escherichia coli) analysis were gathered from the analysis of eight flooding events at the two main outlets. In these karst springs, partially captured for drinking water supply, the recurrent turbid groundwater episodes suppose an important limitation for groundwater exploitation during several days, but also a concerning human health risk. The results revealed the different flow and sediment dynamics and mixing processes which determine the impact of faecal contamination derived from human activities on the karst groundwater drained by each spring. The described processes control the variable influence of allogenic recharge, which provokes notable differences regarding response times and maximum values of turbidity and associated bacterial activity in the investigated outlets. The outcomes of this work highlight the usefulness of the applied methodological framework to set the bases for an efficient implementation of early-warning strategies to prevent public health issues worldwide.

Pepper mild mottle virus as an effective tool in microbial source tracking for deficient domestic on-site water treatment systems.

Pollution from domestic on-site wastewater treatment systems (OWTS) is a significant contaminant pressure in many rural catchments. However, due to their design, and dispersed proliferation, it is difficult to assess their impact. Water testing methodologies employ bacterial culturing methods and chemical analysis which may lose resolution and/or specificity being confounded by diffuse agricultural sources within a rural environment. In this study, we successfully assessed the applicability of Pepper Mild Mottle Virus (PMMoV) as a human faecal source tracker for deficient on-site wastewater treatment systems. The transport of PMMoV was first studied in the effluent of a 30 cm deep soil column which was dosed for 510 days with primary influent from a conventional septic system. The removal of PMMoV through the 30 cm deep soil column was quantified with a 5-day seeding trial employing primary influent mixed with PMMoV sourced from Tabasco pepper product ®. The trial was then carried out at field scale with the seeding solution dosed into an operational percolation trench receiving septic tank effluent which had been instrumented for porewater sampling. Samples were taken at depths of 10 cm, 30 cm, and 50 cm across the length of the trench at distances of 1 m, 7.5 m, and 17.5 m from the inlet of the trench. PMMoV was detected on all days of the trial, with a peak concentration of 1 × 106 found at the rear of the trench on day 2 of the seeding trial. Finally, to assess the effectiveness of PPMoV as a microbial source tracking tool from a water receptor perspective, three rural catchments with high densities of OWTSs were sampled and analysed for hourly variations in biological parameters which included total coliforms, Escherichia coli, PMMoV, and chemical parameters total organic carbon, total nitrogen, and total carbon. PMMoV was detected in all river samples over a 24-hour period, thereby indicating its suitability as a tracer of human wastewater effluent in such environments with multiple diffuse sources.

Current status of microbial source tracking applications in constructed wetlands serving as nature-based solutions for water management and wastewater treatment.

Microbial source tracking (MST) has been recognised as an effective tool for determining the origins and sources of faecal contamination in various terrestrial and aquatic ecosystems. Thus, it has been widely applied in environmental DNA (eDNA) surveys to define specific animal- and human-associated faecal eDNA. In this context, identification of and differentiation between anthropogenic and zoogenic faecal pollution origins and sources are pivotal for the evaluation of waterborne microbial contamination transport and the associated human, animal, and environmental health risks. These concerns are particularly pertinent to diverse nature-based solutions (NBS) that are being applied specifically to secure water safety and human and ecosystem well-being, for example, constructed wetlands (CWs) for water and wastewater treatment. The research in this area has undergone a constant evolution, and there is a solid foundation of publications available across the world. Hence, there is an early opportunity to synthesise valuable information and relevant knowledge on this specific topic, which will greatly benefit future work by improving NBS design and performance. By selecting 15 representative research reports published over 20 years, we review the current state of MST technology applied for faecal-associated contamination measures in NBS/CWs throughout the world.

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.

Quantitative source apportionment of faecal indicator bacteria from anthropogenic and zoogenic sources of faecal contamination.

Recreational bathing waters are complex systems with diverse inputs from multiple anthropogenic and zoogenic sources of faecal contamination. Faecal contamination is a substantial threat to water quality and public health. Here we present a comprehensive strategy to estimate the contribution of faecal indicator bacteria (FIB) from different biological sources on two at-risk beaches in Dublin, Ireland. The daily FIB loading rate was determined for three sources of contamination: a sewage-impacted urban stream, dog and wild bird fouling. This comparative analysis determined that the stream contributed the highest daily levels of FIB, followed by dog fouling. Dog fouling may be a significant source of FIB, contributing approximately 20 % of E. coli under certain conditions, whereas wild bird fouling contributed a negligible proportion of FIB (<3 %). This study demonstrates that source-specific quantitative microbial source apportionment (QMSA) strategies are vital to identify primary public health risks and target interventions to mitigate faecal contamination.

Hand hygiene and water quality assessment in schools of Muthanna province, Southern Iraq.

INTRODUCTION: The severe drought and prolonged heat waves in Iraq have adversely affected the water quality supplied to public facilities. Schools are among the most affected facilities by water scarcity. This work aims to evaluate the level of students' hand hygiene, and the quality of municipal (MW) and drinking water (DW) in some schools of Al-Muthanna Province, Iraq. METHODOLOGY: Between October 2021 and June 2022, a total of 324 water samples from 162 schools and 2,430 hand swabs (HSs) from 1,620 students (1,080 males and 540 females) were collected. Some physicochemical standards of water were assessed besides investigating faecal contamination in water and students' hands using Escherichia coli as an indicator. RESULTS: All MW samples were faecally contaminated with poor standards of pH, turbidity, total dissolved solids, color, and chlorine. Despite the good physicochemical standards of all DW samples, E. coli was observed in 12% of samples. Hand hygiene levels dropped by 2.5-fold within a few hours after school entry compared to early-morning levels (before school entry). Male students were 1.5- and 1.7-fold more prone to hand contamination than female students either inside or outside school, respectively. An increasing chlorine tolerance by E. coli was observed in water samples with turbidity > 5 NTU and pH > 8. CONCLUSIONS: The students' hand hygiene level decreases within a few hours of entering school, particularly among male students. Residual-free chlorine < 0.5 mg/L with high turbidity and alkalinity in water is insufficient for 100% prevention of E. coli contamination.