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Anecdotal evidence and available literature indicated that contaminated water played a major role in spreading the prolonged cholera epidemic in Malawi from 2022 to 2023. This study assessed drinking water quality in 17 cholera-affected Malawi districts from February to April 2023. Six hundred and thirty-three records were analysed. The median counts/100 ml for thermotolerant coliform was 98 (interquartile range (IQR): 4-100) and that for Escherichia coli was 0 (IQR: 0-9). The drinking water in all (except one) districts was contaminated by thermotolerant coliform, while six districts had their drinking water sources contaminated by E. coli. The percentage of contaminated drinking water sources was significantly higher in shallow unprotected wells (80.0% for E. coli and 95.0% for thermotolerant coliform) and in households (55.8% for E. coli and 86.0% for thermotolerant coliform). Logistic regression showed that household water has three times more risk of being contaminated by E. coli and two and a half times more risk of being contaminated by thermotolerant coliform compared to other water sources. This study demonstrated widespread contamination of drinking water sources during a cholera epidemic in Malawi, which may be the plausible reason for the protracted nature of the epidemic. [ABSTRACT FROM AUTHOR]

Discharge of untreated wastewater into water bodies pollutes the receiving waters. This study assessed the impact of abattoir and Kampala designers' effluent discharge on the water quality of the Yemoja River in Abeokuta, Nigeria. Twenty-seven water samples collected at three points, covering 180 m length, for 6 months were assessed for physicochemical parameters and metals and compared with the World Health Organization (WHO) and Standard Organization of Nigeria (SON) permissible standards. Most discharge point levels were found to be higher than their corresponding upstream and downstream values. Temperature, turbidity, magnesium, alkalinity, DO, TSS, phosphate, lead, BOD and potassium were found to be higher than normal levels for river water as prescribed by the WHO and SON while parameters like TDS, TS, calcium, chloride, nitrate, sulphate, iron and COD were lower than the standards. The total coliform values were higher than both national and international permissible limits, indicating contamination by human sewage or animal droppings. The water quality index indicated polluted water that is unfit for consumption. Findings from this research indicate that butchering and tie-and-dye activities have impacted river Yemoja water quality. Therefore, wastewater from the abattoir and textile industries be treated before discharge into water bodies. [ABSTRACT FROM AUTHOR]

Rivers are impacted by microbial faecal pollution from various sources. We report on a short-term faecal pollution event at the pre-alpine Austrian river Traisen caused by the large cultural event FM4 Frequency music festival, with around 200,000 visitors over 4 days. We observed a massive increase of the faecal indicator bacteria (FIB) intestinal enterococci during the event, while Escherichia coli concentrations were only slightly elevated. This increase poses a significant potential health threat to visitors and people recreating downstream of the festival area. A plausible explanation for the uncoupling of the two FIBs may have been a differential persistence caused by a combination of factors including water temperature, solar radiation, and the excessive presence of personal care products (PCPs) in the river water. However, a potential impact of PCPs on FIB assay performance cannot be ruled out. Our observations are relevant for other intensively used bathing sites; detailed investigations on persistence and assay performance of the FIB in response to different ingredients of PCPs are highly recommended. We conclude that for future festivals at this river or other festivals taking place under similar settings, a more effective management is necessary to reduce deterioration in water quality and minimise health risks. [ABSTRACT FROM AUTHOR]

The potability of water, including underground sources, is constantly affected by human activities. To assess water quality and water security in rural and urban areas of southern Brazil, a quantitative, retrospective analysis of water samples collected monthly by the Brazilian health authorities (19,687 samples from 2013 to 2021) was performed. In rural areas, 5,979 water samples (77.54%) were found to be contaminated by coliform bacteria and 3,431 (44.50%) by Escherichia coli. In addition, 1,616 (20.95%) of the contaminated samples were significantly correlated with rainfall amount. In urban areas, 1,268 (10.95%) of the samples contained coliform bacteria and 293 (2.53%) of these samples contained E. coli, with the factor of rainfall associated with 1,081 samples (9.33%) with bacterial contamination. In terms of physicochemical parameters, turbidity exceeded the national standard (5 uT) in 448 (2.32%) samples and fluoride fell below the required level (0.8 mg/L) in 106 samples (0.54%). The presence of free residual chlorine (0.2–2.0 mg/L) was verified in 846 samples (14.38%) in rural areas and in 10,825 samples (56.13%) in urban areas. These results suggest a strong association between rainfall factors and physicochemical alterations, as well as the risk of greater microbial contamination of water for human consumption. [ABSTRACT FROM AUTHOR]

The presence and level of faecal indicator bacteria are important factors in estimating the microbiological quality of surface water and the risk of human infection upon exposure to this water. Until 2014, ISO 9308-1:2000 was available and used to enumerate faecal indicator Escherichia coli in bathing water. In 2014, this ISO was technically revised and replaced by ISO 9308-1:2014. This ISO introduced a less selective method for enumeration of E. coli that allows non-specific growth from waters containing high levels of bacteria, such as surface waters. This implies that currently there is no suitable reference membrane filtration method for the compliance monitoring of official bathing sites for E. coli according to the European Bathing Water Directive. Here, the performance characteristics of three chromogenic culture media, namely Tryptone Bile X-glucuronide (TBX) agar, Chromogenic Coliform Agar (CCA), and CHROMagar E. coli/Coliform (ECC) were investigated at 44 °C for water with varying levels of bacteria according to ISO 13843:2017. Based on performance characteristics, colony counts, and practical usage, TBX appeared the most suitable culture medium for the enumeration of E. coli in bathing water and other waters with high levels of background bacteria, such as surface water in agricultural areas and wastewater discharge points. [ABSTRACT FROM AUTHOR]

The coastal area of the southern Lake Baikal with the population over 35,000 people remains an attractive spot for both tourists and local residents. Despite high anthropogenic impact, a detailed assessment of water quality in this area has not been performed so far. Here, we performed a comprehensive evaluation of the quality of the surface, bottom and interstitial water in rivers, lacustrine water and wastewater in the southern Lake Baikal region. We analyzed 37 samples for the presence of fecal enterococci, Escherichia coli and assessed their hydrochemical parameters: concentrations of nutrients (nitrate-N, nitrite-N, ammonium-N and phosphate-P), dissolved oxygen and amount of ions (HCO3- + SO4 2- + Cl- + Ca2+ + Mg2+ + Na+ + K+). In addition, the temperature, pH and electrical conductivity were also measured. We found that multiple areas around South Baikal suffer from microbiological and hydrochemical pollution. We conclude that ecological situation in this area requires immediate attention from local authorities, more efficient wastewater management systems should be constructed in the settlements. We also conclude that interstitial waters from the lake's splash zone represent an effective and sensitive indicator of sanitary-microbiological and hydrochemical pollution and their analysis can be included in the standard protocol of water quality assessment for all types of water bodies. [ABSTRACT FROM AUTHOR]

Recreational water use is an important source of human enteric illness. Enhanced (episodic) surveillance of natural recreational waters as a supplement to beach monitoring can enrich our understanding of human health risks. From 2011 to 2013, water sampling was undertaken at recreational sites on a watershed in eastern Canada. This study compared the prevalence and associations of human enteric pathogens and fecal indicator organisms. Beach water samples had lower pathogen presence than those along the main river, due to different pollution sources and the hydrological disposition. Pathogen profiles identified from the beach sites suggested a more narrow range of sources, including birds, indicating that wild bird management could help reduce public health risks at these sites. The presence and concentration of indicator organisms did not differ significantly between beaches and the river. However, higher concentrations of generic Escherichia coli were observed when Salmonella and Cryptosporidium were present at beach sites, when Salmonella was present at the river recreational site, and when verotoxigenic E. coli were present among all sites sampled. In this watershed, generic E. coli concentrations were good indicators of potential contamination, pathogen load, and elevated human health risk, supporting their use for routine monitoring where enhanced pathogen testing is not possible. [ABSTRACT FROM AUTHOR]

Laguna Lake is an economically important resource in the Philippines, with reports of declining water quality due to fecal pollution. Currently, monitoring methods rely on counting fecal indicator bacteria, which does not supply information on potential sources of contamination. In this study, we predicted sources of Escherichia coli in lake stations and tributaries by establishing a fecal source library composed of rep-PCR DNA fingerprints of human, cattle, swine, poultry, and sewage samples (n = 1,408). We also evaluated three statistical methods for predicting fecal contamination sources in surface waters. Random forest (RF) outperformed k-nearest neighbors and discriminant analysis of principal components in terms of average rates of correct classification in two- (84.85%), three- (82.45%), and five-way (74.77%) categorical splits. Overall, RF exhibited the most balanced prediction, which is crucial for disproportionate libraries. Source tracking of environmental isolates (n = 332) revealed the dominance of sewage (47.59%) followed by human sources (29.22%), poultry (12.65%), swine (7.23%), and cattle (3.31%) using RF. This study demonstrates the promising utility of a library-dependent method in augmenting current monitoring systems for source attribution of fecal contamination in Laguna Lake. This is also the first known report of microbial source tracking using rep-PCR conducted in surface waters of the Laguna Lake watershed. [ABSTRACT FROM AUTHOR]

Laguna Lake is the largest inland freshwater body in the Philippines. Although it is classified to be usable for agricultural and recreational purposes by the country's Department of Environment and Natural Resources (DENR), studies looking at lake ecology revealed severe fecal contamination which contributes to the deterioration of water quality. Determining the sources of fecal contamination is necessary for lake protection and management. This study utilized a library-independent method of microbial source tracking (LIM-MST) to identify sources of fecal contamination in selected Laguna Lake stations and tributaries. Genetic markers of the host-associated Escherichia coli, heat-labile toxin (LTIIA) and heat-stable II (STII), were used to identify cattle and swine fecal contaminations, respectively. Meanwhile, human mitochondrial DNA (mtDNA) was used to identify human fecal contamination. Results identified the presence of agricultural and human fecal contamination in Laguna Lake Stations 1 and 5, Mangangate River, and Alabang River. The selected sites are known to be surrounded by residential and industrial complexes, and most of their discharges find their way into the lake. The identification of the specific sources of fecal contamination will guide management practices that aim to regulate the discharges in order to improve the water quality of Laguna Lake. [ABSTRACT FROM AUTHOR]

Water quality deterioration in source waters poses increased health, environmental, and economic risks. Here, we genotyped Cryptosporidium spp. obtained from water samples of Laguna Lake, Philippines, and its tributaries for the purpose of source-tracking fecal contamination. A total of 104 surface water samples were collected over a 1-year period (March 2018 to April 2019). Detection of Cryptosporidium was carried out using genus-specific primers targeting a fragment of the small subunit (SSU) rRNA gene. The study revealed 8 (14%) tributary samples and 1 (2.77%) lake sample positive for contamination. The species were determined to be C. parvum (n = 4), C. muris (n = 2), C. hominis (n = 1), C. galli (n = 1), C. baileyi (n = 1), C. suis (n = 1), as well as rat genotype IV (n = 1). Two species were detected in duck (C. baileyi) and cattle (C. parvum) fecal samples. The data presented suggest that Cryptosporidium contamination is likely to come from sewage or human feces as well as various agricultural sources (i.e. cattle, swine, and poultry). This information reveals the importance of mitigating fecal pollution in the lake system and minimizing health risks due to exposure to zoonotic Cryptosporidium species. [ABSTRACT FROM AUTHOR]

Fecal pollution of water is a serious concern because it is associated with the transmission of pathogens. The aim of this study was to analyze the occurrence of group A rotavirus (RVA) in surface waters from the Arias--Arenales River in Salta, a northern city in Argentina, and to define possible sources of fecal viral pollution. A total of 116 water samples were analyzed and RVA was detected in 3.4% (95% CI: 0.1-7.0%), with concentrations ranging from 1.9 X 105 to 3.8 X 106 genome copies per liter. RVA strains were characterized as G1P[8], G4P[8] and G9P[8], which are common genotypes circulating in the local population. The Arias--Arenales River presented unusual and sporadic contamination by RVA, originated from stormwater discharges and a variety of non-identified sources, and support the essential need of viral indicators for enhanced monitoring of water quality. [ABSTRACT FROM AUTHOR]

The aim of this study was to identify the main sources of fecal pollution at popular beaches and rivers in the island of Trinidad. Escherichia coli enumeration and microbial source tracking (MST) were used to identify the primary sources of fecal bacteria contamination at the sites. Nineteen sites exceeded USEPA water quality standards for safe recreational use. Highest levels of fecal contamination were recorded on the central and west coasts of the island and included Brickfield River (4,839 MPN 100 ml¹), Orange Valley Bay (2,406.6 MPN 100 ml¹) and Chaguaramas Bay (1,921.2 MPN 100 ml¹). MST detected human (HF183) fecal pollution at ~63%, birds at ~67%, chicken at ~36% and cattle (BacCow) at ~34% of the sites. MST is a useful and rapid method for identifying major sources of fecal pollution in rivers and beaches. In Trinidad water bodies, the main sources of fecal pollution were humans and birds. The large number of sites with elevated levels of fecal pollution detected is particularly alarming and represents a serious public health risk. [ABSTRACT FROM AUTHOR]

Proper water quality monitoring is a valuable tool for water resource management, helping to identify polluting sources and risks related to the use of water resources. One of the main types of contamination found in Brazilian water bodies is fecal contamination, which originates mainly from point source pollution through wastewater disposal. Thus, this study analyzed water quality monitoring data from the responsible environmental body (Minas Gerais Institute of Water Management, IGAM), related to the fecal contamination indicator (FCI), for the years 2000--2018. This was done for the Minas Gerais portion of the São Francisco River basin (SFRB-MG), one of the most important basins in the country. The 10 sub-basins in the area were compared using statistical tools. The work found significant differences between the sub-basins in terms of FCI concentration, highlighting the most impacted ones (SF2, SF3, and SF5) as also being the most densely populated. It is necessary to invest in sanitation measures in order to ensure that water resources are preserved, as well as to reduce the public health risks of downstream municipalities that are supplied with previously contaminated water. [ABSTRACT FROM AUTHOR]

Water is an indispensable commodity for the survival of all living beings and for their well-being. The objective of this work is to evaluate the level of pollution of different drinking water sources consumed and its link with health in Pelengana commune, Mali. Samples of water were taken from various sources, namely, hand pumps, boreholes, dug wells, and shallow wells for physical, chemical, heavy metals, and bacteriological analyses, using American Public Health Association (APHA) Standard Techniques. Results revealed that the nitrate-nitrogen (NO3 N) values of the water samples from the different water sources had concentrations exceeding the United States Environmental Protection Agency's (US-EPA) regulation of 10 mg/L, as well as World Health Organization Guideline for Drinking Water Quality (WHO GDWQ) (11 mg/L). The same applies to heavy metals such as Cd, Pb, and Fe, in which, concentrations exceed their allowable limits in certain locations. Moreover, apart from water samples from some different boreholes, total coliform, and Escherichia coli have been detected in all selected water sources, which indicates fecal contamination. In all, there is a pressing need to stop the consumption of drinking water from contaminated sources and to effect appropriate treatment. [ABSTRACT FROM AUTHOR]

Water-borne diseases like diarrheagenic Escherichia coli (DEC)-induced gastroenteritis are major public health problems in developing countries. In this study, the microbiological quality of water from mines and shallow wells was analyzed for human consumption. Genotypic and phenotypic characterization of DEC strains was performed. A total of 210 water samples was analyzed, of which 153 (72.9%) contained total coliforms and 96 (45.7%) E. coli. Of the E. coli isolates, 27 (28.1%) contained DEC genes. The DEC isolates included 48.1% Shiga toxin-producing E. coli (STEC), 29.6% enteroaggregative E. coli (EAEC), 14.9% enteropathogenic E. coli (EPEC), 3.7% enterotoxigenic E. coli (ETEC), and 3.7% enteroinvasive E. coli (EIEC). All the STECs had cytotoxic effects on Vero cells and 14.8% of the DEC isolates were resistant to at least one of the antibiotics tested. All DEC formed biofilms and 92.6% adhered to HEp-2 cells with a prevalence of aggregative adhesion (74%). We identified 25 different serotypes. One EPEC isolate was serotype O44037:H7, reported for the first time in Brazil. Phylogenetically, 63% of the strains belonged to group B1. The analyzed waters were potential reservoirs for DEC and could act as a source for infection of humans. Preventive measures are needed to avoid such contamination. [ABSTRACT FROM AUTHOR]

Residents in rural communities across Canada collect potable water from aquifers. Fecal contaminants from sewage and agricultural runoffs can penetrate aquifers, posing a public health risk. Standard methods for detecting fecal contamination test for fecal indicator bacteria (FIB), but the presence of these do not identify sources of contamination. In contrast, DNA-based diagnostic tools can achieve this important objective. We employed quantitative polymerase chain reaction (qPCR) and high-throughput DNA sequencing to trace fecal contamination sources in Wainfleet, a rural Ontario township that has been under the longest active boil water advisory in Canada due to FIB contamination in groundwater wells. Using traditional methods, we identified FIBs indicating persistent fecal pollution in well waters. We used 16S rRNA sequencing to profile groundwater microbial communities and identified Campylobacteraceae as a fecal contamination DNA marker in septic tank effluents (STEs). We also identified Turicibacter and Gallicola as a potential cow and chicken fecal contamination marker, respectively. Using human specific Bacteroidales markers, we identified leaking septic tanks as the likely primary fecal contamination source in some of Wainfleet's groundwater. Overall, the results support the use of sequencing-based methods to augment traditional water quality testing methods and help end-users assess fecal contamination levels and identify point and non-point pollution sources. [ABSTRACT FROM AUTHOR]

The study's objectives were to assess the extent to which packaged water producers follow product registration procedures and to assess the relationship between product registration and drinking water quality in Accra, Ghana. Following preliminary analysis of a national water quality survey, 118 packaged sachet water samples were collected by sampling all brands sold by 66 vendors. A sample of vendors was selected from two high-income and two low-income areas of Accra, Ghana. Sachet packaging and labelling details were recorded and compared to a regulatory database to assess product registration. All samples were weighed and tested for faecal indicator bacteria and selected physico-chemical parameters. Product registration numbers and brand names could be matched to regulatory records for 77 of 118 sachets (65.2%). All samples tested were compliant with national water quality standards for faecal indicator bacteria and nitrate. Brand registration was not associated with any of the quality indicators considered. The results of this study suggest that while a substantial proportion of sachet water is sold without formal product registration, the microbial quality of the unlicensed water is consistently high in Accra, Ghana. Further examination of regulatory enforcement and monitoring will be needed to ensure sustained high water quality over time. [ABSTRACT FROM AUTHOR]

Because Clostridium perfringens spores are both specific to sewage contamination and environmentally stable, they are considered as possible conservative indicators of human fecal contamination and possible surrogates for environmentally stable pathogens. This review discusses the reasons and summarizes methods for monitoring spores in water. Cultural methods are still preferred over qPCR for routine water quality monitoring because of their low costs. Membrane filter (MF) methods are preferred over the more laborious and less accurate most probable number methods. The most commonly used MF media are TSC medium and mCP medium. TSC normally allows higher recoveries than mCP. TSC produces fewer false-positive results than mCP; however, it does produce more false-negatives. Two newer methods have substantial potential, CP Chromo Select agar, which allows better recoveries and greater specificity than mCP, and the Fung double tube method, which creates anaerobic conditions and allows enumeration of colonies in tubes in 5-6 hours. Aerobic spores are not associated with fecal contamination but they can be surrogates for environmentally stable pathogens in monitoring water for treatment efficacy; Bacillus cereus spores are normally measured on nutrient agar by the MF method. [ABSTRACT FROM AUTHOR]

Urbanization affects the microbial loading into tropical streams, but its impact on water quality varies across watersheds. Rainfall in tropical environments also complicates microbial dynamics due to high seasonal and annual variations. Understanding the dynamics of fecal contamination in tropical surface waters may be further hindered by limitations from the utilization of traditional microbial indicators. We measured traditional (Enterococcus spp. and Escherichia coli), as well as alternate (enterophages and coliphages) indicators of fecal contamination in a tropical watershed in Puerto Rico during a 1-year period, and examined their relationship with rainfall events across an urbanization gradient. Enterococcus spp. and E. coli concentrations were 4 to 5 logs higher in non-urbanized or pristine sites when compared to enterophages and coliphages, suggesting that traditional fecal indicator bacteria may be natural inhabitants of pristine tropical waters. All of the tested indicators were positively correlated with rainfall and urbanization, except in the most urbanized sites, where rainfall may have had a dilution effect. The present study indicates that utilizing novel indicators of microbial water quality may improve the assessment of fecal contamination and pathogen risk for tropical watersheds. [ABSTRACT FROM AUTHOR]

Inadequate protection of water sources, and poor household hygienic and handling practices have exacerbated fecal water contamination in Kenya. This study evaluated the rate and correlates of thermotolerant coliform (TTC) household water contamination in Kericho District, Western Kenya. Culture and multiplex polymerase chain reaction (PCR) techniques were used to characterize TTCs. The disk diffusion method was used for antibiotic susceptibility profiling of pathogenic Escherichia coli. Out of the 103 households surveyed, 48 (46.6%) had TTC contaminated drinking water (TTC levels of >10 cfu/100 mL). Five of these households were contaminated with pathogenic E. coli, including 40% enteroaggregative E. coli, 40% enterotoxigenic E. coli, and 20% enteropathogenic E. coli. All these pathogenic E. coli strains were multidrug resistant to sulfamethoxazole/trimethoprim, ampicillin, tetracycline and ampicillin/sulbactam. Rural household locality, drinking water hand contact, water storage container cleaning practice, hand washing before water withdrawal, water source total coliforms <10 cfu/100 mL, temperature, and free chlorine levels were associated with TTC contamination of household drinking water. Significant proportions of household drinking water in Kericho District are contaminated with TTCs including with pathogenic multidrug-resistant E. coli. Source and household hygiene and practices contribute significantly to drinking water contamination. [ABSTRACT FROM AUTHOR]

A rational-based physical descriptive model (PDM) has been developed to predict the levels of Escherichia coli in water at a beach with dynamic conditions in the Greater Toronto Area (GTA), Ontario, Canada. Bacteria loadings in the water were affected not only by multiple physical factors (precipitation, discharge, wind, etc.), but also by cumulative effects, intensity, duration and timing of storm events. These may not be linearly related to the observed variations in bacteria levels, and are unlikely to be properly represented by a widely used multiple linear regression model. In order to account for these complex relationships, the amounts of precipitation and nearby creek discharge, the impact of various time-related factors, lag time between events and sample collection, and threshold for different parameters were used in determining bacteria levels. This new comprehensive PDM approach improved the accuracy of the E. coli level predictions in the studied beach water compared to the previously developed statistical predictive and presently used geometric mean models. In spite of the complexity and dynamic conditions at the studied beach, the PDM achieved 75% accuracy overall for the five case years examined. [ABSTRACT FROM AUTHOR]

Rising populations around coastal systems are increasing the threats to marine water quality. To assess anthropogenic fecal influence, subtidal waters were examined monthly for human- and ruminant-sourced Bacteroidales markers at 80 sites across six oceanographic basins of the Salish Sea (Washington State) from April through October, 2011. In the basins containing cities with individual populations >190,000, >50% of sites were positive for the human marker, while in the basins with high densities of dairy and cattle operations, ~30% of sites were positive for the ruminant marker. Marker prevalence was elevated in spring (April and May) and fall (October) and reduced during summer (June through September), corresponding with seasonal precipitation. By logistic regression, the odds of human marker detection increased with percentage of adjacent catchment impervious surface, dissolved nitrate concentration, and abundance of low nucleic acid bacteria, but decreased with salinity and chlorophyll fluorescence. The odds of ruminant marker detection increased with dissolved ammonium concentration, mean flow rate for the nearest river, and adjacent shoreline length. These relationships are consistent with terrestrial to marine water flow as a transport mechanism. Thus, Bacteroidales markers traditionally used for identifying nearby sources can be used for assessing anthropogenic fecal inputs to regional marine ecosystems. [ABSTRACT FROM AUTHOR]

Splash parks have been associated with infectious disease outbreaks as a result of exposure to poor water quality. To be able to protect public health, risk factors were identified that determine poor water quality. Samples were taken at seven splash parks where operators were willing to participate in the study. Higher concentrations of Escherichia coli were measured in water of splash parks filled with rainwater or surface water as compared with sites filled with tap water, independent of routine inspection intervals and employed disinfection. Management practices to prevent fecal contamination and guarantee maintaining good water quality at splash parks should include selection of source water of acceptable quality. [ABSTRACT FROM AUTHOR]

A prospective cohort epidemiological pilot study was performed at three tropical beaches with point-and non-point-sources of fecal pollution to characterize the risk of illness among swimmers and non-swimmers. There was an increased risk of illness in swimmers as compared to non-swimmers, even when waters met current microbial standards for recreational water quality. Illnesses included gastrointestinal (GI), skin and respiratory symptoms, earache and fever. Odds ratios (ORs) ranged from 0.32 to 42.35 (GI illness), 0.69 to 3.12 (skin infections), 0.71 to 3.21 (respiratory symptoms), 0.52 to 15.32 (earache) and 0.80 to 1.68 (fever), depending on the beach sampled. The indicators that better predicted the risks of symptoms (respiratory) in tropical recreational waters were total (somatic and male-specific) coliphages (OR 1/4 1.56, p<0.10, R² 1/4 3.79%) and Escherichia coli (OR 1/4 1.38, p<0.10, R² 1/4 1.97%). The present study supports the potential of coliphages as good predictors of risks of respiratory illness in tropical recreational waters. This is the first study that has determined risks of illness after exposure to tropical recreational waters with point- and non-point sources of fecal contamination. The results give an opportunity to perform epidemiological studies in tropical recreational waters in Puerto Rico which can include more participants and other indicators and detection techniques. [ABSTRACT FROM AUTHOR]

Diverse fecal and nonfecal bacterial contamination and nutrient sources (e.g. agriculture, human activities and wildlife) represent a considerable non-point source load entering natural recreational waters which may adversely affect water quality. Monitoring of natural recreational water microbial quality is most often based mainly on testing a set of microbiological indicators. The cost and labour involved in testing numerous water samples may be significant when a large number of sites must be monitored repetitively over time. In addition to water testing, ongoing monitoring of key environmental factors known to influence microbial contamination may be carried out as an additional component. Monitoring of environmental factors can now be performed using remote sensing technology which represents an increasingly recognized source of rigorous and recurrent data, especially when monitoring over a large or difficult to access territory is needed. To determine whether this technology could be useful in the context of recreational water monitoring, we evaluated a set of agroenvironmental determinants associated with fecal contamination of recreational waters through a multivariable logistic regression model built with data extracted from satellite imagery. We found that variables describing the proportions of land with agricultural and impervious surfaces, as derived from remote sensing observations, were statistically associated (odds ratio, OR = 11 and 5.2, respectively) with a higher level of fecal coliforms in lake waters in the southwestern region of Quebec, Canada. From a technical perspective, remote sensing may provide important added-value in the monitoring of microbial risk from recreational waters and further applications of this technology should be investigated to support public health risk assessments and environmental monitoring programs relating to water quality. [ABSTRACT FROM AUTHOR]

The present study sought to identify Escherichia coil sources in a small catchment and to use th agro-hydrological model soil and water assessment tool (SWAT) to estimate their impact on river water quality. The innovative aspects of this research are to assess the hourly variations of fecal contamination and to take these variations into account in the model to provide a better evaluation of river quality. Thus, water samples were taken weekly at the river outlet (n = 4) and 24-h monitorin sessions were performed during low and high-flow periods (n = 74). E. coil variations were found to be primarily linked to rainfall and not to resuspension mechanisms. Subdaily fluctuations and deviations were ±0.33 log10 cfu/100 mL and ±0.70 log10 cfu/100 mL for dry (<3 mm/day) and wet (>3 mm/day) weather, respectively. After river flow calibration, all known pollution sources (septic systems, manure spreading, farm discharges) were introduced into SWAT. The model reproduced th fecal contamination in the river and the use of subdaily deviations allowed us to evaluate the simulation quality and compare grab samplings with simulated daily E. coil concentration, thus confirming that the performance of the model is better when additional information on hourly concentration variations is used. [ABSTRACT FROM AUTHOR]

In order to understand the current status of rainwater harvesting (RWH) practices in Taiwan's schools, a study was carried out to examine the RWH system performance, water usage, and water quality in these sites. A total of 29 schools in various regions were selected for this investigation, including 7 in the northern, 7 in the central, 8 in the southern, and 7 in the eastern regions of Taiwan. Water quality indicators tested were: pH, temperature, conductivity, oxidation-reduction potential, suspended solid, total organic carbon, fecal coliform, and total coliform. From this study, it was found that RWH systems in these sites generally had two different designs: one that collected rainwater only, and one that collected both rainwater and grey water. From statistical analysis, it was found that water quality indicators such as suspended solids, total organic carbon, and fecal coliform were significantly affected by the water source and site location. Fecal coliforms in most of the sites we studied were high and not qualified for toilet flushing. The average water retention time of 2.4 months was long and considered to be the main reason to cause high fecal coliform counts. Finally, the benefit analysis was conducted to evaluate economic feasibility of rainwater harvesting for these schools. It turned out that 20% of them were able to gain economic benefits from using rainwater. [ABSTRACT FROM AUTHOR]

Same-day microbial water quality assessments are not possible with standard methods, which increases the possibility of public exposure to fecal pathogens. This study examined the efficacy of high-volume hollow fibre ultrafiltration coupled to biosensor detection for enterococci in marine waters to allow same-day public notification of poor water quality. Fifty-six 100 l ultrafiltered samples and 100 ml grab samples were collected weekly from May to July 2007. Post-ultrafiltration processing included sonication and micron sieve passage to remove interfering particulates, followed by centrifugation for secondary concentration. Levels of enterococci in grab and ultrafiltration samples were determined by a standard method (EPA method 1600) for calculation of recovery efficiencies and concentration factors. Each final retentate was analysed with the RAPTOR evanescent wave biosensor. Enterococci levels increased over 26,000-fold in final retentates. Enterococci were detected when ambient concentrations exceeded the regulatory standard for a single sample (≥105 CFU/100 ml), and detection was highly correlated with breaches of the single-sample regulatory limit. The combined procedure required 2.5 h for detection compared with 24 h for EPA method 1600. This field study achieved rapid detection of enterococci by ultrafiltration, secondary concentration and biosensor analysis, and demonstrates its potential usefulness for water quality monitoring. [ABSTRACT FROM AUTHOR]

Better understanding of Escherichia coli population dynamics and genetic variability in the secondary habitat is essential to improve fecal contamination monitoring and contamination pathway characterization. In this study, water samples were collected monthly over a one-year period at eight locations in the Catoma Creek watershed, a mixed land-use watershed in Central Alabama. E. coli concentrations varied from 17 to 12,650 CFU/100 ml and were well correlated with stream flow rates. Repetitive sequence-based PCR DNA fingerprinting was used to generate 271 unique DNA fingerprint patterns from 502 E. coli isolated from water samples. Cluster analysis showed an overall similarity of 32.8% across all DNA fingerprints. Multivariate analysis of variance (MANOVA) showed that E. coli genotypes had a tendency to cluster according to season and stream flow rather than sampling sites. MANOVA of a subset of data within a given season and flow rate, however, revealed some geographical differentiation between urban and rural sampling sites. The results indicate that genetic diversity of E. coli populations was not only high in the secondary habitat but also varied with season, flow conditions and, to a lesser extent, sampling location. To our knowledge, this is the first report relating E. coli genotype to stream flow. [ABSTRACT FROM AUTHOR]

Water-borne illness, primarily caused by fecal contamination of drinking water, is a major health burden in the state of Andhra Pradesh, India. Currently drinking water is treated at the reservoir level and supplied on alternate days, necessitating storage in households for up to 48 hrs. We hypothesized that fecal contamination occurs principally during storage due to poor water handling. In this study we tested for coliform bacteria in water samples collected at distribution points as household storage containers were filled, and then tested containers in the same households 24-36 hours after collection. We also conducted an observational survey to make an assessment of water handling and hygiene. Ninety-two percent (47/51) of samples tested at supply points were adequately chlorinated and bacterial contamination was found in two samples with no residual chlorine. Samples collected from household storage containers showed an increase in contamination in 18/50 houses (36%). Households with contaminated stored samples did not show significant differences in demographics, water handling, hygiene practices, or sanitation. Nevertheless, the dramatic increase in contamination after collection indicates that until an uninterrupted water supply is possible, the point at which the biggest health impact can be made is at the household level. [ABSTRACT FROM AUTHOR]

The 'H2S test' is being advanced for microbiological water quality testing where conventional coliform based methods are impractical or too expensive. It involves ambient temperature incubation of water samples with nutrient formulated to generate hydrogen sulphide when 'faecal' bacteria are present. Recently a WHO review identified several concerns including the limited number of comparative studies, formulation variability, and false positives and negatives. In response we have compared the H2S test's ability to detect and quantify faecal contamination in an aquifer impacted by septic tank leachfields with measurements obtained concurrently using conventional bacterial indicators, coliphages, faecal sterol biomarkers, Cryptosporidium and Giardia. Like these other analytes, H2S testing detected a contamination gradient ranging from high (septic liquid) to moderate (exfiltration zones), to background (e.g. domestic bores), corresponding to indicator removal + dilution by factors >106>>>>>>>>>. Presence/absence tests could not distinguish between heavily and slightly contaminated waters, whereas multi-tube testing (e.g. 10 x 10 mL arrays) did. It was concluded that while the WHO review concerns are justified, the H2S test performance shows promise in sanitary survey work, can be improved by employing an mpn approach and has potential to aid in the protection of source water and identifying contaminated groundwater. [ABSTRACT FROM AUTHOR]

To ensure optimum quality at Bathing Waters, the control of diffuse sources of bacterial contamination is receiving increasing attention. As part of an initiative to improve the quality of the EU designated bathing waters on the Fylde Coast (North West England), a project was undertaken to quantify the faecal indicator load from birds and assess the significance on water quality. High bird counts are encountered on the Fylde Coast with gulls, feral pigeons and starlings being prominent. The piers at Blackpool make an attractive roost for starlings with numbers peaking at over 30,000 in late summer. Systematic recording of bird numbers and locations was undertaken during 2001/2. Estimates were also made of the daily faecal organism production by the different species. The spatial distribution of faecal organisms from the bird population was statistically linked to synoptic water quality data. This allowed estimates to be made of the contribution from birds to the faecal pollution load at the bathing waters. The work confirmed a statistically significant link between bird populations and water quality with a marked seasonal bias. [ABSTRACT FROM AUTHOR]

Achieving compliance with the mandatory standards of the 1976 Bathing Water Directive (76/160/EEC) is required at all UK identified bathing waters. In recent years, the Fylde coast has been an area of significant investments in 'point source' control, which have not proven, in isolation, to satisfactorily achieve compliance with the mandatory, let alone the guide, levels of water quality in the Directive. The potential impact of riverine sources of pollution was first confirmed after a study in 1997. The completion of sewerage system enhancements offered the potential for the study of faecal indicator delivery from upstream sources comprising both point sources and diffuse agricultural sources. A research project to define these elements commenced in 2001. Initially, a desk study reported here, estimated the principal infrastructure contributions within the Ribble catchment. A second phase of this investigation has involved acquisition of empirical water quality and hydrological data from the catchment during the 2002 bathing season. These data have been used further to calibrate the 'budgets' and 'delivery' modelling and these data are still being analysed. This paper reports the initial desk study approach to faecal indicator budget estimation using available data from the sewerage infrastructure and catchment sources of faecal indicators. [ABSTRACT FROM AUTHOR]

Increasing concern about bathing water quality in Scotland has led to renewed interest in diffuse sources, as well as the already closely monitored municipal sewage effluents and combined sewer overflows (CSOs) that have been the subject of multi-million pound capital expenditure schemes for several years. Early investigations of diffuse sources focused on rural land uses. This paper is an initial effort to consider the possible significance of urban diffuse sources. A review of the potential for diffuse urban sources includes consideration of sewage pollution in surface water sewers, as well as non-human sources such as pigeon and other bird roosts, and faecal material from pets such as dogs and cats. Portobello beach in Edinburgh is the case study selected, because of earlier work done by Scottish Water and SEPA. The Figgate Burn crosses Edinburgh to discharge onto the beach at Portabello, and pollution sources in its catchment are described. Additional information is reported from Dunfermline, where the sewer network has provided examples of three ways in which sewage pollution can occur in urban streams, and also Scottish examples of measures to control some non-human sources (e.g. SUDS). [ABSTRACT FROM AUTHOR]

The supply of unfiltered disinfected drinking water from Melbourne's fully protected catchments means that the water-quality managers must ensure that the source water poses no public health risk. High turbidity is currently used as a surrogate of pathogens, and harvesting of water is based on its measurement. The work presented here summarises suspended particle and associated pathogen, microbial indicator and faecal biomarker concentrations collected to (a) quantify turbidity in an Australian water supply system and (b) assess the possibility of increasing water harvesting from selected tributaries. Pathogens and microbial indicators were present in low numbers in these source waters; increased turbidity during storm events was not associated with an increase in pathogen concentration. The results confirmed that protected catchments, along with good management, were effective barriers to pathogen contamination. Aesthetic issues still need to be addressed, but no measurable increase in microbiological risk was associated with storm-generated particles. [ABSTRACT FROM AUTHOR]

In this study the assessment of randomly amplified polymorphic DNA (RAPD) analysis was established as a molecular epidemiological tool. RAPD analysis was performed to differentiate faecal Escherichia coli isolates from human and animal sources. E. coli strains (128) were isolated from human and animal faeces (from cattle and sheep). Genomic DNA was extracted and randomly amplified polymorphic DNA-PCR (RAPD-PCR) fingerprinting was performed. Seven arbitrary primers were tested with a view to discriminating between E. coli isolates from humans and E. coli isolates from animals. RAPD profiles were analysed with hierarchical cluster analysis using an unweighted pair group method. RAPD profiles obtained with three of the tested primers (1247, 1290 and 1254) established a distinct differentiation between E. coli isolates from humans and E. coli from animals. Low levels of misclassification and high levels of specificity make RAPD a sensitive, efficient and reliable means of distinguishing closely related strains. [ABSTRACT FROM AUTHOR]

A survey of the microbiological and chemical quality of water supplies in the Bindura urban and peri-urban area was carried out over a three-year period from January 2000 to July 2003. Bindura is the provincial city of Mashonaland Central, situated 88 km from the national capital, Harare. Large-scale farming and mining activities in the area predispose water bodies to eutrophication and chemical pollutants, raising concerns about the safety of local water supplies. In this study, thermotolerant (faecal) coliform levels, total aerobic bacterial counts and physicochemical profiles were determined for municipal and borehole water as well as water supplies to mining and squatter communities. Although municipal and mining compound water supplies were of satisfactory microbial and chemical quality, borehole water supplies showed a seasonal fluctuation, with higher coliform counts in the wet season from November to March. Stream water supplies to a squatter camp in the peri-urban area consistently recorded coliform levels >1,800/100 mL and total aerobic plate counts of <2.8 x 106 CFU/mL. All cholera incidents recorded in 1999 and 2000 at the Provincial hospital were from peri-urban settlements and surrounding commercial farms while 1,045 to 2,632 cases of dysentery were also reported each year at the provincial hospital during the period 1997-2002. [ABSTRACT FROM AUTHOR]

Details are given of the application of Artificial Neural Networks (ANNs) to predicting the compliance of bathing waters along the coastline of the Firth of Clyde, situated in the south west of Scotland, UK. Water quality data collected at 7 locations during 1990-2000 were used to set up the neural networks. In this study faecal coliforms were used as a water quality indicator, i.e. output, and rainfall, river discharge, sunlight and tidal condition were used as input of these networks. In general, river discharge and tidal ranges were found to be the most important parameters that affect the coliform concentration levels. For compliance points close to the meteorological station, the influence of rainfall was found to be relatively significant to the concentration levels. [ABSTRACT FROM AUTHOR]

Enzymatic hydrolysis of fluorogenic substrates (4-methylumbelliferyl-β-D-galactoside, 4-methylumbelliferyl-β-D-glucuronide) has been used for rapid (25min) detection of indicators of faecal water pollution, i.e. coliform and tbermotolerant coliform bacteria. In the present work, enzymatic activities and different groups of bacteria (i.e. thermotolerant coliforms, coliforms, β-galactosidase positive and β-glucuronidase positive bacteria) from sewage effluent and polluted river water have been investigated. Ratios of the order of 1:10 between coliforms and β-galactosidase positive bacteria were demonstrated. The contribution from β-galactosidase positive non-coliform bacteria to the measured enzyme activity should not, therefore, be neglected. Numbers of β-glucuronidase positive non-coliforms indicate interference of this group in the rapid assay. [ABSTRACT FROM AUTHOR]

CHROMagar Liquid ECC (CLECC) was compared with membrane lauryl sulphate broth plus urea (mLS-UA) used routinely in Hong Kong for E. coli enumeration. E. coli appear as distinctive greenish-blue colonies on CLECC while other faecal coliforms are red in colour. CLECC performance was comparable to mLS with mixtures of faecal coliforms, E. coli and non-faecal coliforms. Beach, river, ground and waste water samples were used for further comparison. Results given by the two media were significantly correlated (P = <0.001). CLECC was superior to mLS-UA in sensitivity (99.1% vs 87.2%) and specificity (96.9% vs 59.8%) for detecting E. coli. On CLECC 95% of E. coli colonies were correctly identified but only 66.9% on mLS-UA. On average, time required for performing one E. coli enumeration test with CLECC was 1.2min/sample less than with mLS-UA. CLECC may enable the development of complete automation for enumerating E. coli. [ABSTRACT FROM AUTHOR]

A randomly amplified polymorphic DNA (RAPD) marker, localised to the glycine decarboxylase gene (gcvP) of Escherichia coli, has shown promise for use as a molecular marker for the identification E. coli isolates of human origin. Characterisation of the RAPD polymorphism has enabled development of target-specific primers for direct PCR detection of E. coli of human origin. A field trial was undertaken to investigate the suitability of the marker for detecting E. coli derived from sewage effluent discharged to a rural stream which already contained a substantial background level E. coli of animal origin. Multiplex PCR was performed on E. coli isolates from each sample site using the marker-specific primers in conjunction with primers directed towards a region of the β-glucuronidase (gusA) gene which served as an internal PCR control. Marker-positive strains were detected in raw sewage, treated effluent, stream water collected from immediately downstream of the effluent discharge and from a small tributary which ran down one side of the treatment plant. However, no marker-positive isolates were detected upstream of the treatment plant, despite the relatively high faecal coliform levels (mean = 3.5xl0³cfu/100ml) recorded at these sites. Further investigations on the side tributary revealed a possible entry point for sewage from the treatment system. Thus the PCR-based approach described here shows promise for the detection of human faecal contamination in rural environments and may be of use far other environmental applications such as the detection of septic tank leachate in rural catchments. [ABSTRACT FROM AUTHOR]

Oocysts of Cryptosporidium parvum can survive for several months in surface water, one of the main factors determining their success in environmental transmission and thus their health hazard via water. Several factors in the environment, e.g. temperature, presence of predators and exo-enzymes will probably influence oocyst survival. The high persistence of oocysts may also limit the value of traditional faecal indicator bacteria. The aim of this study was to determine the rate at which C parvum oocysts, E coli, faecal enterococci and C perfringens spores die in surface water and the influence of temperature and the presence of autochthonous (micro)organisms on the die-off rate. Microcosms with autoclaved river water were inoculated with the organisms. Microcosms with untreated river water were inoculated with concentrated primary effluent containing the bacteria and with C parvum oocysts. Microcosms were incubated at 5°C or 15°C at 100rpm. Viability of oocysts was monitored by in vitro excystation and dye-exclusion; viability of the bacteria was determined on appropriate selective media. When pseudo first-order die-off kinetics were assumed, the die-off rate of oocysts at 5°C was 0.010 log10/d and at 15°C, 0.006-0.024 log10/d. These rates underestimate die-off since oocyst disintegration was not accounted for. Incubation in autoclaved or untreated water did influence the die-off rate of oocysts at 15°C but not at 5°C. The die-off rate of E coli and enterococci was faster in the non-sterile river water than in autoclaved water at both temperatures. At 15°C, E coli (and possibly E faecium) even multiplied in autoclaved water. In untreated river water, the die-off of E coli and enterococci was approximately 10x faster than die-off of oocysts but die-off rates of C perfringens were lower than those of oocysts. As for oocysts, die-off of the bacteria and spores was faster at 15°C than at 5°C. Oocysts are very persistent in river water: the time required for a 10x reduction in viability being 40-160d at 15°C and 100d at 5°C. Biological/biochemical activity influenced oocyst survival at 15°C and survival of both vegetative bacteria at 5 and 15°C. The rapid die-off of E coil and enterococci makes them less suitable as indicators of oocyst presence in water. As C perfringens survived longer in untreated river water than oocysts, it may prove useful as an indicator of the presence of C parvum. [ABSTRACT FROM AUTHOR]

This study assessed the contribution of water from a stream on the microbial quality of a swimming beach. The faecal indicator bacterial concentrations/100mL in Kaelepulu Stream greatly exceeded the three USEPA recreational water quality standards (200 faecal coliform, 126 E. coli, 33 enterococci). The primary sources for these indicator bacteria were determined to be environmental/non-point sources (tributary streams, storm drains, duck faeces, soil, rain). Sewage discharge is another, although sporadic source. Monitoring waters for C. perfringens was the most reliable indicator of sewage contamination primarily because soil is not a major source of this bacterium. Water from this inland system was a source of faecal indicator recovered from shoreline water samples obtained from Kailua Beach, one of the most popular beaches in the state of Hawaii. [ABSTRACT FROM AUTHOR]

The general improvement in UK marine recreational water quality is attributed to the implementation of the EU Directives designed to protect the health of bathers and ensure adequate treatment of urban wastewaters. The effect of this legislation is often to remove the dominant source of faecal indicators which previously masked non-outfall sources. These have the potential to prevent the compliance of identified EU bathing waters with Directive 76/160/EEC standards for faecal coliform bacteria. Detailed investigative methods are outlined which have been employed to identify, quantify and reduce these sources. This problem requires detailed site specific investigation which is expensive when compared to the significant expenditures being committed to sewage treatment. [ABSTRACT FROM AUTHOR]