Article

Assessment of Enteric Pathogen Shedding by Bathers during Recreational Activity and its Impact on Water Quality

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Abstract

An assessment was made to determine the potential loading of enteric pathogenic protozoa and viruses into drinking water supply reservoirs by body contact recreation. These and other organisms of fecal origin are shed from the body during bathing. A literature review was conducted on the concentration of selected enteric viruses and protozoa during infection, the incidence of these infections, and duration of excretion. In addition, from existing literature, the amount of fecal material released during bathing was estimated from the shedding of fecal coliforms by bathers. The mean amount of fecal material shed per bather was estimated at 0.14[emsp4 ]gram. The concentration of protozoan parasites (Giardia or Cryptosporidium) in feces of infected persons can range from 105 to 107 per gram and enteric viruses (enteroviruses, adenoviruses, rotavirus) from 105 to 1012 per gram. From this information, the concentration of enteric pathogens, shed into the water, could be calculated for a group of bathers. This information can be used to model the impact of body contact recreation on water quality in reservoirs used for drinking water supplies. Such information is useful in assessing the required treatment of the water to meet water quality regulations.

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... This assumed that most of the variation is due to differences in bacterial concentration in fecal matter among individuals, with the rest coming from variations in the rate of fecal matter release. An alternative estimate is available in the model using 15-minute shower graywater data for the quantity of fecal coliforms divided by their concentration [47]. These rates are shown in Table 2. ...
... Age Group Low Mean High [46] All a 0.04 0.70 3.5 [47] Children b 0.67 21.1 c 667 [47] Adult 0.0067 0.21 c 6.67 a Values for 25 adults aged 20-84 in indoor pool C. Similar results were seen in the referenced study for the only child (10 years old) in outdoor pool D. b Families with small children 18 months to 9 years of age. c Geometric mean of the low and high rates. ...
... Age Group Low Mean High [46] All a 0.04 0.70 3.5 [47] Children b 0.67 21.1 c 667 [47] Adult 0.0067 0.21 c 6.67 a Values for 25 adults aged 20-84 in indoor pool C. Similar results were seen in the referenced study for the only child (10 years old) in outdoor pool D. b Families with small children 18 months to 9 years of age. c Geometric mean of the low and high rates. ...
Article
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Current regulatory codes for swimming pool disinfection separately regulate free chlorine (FC) and cyanuric acid (CYA). It is well-known that CYA affects disinfection rates by reversibly binding to FC in aqueous solutions. However, limits for these regulated parameters have neither systematically accounted for this chemistry nor been based on the risk of gastrointestinal illness. This study was intended to determine the minimum concentration of FC relative to CYA based on the risk of gastrointestinal illness from normal fecal sloughing of selected pathogens and to find a simple regulatory rule for jointly managing FC and CYA for consistent disinfection. Literature data on CYA’s effect on microbial inactivation rates were reanalyzed based on the equilibria governing hypochlorous acid (HOCl) concentration. A model was developed that considers the rates of pathogen introduction into pool water, disinfection, turbulent diffusive transport, and pathogen uptake by swimmers to calculate the associated risk of illness. Model results were compared to U.S. Environmental Protection Agency (EPA) untreated recreational water acceptable gastrointestinal illness risk. For Cryptosporidium, correlation between log inactivation and Chick–Watson Ct was far better when C refers to HOCl concentration than to FC (r = −0.96 vs. −0.06). The HOCl concentration had a small variation (± 1.8%) at a constant CYA/FC ratio for typical FC and CYA ranges in swimming pools. In 27 U.S. states, the allowed FC and CYA results in HOCl concentrations spanning more than a factor of 500. Using conservative values for a high bather load pool with 2 mg/L FC and 90 mg/L CYA, the model predicted a 0.071 annual probability of infection for Giardia, exceeding the EPA regulatory 0.036 limit for untreated recreational waters. FC and CYA concentrations in swimming pools should be jointly regulated as a ratio. We recommend a maximum CYA/FC ratio of 20.
... C&G are: resistant to chlorine, extremely small, require advanced filtration, present in high numbers, survive long periods in water, highly infectious at low doses and pose serious health consequences for immune-compromised individuals. Gerba (2000) describes the relationship between number of recreational visitors and percentage that shed enteric protozoans. Furthermore, on immersion, faecal shedding occurs with the release of faecal material with maximum shedding in the first 15 to 30 minutes. ...
... Furthermore, on immersion, faecal shedding occurs with the release of faecal material with maximum shedding in the first 15 to 30 minutes. Once faecal material is shed, Gerba (2000) found that the number of protozoan parasites ranged between 10 4 and 10 8 oocysts. Thus, C&G released in faeces are easily transmitted by humans through faecal shedding or alternatively by accidental faecal release (AFR). ...
... The numeric model was developed and configured to quantify and link recreation activity, faecal shedding of oocysts, sedimentation and surface mixing in a reservoir. The model was based on the approach of Gerba (2000) and extended to simulate the daily variation of Cryptosporidium oocysts based on: recreation visitor numbers, faecal shedding rate, dilution and sedimentation of oocysts within the reservoir. The model was enhanced to include mixing of oocysts within the surface layer during the summer (October through to June) when Logue Brook Dam is stratified. ...
Conference Paper
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Microbiological contamination of drinking water poses the greatest risk to public health. Recent studies show a strong link between recreation and contamination with the human infectious Cryptosporidium hominis. Furthermore, where recreation is allowed on a drinking water reservoir, the increased pathogen challenge is estimated to necessitate a 100-fold increase in the cost of treatment. The recent Parliamentary Inquiry in WA attracted considerable interest across Australia. The report endorsed the need to protect water sources, but also recognised societal benefits of recreation. The report also recommended increased protection of key strategic catchments and increased penalties for infringement. An Interagency Working Group is now formed and tasked with implementing the recommendations. This paper shows there is an optimal balance between allowing recreation activity in a drinking water catchment and still maintaining natural processes that provide safe drinking water at an affordable cost.
... This behavior pattern is accepted widely around the world (Dagevos & Voordouw, 2013). It is expected that by 2030 the demand for food of animal origin will be more than 50% compared to 2000(van Wagenberg et al., 2017 and according to Derner et al. (2017) the animal production should increase by 70% by 2050 to satisfy consumers' demands for meat and muscle products. This increase in demands requires the changes in the current livestock production patterns, which should be able to avoid extra pressure on the ecosystem, and aim for the "sustainability." ...
... Enteric viruses have fecal-oral route and are excreted in diarrheic feces in large concentrations (up to 10 11 viral particles per g) (Gerba, 2000). They have low infective doses (1-100) and are much more stable in the environment than enteric bacteria, usually used as fecal contamination indicators (for example Escherichia coli, or Salmonella spp.) (Noble, Lee, & Schiff, 2004). ...
... Sustainable development goals (SDGs; 2015-2030), constitute an extension of millennium development goals (MDGs;2000, and were adopted by all United Nations Member States as universal call to action for poverty eradication, global prosperity, and environment protection (Sachs, 2012;World Health Organization., 2015). ...
Chapter
The production of minimally processed foods is a critical process as the organoleptic characteristics of the food must be maintained. However, the treatments applied to this type of food may not be enough to eliminate the pre and postharvest foodborne microbiological contamination that can occur during the irrigation, fertilization, as well as the handling up to delivery and final consumption. In addition to bacterial and parasitic foodborne pathogens, enteric viruses pose health risks to consumers as they can be resistant to many of the standard procedures in the elaboration of minimally processed foods, while remaining stable at room temperature and refrigeration, as well as in raw or lightly cooked products (for example, bivalve molluscs). This chapter reviews human and zoonotic viral contamination in minimally processed foods and the current strategies for their control.
... This behavior pattern is accepted widely around the world (Dagevos & Voordouw, 2013). It is expected that by 2030 the demand for food of animal origin will be more than 50% compared to 2000(van Wagenberg et al., 2017 and according to Derner et al. (2017) the animal production should increase by 70% by 2050 to satisfy consumers' demands for meat and muscle products. This increase in demands requires the changes in the current livestock production patterns, which should be able to avoid extra pressure on the ecosystem, and aim for the "sustainability." ...
... Enteric viruses have fecal-oral route and are excreted in diarrheic feces in large concentrations (up to 10 11 viral particles per g) (Gerba, 2000). They have low infective doses (1-100) and are much more stable in the environment than enteric bacteria, usually used as fecal contamination indicators (for example Escherichia coli, or Salmonella spp.) (Noble, Lee, & Schiff, 2004). ...
... Sustainable development goals (SDGs; 2015-2030), constitute an extension of millennium development goals (MDGs;2000, and were adopted by all United Nations Member States as universal call to action for poverty eradication, global prosperity, and environment protection (Sachs, 2012;World Health Organization., 2015). ...
Chapter
In the last decades, the interest in new food products with improved functional properties that promote health benefits is growing. Agri-food by-products constitute an excellent bio-resource to obtain new prebiotics and functional oligosaccharides. Particularly, pectin-rich agricultural by-products are potential cost-effective sources of functional pectooligosaccharides (POS) that have been outlined in recent years as emerging prebiotics with numerous health-promoting effects. An important aspect that influences the functionalities of the POS is the extraction methods. In this sense, a variety of alternative methods have been described to obtain POS using different sources including conventional and emerging intensification technologies. Several biological activities of POS such as prebiotic, antidiabetic, anticholesterolemic, antiobesity, antitumor, antioxidant, antiinflamatory, and antimicrobial, among other, have been described. Therefore, POS could be excellent candidates to formulate functional food by the nutraceutical industry. This chapter collects the aforementioned aspects to give an overview of the potential of POS as functional compounds obtained from renewable resources.
... Viral contamination of aquatic environments represents a major public health concern, because these environments can become major routes of exposure to pathogens associated with outbreaks of acute gastrointestinal illnesses in humans, by the inadvertent ingestion of contaminated water during recreational activities (Koh et al. 2011;Vergara et al. 2016;Kauppinen et al. 2017). In addition, bathers may release a significant concentration of enteric viruses into the water through the release of feces during body contact recreation (Gerba, 2000). ...
... Water quality variables outlined in the regulations for Mexico (NOM-127-SSA1-1994:2000 include total coliforms and E. coli. However, bacterial indicators provide little to no information about other human pathogens that might be present, including viruses, which can lead to minimizing the potential for identification of additional health risks (Lee et al. 2013). ...
Article
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Aims: To determine the seasonal occurrence and diversity of norovirus (NoV) and human adenovirus (HAdV) in groundwater from sinkholes, and brackish water used for recreational activities in the karst aquifer of the Yucatan Peninsula, Mexico. Methods and results: Hollow fiber ultrafiltration was used to concentrate viruses and standard plaque assay methods were used to enumerate somatic and F+ specific coliphages as viral indicators. Real time quantitative polymerase chain reaction (qPCR) assays were used to estimate the number of genome copies for NoV strains GI, and GII, and HAdVs. The predominant NoV genotypes and HAdV serotypes were identified by comparative sequence analysis. Somatic and male F+ specific coliphages were detected at concentrations up to 94 and 60 plaque-forming units per 100 ml, respectively. The NoV genogroup I (GI) was associated with 50% of the sampled sites during the rainy season only, at concentrations ranging from 120 to 1,600 genome copies per liter (GC l-1 ). The NoV genogroup II (GII) was detected in 30% and 40% of the sampled sites during the rainy and dry seasons, respectively, at concentrations ranging from 10 to 290 GC l-1 . During the rainy and dry seasons, HAdVs were detected in 20% of the sites, at concentrations ranging from 24 to 690 GC l-1 . Identification of viral types revealed the presence of NoV GI.2, GII.Pe, GII.P16, and GII.P17, and HAdV F serotypes 40 and 41. Conclusions: These findings demonstrate that NoVs and HAdVs are prevalent as virus contaminants in the karst aquifer, representing potential health risks particularly during the rainy season, in one of the most important areas used for tourism in Mexico. Significance and impact of study: This is one of few studies conducted in karst aquifers that provide a foundational baseline of the distribution, concentrations, and diversity of NoVs and HadVs in these particular environments. This article is protected by copyright. All rights reserved.
... The list of viruses, which is summarized in Table 1, is very long (Fabiszewski de Aceituno et al., 2013) and includes viruses primarily transmitted via food or drinking water, such as enteroviruses, hepatitis A virus, hepatitis E virus, norovirus, and rotavirus (Vasickova et al., 2005;Bosch et al., 2018;Velebit et al., 2019). Humans infected with these viruses often shed large amounts of virus particles in the diarrheal feces (~10 5 to >10 12 infectious particles per ml or g) (Gerba, 2000;Bishop, 1996) while the infective dose is relatively low (~10 1 to 10 2 infectious particles) which easily leads to infection upon ingestion of the contaminated food (Anderson and Weber, 2004;Todd et al., 2008). The Table 1 list also includes some emerging zoonotic viruses capable of being transmitted via food (Koopmans and Duizer, 2004), such as SARS-CoV, Nipah virus (Luby et al., 2006), and highly pathogenic avian influenza (HPAI) virus (FAO/WHO Food and Agriculture Organization of the United Nations/World Health Organization, 2008) that can replicate in the human gastrointestinal tract and have animal reservoirs and are therefore a permanent threat for pandemics (Bosch et al., 2018). ...
... The more virus consumed in a food, the more likely an illness will result (Todd et al., 2008). Foodborne virus infections often result in shedding large amounts of virus particles in the diarrheal feces or vomitus (~10 5 to >10 12 infectious particles per ml or g) (Gerba, 2000;Bishop, 1996) that easily lead to infection upon ingestion of the contaminated food (Anderson and Weber, 2004;Todd et al., 2008). Since viruses do not replicate in non-living cells, the amount of infectious SARS-CoV-2 transferred this way would have to be massive to be sufficient to infect. ...
Article
Outbreaks of COVID-19 (coronavirus disease 2019) have been reported in workers in fish farms and fish processing plants arising from person-to-person transmission, raising concerns about aquatic animal food products' safety. A better understanding of such incidents is important for the aquaculture industry's sustainability, particularly with the global trade in fresh and frozen aquatic animal food products where contaminating virus could survive for some time. Despite a plethora of COVID-19-related scientific publications, there is a lack of reports on the risk of contact with aquatic food animal species or their products. This review aimed to examine the potential for Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2) contamination and the potential transmission via aquatic food animals or their products and wastewater effluents. The extracellular viability of SARS-CoV-2 and how the virus is spread are reviewed, supporting the understanding that contaminated cold-chain food sources may introduce SAR-CoV-2 via food imports although the virus is unlikely to infect humans through consumption of aquatic food animals or their products or drinking water; i.e., SARS-CoV-2 is not a foodborne virus and should not be managed as such but instead through strong, multifaceted public health interventions including physical distancing, rapid contact tracing, and testing, enhanced hand and respiratory hygiene, frequent disinfection of high-touch surfaces, isolation of infected workers and their contacts, as well as enhanced screening protocols for international seafood trade.
... Un baigneur apporte environ 35 millions de micro-organismes par l'intermédiaire de la peau, des muqueuses, des sécrétions rhinopharyngées des matières fécales, etc. (Spinasse, 2000). La quantité moyenne de selles émise par baigneur, en l'absence de tout incident de défécation, a été estimée à 140 mg, les enfants rejetant entre 10 mg et 10 g, les adultes entre 0,1 et 100 mg (Gerba, 2000). Les baigneurs rejettent des quantités importantes de germes pendant les 15 premières minutes d'immersion (Elmir et al., 2007). ...
... L'excrétion fécale par l'homme est estimée à 10 11 particules virales par gramme de selle (Gerba, 2000). ...
... Various studies have shown that bathers contribute to contamination of water, namely with Staphylococcus aureus, enteric viruses, protozoan parasites, IE, and fecal coliforms (Breittmayer and Gautier, 1978;Gerba, 2000;Elmir et al., 2007). In particular, it has been shown that bathers may develop enteric infections from contamination with stools of other bathers (Keene et al., 1994). ...
... Indeed, during this study, we observed parents encouraging children under 5 to urinate and defecate in the water, and others collected baby diapers after wringing them out in seawater. Gerba (2000) showed in a review of the literature that bathers of all ages shed enteric microorganisms through normal recreational water contact or accidental fecal release. In our study of the Prophète beach, the same issues were highlighted. ...
Article
Full-text available
A highly frequented beach in Marseille, France, was monitored on an hourly basis during a summer day in July 2018, to determine possible water and sand fecal pollution, in parallel with influx of beach users from 8 a.m. to 8 p.m. Fecal indicator bacteria were enumerated, together with four host-associated fecal molecular markers selected to discriminate human, dog, horse, or gull/seagull origins of the contamination. The antimicrobial resistance of bacteria in water and sand was evaluated by quantifying (i) the class 1, 2, and 3 integron integrase genes intI , and (ii) bla TEM , bla CTX–M , and bla SHV genes encoding endemic beta-lactamase enzymes. The number of beach users entering and leaving per hour during the observation period was manually counted. Photographs of the beach and the bathing area were taken every hour and used to count the number of persons in the water and on the sand, using a photo-interpretation method. The number of beach users increased from early morning to a peak by mid-afternoon, totaling more than 1,800, a very large number of users for such a small beach (less than 1 ha). An increase in fecal contamination in the water corresponded to the increase in beach attendance and number of bathers, with maximum numbers observed in the mid-afternoon. The human-specific fecal molecular marker HF183 indicated the contamination was of human origin. In the water, the load of Intl 2 and 3 genes was lower than Intl 1 but these genes were detected only during peak attendance and highest fecal contamination. The dynamics of the genes encoding B-lactamases involved in B-lactams resistance notably was linked to beach attendance and human fecal contamination. Fecal indicator bacteria, integron integrase genes intI , and genes encoding B-lactamases were detected in the sand. This study shows that bathers and beach users can be significant contributors to contamination of seawater and beach sand with bacteria of fecal origin and with bacteria carrying integron-integrase genes and beta lactamase encoding genes. High influx of users to beaches is a significant factor to be considered in order to reduce contamination and manage public health risk.
... Un baigneur apporte environ 35 millions de micro-organismes par l'intermédiaire de la peau, des muqueuses, des sécrétions rhinopharyngées des matières fécales, etc. (Spinasse, 2000). La quantité moyenne de selles émise par baigneur, en l'absence de tout incident de défécation, a été estimée à 140 mg, les enfants rejetant entre 10 mg et 10 g, les adultes entre 0,1 et 100 mg (Gerba, 2000). Les baigneurs rejettent des quantités importantes de germes pendant les 15 premières minutes d'immersion (Elmir et al., 2007). ...
... L'excrétion fécale par l'homme est estimée à 10 11 particules virales par gramme de selle (Gerba, 2000). ...
... The frequency and duration of contact and the degree of exposure are, in fact, greater for soccer players than golfers. The risk of As exposure through the pathway of dermal absorption with contaminated soil is based on the assumption that As is in a form that may cause cancer (i.e., in an inorganic form) [56,70]. Such an assumption is fully reasonable for As in the irrigation water, in which As has been presumed to exist as arsenate species [44]. ...
... Furthermore, within the scenarios, exposure time, frequency of contact with soil, and fraction of body parts exposed may be greater than in our calculation. For example, during the windy season, which The risk of As exposure through the pathway of dermal absorption with contaminated soil is based on the assumption that As is in a form that may cause cancer (i.e., in an inorganic form) [56,70]. Such an assumption is fully reasonable for As in the irrigation water, in which As has been presumed to exist as arsenate species [44]. ...
Article
Full-text available
The aim of this research was to estimate the risk of human exposure to arsenic due to sporting activities in a private soccer club in Mexico, where arsenic-contaminated water was regularly used for irrigation. For this purpose, the total concentration in the topsoil was considered for risk assessment. This was accomplished through three main objectives: (1) measuring arsenic concentrations in irrigation water and irrigated soils, (2) determining arsenic spatial distribution in shallow soils with Geographical Information Systems (GIS) using geostatistical analysis, and (3) collecting field and survey data to develop a risk assessment calculation for soccer activities in the soccer club. The results showed that the average arsenic concentrations in shallow soils (138.1 mg/kg) were 6.2 times higher than the Mexican threshold for domestic soils (22 mg/kg). Furthermore, dermal contact between exposed users and contaminated soils accounted for a maximum carcinogenic risk value of 1.8 × 10 −5 , which is one order of magnitude higher than the recommended risk value, while arsenic concentrations in the irrigation water were higher (6 mg/L) than the WHO's permissible threshold in drinking water, explaining the contamination of soils after irrigation. To the best of our knowledge, this is the first risk study regarding dermal contact with arsenic following regular grass irrigation with contaminated water in soccer pitches.
... 3.1.7 Les autres sources possibles de contamination D'autres sources possibles de contamination existent, par exemple dues aux baigneurs et à des déversements illicites (Gerba 2000;O'Keefe, D'arcy et al. 2005;Sobsey, Perdue et al. 2003). Gerba (2000) a estimé que la charge fécale de 7000 personnes fréquentant une plage un week-end pouvait représenter entre 10 11 et 10 16 virus. ...
... Les autres sources possibles de contamination D'autres sources possibles de contamination existent, par exemple dues aux baigneurs et à des déversements illicites (Gerba 2000;O'Keefe, D'arcy et al. 2005;Sobsey, Perdue et al. 2003). Gerba (2000) a estimé que la charge fécale de 7000 personnes fréquentant une plage un week-end pouvait représenter entre 10 11 et 10 16 virus. Ces sources sont principalement saisonnières (saison estivale) ou hebdomadaire (fin de semaine). ...
... A number of studies have linked bather shedding to pathogen levels (Elmir et al. 2007, Graczyk et al. 2010). Gerba (2000) estimated that the average person in contact with recreational water sheds about 0.14 g fecal matter per bathing event. Previous work has also found correlations between bather density and Cryptosporidium parvum, Giardia duodenalis, Enterocytozoon bieneusi (Graczyk et al. 2010), Staphylococcus aureus (including methicillin-resistant strains, (Elmir et al. 2007, Enns et al. 2012, and fungal (Brandão et al. 2002, Stevens et al. 2012) abundance at beaches. ...
Preprint
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Humans may be exposed to microbial pathogens at recreational beaches via environmental sources, such as water, sand, and aerosols. Although infectious disease risk from exposure to waterborne pathogens has been an active area of research for decades, sand is a relatively unexplored reservoir of pathogens and fecal indicator bacteria (FIB). Beach sand and water habitats provide unique advantages and challenges to pathogen introduction, growth, and persistence, as well as continuous exchange between habitats. Models of FIB and pathogen fate and transport in sandy beach habitats can help predict the risk of infectious disease from recreational water use, but filling knowledge gaps such as decay rates and potential for microbial growth in beach habitats is necessary for accurate modeling. Climatic variability, whether natural or anthropogenically-induced, adds complexity to predictive modeling, but may increase human exposure to waterborne pathogens via extreme weather events, warming of water bodies and sea level rise in many regions. The popularity of human recreational beach activities, combined with predicted climate change scenarios, could amplify the risk of human exposure to pathogens and related illnesses. Other global change trends such as increased population growth and urbanization are expected to exacerbate contamination events and the predicted impacts of increasing levels of waterborne pathogens on human health. Such changes will alter microbial population dynamics in beach habitats, and will consequently affect the assumptions and relationships used in population models and quantitative microbial risk assessment (QMRA). Here, we discuss the literature on microbial population and transport dynamics in sand-water continuum habitats at beaches, how these dynamics can be modeled, and how climate change and other anthropogenic influences (e.g., land use, urbanization) should be considered when using and developing more holistic, beachshed-based models.
... Noroviruses can be found in faeces in variable numbers even before the onset of symptoms in infected individuals. On average, people have ca 0.14 g of faeces on their bodies when they enter a swimming pool [7]. For children, this amount can vary from 0.01 to 10 g [8]. ...
Article
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In October 2016, an outbreak of norovirus occurred among attendees of a Halloween-themed party at a public swimming pool in the south-east of England. Norovirus genogroup II was confirmed in 11 cases. In the retrospective cohort study of pool users, 68 individuals (37 female and 31 male), with a median age of 11 years (range: 0-50 years), met the case definition of developing diarrhoea or vomiting between 6 and 72 h after the pool visit. Multivariable analysis showed that increasing age was associated with a reduced risk of illness (odds ratio = 0.91; 95% confidence interval: 0.83-0.99). Pool behaviours (swallowing water) and the timing of visit (attending pool party after automatic dosing system was switched off) were independently associated with increased risk. Environmental investigations revealed that the automatic dosing system was switched off to reduce chlorine levels to an intended range of 0.5-1 parts per million to facilitate the use of a commercial red dye. There was a lack of compliance with the operator's own pool operating procedures, particularly on maintaining effective chlorine levels in pool water, recording of test results and recording of actions undertaken. This outbreak highlights the risks of lowering chlorine levels when using pool water colourants.
... It is because the microorganisms are excreted in faces and body fluids. The faces are the source of different pathogens such as Salmonella spp., Shigella spp., Escherichia coli, noroviruses, rotaviruses, hepatitis A, Cryptosporidium spp., Giardia lamblia (Chan et al., 2006;Ozawa et al., 2007;Gerba, 2000;Kohl et al., 2002;Medus et al., 2006). The research indicates that during diarrhoea hands may be easily contaminated with billions of pathogens cells (Barker & Jones, 2005). ...
Chapter
Design activity is a broad concept, and in general it is a process in which certain functional requirements of customers are met by shaping or configuring products, services and processes. Any operations managers, who are involved in designing, are called designers. When the position of equipment or way of working in the process is changed, it is a design decision because it influences the physical shape and nature of processes. At the strategic level, design is defined as shaping the network of operations providing products and services. At the operational level, it is defined as the systems of processes, technologies and people that constitute operational processes. In this chapter, selected aspects of production processes design have been highlighted.
... This beach had a high density of swimmers who remained in the water for extended periods and had little wave action, potentially increasing the risk for NoV transmission. Even asymptomatic infected individuals can have high densities of NoV in stool (10 5 −10 9 per gram of feces) [25] and swimmers without symptoms can shed approximately 0.14 grams of fecal material per swimming event [26]. Nearly all immunoconversions were unaccompanied by gastrointestinal symptoms. ...
Article
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Background Swimming in fecally-contaminated waterbodies can result in gastrointestinal infections. However, the pathogenic microorganisms responsible are not well understood because sporadic cases of illness are not reported completely, exposure information is often not collected, and epidemiology studies rely on self-reported symptoms. Noroviruses are considered a likely cause because they are found in high densities in sewage, resistant to wastewater treatment and survive in the environment. In this study, saliva samples were collected from subjects at a beach in Puerto Rico and tested for evidence of norovirus-specific IgG responses as an indicator of incident norovirus infection. Methods Saliva samples were collected from 1298 participants using an oral swab. Samples were collected on the day of the beach visit (S1); after 10–12 days (S2); and after three weeks (S3). Saliva was tested for IgG responses to GI.1 and GII.4 noroviruses using a microsphere based multiplex salivary immunoassay. Immunoconversion was defined as a four-fold increase in median fluorescence intensity (MFI) from S1 to S2 with the S3 sample at least three times above the S1 MFI. Results Thirty-four subjects (2.6%) immunoconverted to GI.1 or GII.4 norovirus. Swimmers who immersed their head in water had a higher rate of immunoconversion (3.4%), compared to either non-swimmers (0.0%, p = 0.003) or waders and non-swimmers combined (0.4%, Odds Ratio: 5.07, 95% Confidence Interval:1.48–17.00). Immunoconversion was not associated with gastrointestinal symptoms. Conclusions This is the first study to demonstrate an association between swimming at a beach impacted by fecal contamination and asymptomatic norovirus infection. The findings implicate recreational water as potentially important transmission pathway for norovirus infection.
... Coliform has been used as an indicator for the fecal contamination in water (Gerba, 2000). In particular, E. coli (which is a subgroup of fecal coliforms) has become the preferred indicator. ...
Thesis
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In arid countries, reclaimed water in irrigation is a widespread practice. Therefore, robust treatment designs are prerequisite to obtain effluent quality that conforms to the legal requirements and guidelines for reuse and health standards. Vertical flow constructed wetlands (VFCWs) are attractive decentralized treatment plants in many countries and communities. VFCWs are capable of providing adequate treatment for organic and solids removal, even though there are limitations on nutrient and pathogen removal. Within the context of the SMART project, various VFCW systems were investigated, in Germany and Jordan, to optimize nitrogen removal using sustainable and low cost options to guarantee the safe reuse and conform to the reuse standards in Jordan. In Germany at Langenreichenbach research facility, two-stage VFCWs planted (Phragmites australis) and unplanted were evaluated and modified to compare the role of plants over two years. Generally, there was no significant role of plants on the treatment performance. Both systems showed high removal efficiency for TOC, BOD5, and TSS over the study period. On the other hand, during the first year of the study, effluent TN concentrations ranged from 60 – 61 mg/L in both systems as a result of high effluent NO3--N concentrations (50 - 52 mg/L). In the second year, the systems were modified by adopting a saturated layer in the 1st stage to enhance denitrification. Average effluent TN concentrations were reduced to 45 mg /L in both systems. In addition, the operational modifications optimized the E. coli removal such that both systems achieved 4 log concentration reduction instead of 2 log concentration reduction during the first year of the study. In Jordan at the Fuhais research facility, two VFCW systems were investigated considering category-A (TN: 45 mg/L and NO3-N: 30 mg/L) in the Jordanian Standards (JS) for reuse in irrigation (JS 893/2006). Recirculating (ECO-1) and Multi-stage (ECO-2) VFCW designs have shown high removal efficiency of COD, TSS, and BOD5 over three years of monitoring. ECO-1 is a modified VFCW system, combing simultaneous nitrification and denitrification by recycling portion of nitrified effluent (circulation ratio 3:1) into the recirculation tank. However, effluent TN and NO3--N concentrations were 55 and 44 mg/L, respectively, that the system conformed to the JS category-B (TN: 70 mg/L and NO3-N: 45 mg/L) during monitoring phase. Therefore, ECO-1 was modified by installing plastic media in the recirculation tank that attached growth increases the abundance and activity of microorganisms. TN concentration was reduced effectively of 40 mg/L, conforming to the JS category-A, whereas, NO3--N concentration was reduced to 37 mg/L, conforming to the JS category-B. However, over the study period, E. coli concentrations were not compatible with the JS (category-A: 100 MPN/100 mL and category-B: 1000 MPN/100 mL), but it was conformed to the JS category-C (more than 1000 MPN/100 mL). ECO-2 consists of two unsaturated VFCWs in series; single-pass unplanted filter followed by planted filter (Phragmites australis). E. coli removal was relatively high before operational modification that the effluent conformed to the JS category-B, achieving 4.4 log concentration reductions. The effluent TN and NO3--N concentrations did not conform to the JS of 77 and 76 mg/L, respectively, due to insufficiency of carbon source to promote denitrification (high BOD5 removal in VFCW) during monitoring phase of the study. Thus, ECO-2 was modified adoptingraw wastewater step-feeding strategy that a specific volume of raw wastewater was mixed with 1st stage effluent in the mixing tank. TN and NO3--N concentrations were reduced to 52 and 50 mg/L, respectively; conforming to the JS category-B. Whereas, E. coli removal was influenced by E. coli ingress from raw step-feeding, achieving 3.5 log concentration reductions, conforming to the JS category-C. The short-term impact of irrigation with different water quality and quantity was also investigated at the Fuhais research site. Soil physical, chemical, and biological properties in three parallel experimental reuse plots at Fuhais site were investigated. The plots were cultivated with lemon trees. The irrigation water was supplied via a subsurface irrigation system. Each plot received water from a different source (tap water, ECO-1 and ECO-2 effluent). Moreover, each plot was divided into two sub-parts (A and B) whereby one plot received 11mm/day of irrigation water and the other subplot received 6 mm/day. In the end of the experiment, using treated effluent and tap water showed the same trend of increased soil salinity (ECs). Significant difference in ECs, SAR, Mg+2, Ca+2, and Na+ were observed at 0 - 20 cm as a result of high evaporation and capillary rise that increased salts accumulation in the topsoil. However, using more water in subsurface irrigation system reduced the salts accumulation in sub soil layers due to continuous leaching. On the other hand, results showed no significant variation in soil physical properties (texture, structure, moisture, and infiltration rate) among reuse plots and subparts. In addition, results revealed an absence of total coliform, fecal coliform, and E. coli in the irrigated soils, indicating the effectiveness of using subsurface irrigation as a disinfection step for reuse.
... Rotavirus shedding rates from infected individuals can be as high as 10 12 rotavirus particles/g of faeces (Gerba, 2000;Guardabassi et al., 2003;Christensen, 1995;Walter, 2000;Charles et al., 2003), and virus shedding can continue for up to 30 days (Guardabassi et al., 2003). Thus, when a member of a household with an OWTS is infected with rotavirus, the rotavirus concentrations in the septic tank effluent can be extremely high d up to 8 Â 10 10 rotavirus particles/L during the peak shedding period and 10 6 rotavirus particles/L 30 days after the peak period (Charles et al., 2003). ...
Article
Contamination of potable groundwater by pathogenic viruses from on-site wastewater treatment systems (OWTS) poses a serious health risk. This study investigated the attenuation and transport of rotavirus, bacteriophage MS2 and DNA-labelled-glycoprotein-coated silica nanoparticles (DGSnp) in 2 intact cores of silt loam over gravels dosed with wastewater from an OWTS at 3.53 L/day. To simulate a worst-case scenario, experiments were conducted under saturated conditions. The results from 6 experiments demonstrated that the rotavirus and DGSnp reductions were very similar and markedly greater than the MS2 reduction. This was reflected in the peak concentrations, relative mass recoveries, and temporal and spatial reduction rates. For a given log10 reduction, the estimated soil depth required for MS2 was over twice that required for rotavirus and DGSnp. This is the first study in which DGSnp was used as a rotavirus surrogate in soil under wastewater applications. Consistent with previous studies, DGSnp showed promise at mimicking rotavirus attenuation and transport in porous media. The results suggest DGSnp could be used to assess the attenuation capacity of subsurface media to rotavirus. However, DGSnp is not conservative and will underestimate the setback distances required for rotavirus reductions by 3%. On the other hand, separation distances determined using the rotavirus parameters and criteria but based on MS2 attenuation, can be too conservative in some subsurface media. To determine safe and realistic separation distances, it would be beneficial and complementary to apply both conservative virus surrogate using MS2 bacteriophage and representative but non-conservative new virus surrogates using biomolecule-modified silica nanoparticles.
... Studies explicitly addressing the impacts of sun-screens on freshwater organisms are extremely rare (but see Díaz-Gil et al. 2017). In addition, evidence for microbiological contamination of surface waters due to recreation is based on relatively few studies (Gerba 2000). Hence, additional studies to assess the importance of microbial impacts on the biochemical composition of water and habitat quality are required. ...
Article
Recreational activities on, in, and along freshwaters (e.g., boating, bathing, angling) positively contribute to human well-being but can also concurrently stress aquatic ecosystems. While outdoor recreation, aquatic ecosystems, and human well-being form coupled social-ecological systems, inherent fluxes and interactions between these have rarely been properly quantified. This paper synthesizes information on links between water-based recreational activities, effects on freshwater ecosystems integrity and recreational quality, and proposes a novel framework for assessment and integrated management. This framework is based on understanding relationships between recreational quality, demand and use, and recreational use-induced impacts on ecosystem state and function, as well as ecological and social carrying capacities. Current management approaches of freshwater ecosystems addressing economic, environmental, or recreational aspects are poorly linked and harmonized, and are further constrained by inadequate information on the dynamics and densities of recreational uses. Novel assessment and monitoring methods are needed to capture the short-term peak dynamics of water-based recreational uses, and we argue social media could play an increasingly important role here. An integrative recreation ecology management concept combined with peak usage information has great potential to form the basis for next-generation management approaches of freshwater and other ecosystems.
... Existen además otras fuentes de contaminación entérica en las zonas costeras, como la eliminación de heces de personas infectadas desde buques o barcos, o directamente en las zonas de producción sobre el lecho de los moluscos (Dowell y col., 1995;Gerba, 2000;Kohn y col., 1995). Las acciones ilegales como la recolección de zonas no autorizadas pueden desempeñar un papel importante en la aparición de brotes (Desenclos y col., 1991;Le Guyader y col., 2010). ...
... Important factors expected to influence pathogen removal include mechanical filtration, temperature, adsorption to organic matter, and adhesion to biofilm. Other removal mechanisms include exposure of pathogens to biocides excreted by some wetland plants, the antimicrobial activity of root excretions, and predation by nematodes and protists, (e.g., Cronk, 1996;Gerba et al., 2000;Vymazal, 2005;Kusch et al., 2012;. Table 2 provides a summary of some of the important pathogen removal mechanisms in constructed wetlands and how these mechanisms may differ in a free water surface flow and subsurface flow wetland. ...
Chapter
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Constructed wetlands are a sanitation technology that utilize natural removal mechanisms provided by plant vegetation, soil, and associated microbial populations. The type of wetland can be distinguished according to criteria such as presence/absence of free water surface, use of rooted emergent aquatic plants (or free floating plants), and direction of flow. The three types of constructed wetlands discussed in this chapter are: 1) horizontal subsurface flow constructed wetlands, 2) horizontal free water surface flow constructed wetlands, and 3) vertical flow constructed wetlands. Constructed wetlands have been used to treat both centralized and on-site wastewater. Primary treatment is recommended when there is a large amount of suspended solids or soluble organic matter (measured as BOD and COD). This can be accomplished by placing sanitation technologies such as screening and grit removal, followed by a septic tank or primary sedimentation, waste stabilization pond, or anaerobic reactor prior to the wetland. All types of pathogens are expected to be removed in a constructed wetland; however, greater pathogen removal is expected to occur in a subsurface wetland. In a free water surface flow wetland one can expect 1 to 2 log10 reduction of pathogens; however, bacteria and virus removal may be < 1 log10 reduction in systems that are heavily planted with vegetation. This is because constructed wetlands typically include vegetation which assists in removing other pollutants such as nitrogen and phosphorus. Therefore, the importance of sunlight exposure in removing viruses and bacteria is minimized in these systems. Removal in a properly designed and operated free water surface flow wetland is reported to be < 1 to 2 log10 for bacteria, < 1 to 2 log10 for viruses, 1 to 2 log10 for protozoa:, and 1 to 2 log10 for helminths. In subsurface flow wetlands, the expected removal is pathogens is reported to be 1 to 3 log10 for bacteria, 1 to 2 log10 for viruses, 2 log10 for protozoa, and 2 log10 for helminths.
... Enteric viruses generally yield between 105 and 1011 virus particles per gram of individual stool [161,162]. There is no direct relation between the occurrence of bacteria and enteric viruses, hence suggesting the need to separately evaluate the presence of viruses in water supply. ...
Article
Water monitoring technologies are widely used for contaminants detection in wide variety of water ecology applications such as water treatment plant and water distribution system. A tremendous amount of research has been conducted over the past decades to develop robust and efficient techniques of contaminants detection with minimum operating cost and energy. Recent developments in spectroscopic techniques and biosensor approach have improved the detection sensitivities, quantitatively and qualitatively. The availability of in-situ measurements and multiple detection analyses has expanded the water monitoring applications in various advanced techniques including successful establishment in hand-held sensing devices which improves portability in real-time basis for the detection of contaminant, such as microorganisms, pesticides, heavy metal ions, inorganic and organic components. This paper intends to review the developments in water quality monitoring technologies for the detection of biological and chemical contaminants in accordance with instrumental limitations. Particularly, this review focuses on the most recently developed techniques for water contaminant detection applications. Several recommendations and prospective views on the developments in water quality assessments will also be included.
... Existen además otras fuentes de contaminación entérica en las zonas costeras, como la eliminación de heces de personas infectadas desde buques o barcos, o directamente en las zonas de producción sobre el lecho de los moluscos (Dowell y col., 1995;Gerba, 2000;Kohn y col., 1995). Las acciones ilegales como la recolección de zonas no autorizadas pueden desempeñar un papel importante en la aparición de brotes (Desenclos y col., 1991;Le Guyader y col., 2010). ...
... Most EVs, excluding Enterovirus 70 (EV70) coxsackievirus A24 (CVA24) are abundant in stool specimens of infected individuals and levels of excretion of PVs are known to reach maximal amounts of 10 6 infectious virons per gram of feces (Dowdle et al., 2002;Hovi et al., 2007). Less information is available for levels of excretion of other enterovirus genotypes; however, the consensus from previous and current references indicates that humans excrete between 10 6 and 10 7 EVs per gram of feces (Feachem et al., 1983b;Gerba, 2000;Melnick and Rennick, 1980). The duration of intestinal virus shedding and thus the spreading (i.e., transmission) of a particular enterovirus may vary among the different genotypes. ...
Chapter
Enteroviruses (EVs), including poliovirus and nonpolio enteroviruses (i.e., coxsackieviruses, echoviruses, enteroviruses) are among the most common genera of the Picornaviridae family that infect humans and therefore are known to circulate widely in human populations throughout the world. New genera of the Picornaviridae family (i.e., Saffold cardiovirus [SAFV]) Cosavirus [common stool-associated picornavirus] Salivirus [stool Aichi-like virus]) have been identified in fecal specimens and wastewaters using conventional and highly-sensitive genomic sequencing technologies. In addition, members of the Echovirus genus originally known as echovirus 22 and 23 have been reclassified within the genus Parechovirus. Likewise, previous rhinovirus species have been reclassified within the Enterovirus genus. Enterovirus (EV) infections are a significant cause of morbidity and mortality throughout the world, primarily in infants and young children. Nevertheless, reliable worldwide estimates of EV-related mortality are not currently available. Enteroviruses like most enteric viruses have evolved stability to adverse environmental conditions, including thermal stability, acid stability, resistant to radiation as well as to oxidants and proteolytic enzymes, which allow survival of these viruses in the environment and facilitate their transmission through multiple environmental routes (e.g., water, food, aerosols, and virus-contaminated inanimate objects or fomites). Human wastes, such as sewage and poorly treated effluents, urban stormwater and combined sewers overflows (CSO) are the primary source of enteroviruses released into aquatic and land environments that subsequently contaminate raw source waters for potable supply, bathing waters, shellfish waters, and waters used for irrigation of crops. Groundwater sources are also vulnerable to contamination with enteroviruses through different routes including direct injection of wastes through wells, percolation of sewage sprayed over the land, leaking or broken sewer lines, seepage from waste lagoons, infiltration of sewage-polluted surface streams, and septic tank effluents. The biophysical properties of enteroviruses (i.e., small-size, genome type and the non-enveloped capsid structure of the virion) play an important role on virus survival in the environment and on the physical removal and inactivation of virus particles through conventional wastewater treatment processes. Membrane bioreactor systems (MBRs) are becoming increasingly applied in developed regions as advanced wastewater treatment technologies to produce treated effluents of very high quality applicable to wastewater discharge and recycling solutions, including non-potable or indirect potable reuse. The distribution and persistence of enteroviruses in sewage-polluted waters may vary geographically depending on the epidemiological status of the population, population density, and the extent of sanitation coverage (i.e., wastewater treatment and wastewater disposal) which influence the viral load released into the environment. Recent estimates by the World Health Organization (WHO)/United Nations Children’s Fund (UNICEF) Joint Monitoring Programme for Water Supply and Sanitation indicate that despite significant progress on sanitation, in 2012, more than one third of the global population - some 2.5 billion people – do not use an improved sanitation facility, and of these 1 billion people still practice open defecation. Sewage represents a useful matrix to derive information on circulating enteroviruses in given populations and to describe the enterovirus epidemiology associated with human disease, also known as environmental surveillance. Environmental poliovirus surveillance is a major goal of the WHO Global Poliovirus Eradication Initiative (GPEI) used to monitor pathways of poliovirus transmission of wild poliovirus and circulating vaccine-derived polioviruses (cVDPVs). A major effort to develop new, improved, and safer live polio vaccine is being promoted by the WHO, Rotary and the Bill & Melinda Gates Foundation. Human enteroviruses have been recovered worldwide from surface waters including coastal waters, rivers streams, and lakes, from ground waters, wastewaters and finished drinking water. Numerous methodological approaches have been recently developed for concentration of human enteric viruses from water and their isolation from the environment. Selection of an appropriate filtration method for the primary concentration of viruses is crucial to successful virus detection. However, an efficient method to recover all viruses has not been developed yet. Integrated cell culture and PCR (ICC-PCR) developed in the late 1980s is still applicable for detection and identification of a suite of infective viral pathogens recovered from environmental samples. The detection of enteroviruses in sources of drinking water and recreational water bodies has been broadly accepted as a marker of a possible failure of the sanitation systems and as an indicator of the potential role of water in disease outbreaks. Moreover, since the natural host for all human enteroviruses is humans, the detection and quantification of amplifiable enterovirus genetic material in environmental waters has been proposed and successfully used as a water quality assessment tool for tracking sources of human fecal pollution.
... Freshwater compartments are likely to fecal contamination sources that are transported from the local watershed, including those from agricultural runoff and sewage, as well as from wild and domestic animals (Howell et al., 1995;Alderisio et DeLuca, 1999;Gerba, 2000;Guber et al., 2006). In the present study, the higher concentration was recorded in sampling stations 15R, 16R, 17R, 19R and 20R, suggesting the Trindade and Laranjeiras village streams as impacted riverine water bodies. ...
Article
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p> Highlights Tourism development on the south coast of Rio de Janeiro; Water quality impacts resulted from human presence; We selected 20 water sampling stations and evaluated the seasonal water quality variation; Water quality changes between seasons became clear; The Water Quality Index (WQI) was very useful for the classification of the waters monitored. Purpose The main objective of the present paper is to detect the tourism influence in the water quality of the municipality of Paraty and surrounding water bodies, analyze individual parameters and use the WQI. Design/methodology/approach In the present paper a simple management tool was applied in order to prevent future tourism impacts in coastal areas. Findings Although considered in its natural state, the area already showed impact signals. Research limitations/implications The analysis need to be more enhanced for finding the spatiotemporal evolution in the estuarine environment. Practical implications The paper provides a starting point for minimizing the negative impacts of tourism. Originality/value The present paper contributes so that tourism may become a positive factor of local development. </p
... PA was detected in 84.6% of samples in the range 1e1950 CFU/100 mL (0.9% of samples > 1000 CFU/100 mL), and SA in 69.1% of samples in a concentration of 1e390 CFU/100 mL (0.7% of samples > 200 CFU/ 100 mL). Our results support the results of the studies by Enns et al. (2012) and Gerba (2000) stating that S. aureus can be used as a good indicator of bather shedding. ...
Article
Bathing water quality is a major public health issue, especially for tourism-oriented regions. Currently used methods within EU allow at least a 2.2 day period for obtaining the analytical results, making outdated the information forwarded to the public. Obtained results and beach assessment are influenced by the temporal and spatial characteristics of sample collection, and numerous environmental parameters, as well as by differences of official water standards. This paper examines the temporal variation of microbiological parameters during the day, as well as the influence of the sampling hour, on decision processes in the management of the beach. Apart from the fecal indicators stipulated by the EU Bathing Water Directive (E. coli and enterococci), additional fecal (C. perfringens) and non-fecal (S. aureus and P. aeriginosa) parameters were analyzed. Moreover, the effects of applying different evaluation criteria (national, EU and U.S. EPA) to beach ranking were studied, and the most common reasons for exceeding water-quality standards were investigated. In order to upgrade routine monitoring, a predictive statistical model was developed.
... old to harbor and transmit enteric protozoa from perineal fecal contamination (Gerba, 2000). The water volumes of both pools similarly act as a factor to the discrepancy between pools. ...
Article
Full-text available
Water-borne protozoan parasites, (i.e. Cryptosporidium and Giardia), have received considerable attention over the past few years because of their role as ubiquitous etiological agents of diarrhea and other related diseases of humans and animals. Cryptosporidium oocysts and Giardia cysts have been found in water samples collected from selected pools in Calamba, Laguna, Philippines. Though differing in terms of density between different pools, Cryptosporidium has been found in all 12 pools (34-2600 oocysts/L) while 10 pools were found to be positive for Giardia (67-700 cysts/L). Analysis of the physico-chemical parameters (temperature, pH, conductivity, DO and pool volume) has shown no significant effects on the densities of both parasites. Private pools were found to have the higher parasite density and prevalence. Children's pools similarly showed greater parasite contamination compared to adult pools. Correlation of parasite density and prevalence with potential contamination factors (e.g. presence of animals, pool protocols, mixed pool use etc.) derived from pool interviews showed no significant relationship between the two. However, qualitative assessment of the study areas revealed that pools with the highest parasite densities were characterized by low adherence to pool regulations.
... Thus, the possibility of microbial contamination is high in coastal areas. (Gerba 2000;Alm et al. 2003). ...
Article
Full-text available
The composition and metabolic properties of cultivable heterotrophic aerobic bacteria, the levels of indicator bacteria, and physicochemical parameters were investigated in the seawater samples collected from 20 stations in coastal areas of the eastern part of the Black Sea, Turkey, between May 2017 and February 2018. The levels of indicator bacteria were detected above the national limit values during the study period. Thirty-five different bacterium species were identified. Enterobacteriaceae was recorded as the most dominant family (34.2%), and Gammaproteobacteria was recorded as the most dominant class (74.2%). Bacteriological threats on human and ecosystem health were determined in coastal areas of the Southeastern Black Sea. The determination of the high levels of indicator bacteria, the high ratio of fecal coliform/fecal streptococci (FC/FS ratio), and pathogenic bacteria regarding human and ecosystem health showed that these coastal areas under the influences of terrestrial and human-sourced bacteriological pollution. This study has contributed to the increase of knowledge of understanding the protection and rehabilitation ways of the Black Sea coastal regions against land-based pollution sources considering the interdependent structure of all Black Sea countries. Coastal areas are accepted as the most fragile part of the marine environments and our findings showed the potential bacteriological risks in coastal areas of the Southeastern Black Sea as an important example. Serious precautions should be taken for the protection in this area and such coastal ecosystems to prevent hazardous problems.
... It is likely that bacterial shedding from the swimmers represents a primary source of the human-source fecal bacteria MST markers detected. Previous studies by others and ourselves have shown that bathers can shed large amounts of fecal and skinassociated bacteria, including Enterococcus, fecal Bacteroides, and Staphylococcus aureus among others (Gerba, 2000;Elmir et al., 2007Elmir et al., , 2009Plano et al., 2011). While there are undoubtedly some incidents of direct defecation into Grotto waters by certain individuals unwilling to hike back up the cliff to the only restroom facility, this human fecal marker signal is more likely attributable to unintentional routine bacterial shedding by general bathers. ...
Article
Full-text available
The Commonwealth of the Northern Mariana Islands (CNMI) recently identified the need to improve its capacity for detecting and tracking land-based sources of pollution (LBSP) in coastal waters, particularly microbial contaminants like fecal indicator bacteria (FIB). Reported here is a baseline study of a suite of host-specific FIB microbial source tracking (MST) markers in the coastal shoreline and reef waters around the island of Saipan. Three sampling campaigns were conducted in September 2017, March 2018, and August 2018. Samples were collected from the nearshore surface waters of Saipan, the reef waters of Saipan Lagoon, and groundwater from beaches along the Saipan Lagoon shoreline. Measurements of submarine groundwater discharge (SGD) into nearshore waters and isotopic source tracking of nitrogen inputs were conducted concurrently with MST. Environmental DNA was extracted from the samples and analyzed by quantitative polymerase chain reaction (qPCR) for MST gene markers of fecal Bacteroidales specifically associated with humans, dogs, cows, and pigs, and for an MST gene marker of Catellicoccus associated with seabirds. MST assessments were combined with local knowledge, assessments of sanitary infrastructure, and routine watershed surveys. This study identified hotspots of human FIB along the western Saipan Lagoon shoreline in both surface waters and groundwater, plus another hotspot of human FIB at a popular tourist bathing area known as the Grotto. FIB hotspots on the Lagoon shoreline coincided with areas of high SGD and nitrogen isotopic data indicating sewage-derived N inputs. It appears that faulty sanitary infrastructure may be contributing to inputs to Saipan Lagoon, while bather shedding is likely a primary input for the Grotto area. Moderate levels of dog fecal contamination were common and widespread across the island. High levels of seabird fecal contamination were more random, both spatially and temporally, and mostly concentrated along the less developed northeast region of Saipan. No significant levels of cow or pig fecal marker were detected in coastal water samples. This study provides demonstration and establishment of analytical capacity to resource management in CNMI for MST technology to aid in trouble-shooting water quality issues involving land-based sources of microbial contaminants to CNMI coastal waters.
... Our results agreed with the prevalence of enteric viruses in different environmental waters in other study (Haramoto, et al, 2018). The mean levels of enteric viruses in infected individuals could range from 10 5 to 10 12 genomic copies of virus per gram of faeces (Gerba, 2000). The estimated levels of the viruses detected by qPCR in groundwater from private wells in rural Alberta would be equivalent to 1.5×10 − 5 to 8.6×10 − 11 gram of faecal contamination in one liter of contaminated water using this calculation. ...
Article
The prevalence and levels of enteric viruses in untreated groundwater of private wells used for drinking and/or agricultural practices in rural Alberta were studied using the qPCR panel assay, integrated cell culture with qPCR and cell culture in the volume of 500 liters per sample through serial sampling. Seven viruses were assessed including adenovirus, rotavirus, norovirus, astrovirus, sapovirus, reovirus and JC virus. Five viruses were detected with an overall positive detection rate of 6.33 % (45 of 711 samples). The most frequently detected virus was adenovirus (48.9%, 22/45) followed by rotavirus (44.4%, 20/45), reovirus (20%, 9/45), JC virus (6.7%, 3/45) and norovirus (6.7%, 3/45). There was no significant difference in the positive detection rates, ranging from 1.1% to 3.4% by various well settings used for broiler farms, cow/calf farms, feedlots and rural acreages. Effects of well characteristics (aquifer type, well depth, static level of water, well seal) and well completion lithology on potential viral contamination of groundwater of private wells were also analyzed upon available data. The findings demonstrate that occurrence of enteric viruses is low and viral contamination is sporadic in groundwater of private wells in rural Alberta. Conventional fecal bacterial indicators (coliform and/or E. coli) were not a representative marker for viral contamination in groundwater wells in rural Alberta.
... 2005). Gerba (2000), günde birey başına 100 ila 200 g dışkı üretildiğinden, enfekte bir kişiden 100 g'lık bir tek bağırsak hareketinde 10 14 kadar enterik patojen hücresi yayılabileceğini belirlemiştir. Barker ve Jones (2005) patojenler dışkıda 10 4 ila 10 11 kob/g seviyesinde bulunabildiğinden, deriye 0.1 mg dışkı maddesi bulaşması halinde, diyarel koşullar altında 106'ya kadar enfeksiyöz bakteri hücresi, parazitik oositler veya viral partiküller içerebildiğini bildirmiştir. ...
Article
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Gıda ile ilgili işlemler sırasında el hijyeni kritik öneme sahiptir. Hasta veya iyileşmiş kişilerin dışkılarında patojenler bulunduğunda, kontaminasyon çoğunlukla fekal-oral yolla gerçekleşmektedir. Kontaminasyonun kökeni ne olursa olsun, patojenlerin çeşitli yüzeylere temas eden ellerden bulaşma olasılığı yüksektir. Gıda kontaminasyonunun risk faktörlerinden biri, gıda hizmetlerinde çalışanların kişisel hijyeninin yetersiz olmasıdır. Bu makale gıda işletmelerinde uygun el hijyeni ve eldiven kullanımı arasındaki ilişkinin halk sağlığı üzerindeki etkilerini değerlendirmek amacıyla hazırlanmıştır. Hand hygiene is critical importance during food-related processes. When pathogens are present in the feces of the patient or healed people, contamination is most often accomplished by the faecal-oral route. Regardless of the origin of contamination, pathogens are likely to be transmitted from hands that touch various surfaces. One of the risk factors of food contamination is the inadequate personal hygiene of those working in food services. This article has been prepared to evaluate the effects of the relationship between appropriate hand hygiene and glove use in food establishments on public health. Review
... Therefore, inadequate adherence to sound disinfection protocols enhances risks for respiratory, ocular, and cutaneous ailments among pool visitors and workers (Fantuzzi et al., 2010;Nickmilder & Bernard, 2007). Furthermore, swimmer shedding of microbial flora (including potential pathogens) occurs in aquatic environments (Gerba, 2000;Smith & Dufour, 1993) and when coupled with insufficient disinfection, this situation presents an increased infectious disease risk to recreators. Studies on untreated recreational waters have demonstrated a positive association between densitites of fecal indicator organisms in water and the risk of experiencing a swimming-associated gas-A b s t r a c t The growth in the number of pools to more than 7.4 million in the U.S. has been accompanied by a rise in recreational water illnesses (RWIs). ...
Article
The growth in the number of pools to more than 7.4 million in the U.S. has been accompanied by a rise in recreational water illnesses (RWIs). Effective pool management, though, can mitigate RWI risks. Inadequate management presumably occurs more frequently where training is less formalized and/or pool operation is a minor aspect of the job of the responsible pool manager(s). During summer 2018, weekly evaluations were performed at public venues in Louisville, Kentucky. Disinfectant levels and other items were monitored and compared with venue-specific (pool or spa) criteria. Among 1,312 venue surveys, 1,173 (89.4%) met criteria and 139 (10.6%) did not meet criteria. Overall, multivariable logistic regression showed a significant association between the likelihood of a venue meeting criteria and setting type. Specifically, hotels had 120% increased odds of not meeting criteria (adjusted odds ratio = 2.2; 95% confidence interval [1.3, 3.8]) compared with other settings. Despite spas having an 80% elevated odds of not meeting criteria compared with pools in a univariate analysis, upon adjusting for setting, spas were not associated with an increased risk of not meeting criteria. Research identifying reasons for these differences in meeting criteria between settings would be beneficial for informing public health interventions for aquatic environments.
... Sewage systems receive enteric viruses excreted by infected individuals. An infected person sheds 10 5 to 10 12 viral particles per gram of fecal matter (Gerba, 2000). In addition to human pathogenic viruses, waterborne viruses that originate from food production, animal husbandry, seasonal surface runoff and other sources are present in wastewater (Corsi et al., 2014). ...
Article
Full-text available
This paper presents an updated and comprehensive review on the different methods used for detection and quantification of viruses in wastewater treatment systems. The analysis of viability of viruses in wastewater and sludge is another thrust of this review. Recent studies have mostly focused on determining the abundance and diversity of viruses in wastewater influents, in samples from primary, secondary, and tertiary treatment stages, and in final effluents. A few studies have also examined the occurrence and diversity of viruses in raw and digested sludge samples. Recent efforts to improve efficiency of virus detection and quantification methods in the complex wastewater and sludge matrices are highlighted in this review. A summary and a detailed comparison of the pre-treatment methods that have been utilized for wastewater and sludge samples are also presented. The role of metagenomics or sequencing analysis in monitoring wastewater systems to predict disease outbreaks, to conduct public health surveillance, to assess the efficiency of existing treatment systems in virus removal, and to re-evaluate current regulations regarding pathogenic viruses in wastewater is discussed in this paper. Challenges and future perspectives in the detection of viruses, including emerging and newly emerged viruses such as the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), in wastewater systems are discussed in this review.
... Most previous reviews of recreation in freshwater ecosystems did not focus on one specific activity (Table 1) but concentrated on disturbance in general (Blumstein et al., 2005;Cayford, 1993;Price, 2008) or on recreational use in general (Blanc et al., 2006;Carney & Sydeman, 1999;Cole & Landres, 1996). In a more specific approach, Gerba (2000) reviewed the shedding of enteric pathogens during recreational swimming, without, however, linking the amount of material shed by bathers to the effect on aquatic organisms. We are not aware of reviews on the ecological effects of swimming, snorkelling, scuba diving, canyoning, walking, biking or relaxing close to an inland water body. ...
Article
With the increasing importance of recreational activities in and around inland water bodies, there is a need for sound knowledge about their ecological impacts. This narrative review summarizes and analyses the ecological effects of the land-based activities walking, biking, nature observing and relaxing on the shoreline as well as the water-based activities swimming, snorkelling, scuba diving, and canyoning. Searching multiple databases with standardized search terms retrieved twenty-six publications for further analyses. While walking was the most studied activity, birds were the most studied organism group, with a focus on individual time budgets and avoidance behaviour. Population-level analyses were exceedingly rare. The most frequently studied activity-effect combinations were walking and birds, walking and terrestrial plants and scuba diving/snorkelling and fishes. Aquatic plants, amphibians, reptiles, water chemical parameters and terrestrial and aquatic algae were underrepresented in the existing literature. No study on mammals was identified. Disturbance often led to temporary behavioural changes of birds and wildlife. Plants were more strongly impacted than animals, suffering from recreation-induced damage and dieback, which led to changes in community composition. The difference in intensity of impact between mobile and sessile organisms calls for different management strategies, depending on local conservation targets. Future studies should focus on underrepresented taxonomic groups and study population or community-level impacts, to collectively provide the sound scientific basis for the sustainable recreational use of inland water bodies, while minimizing or avoiding severe ecological impacts.
... Contributions from landfills, septic tanks, cesspools, and cemeteries can leach through soil directly into groundwater seeping into the recreational water environment [209,210]. Swimmers and bathers in recreational waters might also serve as a source of AMR bacteria and ARGs as they can shed fecal material while recreating [211]. Published evidence linking these sources to AMR bacteria and ARGs in recreational water is not available. ...
Article
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Ambient recreational waters can act as both recipients and natural reservoirs for antimicrobial resistant (AMR) bacteria and antimicrobial resistant genes (ARGs), where they may persist and replicate. Contact with AMR bacteria and ARGs potentially puts recreators at risk, which can thus decrease their ability to fight infections. A variety of point and nonpoint sources, including contaminated wastewater effluents, runoff from animal feeding operations, and sewer overflow events, can contribute to environmental loading of AMR bacteria and ARGs. The overall goal of this article is to provide the state of the science related to recreational exposure and AMR, which has been an area of increasing interest. Specific objectives of the review include (1) a description of potential sources of antibiotics, AMR bacteria, and ARGs in recreational waters, as documented in the available literature; (2) a discussion of what is known about human recreational exposures to AMR bacteria and ARGs, using findings from health studies and exposure assessments; and (3) identification of knowledge gaps and future research needs. To better understand the dynamics related to AMR and associated recreational water risks, future research should focus on source contribution, fate and transport—across treatment and in the environment; human health risk assessment; and standardized methods.
... Faecal shedding: Unintentional shedding of faecal material by bathers is widely documented (Elmir et al. 2009, Elmir et al. 2007, Gerba 2000. The amount of faeces shed per person is highly uncertain and was estimated relying on measurements from the literature of faecal indicator concentrations in bathing waters. ...
Article
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Natural swimming ponds (NSPs) are artificially created bodies of water intended for human recreation, characterised by the substitution of chemical disinfection with natural biological processes for water purification. NSPs are growing in popularity, however little is known regarding the public health risks. A screening level risk assessment was undertaken as an initial step in assessing the first Canadian public NSP located in Edmonton, Alberta. Risk of enteric pathogens originating from pool bathers was assessed under normal conditions and following accidental faecal release events. The performance of the natural treatment train for health protection was quantified with and without the addition of UV disinfection of naturally-treated water, and compared to the US EPA benchmark to provide a reference point to consider acceptability. Estimated levels of pathogen contamination of the pond were dependant upon the discrete number of shedders present, which in turn depended upon the prevalence of infection in the population. Overall performance of the natural disinfection system was dependant upon the filtration rate of the natural treatment system or turnover time. Addition of UV disinfection reduced the uncertainty around the removal efficacy, and mitigated the impact of larger shedding events, however the impact of UV disinfection on the natural treatment biome is unknown. Further information is needed on the performance of natural barriers for pathogen removal, and therefore challenge studies are recommended. Given the identified risks, the pool is posted that there is risk from accidental faecal releases, as in any natural water body with swimmers. Screening level risk assessment was a valuable first step in understanding the processes driving the system and in identifying important data gaps.
... Additionally, other pathogenic agents, like viruses, can also persist in raw wastewater and treated wastewater as well as in the receiving water bodies [11]. One of the main sources of viral pathogens in wastewater is the human fecal matter from infected persons [12][13][14] that can shed 10 5 to 10 12 viral particles per gram of fecal matter [15]. Besides human pathogenic viruses, waterborne viruses that originate from food production, animal husbandry, seasonal surface runoff and other sources are also present in wastewater [16]. ...
Article
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Broad-spectrum fluoroquinolone antibiotics (ciprofloxacin and levofloxacin), carbapenem and fluoroquinolone resistance genes, as well as viral genomes, were detected in grab samples of wastewater effluents. Passive samplers, which are simpler and easier to use and provide information about the concentrations and combination of contaminants present in a certain fluid matrix over time, proved to be extremely promising devices to monitor the presence of the target antibiotics in wastewater effluents. Nanofiltration was tested with a pilot-scale unit installed at a domestic wastewater treatment facility, using a Desal 5DK membrane operated at a constant transmembrane pressure of 6 bar and 70% recovery rate. In a 24 h experimental assay, the variation of the membrane permeance was low (6.3%). High rejections of the target contaminants from the wastewater effluent were obtained by the pilot-scale treatment. Hence, nanofiltration using the Desal 5DK membrane is considered to be a promising treatment to cope with chemical and biological contaminants present in wastewater effluents.
... The DI value was calculated for a hypothetical scenario of inadvertent consumption of spinach leaves exposed to Ag 2 O and TiO 2 NPs or the corresponding Ag and Ti ions. The amount of spinach per serving, i.e., average daily intake of spinach for adults, were set as 0.345 kg/person/day and body weight for adult were set as 60 kg (Gerba, 2000). The concentration of metal in spinach, grown in sludge -mixed NPs were used to project DI of each metal by six age-mass classes from child to adult. ...
Article
Present study carried out pot experiments and evaluated effects of single and binary mixture of nanoparticles (exposed via sludge as soil conditioner) on spinach plant. Exposure of Ag2O NPs (1 and 10 mg/kg) did not show and significant reduction in plant as compared to control. On the other hand TiO2 NPs (exposed as single and in binary mixture) resulted in significant increase in root length (29% and 37%) and fresh weight (60% and 48%) at highest exposure concentration. Total chlorophyll content decreased for Ag2O and binary mixture (7% and 4%) and increased for TiO2 (5%) at 10 mg/kg soil. The toxic interaction between Ag2O and TiO2 NPs was additive at both exposure concentrations. Ag2O NPs had higher tendency of root surface adsorption than TiO2 NPs. Metal content in spinach leaves at highest exposure concentration was Ag: 2.6 ± 0.55 mg/g (for Ag2O NPs) and 1.02 ± 0.32 mg/g plant biomass (for Ag2O + TiO2 NPs) and for Ti: 1.12 ± 0.78 (for TiO2 NPs) mg/g and 0.58 ± 0.41 mg/g (for Ag2O + TiO2 NPs). The inadvertent ingestion of NPs contaminated spinach resulted in projected daily intake (DI) of Ag and Ti for different age-mass classes (child to adult) exceeding the oral reference dose for toxicity during oral ingestion. In conclusion, we report no acute toxicity of single and binary mixture of NPs to spinach but significant accumulation of Ag and Ti metal in spinach leaves. There are high chances that ingestion of spinach grown in such environment might lead to human health risks.
... , Reg. 565, 2018United States Centers for Disease Control and Prevention, 2018). Showering prior to swimming is important because bathers have been estimated to shed an average of 0.14 g of fecal material when swimming, which can contain pathogens such as Cryptosporidium or Giardia (Gerba, 2000). In addition, the presence of organic material from bathers lowers the effectiveness of halogen-based disinfectants such as chlorine (Shields et al., 2008). ...
Article
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Bathers at public swimming pools should shower prior to entering the pool deck to remove organic material (e.g., sweat, lotions, fecal matter) that can increase the risk of recreational water illness and the formation of disinfection by-products. However, little research has been conducted to evaluate bathers’ pre-swimming showering practices. We conducted a cross-sectional study of bathers aged 18 years or older at a public swimming pool in Toronto, Ontario, to evaluate their showering habits. An in-person questionnaire was administered in October and November 2019. Bivariate associations were examined between selected variables and participants’ self-reported showering frequency prior to swimming (often or always vs. never, rarely, or sometimes). A total of 110 bathers agreed to participate. Most participants (63%) were aged 18–34, 56% identified as male, and 78.2% reported always or often showering before swimming. Of these individuals, only 34% reported using soap when showering. Participants that identified as male (vs. female) and an ethnicity other than white were more likely to report often or always showering, as were those that reported reading the pool rules and that observed other bathers taking a shower. Additional efforts are needed to educate bathers about the importance of showering prior to swimming in public pools.
... Pathogenic streptococci and other bacteria could be introduced into seawater by shipping traffic including ballast water [219,220], human activities including recreational activity [221][222][223][224][225] and waste (water) [66,[226][227][228][229] and from the terrestrial environment via rivers and storm water [230,231], wind transport [232,233] or animals, e.g., semi-aquatic mammals, such as pinnipeds, from which streptococci are frequently isolated. For instance, human pathogenic S. agalactiae strains were identified in grey seals indicating that sea mammals were exposed to human pathogens via human effluents that contaminate coastal surface waters [66]. ...
Article
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Marine mammals are sentinels for the marine ecosystem and threatened by numerous factors including infectious diseases. One of the most frequently isolated bacteria are beta-hemolytic streptococci. However, knowledge on ecology and epidemiology of streptococcal species in marine mammals is very limited. This review summarizes published reports on streptococcal species, which have been detected in marine mammals. Furthermore, we discuss streptococcal transmission between and adaptation to their marine mammalian hosts. We conclude that streptococci colonize and/or infect marine mammals very frequently, but in many cases, streptococci isolated from marine mammals have not been further identified. How these bacteria disseminate and adapt to their specific niches can only be speculated due to the lack of respective research. Considering the relevance of pathogenic streptococci for marine mammals as part of the marine ecosystem, it seems that they have been neglected and should receive scientific interest in the future.
... On the other hand, some pathogens may increase in concentration via regrowth capabilities, particularly in moist or humid storage conditions and laundry heavily contaminated with bodily fluids. Here, we evaluate microbial hazards in laundry representative of a nonenveloped respiratory virus (rhinovirus), a nonenveloped enteric virus (rotavirus) and a Gram-negative bacterium (nontyphoidal Salmonella) and estimate from the literature initial concentrations of 10 7 , 10 11 and 10 10 respectively (Table 3) (Gerba, 2000;L'Huillier et al., 2015). Die-off during storage alone may be greater than 4 logs for unwashed laundry contaminated with enveloped or respiratory viruses (Gerhardts et al., 2016;Harbourt et al., 2020;Sakaguchi et al., 2010). ...
Article
Aims: Contaminated laundry can spread infections. However, current directives for safe laundering are limited to healthcare settings and not reflective of domestic conditions. We aimed to use quantitative microbial risk assessment to evaluate household laundering practices (e.g., detergent selection, washing and drying temperatures, and sanitizer use) relative to log10 reductions in pathogens and infection risks during the clothes sorting, washer/dryer loading, folding, and storing steps. Methods and results: Using published data, we characterized laundry infection risks for respiratory and enteric pathogens relative to a single user contact scenario and a 1.0 x 10-6 acceptable risk threshold. For respiratory pathogens, risks following cold water wash temperatures (e.g., median 14.4°C) and standard detergents ranged from 2.2 x 10-5 to 2.2 x 10-7 . Use of advanced, enzymatic detergents reduced risks to 8.6 x 10-8 and 2.2 x 10-11 , respectively. For enteric pathogens, however, hot water, advanced detergents, sanitizing agents, and drying are needed to reach risk targets. Significance and impact of study: Conclusions provide guidance for household laundry practices to achieve targeted risk reductions, given a single user contact scenario. A key finding was that hand hygiene implemented at critical control points in the laundering process was the most significant driver of infection prevention, additionally reducing infection risks by up to six log10 .
... The major source of viruses in wastewater is fecal excretion to the water specifically from the infected individuals. According to an estimate, a single infected individual excretes approximately 10 5 -10 12 viral particles per gram of fecal excretion (Gerba, 2000). Likewise, another study reported that viruses are released into wastewater by more than 10 12 viruses g − 1 of feces from the infected individuals (Drexler et al., 2011;Kirby et al., 2014). ...
Article
Millions of human pathogenic viral particles are shed from infected individuals and introduce into wastewater, subsequently causing waterborne diseases worldwide. These viruses can be transmitted from wastewater to human beings via direct contact and/or ingestion/inhalation of aerosols. Even the advanced wastewater treatment technologies are unable to remove pathogenic viruses from wastewater completely, posing a serious health risk. Recently, coronavirus disease 2019 (COVID-19) has been urged globally due to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), which has resulted in >4.1 million deaths until July 2021. A rapid human-to-human transmission, uncertainties in effective vaccines, non-specific medical treatments, and unclear symptoms compelled the world into complete lockdown, social distancing, air-travel suspension, and closure of educational institutions, subsequently damaging the global economy and trade. Although, few medical treatments, rapid detection tools, and vaccines have been developed so far to curb the spread of COVID-19; however, several uncertainties exist in their applicability. Further, the acceptance of vaccines among communities is lower owing to the fear of side effects such as blood-clotting and heart inflammation. SARS-CoV-2, an etiologic agent of COVID-19, has frequently been detected in wastewater, depicting a potential transmission risk to healthy individuals. Contrarily, the occurrence of SARS-CoV-2 in wastewater can be used as an early outbreak detection tool via water-based epidemiology. Therefore, the spread of SARS-CoV-2 through fecal-oral pathway can be reduced and any possible outbreak can be evaded by proper wastewater surveillance. In this review, wastewater recycling complications, potential health risks of COVID-19 emergence, and current epidemiological measures to control COVID-19 spread have been discussed. Moreover, the viability of SARS-CoV-2 in various environments and survival in wastewater has been reviewed. Additionally, the necessary actions (vaccination, face mask, social distancing, and hand sanitization) to limit the transmission of SARS-CoV-2 have been recommended. Therefore, wastewater surveillance can serve as a feasible, efficient, and reliable epidemiological measure to lessen the spread of COVID-19.
Article
There is limited published information on the impact of bathing on stream water quality and ecology, except on human pathogens and health. We investigated the relationships between environmental quality of streams and recreational activity at five sites in the Australian Wet Tropics. The streams normally had very low concentrations of nutrients and suspended solids (TSS), but concentrations fluctuated widely during spates, thereby causing difficulties in discriminating impacts. Daily bathing activity disturbed sediments causing an increase in TSS and turbidity, which greatly exceeded national guidelines for maintenance of aesthetic qualities. TSS returned to background levels overnight as bathing areas were flushed clean. Total nitrogen and phosphate concentrations also increased with bather numbers, and phosphate concentrations were directly proportional to bather density. Faecal coliform concentrations were elevated by bathers at one site. Ecological effects of bathers were equivocal and greater on algal than invertebrate assemblages. Water quality degradation, although transient, suggested that some sites were close to their carrying capacity for bathers. Our results show that water quality may vary with local conditions and that cost-effective monitoring and management require development of cause-effect models of water quality processes for each stream site.
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The Lower Pinacanauan de San Pablo River, which is one of the main tributaries of the Cagayan River, possesses good water quality as far as physical and chemical characteristics are concerned. Analyzed physical and chemical characteristics did not surpass the level set on water quality criteria for inland freshwaters under the Department of Environment and Natural Resources-Department Administrative Order of 2016, series no. 8 (DENR-DAO 2016-08). Hence, there are observed aquatic fauna that inhabits the river. Unfortunately, very high fecal coliform counts were analyzed, which greatly affected the water quality status as found in its water quality indices. Fecal coliforms may have originated from untreated sewage, from swine, poultry, or livestock production, and human feces. The fecal coliform posts health risks to humans, which should be emphasized priority action. The overall result of the study implies that it is not advisable for bathing due to the tendency of drinking the water. Therefore, the result of the study should be discussed with the local government units and DENR Region 2 for appropriate activities that will help solve the problems of river pollution.
Article
Worldwide, fecal indicator bacteria (FIB) evidence coastal water contamination for which sources are unknown. Here, for two FIB-impacted Santa Barbara recreational beaches, hypothesized fecal sources were investigated over three dry seasons (summers) using nearly 2000 field samples of water (ocean, creek, groundwater), sand, sediments, effluent and fecal sources. In years 1 and 2, gull and dog feces were identified as the probable main FIB sources to surf zone waters, yet HF183 human fecal markers were consistently detected. Determining HF183 sources was therefore prioritized, via year 3 sub-studies. In lower watersheds, human and dog wastes were mobilized by small storms into creeks, but no storm drain outfalls or creeks discharged into surf zones. Beach area bathrooms, sewers, and a septic system were not sources: dye tracing discounted hydraulic connections, and shallow groundwater was uncontaminated. Sediments from coastal creeks, downstream scour ponds, and nearshore marine and inter- and supratidal zones contained neither HF183 nor pathogens. Two nearby wastewater treatment plant (WWTP) outfalls discharged HF183 into plumes that were either deep or distant with uncertain onshore transport. Regardless, local sources were evidenced, as surf zone HF183 detection rates mostly exceeded those offshore and nearshore (around boat anchorages). The presence of swimmers was associated with surf zone HF183, as swimmer counts (on weekdays, holidays, weekends, and during races) significantly correlated (p<0.05, n = 196) to HF183 detections. Besides comprehensively assessing all possible fecal sources, this study provides new explanations of chronic low-level human markers in recreational beach surf zones, suggesting likely lowest achievable HF183 thresholds.
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Laundering of textiles – clothing, linens, cleaning cloths - functionally removes dirt and bodily fluids which, prevent the transmission and re-exposure to pathogens as well as odor control. Thus, proper laundering is key to controlling microbes that cause illness and produce odors. The practice of laundering varies from region to region and is influenced by culture and resources. This review aims to define laundering as a series of steps that influence the exposure of the person processing the laundry to pathogens – with respect to the removal and control of pathogens and odor causing bacteria, while taking into consideration the types of textiles. Defining laundering in this manner will help better educate the consumer, highlight areas where more research is needed, and how to maximize products and resources. Control of microorganisms during laundering involves mechanical (agitation, soaking), chemical (detergent, bleach), and physical processes (detergent, temperature). Temperature plays the most important role in terms of pathogen control, requiring temperatures exceeding 40°C to 60°C for proper inactivation. While detergents play a role in reducing the microbial load of laundering through release of microbes attached to fabrics and inactivation of microbes sensitive to detergents (e.g. enveloped viruses). The use of additives (enzymes) and bleach (chlorine, activated oxygen) become essential in washes with temperatures below 20°C, especially for certain enteric viruses and bacteria. A structured approach is needed which identifies all the steps in the laundering process and attempts to identify each step relative to its importance to infection risk and odor production.
Article
Enteric viruses are widely spread in water environments, some being harmful for human communities. Regular epidemics highlight the usefulness of analysing such viruses in wastewaters as a tool for epidemiologists to monitor the extent of their dissemination among populations. In this context, CNovel™ Powdered Activated Carbon (PAC) was chosen for its high porosity and high adsorption capacity to investigate sorbent ability to be used as part of of virus detection probes. Self-supported PAC Foils (PAC-F), PAC coated Brushes (PAC-B) and PAC Sampler (PAC-S) were used to prospect PAC efficacy in virus adsorption and above all, the feasibility of virus retrieval from them, allowing to further analysis such as molecular analysis quantification. Aiming at the development of a field-operational tool, PAC saturation and reusability were also investigated, as well as PAC-polarisation effect on its adsorption capacity. Our results pointed out that sorbent-based probes exhibited a high adsorption efficacy of spiked Murine Norovirus (MNV-1) in bare 0.1 M NaCl solution (>90 % for PAC-B and >86 % for PAC-F at ≈10⁷ genome unit virus concentration), with no saturation within our experimental framework. On the other hand, polarisation assays using PAC-F as electrode, did not demonstrate any adsorption improvement. Experiments on PAC probes reusability suggested that they should be used three times at the most for a maximum efficiency. Values of virus retrieval were low (up to 11 % with PAC-B and up to 14 % with PAC-F in 0.1 M NaCl virus suspensions), illustrating the need for the techniques to be improved. A preliminary field assay using PAC-S, demonstrated that our catch-and-retrieve protocol yielded to the detection of autochthonous human Norovirus Genogroup I (NoV GI) and Adenovirus (AdV), in wastewaters suggesting its promising application as virus detection tool in such high loaded and complex waters.
Article
As urban communities continue to grow, demand for recreational access (including swimming) in drinking water sources have increased, yet relatively little is understood about the public health implications this poses for drinking water consumers. Preventative risk-based approaches to catchment management, informed by quantitative microbial risk assessment (QMRA), requires accurate input data to effectively model risks. A sound understanding of the knowledge gaps is also important to comprehend levels of uncertainty and help prioritise research needs. Cryptosporidium is one of the most important causes of waterborne outbreaks of gastroenteritis globally due to its resistance to chlorine. This review was undertaken by Water Research Australia to provide the most up-to-date information on current Cryptosporidium epidemiological data and underlying assumptions for exposure assessment, dose response and risk assessment for generic components of QMRA for Cryptosporidium and highlights priorities for common research. Key interim recommendations and guidelines for numerical values for relatively simple screening level QMRA modelling are provided to help support prospective studies of risks to drinking water consumers from Cryptosporidium due to body-contact recreation in source water. The review does not cover site-specific considerations, such as the levels of activity in the source water, the influence of dilution and inactivation in reservoirs, or water treatment. Although the focus is Australia, the recommendations and numerical values developed in this review, and the highlighted research priorities, are broadly applicable across all drinking source water sources that allow recreational activities.
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This study was designed to evaluate the microbial quality and safety of graywater for reuse purposes. The microbial and chemical composition of graywater from shower/bath, wash cycle and rinse cycle of a clothes washing machine was determined. Graywater composed from all sources within a house was also monitored each week over a 2–3-month time period. Samples were taken from a diverse group of families with children (18 months–9 years of age) and without children. Standard plate count bacteria (SPC) ranged from 105 to 1010 colony forming units (cfu) per 100 ml for shower and bath water, and an average of 104 to 106 cfu per 100 ml for total coliforms. Families with small children produced wash cycle graywater containing 106 cfu per 100 ml of fecal coliforms. During investigations on storage of graywater, it was found that total bacterial SPC and coliform baceria increased one order of magnitude. Salmonella atyphimurium and Shigella dysenteriae seeded into graywater were found to persist for at least several days. Poliovirus type 1 added to graywater decreased 99 and 90% at 25 and 17°C, respectively, after 6 d of storage in graywater. These data imply that there may be some risk associated with reuse of graywater when these pathogenic bacteria or viruses are being excreted by an individual producing the graywater.
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Bacteriological studies in 1968 and 1969 corroborated earlier findings that a municipal watershed which had been closed to public entry since 1917 yielded water with four to six times the coliform count found in an adjacent mountain watershed open to recreational activities. Similarly, chemical investigations showed higher concentrations of most ions in water from the closed area. Physiological differentiation of coliform and enterococcal bacteria revealed similar types of organisms in both animal droppings and stream water, with fecal coliforms accounting for as much as 70% of the coliform counts observed in the closed area in 1969. Opening of the closed drainage for limited recreation and expanded logging operations in the spring of 1970 coincided with an unexpected decrease in bacterial contamination of that stream. It is postulated that these human activities drove from the watershed a large wild animal population which had contributed substantially to the previous bacterial pollution. It would seem that the practice of closing high-mountain watersheds to public entry is questionable if governmental standards for water quality are to be met, and it also seems that the standards themselves should be reexamined.
Article
An outbreak of gastrointestinal illness in which headache, low grade fever and myalgia were common symptoms occurred among persons who visited a recreational park in Macomb County, Michigan, on July 13–16, 1979. The temporal clustering of onsets of 121 persons who were the first in their house holds to become ill suggested an incubation period ranging from 4–77 hours. A history of swimming in the park's lake was elicited with significantly greater frequency from these persons than from park visitors who were not ill (age standardized odds ratio = 4.8; 95% confidence interval, 1.8–12.7). One hundred twenty-six park visitors who became ill were household contacts of index patients who had swum in the lake; at least 62 of these 126 cases were probably due to secondary transmission. A secondary attack rate of 19% was observed in household contacts who had not visited the park. Serologic studies identified Norwalk virus as the etiologic agent. The source of the contamination of the lake could not be determined. Although some water samples collected just before and after the epidemic period had high coliform counts, the geometric mean coliform density of all samples collected on those days was within the limits established by the Environmental Protection Agency as acceptable for recreational contact water.
Article
For 1991 and 1992, 17 states and territories reported 34 outbreaks of disease associated with drinking water, which affected an estimated 17,464 people. A protozoal parasite (Giardia lamblia or Cryptosporidium) was identified as the etiologic agent for seven of the eleven outbreaks for which an agent was determined; the remaining four were due to hepatitis A, Shigella sonnet, or chemicals. A lack of treatment or inadequate treatment accounted for the majority of outbreaks, and most (76 percent) were associated with well water. In addition, eight states reported eleven outbreaks of gastroenteritis associated with unintentional ingestion of recreational water. Six of these outbreaks were caused by Giardia or Cryptosporidium. Ongoing for 22 years, this national surveillance of waterborne disease helps to identify deficiencies in water systems and the etiologic agents associated with outbreaks.
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Before the controversy is settled as to whether the public should be allowed to use water supply sources for sport and play, it must first be determined how recreational use affects water quality— if at all. Five completed studies provide arguments for both sides of the question, and two studies yet to be concluded promise further data for resolving the question.
Article
The bacterial contamination from bathers in the water and sand at a beach was investigated. Measurements were made of the composition of the cutaneous bacterial flora released by two bathers as well as the sensitivity of the main contaminants to solar radiation. The variations in bacterial concentration of the sea water and sand were determined at the sea shore over three complete day cycles. Broadly speaking, the concentration of some bacteria increases with the frequency with which the beach is used. Nevertheless, short-period variations seem to be masked by the opposing effects of solar radiation and bathers.
Article
A modeling study was conducted to evaluate the impact of body-contact recreation (e.g., water skiing, jet skiing, swimming) on pathogen concentrations in a source drinking water reservoir under construction in eastern Riverside County in Southern California. A hybridized Monte Carlo-finite segment model was used to predict pathogen concentrations in the reservoir resulting from pathogen inputs associated with shed fecal material and accidental fecal releases (AFRs). Monte Carlo techniques were incorporated into the finite segment model to define characteristics about individual recreators which affect pathogen loading to the reservoir (e.g., infection, pathogen shedding rate, location). Results of simulations are provided in the form of cumulative distribution and probability density functions derived from uncertainty analyses. The model predicted considerable spatial and temporal variability in pathogen concentrations within the reservoir, with elevated levels of Cryptosporidium, rotavirus, and poliovirus in the epilimnion during periods of high recreational use. Predicted Giardia concentrations were lower than the other pathogens. Hypolimnetic concentrations of all pathogens were generally 1–3 orders of magnitude lower than the overlying epilimnetic concentrations. Model results also suggest that field sampling will underestimate the mean, range and variance of pathogen concentrations in the reservoir. The model was further modified to include a particle tracking scheme to allow for transport of aggregated fecal material. Results from simulations using this approach demonstrate a potential for high pathogen loads due to body-contact recreation periodically reaching treatment plants.
Article
In order to examine the temporal relationship between bather load and water quality indicator levels, faecal pollution indicator (faecal coliforms and faecal streptococci) and opportunistic pathogen (Candida albicans and Pseudomonas aeruginosa) levels were monitored hourly in the nearshore waters of a shallow Lake Ontario bathing beach on a hot August day when the bather load was high, and on two overcast August days when the bather load was negligible. On the high bather load day, an increase occurred in the numbers of faecal coliforms and faecal streptococci in the beach water in conjunction with an increase in the bather load; P. aeruginosa levels increased later in the day. There was little apparent relationship between C. albicans levels and the other parameters on the high bather load day. No corresponding increases were observed for any of the monitored parameters on the low bather load days. The results indicate that bather load and sample collection time may influence estimations of recreational water quality based on faecal pollution indicator and P. aeruginosa levels.
Article
Recent epidemiological studies have shown a relationship between swimming in recreational waters meeting bacteriological standards and gastroenteritis with a suggested viral etiology. No previous studies have been conducted in the United States on the occurrence of human pathogenic enteric viruses in freshwater recreational areas. The presence of enteroviruses and rotaviruses was investigated in Oak Creek, Arizona, a heavily used recreational area. Water samples were filtered through positively charged filters (168–1555 I.), eluted with beef extract, and assayed for human enteroviruses and rotaviruses. Eighteen of the 41 recreational water samples were positive for enterovirus or rotavirus. Of these, nine samples exceeded the Arizona State recommended limit of 1 PFU 40 l−1 for full body contact in effluent dominated recreational waters. Several virus positive samples met the recommended fecal coliform standards (200 CFU 100 ml−1) for recreational waters indicating the inadequacy of bacterial standards for monitoring viral water quality. The isolation of the pathogenic enteric viruses (i.e., poliovirus 1, echovirus 1, coxsackievirus B1 and B6 and rotavirus) from this popular recreational water demonstrates the potential for transmission of viral disease.
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"An Official report of the American Public Health Association" Incluye índice
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The microbiological quality of forest surface waters in the Greenwater River watershed was examined to investigate the influence of heavy motorized camping in an area with no sanitary facilities. Indicator densities increased during weekend human-use periods when compared to weekdays. Increases in indicator densities were also noted downstream from heavily used camping areas when compared to upstream sites. Seasonal, weekly, and diurnal fluctuations in indicator densities were observed. This study suggests that potential health hazards exist in this watershed during periods of human use.
Article
In August and September 1975, an outbreak of diarrhea occurred in children 1 to 3 1/2 years old attending a day-care center. An investigation revealed overlapping epidemics of shigellosis and giardiasis, with 54% of the children infected with Giardia lamblia. At two other centers 29% and 38% of the children had G. lamblia infection, but none had Shigella. The prevalence of G. lamblia in the day-care children was significantly higher than the 2% prevalence in age-matched children not in day-care centers. Epidemiologic data suggested fecal-oral transmission of the parasite from child to child in the centers and from infected children to other family members.
Article
In July and August 1988, an outbreak of gastroenteritis affected 44 of 60 (73%) persons from 5 separate swimming groups who had used the same swimming pool in Los Angeles. Cryptosporidium was identified in 5 of 8 (63%) stool specimens, and the clinical picture was consistent with Cryptosporidium infection. Resistance of Cryptosporidium to chlorine, an inadequately maintained pool filtration system, repeated exposure to pool water, and possible continuing pool contamination may have contributed to ongoing transmission. Cryptosporidium should be considered a potential etiologic agent of gastroenteritis associated with recreational water use.
Article
To determine the timing of symptoms and oocyst excretion after the acquisition of cryptosporidium infection, we used a screening parasitologic stool examination to identify patients and then contacted them for the collection of retrospective histories and follow-up stool specimens. The study included 68 otherwise healthy patients with an identifiable source and time of infection. All 68 had diarrhea, 61 had abdominal pain, most also had other gastrointestinal symptoms, 33 had fever, and all recovered spontaneously. Among the 50 patients who submitted follow-up stool samples, more than 90 percent of the 610 symptomatic days and of the 136 oocyst-positive stools occurred between days 7 and 28 of infection, the mean incubation period was 7.2 days (range, 1 to 12), and the mean duration of illness was 12.2 days (range, 2 to 26). During the oocyst-excretion period cryptosporidium was detected in 90 percent of Ziehl-Neelsen-stained fecal concentrates. The end of oocyst excretion could be accurately determined in 26 patients; 19 (73 percent) had positive stools after the cessation of symptoms for a mean period of 6.9 days (range, 1 to 15). Fourteen patients were studied for two or more months, and in three of them asymptomatic episodes of oocyst excretion were detected up to two months after clinical recovery. We conclude that many cases of symptomatic cryptosporidiosis occur among immunocompetent patients, some of whom may excrete oocysts even when they have become asymptomatic. Conversely, infected symptomatic patients may occasionally have intermittently negative stools.
Article
During 29 months of prospective longitudinal study of diarrhea in the home, human rotaviruses (HRVs) infected one or more members in 51% of 65 families, 35 of 126 children (28%) and 16 of 124 adults (13%). Within the 33 affected families, 57% of 62 children and 25% of 65 adults were infected. HRV gastroenteritis peaked at 40/100 person years at ages 12 to 23 months and decreased to 5 episodes/100 person years in adults. Among 25 children 0 through 36 months of age who had HRV infection, 88% were symptomatic. Of the 22 children with symptomatic HRV infection, 1 required hospitalization and 8 were seen by their physician for supportive care. HRVs were found in 12% of 216 stools obtained during gastrointestinal illness, but in only 0.2% of 1238 non-illness stools tested. HRV infections were noted as early as October and as late as April. Of 33 families who were studied for 2 seasons, at least 1 individual in each of 3 families experienced HRV infections in both years, but only one, an adult, shed virus and had symptoms in both seasons.
Article
One-hundred-ninety-two stool samples were tested for the presence of human Hepatitis A antigen. Sixteen of these were also evaluated for the presence of infectious virus. All samples were obtained from young and apparently healthy people from endemic areas for Hepatitis A disease. The isolation of the infectious virus from these stools demonstrates clearly the wide diffusion of the virus in these areas, and its transmission by the oral-fecal route.
Article
In the fall of 1985, an outbreak of giardiasis occurred among several swimming groups at an indoor pool in northeast New Jersey. Nine clinical cases were identified, eight of whom had Giardia positive stool specimens. All were female; seven were adults (greater than 18 years) and two were children. The attack rate was highest (39 per cent, 5/13) for the ladies lap group who had exposure on one day. These cases had no direct contact with children or other risk factors for acquiring Giardia. Infection most likely occurred following the ingestion of swimming pool water contaminated with Giardia cysts. The source of Giardia contamination was a handicapped child who had a fecal accident in the pool. He was a member of a group that swam at the same time as the ladies lap group. A stool survey of the handicapped group showed that of the 20 persons tested, nine were positive for Giardia, including the specimen from this child. Examination of the pool records showed that no chlorine levels had been taken on the day of the fecal accident and that on the following day the chlorine level was zero. This is the second report of Giardia transmission among swimming pool attendees. It emphasizes the need to maintain appropriate chlorine levels in swimming pools and to institute measures to clear pools after a fecal accident.
Article
Five healthy young women swam in untreated water of known bacterial quality under a variety of hygienic conditions. Evidence based on bacteriological examination of water samples leads to the following conclusions: 1. There is a marked variation in the number and types of bacteria shed by a bather while swimming and the variations do not seem to be correlated to the differences in personal hygiene or the menstrual period. 2. Faecal organisms may be discharged in considerable numbers by a swimmer after a thorough and careful shower with soap and warm water and yet not be discharged in appreciable numbers by a bather who does not take a shower before swimming. 3. Faecal organisms constitute only a small minority of the total number of viable bacteria that are discharged in swimming pool water by a bather during the act of swimming and as such seem to have limited use as indicators of total bacterial pollution. 4. Members of the genus Staphylococcus are shed in large numbers under all conditions and Staph. aureus is consistently present. Therefore, this genus appears to be a good choice as an index for the determination of body contamination. 5. Further studies are indicated under more stringently controlled hygienic conditions to determine the value of hexachlorophene in reducing microbial flora that a given individual may shed during swimming.
Article
A prospective study was carried out on 200 patients admitted to Fairfield Hospital, Melbourne, Australia, with acute hepatitis A to determine the frequency with which virus could be detected in their feces. Evidence of infection with hepatitis A virus (HAV) was obtained by detecting IgM specific for HAV in a single serum sample or by demonstrating a rising titer of antibody in paired sera by solid-phase radioimmunoassay. HAV was detected in the feces of 59 of the 200 patients by solid-phase radioimmunoassay and immune electron microscopy. When patients were admitted within one week of the onset of dark urine, 45% were found to be shedding HAV, whereas only 11% of specimens obtained from patients admitted during the second week contained virus. HAV was not detected in fecal specimens collected more than 14 days after the onset of dark urine. These findings suggest that patients admitted to hospital with hepatitis A may still be infectious and that appropriate precautions against fecal contamination should be maintained.
Article
Data have been gathered and collated from a variety of sources both published and unpublished, dealing with the concentration of enteroviruses in human stools. For polioviruses, a general range of 3.0–6.5 log10 TCD50* per gram of stool was reported, whereas for coxsackieviruses and echoviruses the range has been from 2.0–5.5 log10 TCD50. As human stools average about 100 gm, it is not unusual for an infected person to excrete as much as 10–300 million TCD50 of virus daily. The results of enterovirus titrations are significantly affected by the types of cultures in which the tests are conducted. With certain kinds of cultures (eg, human kidney for polioviruses), comparative tests showed titers to be at least one log unit higher per gram of stool than the titers of the same strains titrated in monkey kidney cultures. Since almost all of the titrations included in this report were carried out in monkey kidney cultures, the concentration of virus in many cases may be assumed to be ten times higher than that reported. Some of the data collected also contributed information on the duration of enterovirus excretion. These data reemphasize the fact that a person in the course of an asymptomatic enterovirus infection may excrete the virus over a period of many weeks, with about 50% of those infected continuing to shed virus into the third and fourth weeks of infection.
Article
An outbreak of gastrointestinal illness in which headache, low grade fever and myalgia were common symptoms occurred among persons who visited a recreational park in Macomb County, Michigan, on July 13-16, 1979. The temporal clustering of onsets of 121 persons who were the first in their households to become ill suggested an incubation period ranging from 4-77 hours. A history of swimming in the park's lake was elicited with significantly greater frequency from these persons than from park visitors who were not ill (age standardized odds ratio = 4.8; 95% confidence interval, 1.8-12.7). One hundred twenty-six park visitors who became ill were household contacts of index patients who had swum in the lake; at least 62 of these 126 cases were probably due to secondary transmission. A secondary attack rate of 19% was observed in household contacts who had not visited the park. Serologic studies identified Norwalk virus as the etiologic agent. The source of the contamination of the lake could not be determined. Although some water samples collected just before and after the epidemic period had high coliform counts, the geometric mean coliform density of all samples collected on those days was within the limits established by the Environmental Protection Agency as acceptable for recreational contact water.
Article
Biophysical and biochemical analysis of hepatitis A virus has shown it to be a 27- to 32-nm icosahedral particle with 32 capsomers. The mature virion has a buoyant density of 1.33-1.34 g/cm3, a sedimentation coefficient of 156-160S, and is composed of four polypeptides with molecular weights of 30,000-33,000 (VP1), 24,000-27,000 (VP2), 21,000-23,000 (VP3), and 7,000-14,000 (VP4). The genome of hepatitis A virus consists of a single piece of single-stranded RNA which sediments at 32-35S and has a buoyant density of 1.64 g/cm3. The molecular weight of RNA is 2.25 x 10(6) when measured under nondenaturing conditions and 2.8 x 10(6) when measured under fully denaturing conditions. The genome contains a 40-80 nucleotide sequence of polyadenylic and is capable of infecting cell cultures. These findings, together with the observation that the virion is stable at pH 3.0 and resistant to ether and a temperature of 60 degrees for 1 h, indicate that hepatitis A virus should now be classified as an Enterovirus within the family Picornaviridae.
Article
In June 1977 an outbreak of acute gastroenteritis affected 103 students and teachers at an elementary school in Ohio. The illness typically lasted 24 hours or less and was characterized by vomiting (86%) and cramping (70%), but more than half of the persons involved also reported having nausea, diarrhea, and headache. Similar illness frequently followed in household members (29%) of families with primary cases. Investigation revealed that 70% of the children and teachers who swam in a pool at an all day outing June 1 (4 classrooms) and 55% of those who swam during a similar outing June 2 (2 classrooms) had the onset of acute illness from 12--48 hours later. None of the children who attended the outings but did not swim had a similar illness. The evidence suggested that the primary outbreak was caused by contaminated water in the pool and that person-to-person spread of illness followed. Results of a microbiologic study of pool water were negative for bacterial and viral pathogens. Throat washings, stool specimens, and paired blood samples studied for evidence of pathogens were negative initially, but subsequent serologic studies suggested that infection by Norwalk virus was the cause of the outbreak. The pool chlorinator which was inadvertently unconnected at the time of the school visits was reconnected and an underground leak in the water supply pipes was corrected. No more cases were reported after the pool was drained, cleaned, and reopened.
Article
Enteric illnesses in residents of Tecumseh, Michigan, were studied from 1976 to 1981. The frequency of illness among adults and children increased each year in the late autumn, usually in November. This peak of illness preceded the main period of appearance of the rotaviruses, which were less regularly associated with another peak of illness. Rotaviruses were identified in 3.8% of all stool specimens collected; in specimens from children under two years of age, the annual rate of rotavirus identification was 10.4%. All rotaviruses were identified during the period from late December to early April. Bacterial pathogens were isolated from 3.3% of stool specimens, with no concentration in any age group or season. However, most enteric illnesses in the community were not associated with recognized pathogens. Testing of blood specimens collected in 1976–1978 by complement fixation confirmed the seasonal pattern of rotavirus activity. Rotavirus infections were documented in all age groups, even in older adults, and were associated with symptomatic illness.
Article
From September 1979 to July 1980 inclusive, rotaviruses were prospectively detected by electron microscopy (EM) and ELISA in 82 (29%) of 283 children under two years of age who were admitted to a general pediatric ward in Paris. Rotavirus was found in 43 (36%) of 119 children with diarrhea and in 40 (24%) of 164 children without diarrhea; thus of 83 children shedding rotavirus, 40 (48%) were not diarrheic. Virus shedding that was not associated with diarrhea was observed in 71% of neonates, in 50% of one- to six-month-old children, and in 26% of 7–24-month-old children. Rotavirus shedding was statistically correlated (P < .01) only with those cases of diarrhea with fever and vomiting (DFV syndrome). Consequently, relative risk (RR) for the DFV syndrome in patients who were shedding virus was 2.07 (P < .001) vs. 0.95 for other types of diarrhea. These observations show that asymptomatic rotaviral infection is not an infrequent occurrence; that the association between rotavirus and diarrhea is not necessarily an etiologic one; and that the DFV syndrome appears as a major clinical expression of rotaviral disease. Consequently, recovery of rotavirus from feces is of little diagnostic significance since it does not give a differentiation between rotavirus-induced and rotavirus-associated diarrhea.
Article
A Giardia infected Washington State child was found to participate in an infant and toddler swim class. A stool survey of 70 child participants revealed a 61 per cent prevalence of Giardia infection. Also, 39 per cent of 53 mothers and 28 per cent of 21 fathers were Giardia positive. None of the non-swimming playmates were positive. Thirty-five per cent of 23 children exposed only at a better maintained pool to which the classes had been moved four weeks prior to the survey were positive. No evidence of transmission to non-swim class pool users was found.
Article
We prospectively evaluated excretion of Giardia lamblia in children in day care centers in Houston by conducting two prevalence studies of 600 children enrolled in 30 DCC, day care centers, and an 18-month longitudinal study in 82 children in one center. In the two prevalence surveys, Giardia cysts were identified in 72 (21%) and 67 (26%) children, respectively, who provided stool specimens. Trophozoites were found in 15 (4%) and 8 (3%), respectively. There was no correlation between the frequency of recent diarrheal episodes and the finding of Giardia. Stool specimens containing cysts were significantly (P less than 0.0001) more frequent in the 13- to 30-month-old children than in children younger than 12 months. Children attending day care centers for more than 3 months were more likely to be excreting Giardia than those attending for less than 3 months. In the longitudinal study, cysts were detected in stool specimens from 27 (33%) of the 82 children at least once during the survey. Twelve children had Giardia cysts in weekly stool specimens for a mean of 6.2 +/- 1.2 months and trophozoites for 3.3 +/- 1.2 months. The number of enteric symptoms observed in children and the classification of nutritional status based on monthly height and weekly weight measurements did not differ significantly when infected and noninfected children were compared. Asymptomatic Giardia excretion in children younger than 36 months is common and appears to be well tolerated.
Article
Five surveys of 1,731 children for stool ova and parasites (1971 to 1981) in a rural county provide a unique perspective on naturally occurring, nonepidemic giardiasis. Currently white children in day care centers in Hampton County, South Carolina, experience attack rates of 26%. They enter the first grade with at least six times as much infection as those who do not attend day care. A trend toward more giardiasis linked to working mothers and day care is evident among white preschool children. This has not yet occurred among black preschool-aged children. These and other epidemiologic data indicate that as few as 100 children can maintain endemic levels of infection in a county of 18,000 residents. Person-to-person transmission in the day care setting is sufficient to explain this county's rising rate of stool positivity of infection (8% of all stool specimens submitted to the state laboratory).