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Zeng J, Nakanishi T, Itoh S. Two-year Monitoring of Microbiological Water Quality in Small Water Supply Systems: Implications for Microbial Risk Management. ENVIRONMENTAL MANAGEMENT 2024:10.1007/s00267-024-01988-0. [PMID: 38767663 DOI: 10.1007/s00267-024-01988-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Accepted: 05/06/2024] [Indexed: 05/22/2024]
Abstract
Small water supply systems (SWSSs) are often more vulnerable to waterborne disease outbreaks. In Japan, many SWSSs operate without regulation under the Waterworks Law, yet there is limited investigation into microbial contamination and the associated health risks. In this study, the microbiological water quality of four SWSSs that utilize mountain streams as water sources and do not install water treatment facilities were monitored for over 2 years. In investigated SWSSs, the mean heterotrophic plate counts were below 350 CFU/mL, and the total bacterial loads (16S rDNA concentration) ranged from 4.71 to 5.35 log10 copies/mL. The results also showed the consistent presence of fecal indicator bacteria (FIB), i.e., Escherichia coli and Clostridium perfringens, suggesting the potential of fecal pollution. E. coli was then utilized as an indicator to assess the health risk posed by E. coli O157:H7 and Campylobacter jejuni. The results indicated that the estimated mean annual risk of infection and disability-adjusted life years (DALYs) exceeded acceptable levels in all SWSSs for the two reference pathogens. To ensure microbial water safety, implementing appropriate water treatment facilities with an estimated mean required reduction of 5-6 log10 was necessary. This study highlighted the potential microbial contamination and health risk level in SWSSs that utilize mountain streams as water sources, even though the water sources were almost not affected by human activities. Furthermore, this study would also be helpful in supporting risk-based water management to ensure a safe water supply in SWSSs.
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Affiliation(s)
- Jie Zeng
- Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, Kyoto University Katsura, Nishikyo, Kyoto, 615-8540, Japan
| | - Tomohiro Nakanishi
- Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, Kyoto University Katsura, Nishikyo, Kyoto, 615-8540, Japan.
| | - Sadahiko Itoh
- Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, Kyoto University Katsura, Nishikyo, Kyoto, 615-8540, Japan
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2
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Abe H, Kawasaki S. Modeling strain variability in Campylobacter jejuni thermal inactivation by quantifying the number of strains required. Int J Food Microbiol 2024; 414:110618. [PMID: 38340547 DOI: 10.1016/j.ijfoodmicro.2024.110618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 12/21/2023] [Accepted: 02/04/2024] [Indexed: 02/12/2024]
Abstract
There is a limited understanding of the survival responses of Campylobacter jejuni during thermal processing, which must be investigated for appropriate risk assessment and processing. Therefore, we aimed to elucidate the survival response of C. jejuni and develop a predictive model considering strain variability and uncertainty, which are important for quantitative microbial risk assessment (QMRA) or risk-based processing control measures. We employed the most probable curve (MPC) method to consider the uncertainty in cell concentrations. Further, the multivariate normal (MVN) distribution served as a model for strain variability in bacterial survival behavior. The prediction curves from the MVN successfully captured the parameter variability of the most probable curves of each strain. More than ten reference strains effectively described the strain variability in parameters using the MVN distribution. The findings indicated that, with sufficient strain data, the MVN could estimate the strain variability, including unknown strains. The multi-level model for strain variability can potentially become a specialized tool for QMRA and risk-based processing controls. The combined approach of MPC and MVN provides valuable insights into strain variability, emphasizing the importance of accounting for variability and uncertainty in predictive models for QMRA and risk-based processing control measures.
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Affiliation(s)
- Hiroki Abe
- Institute of Food Research, National Agriculture and Food Research Organization, Kannondai 2-1-12, Tsukuba 305-8642, Japan.
| | - Susumu Kawasaki
- Institute of Food Research, National Agriculture and Food Research Organization, Kannondai 2-1-12, Tsukuba 305-8642, Japan
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3
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Rytkönen A, Meriläinen P, Valkama K, Hokajärvi AM, Ruponen J, Nummela J, Mattila H, Tulonen T, Kivistö R, Pitkänen T. Scenario-based assessment of fecal pathogen sources affecting bathing water quality: novel treatment options to reduce norovirus and Campylobacter infection risks. Front Microbiol 2024; 15:1353798. [PMID: 38628869 PMCID: PMC11018956 DOI: 10.3389/fmicb.2024.1353798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Accepted: 03/12/2024] [Indexed: 04/19/2024] Open
Abstract
Wastewater discharge and runoff waters are significant sources of human and animal fecal microbes in surface waters. Human-derived fecal contamination of water is generally estimated to pose a greater risk to human health than animal fecal contamination, but animals may serve as reservoirs of zoonotic pathogens. In this study, quantitative microbial risk assessment (QMRA) tools were used to evaluate the hygienic impact of sewage effluents and runoff water from municipalities and animal farms on surface and bathing waters. The human-specific microbial source tracking (MST) marker HF183 was used to evaluate the dilution of fecal pathogens originating from the sewage effluent discharge to the downstream watershed. As novel risk management options, the efficiency of UV-LED disinfection and wetland treatment as well as biochar filtration was tested on-site for the contamination sources. According to the dilution pattern of the MST marker HF183, microbes from wastewater were diluted (2.3-3.7 log10) in the receiving waters. The scenario-based QMRA revealed, that the health risks posed by exposure to human-specific norovirus GII and zoonotic Campylobacter jejuni during the bathing events were evaluated. The risk for gastroenteritis was found to be elevated during wastewater contamination events, where especially norovirus GII infection risk increased (1-15 cases per day among 50 bathers) compared with the business as usual (BAU) situation (1 case per day). The noted C. jejuni infection risk was associated with animal farm contamination (1 case per day, versus 0.2-0.6 cases during BAU). Tertiary treatment of wastewater with wetland treatment and UV-LED disinfection effectively reduced the waterborne gastroenteritis risks associated with bathing. Based on the experiences from this study, a QMRA-based approach for health risk evaluations at bathing sites can be useful and is recommended for bathing site risk assessments in the future. In case of low pathogen numbers at the exposure sites, the MST marker HF183 could be used as a pathogen dilution coefficient for the watershed under evaluation. The full-scale implementation of novel tertiary treatment options at wastewater treatment plants (WWTPs) as well as on-site runoff water treatment options should be considered for infection risk management at locations where scenario-based QMRA implies elevated infection risks.
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Affiliation(s)
- Annastiina Rytkönen
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | - Päivi Meriläinen
- Department of Health Security, Finnish Institute for Health and Welfare, Kuopio, Finland
| | - Kristiina Valkama
- Department of Health Security, Finnish Institute for Health and Welfare, Kuopio, Finland
| | - Anna-Maria Hokajärvi
- Department of Health Security, Finnish Institute for Health and Welfare, Kuopio, Finland
| | - Josefiina Ruponen
- Lammi Biological Station, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
- Bio Research Unit, Häme University of Applied Sciences, Hämeenlinna, Finland
| | - Jarkko Nummela
- Bio Research Unit, Häme University of Applied Sciences, Hämeenlinna, Finland
| | - Harri Mattila
- Bio Research Unit, Häme University of Applied Sciences, Hämeenlinna, Finland
| | - Tiina Tulonen
- Lammi Biological Station, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Rauni Kivistö
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | - Tarja Pitkänen
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
- Department of Health Security, Finnish Institute for Health and Welfare, Kuopio, Finland
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4
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Luoto J, Keto-Timonen R, Kivistö R. Campylobacter species and genotype distribution in Finnish beef liver - Retail liver juice ideal for isolation and quantification. Int J Food Microbiol 2024; 411:110524. [PMID: 38118359 DOI: 10.1016/j.ijfoodmicro.2023.110524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 10/18/2023] [Accepted: 12/10/2023] [Indexed: 12/22/2023]
Abstract
Campylobacteriosis, primarily caused by Campylobacter jejuni and C. coli, is the main bacterial zoonosis worldwide. While poultry is recognized as the main reservoir, bovines are considered another important reservoir for Campylobacter spp. found in human infections. In contrast to chicken, retail beef is seldom contaminated by Campylobacter species. However, beef liver is recognized to be frequently contaminated and has been linked to human infections via epidemiological investigations. Our aims were to evaluate the prevalence of Campylobacter spp. inside and on the surface of beef liver pieces at retail in Finland and to analyse the population in more detail using whole genome sequencing (WGS) to assess the public health relevance. A total of 90 retail beef livers were studied using both enrichment of the external peptone-saline rinse of the liver piece and direct culture from the inside after surface sterilization. Furthermore, 46 of the livers were also studied using direct culture of retail beef liver juice collected from the bottom of the consumer package to estimate the concentration of Campylobacter species. Overall, 44 (49 %) of the samples were positive for Campylobacter species, C. jejuni, C. fetus and C. lari being identified in 42 %, 8.9 % and 1.1 % of the samples, respectively. Direct culture of retail liver juice was a sensitive and convenient method for Campylobacter spp. detection, resulting in 48 % prevalence and a mean concentration of 49 cfu/ml (maximum 335 cfu/ml). Two samples (2.2 %), containing large hepatic ducts, were positive for C. jejuni internally, representing multilocus sequence typing (MLST) sequence type ST-19 and ST-21. WGS, core genome phylogeny and core genome MLST revealed that in most cases only one clearly distinct clone of clinically relevant C. jejuni or C. fetus was isolated from a single lot of samples. However, in some cases several distinct clones were identified simultaneously even from a single liver piece. In epidemiological investigations, it is thus highly advisable to genotype multiple isolates to capture the whole diversity of Campylobacter spp. from suspected food sources. Good kitchen hygiene, avoidance of cross-contamination and thorough cooking are important for limiting the transmission of campylobacteriosis.
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Affiliation(s)
- Jenna Luoto
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | - Riikka Keto-Timonen
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | - Rauni Kivistö
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland.
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Eriksson D, Råhlén E, Bergenkvist E, Skarin M, Fernström LL, Rydén J, Hansson I. Survival of Campylobacter jejuni in frozen chicken meat and risks associated with handling contaminated chicken in the kitchen. Food Control 2023. [DOI: 10.1016/j.foodcont.2022.109471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Bhatt A, Dada AC, Prajapati SK, Arora P. Integrating life cycle assessment with quantitative microbial risk assessment for a holistic evaluation of sewage treatment plant. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 862:160842. [PMID: 36509266 DOI: 10.1016/j.scitotenv.2022.160842] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 11/12/2022] [Accepted: 12/07/2022] [Indexed: 06/17/2023]
Abstract
An integrated approach was employed in the present study to combine life cycle assessment (LCA) with quantitative microbial risk assessment (QMRA) to assess an existing sewage treatment plant (STP) at Roorkee, India. The midpoint LCA modeling revealed that high electricity consumption (≈ 576 kWh.day-1) contributed to the maximum environmental burdens. The LCA endpoint result of 0.01 disability-adjusted life years per person per year (DALYs pppy) was obtained in terms of the impacts on human health. Further, a QMRA model was developed based on representative sewage pathogens, including E. coli O157:H7, Giardia sp., adenovirus, norovirus, and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The public health risk associated with intake of pathogen-laden aerosols during treated water reuse in sprinkler irrigation was determined. A cumulative health risk of 0.07 DALYs pppy was obtained, where QMRA risks contributed 86 % of the total health impacts. The annual probability of illness per person was highest for adenovirus and norovirus, followed by SARS-CoV-2, E. coli O157:H7 and Giardia sp. Overall, the study provides a methodological framework for an integrated LCA-QMRA assessment which can be applied across any treatment process to identify the hotspots contributing maximum environmental burdens and microbial health risks. Furthermore, the integrated LCA-QMRA approach could support stakeholders in the water industry to select the most suitable wastewater treatment system and establish regulations regarding the safe reuse of treated water.
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Affiliation(s)
- Ankita Bhatt
- Department of Hydro and Renewable Energy, Indian Institute of Technology Roorkee, Uttarakhand, India
| | | | - Sanjeev Kumar Prajapati
- Department of Hydro and Renewable Energy, Indian Institute of Technology Roorkee, Uttarakhand, India
| | - Pratham Arora
- Department of Hydro and Renewable Energy, Indian Institute of Technology Roorkee, Uttarakhand, India.
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7
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Ito S, Kishimoto M. Development of a Sampling and Real-time PCR Method for the Quantitative Detection of Campylobacter spp. in Retail Chicken Meat Without DNA Extraction. J Food Prot 2023; 86:100028. [PMID: 36916587 DOI: 10.1016/j.jfp.2022.100028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 12/05/2022] [Accepted: 12/08/2022] [Indexed: 12/23/2022]
Abstract
Campylobacter food poisoning is caused by consumption of the contaminated foods, especially poultry meat. Continuous quantitative measurement of Campylobacter spp. in contaminated foods is crucial to develop preventive measures. We developed a direct-qPCR method for determining the viable cell counts of Campylobacter spp. using qPCR without DNA extraction from enriched food samples and a sampling method (the wrap procedure) in which the sample is wrapped in a sheet, different from the conventional homogenization procedure. The viable cell counts of Campylobacter spp. before and after enrichment of the samples sampled using the wrap and homogenization procedures from chicken samples inoculated with Campylobacter jejuni were determined using the culture method, and the cycle threshold (CT) values after enrichment were determined using the direct-qPCR. An enrichment regression equation was generated from the viable cell counts obtained before and after enrichment, and a direct-qPCR regression equation was generated from the CT values and viable cell counts obtained after enrichment, enabling the viable cell counts before enrichment to be estimated from the CT values. Estimated viable cell counts were similar for the culture method when sampled by the homogenization procedure, but lower for the wrap procedure. However, the detection rate of direct-qPCR was 37.5% for liver and 89.7% for breast fillet using the homogenization procedure, whereas using the wrap procedure, it was 100% for both samples. The detection rate of direct-qPCR for retail chicken was 30.4-35.7% for the homogenization procedure, and 85.7-100% for the wrap procedure. Colonies were observed using the culture method, but their quantification was difficult due to swarming or their low number. However, estimating viable cell counts using the combination of wrap procedure and direct-qPCR methods is possible. The developed method can provide baseline data for the risk assessment Campylobacter food poisoning.
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Affiliation(s)
- Satoshi Ito
- Faculty of Nutrition, Kobe Gakuin University, Kobe, Hyogo 651-2113, Japan.
| | - Michiru Kishimoto
- Graduate School of Nutritional Sciences, Nagoya University of Arts and Sciences Graduate School, Nagoya, Aichi 470-0196, Japan
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8
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Oudega TJ, Lindner G, Sommer R, Farnleitner AH, Kerber G, Derx J, Stevenson ME, Blaschke AP. Transport and removal of spores of Bacillus subtilis in an alluvial gravel aquifer at varying flow rates and implications for setback distances. JOURNAL OF CONTAMINANT HYDROLOGY 2022; 251:104080. [PMID: 36179584 DOI: 10.1016/j.jconhyd.2022.104080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 07/29/2022] [Accepted: 09/17/2022] [Indexed: 06/16/2023]
Abstract
To guarantee proper protection from fecally transmitted pathogen infections, drinking water wells should have a sufficiently large setback distance from potential sources of contamination, e.g. a nearby river. The aim of this study was to provide insight in regards to microbial contamination of groundwater under different flow velocities, which can vary over time due to changes in river stage, season or pumping rate. The effects of these changes, and how they affect removal parameters, are not completely understood. In this study, field tracer tests were carried out in a sandy gravel aquifer near Vienna, Austria to evaluate the ability of subsurface media to attenuate Bacillus subtilis spores, used as a surrogate for Cryptosporidium and Campylobacter. The hydraulic gradient between injection and extraction was controlled by changing the pumping rate (1, 10 l/s) of a pumping well at the test site, building upon previously published work in which tracer tests with a 5 l/s pumping rate were carried out. Attachment and detachment rate coefficients were determined using a HYDRUS-3D model and ranged from 0.12 to 0.76 and 0-0.0013 h-1, respectively. Setback distances were calculated based on the 60-day travel time, as well as a quantitative microbial risk assessment (QMRA) approach, which showed similar results at this site; around 700 m at the highest pumping rate. Removal rates (λ) in the field tests ranged from 0.2 to 0.3 log/m, with lower pumping rates leading to higher removal. It was shown that scale must be taken into consideration when determining λ for the calculation of safe setback distances.
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Affiliation(s)
- Thomas J Oudega
- Institute of Hydraulic Engineering and Water Resources Management E222/2, TU Wien, Karlsplatz 13, A-1040 Vienna, Austria; Interuniversity Cooperation Centre (ICC) Water & Health, www.waterandhealth.at, Austria
| | - Gerhard Lindner
- Institute of Hydraulic Engineering and Water Resources Management E222/2, TU Wien, Karlsplatz 13, A-1040 Vienna, Austria; Medical University of Vienna, Institute for Hygiene and Applied Immunology, Water Hygiene, Kinderspitalgasse 15, A-1090 Vienna, Austria; Interuniversity Cooperation Centre (ICC) Water & Health, www.waterandhealth.at, Austria
| | - Regina Sommer
- Medical University of Vienna, Institute for Hygiene and Applied Immunology, Water Hygiene, Kinderspitalgasse 15, A-1090 Vienna, Austria; Interuniversity Cooperation Centre (ICC) Water & Health, www.waterandhealth.at, Austria
| | - Andreas H Farnleitner
- Research Group Microbiology and Molecular Diagnostics 166/5/3, Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorferstraße 1a, A-1060 Vienna, Austria; Karl Landsteiner University for Health Sciences, Department of Pharmacology, Physiology and Microbiology, Research Division Water & Health, Krems, Austria; Interuniversity Cooperation Centre (ICC) Water & Health, www.waterandhealth.at, Austria
| | - Georg Kerber
- Gruppe Wasser - Ziviltechnikergesellschaft für Wasserwirtschaft GmbH, Braunhirschengasse 28, 1150 Vienna, Austria
| | - Julia Derx
- Institute of Hydraulic Engineering and Water Resources Management E222/2, TU Wien, Karlsplatz 13, A-1040 Vienna, Austria; Interuniversity Cooperation Centre (ICC) Water & Health, www.waterandhealth.at, Austria
| | - Margaret E Stevenson
- Institute of Hydraulic Engineering and Water Resources Management E222/2, TU Wien, Karlsplatz 13, A-1040 Vienna, Austria; Interuniversity Cooperation Centre (ICC) Water & Health, www.waterandhealth.at, Austria.
| | - Alfred P Blaschke
- Institute of Hydraulic Engineering and Water Resources Management E222/2, TU Wien, Karlsplatz 13, A-1040 Vienna, Austria; Interuniversity Cooperation Centre (ICC) Water & Health, www.waterandhealth.at, Austria
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9
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Teunis PFM. Dose response for Salmonella Typhimurium and Enteritidis and other nontyphoid enteric salmonellae. Epidemics 2022; 41:100653. [PMID: 36436317 DOI: 10.1016/j.epidem.2022.100653] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 10/28/2022] [Accepted: 11/11/2022] [Indexed: 11/18/2022] Open
Abstract
This dose response assessment combines data from 6 human challenge studies and 44 outbreaks to determine infectivity and pathogenicity of several serotypes of nontyphoid Salmonella. Outcomes focus on the major serotypes Salmonella Enteritidis and Typhimurium, showing that Typhimurium is less infectious and has a lower probability of causing acute illness in infected subjects. The dose response relation of Salmonella Enteritidis is less steep than that of Typhimurium, indicating greater heterogeneity in infectivity and pathogenicity. This study revisits an older study with less flexible methods that could not combine the widely different outcomes of challenge studies and outbreaks, and had limited capability for dealing with missing information. Reported outcomes are in a format that allows use in calculations of uncertainty for quantitative risk assessment.
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Affiliation(s)
- Peter F M Teunis
- Center for Global Safe WASH, Rollins School of Public Health, Emory University, 1518 Clifton Rd, CNR Bldg. 6050 Atlanta, GA 30322, USA.
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10
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Molecular Epidemiological Evidence Implicates Cattle as a Primary Reservoir of Campylobacter jejuni Infecting People via Contaminated Chickens. Pathogens 2022; 11:pathogens11111366. [DOI: 10.3390/pathogens11111366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 11/07/2022] [Accepted: 11/08/2022] [Indexed: 11/18/2022] Open
Abstract
The study aimed to determine the relative contribution of cattle to the burden of illness in a model agroecosystem with high rates of human campylobacteriosis (≥ 115 cases/100 K), and high densities of cattle, including large numbers of cattle housed in confined feeding operations (i.e., in southwestern Alberta, Canada). To accomplish this, a large-scale molecular epidemiological analysis of Campylobacter jejuni circulating within the study location was completed. In excess of 8000 isolates of C. jejuni from people (n = 2548 isolates), chickens (n = 1849 isolates), cattle (n = 2921 isolates), and water (n = 771 isolates) were subtyped. In contrast to previous studies, the source attribution estimates of clinical cases attributable to cattle vastly exceeded those attributed to chicken (i.e., three- to six-fold). Moreover, cattle were often colonized by C. jejuni (51%) and shed the bacterium in their feces. A large proportion of study isolates were found in subtypes primarily associated with cattle (46%), including subtypes infecting people and those associated with chickens (19%). The implication of cattle as a primary amplifying reservoir of C. jejuni subtypes in circulation in the study location is supported by the strong cattle association with subtypes that were found in chickens and in people, a lack of evidence indicating the foodborne transmission of C. jejuni from beef and dairy, and the large number of cattle and the substantial quantities of untreated manure containing C. jejuni cells. Importantly, the evidence implicated cattle as a source of C. jejuni which was infecting people through a transmission pathway from cattle to people via the consumption of chicken. This has implications for reducing the burden of campylobacteriosis in the study location and elsewhere.
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11
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Viñas V, Sokolova E, Malm A, Bergstedt O, Pettersson TJR. Cross-connections in drinking water distribution networks: Quantitative microbial risk assessment in combination with fault tree analysis and hydraulic modelling. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 831:154874. [PMID: 35358515 DOI: 10.1016/j.scitotenv.2022.154874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 02/25/2022] [Accepted: 03/24/2022] [Indexed: 06/14/2023]
Abstract
Deficiencies in drinking water distribution networks, such as cross-connections, may lead to contamination of the drinking water and pose a serious health risk to consumers. Cross-connections and backflows are considered among the most severe public health risks in distribution networks. The aim of this paper was to provide a framework for estimating the risk of infection from cross-connection and backflow events. Campylobacter, norovirus, and Cryptosporidium were chosen as reference pathogens for this study. The theoretical framework was constructed based on the fault tree analysis methodology. National aggregated cross-connection incident data was used to calculate the probability of a contamination event occurring in Swedish networks. Three risk cases were evaluated: endemic, elevated, and extreme. Quantitative microbial risk assessment (QMRA) was used to assess daily risk of infection for average national estimates. The framework was also evaluated using local data from the Gothenburg network. The daily risk of infection from cross-connection and backflow events in Swedish networks was generally above an acceptable target level of 10-6 for all reference pathogens and modelled cases; the exception was for the Gothenburg system where the risk was lower than 10-7. An outbreak case study was used to validate the framework results. For the outbreak case study, contaminant transport in the network was simulated using hydraulic modelling (EPANET), and risk estimates were calculated using QMRA. The outbreak simulation predicted between 97 and 148 symptomatic infections, while the epidemiological survey conducted during the outbreak reported 179 cases of illness. The fault tree analysis framework was successfully validated using an outbreak case study, though it was shown on the example of Gothenburg that local data is still needed for well-performing systems. The framework can help inform microbial risk assessments for drinking water suppliers, especially ones with limited resources and expertise in this area.
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Affiliation(s)
- Victor Viñas
- Department of Architecture and Civil Engineering, Water Environment Technology, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden.
| | - Ekaterina Sokolova
- Department of Architecture and Civil Engineering, Water Environment Technology, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden; Department of Earth Sciences, Uppsala University, Uppsala, Sweden
| | - Annika Malm
- Department of Architecture and Civil Engineering, Water Environment Technology, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden; Kungsbacka Municipality, Kungsbacka, Sweden
| | - Olof Bergstedt
- Department of Architecture and Civil Engineering, Water Environment Technology, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden; Sustainable Waste and Water, City of Gothenburg, Gothenburg, Sweden
| | - Thomas J R Pettersson
- Department of Architecture and Civil Engineering, Water Environment Technology, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
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12
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Hazeleger WC, Jacobs-Reitsma WF, Den Besten HMW. Level of Detection (LOD 50) of Campylobacter Is Strongly Dependent on Strain, Enrichment Broth, and Food Matrix. Front Microbiol 2022; 13:834568. [PMID: 35572641 PMCID: PMC9093705 DOI: 10.3389/fmicb.2022.834568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 03/24/2022] [Indexed: 12/02/2022] Open
Abstract
The detection of thermotolerant Campylobacter in food may be difficult due to the growth of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae during enrichment, resulting in false-negative samples. Therefore, the ISO protocol (ISO 10272-1:2017) suggests that, next to Bolton broth (BB), Preston broth (PB) is used as an enrichment broth to inhibit competitive flora in samples with suspected high levels of background microorganisms, such as ESBL-producing bacteria. However, the application of the strains used for validation of this ISO was not clearly characterized. This study examined the LOD50 (level of detection, the concentration where the probability of detection is 50%) of the validation strains (three C. jejuni and two C. coli strains) in BB and PB using different food matrices, namely, raw milk, chicken skin, frozen minced meat, and frozen spinach. The LOD50 was calculated by inoculating multiple portions with at least two inoculum levels. For each reproduction, eight test portions were used for each inoculum level and the test portion size was 10 g (chicken skin, frozen minced meat, and frozen spinach) or 10 mL (raw milk). Furthermore, the effect of artificially inoculated ESBL-producing E. coli on the LOD50 was examined to mimic the presence of ESBL-producing background microorganisms in the food matrices, namely, raw milk and chicken skin. In BB, the LOD50 of all strains tested in raw milk, chicken skin, and frozen spinach was rather low (0.4–37 CFU/test portion), while the LOD50 in frozen minced meat was higher and much more variable (1–1,500 CFU/test portion), depending on the strain. Generally, enrichment in PB resulted in higher LOD50 than in BB, especially for C. coli. Co-inoculation with ESBL-producing E. coli increased the LOD50 in BB, while PB successfully inhibited the growth of this competitive microorganism. In conclusion, food matrix and enrichment broth may have a large influence on the LOD50 of different Campylobacter strains. Therefore, it is not possible to give an unequivocal advice on when to use which enrichment broth, and this advocates the use of both methods in case of doubt. Furthermore, this study indicates specific strains that would be a good choice to use for Campylobacter method verification as described in ISO 16140-3:2021.
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Affiliation(s)
- Wilma C Hazeleger
- Food Microbiology, Wageningen University & Research, Wageningen, Netherlands
| | - Wilma F Jacobs-Reitsma
- Laboratory Food Microbiology, National Institute for Public Health and the Environment (RIVM), Bilthoven, Netherlands
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Risk-Based Evaluation of Improvements in Drinking Water Treatment Using Cost-Benefit Analysis. WATER 2022. [DOI: 10.3390/w14050782] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Reliable and safe drinking water supply requires adequate risk management. Decision support models can aid decisionmakers to effectively evaluate risk mitigation measures and allocate societal resources. Here, a Swedish case study illustrates how the installation of ultrafiltration membranes can be evaluated by combining risk assessment and cost-benefit analysis. Quantitative microbial risk assessment was used to assess several contamination sources and estimate the achieved risk reduction from waterborne pathogens using Campylobacter, Norovirus, and Cryptosporidium as reference pathogens. The societal value of the improved water quality was estimated in the cost-benefit analysis by monetising the gained quality adjusted life years and aesthetic water quality improvements. The calculated net present value (mean of 7 MEUR) indicated that the installation of the ultrafiltration membranes was a sound investment from a societal economic perspective. The ultrafiltration membranes reduced the annual probability of infection from 3 × 10−2 to 10−7, well below the U.S. EPA’s acceptable level, as well as improving the aesthetic quality of the drinking water. The results provide a novel example of the importance for water distributors to consider not only health-related metrics when evaluating treatment options or monitoring the drinking water quality, but to also consider the aesthetic quality of the drinking water.
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14
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Recommended Practices to Eliminate Campylobacter from Live Birds and Chicken Meat in Japan. Food Saf (Tokyo) 2021; 9:57-74. [PMID: 34631334 PMCID: PMC8472096 DOI: 10.14252/foodsafetyfscj.d-20-00021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 06/10/2021] [Indexed: 01/13/2023] Open
Abstract
Campylobacter food poisoning
is one of the major bacterial foodborne diseases
resulting in numerous outbreaks worldwide.
Particularly in Japan, one-fourth of the total
food poisoning is caused by Campylobacter
jejuni/coli. Raw and/or undercooked
poultry meat and meat products are known as the
main cause of campylobacteriosis. Consequently,
effective and immediate actions are needed to
eliminate or at least reduce campylobacteriosis.
This study aimed at examining the Japanese food
regulation system, comparing it with those in the
USA and Australia, and making necessary
recommendations for a better control of
campylobacteriosis in Japan. The study was
conducted by a thorough investigation of published
literatures, governmental documents, statistical
and epidemiological data and public information.
The results led to recommendations that the
Japanese food regulation authority should consider
the following suggestions in order to control
campylobacteriosis: 1) assess the
Campylobacter safety at the end
of processing stage of chicken supply chain based
on risk assessment using quantitative/qualitative
baseline data collected over Japan, 2) establish a
national Campylobacter strategy,
including specific campylobacteriosis reduction
goals and criteria, and 3) provide the small food
business operators with sufficient training and
support to implement a Hazard Analysis Critical
Control Points (HACCP) as an obligatory food
safety requirement. It is acknowledged that it
would be difficult to apply foreign regulations
directly to Japanese food regulation system due to
differences in food culture, regulation, industry
structure, and data collection systems. Thus,
flexible application is required. Finding and
conducting effective
Campylobacter control measures
can decrease contaminated live birds and chicken
meat in Japan, home to a unique food culture of
eating raw and/or undercooked chicken meat called
Torisashi such as sashimi, tataki and yubiki
chicken. Consequently, potentially available
research data may be instrumental in finding
solutions for reducing campylobacteriosis.
Eliminating Campylobacter food
poisoning cases in Japan will be a significant
achievement in ensuring Japanese and global food
safety.
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15
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Fuchisawa Y, Abe H, Koyama K, Koseki S. Competitive growth kinetics of Campylobacter jejuni, Escherichia coli O157:H7 and Listeria monocytogenes with enteric microflora in a small-intestine model. J Appl Microbiol 2021; 132:1467-1478. [PMID: 34498377 PMCID: PMC9291610 DOI: 10.1111/jam.15294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 08/09/2021] [Accepted: 09/04/2021] [Indexed: 11/29/2022]
Abstract
Aims The biological events occurring during human digestion help to understand the mechanisms underlying the dose–response relationships of enteric bacterial pathogens. To better understand these events, we investigated the growth and reduction behaviour of bacterial pathogens in an in vitro model simulating the environment of the small intestine. Methods and Results The foodborne pathogens Campylobacter jejuni, Listeria monocytogenes and Escherichia coli O157:H7 were cultured with multiple competing enteric bacteria. Differences in the pathogen's growth kinetics due to the relative amount of competing enteric bacteria were investigated. These growth differences were described using a mathematical model based on Bayesian inference. When pathogenic and enteric bacteria were inoculated at 1 log CFU per ml and 9 log CFU per ml, respectively, L. monocytogenes was inactivated over time, while C. jejuni and E. coli O157:H7 survived without multiplying. However, as pathogen inocula were increased, its inhibition by enteric bacteria also decreased. Conclusions Although the growth of pathogenic species was inhibited by enteric bacteria, the pathogens still survived. Significance and Impact of the Study Competition experiments in a small‐intestine model have enhanced understanding of the infection risk in the intestine and provide insights for evaluating dose–response relationships.
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Affiliation(s)
- Yuto Fuchisawa
- Graduate School of Agriculture, Hokkaido University, Sapporo, Japan
| | - Hiroki Abe
- Graduate School of Agriculture, Hokkaido University, Sapporo, Japan
| | - Kento Koyama
- Graduate School of Agriculture, Hokkaido University, Sapporo, Japan
| | - Shigenobu Koseki
- Graduate School of Agriculture, Hokkaido University, Sapporo, Japan
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16
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Implementing a new dose-response model for estimating infection probability of Campylobacter jejuni based on the key events dose-response framework. Appl Environ Microbiol 2021; 87:e0129921. [PMID: 34347512 DOI: 10.1128/aem.01299-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Understanding the dose-response relationship between ingested pathogenic bacteria and infection probability is a key factor for appropriate risk assessment of foodborne pathogens. The objectives of this study were to develop and validate a novel mechanistic dose-response model for Campylobacter jejuni and simulate the underlying mechanism of foodborne illness during digestion. Bacterial behavior in the human gastrointestinal environment, including survival at low pH in the gastric environment after meals, transition to intestines, and invasion to intestinal tissues, was described using a Bayesian statistical model based on the reported experimental results of each process while considering physical food types (liquid or solid) and host age (young adult or elderly). Combining the models in each process, the relationship between pathogen intake and the infection probability of C. jejuni was estimated and compared with reported epidemiological dose-response relationships. Taking food types and host age into account, the prediction range of the infection probability of C. jejuni successfully covered the reported dose-response relationships from actual C. jejuni outbreaks. According to sensitivity analysis of predicted infection probabilities, the host age factor and the food type factor have relatively higher relevance than other factors. Thus, the developed Key Events Dose Response Framework can derive novel information for quantitative microbiological risk assessment in addition of dose-response relationship. The developed framework is potentially applicable to other pathogens to quantify the dose-response relationship from experimental data obtained from digestion. Importance Based on the mechanistic approach called Key Events Dose Response Framework alternative to previous non-mechanistic approach, the dose-response models for infection probability of C. jejuni were developed considering with age of people who take pathogen and food type. The developed predictive framework illustrated highly accurate prediction of dose (minimum difference 0.21 log CFU) for a certain infection probability compared with the previously reported dose-response relationship. In addition, the developed prediction procedure revealed that the dose-response relationship strongly depends on food type as well as host age. The implementation of Key Event Dose Response Framework will mechanistically and logically reveal the dose-response relationship and provide useful information with quantitative microbiological risk assessment of C. jejuni on foods.
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17
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Shoults DC, Li Q, Petterson S, Rudko SP, Dlusskaya L, Leifels M, Scott C, Schlosser C, Ashbolt NJ. Pathogen performance testing of a natural swimming pool using a cocktail of microbiological surrogates and QMRA-derived management goals. JOURNAL OF WATER AND HEALTH 2021; 19:629-641. [PMID: 34371499 DOI: 10.2166/wh.2021.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
In recent decades, natural swimming pools (NSPs) have gained popularity in Europe, especially in Germany and Austria. NSPs differ from swimming pools in that they utilize biological treatment processes based on wetland processes with no disinfection residual. However, data are missing on the specific log-reduction performance of NSPs to address enteric virus, bacteria, and parasitic protozoa removal considered necessary to meet the North American risk-based benchmark (<35 illnesses per 1,000 swimming events) set by the USEPA for voluntary swimming. In this study, we examined Canada's first NSP at Borden Park, Edmonton, Canada, to address the following three questions: (1) Given normal faecal shedding rates by bathers, what is the total log reduction (TLR) theoretically needed to meet the EPA benchmark? (2) what is the in-situ performance of the NSP based on spiking suitable microbial surrogates (MS2 coliphage, Enterococcus faecalis, and Saccharomyces cerevisiae [Baker's yeast])? and (3) how much time is required to reach acceptable bather risk levels under different representative volume-turnover rates? A reverse-quantitative microbial risk assessment (QMRA) revealed that of the four reference pathogens selected (Norovirus, Campylobacter, Cryptosporidium, and Giardia), only Norovirus was estimated to exceed the risk benchmark at the 50th, 75th, and 95th percentiles, while Campylobacter was the only other reference pathogen to exceed at the 95th percentile. Log-reduction values (LRVs) were similar to previous reports for bacterial indicators, and novel LRVs were estimated for the other two surrogates. A key finding was that more than 24 h treatment time would be necessary to provide acceptable bather protection following heavy bather use (378 bathers/day for main pool and 26 bathers/day for children's pool), due to the mixing dynamics of the treated water diluting out possible residual pool faecal contamination. The theoretical maximum number of people in the pool per day to be below USEPA's 35 gastro cases in 1,000 swimming events was 113, 47, and 8, at the 50th, 75th, and 95th percentiles. Further, the use of ultra-violet disinfection to the pool return flow had little effect on reducing the treatment time required.
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Affiliation(s)
- David C Shoults
- Centre for Water Resources Studies, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Qiaozhi Li
- School of Public Health, University of Alberta, Edmonton, Alberta T6G 2G7, Canada E-mail:
| | - Susan Petterson
- Water & Health Pty Ltd, North Sydney, NSW 2060, Australia; School of Medicine, Griffith University, Gold Coast, QLD 4222, Australia
| | - Sydney P Rudko
- School of Public Health, University of Alberta, Edmonton, Alberta T6G 2G7, Canada E-mail:
| | - Lena Dlusskaya
- School of Public Health, University of Alberta, Edmonton, Alberta T6G 2G7, Canada E-mail:
| | - Mats Leifels
- Singapore Centre of Environmental Life Sciences Engineering, Nanyang Technological University, Singapore 637551, Canada
| | - Candis Scott
- School of Public Health, University of Alberta, Edmonton, Alberta T6G 2G7, Canada E-mail:
| | - Cyndi Schlosser
- Borden Park, City of Edmonton, Edmonton, Alberta T5B 4W8, Canada
| | - Nicholas J Ashbolt
- School of Public Health, University of Alberta, Edmonton, Alberta T6G 2G7, Canada E-mail: ; Faculty of Science and Engineering, Southern Cross University, East Lismore, NSW 2480, Australia
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18
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Petterson S, Li Q, Ashbolt N. Screening Level Risk Assessment (SLRA) of human health risks from faecal pathogens associated with a Natural Swimming Pond (NSP). WATER RESEARCH 2021; 188:116501. [PMID: 33091804 PMCID: PMC7535628 DOI: 10.1016/j.watres.2020.116501] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 10/01/2020] [Accepted: 10/05/2020] [Indexed: 06/11/2023]
Abstract
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.
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Affiliation(s)
- Susan Petterson
- Water & Health Pty Ltd, North Sydney, NSW 2060, Australia; School of Medicine, Griffith University, Gold Coast QLD 4222, Australia.
| | - Qiaozhi Li
- School of Public Health, University of Alberta, Edmonton, Alberta T6G 1C9, Canada
| | - Nicholas Ashbolt
- School of Public Health, University of Alberta, Edmonton, Alberta T6G 1C9, Canada; Southern Cross University, Lismore, NSW 2480, Australia
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Modeling Invasion of Campylobacter jejuni into Human Small Intestinal Epithelial-Like Cells by Bayesian Inference. Appl Environ Microbiol 2020; 87:AEM.01551-20. [PMID: 33067190 DOI: 10.1128/aem.01551-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 10/13/2020] [Indexed: 01/22/2023] Open
Abstract
Current approaches used for dose-response modeling of low-dose exposures of pathogens rely on assumptions and extrapolations. These models are important for quantitative microbial risk assessment of food. A mechanistic framework has been advocated as an alternative approach for evaluating dose-response relationships. The objectives of this study were to investigate the invasion behavior of Campylobacter jejuni, which could arise as a foodborne illness even if there are low counts of pathogens, into Caco-2 cells as a model of intestinal cells and to develop a mathematical model for invading cell counts to reveal a part of the infection dose-response mechanism. Monolayer-cultured Caco-2 cells and various concentrations of C. jejuni in culture were cocultured for up to 12 h. The numbers of C. jejuni bacteria invading Caco-2 cells were determined after coculture for different time periods. There appeared to be a maximum limit to the invading bacterial counts, which showed an asymptotic exponential increase. The invading bacterial counts were higher with higher exposure concentrations (maximum, 5.0 log CFU/cm2) than with lower exposure concentrations (minimum, 0.6 log CFU/cm2). In contrast, the ratio of invading bacteria (number of invading bacteria divided by the total number of bacteria exposed) showed a similar trend regardless of the exposure concentration. Invasion of C. jejuni into intestinal cells was successfully demonstrated and described by the developed differential equation model with Bayesian inference. The model accuracy showed that the 99% prediction band covered more than 97% of the observed values. These findings provide important information on mechanistic pathogen dose-response relationships and an alternative approach for dose-response modeling.IMPORTANCE One of the infection processes of C. jejuni, the invasion behavior of the bacteria in intestinal epithelial cells, was revealed, and a mathematical model for prediction of the cell-invading pathogen counts was developed for the purpose of providing part of a dose-response model for C. jejuni based on the infection mechanism. The developed predictive model showed a high accuracy of more than 97% and successfully described the C. jejuni invading counts. The bacterial invasion predictive model of this study will be essential for the development of a dose-response model for C. jejuni based on the infection mechanism.
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Schoen ME, Boehm AB, Soller J, Shanks OC. Contamination Scenario Matters when Using Viral and Bacterial Human-Associated Genetic Markers as Indicators of a Health Risk in Untreated Sewage-Impacted Recreational Waters. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:13101-13109. [PMID: 32969642 PMCID: PMC8215692 DOI: 10.1021/acs.est.0c02189] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Fecal pollution at beaches can pose a health risk to recreators. Quantitative microbial risk assessment (QMRA) is a tool to evaluate the use of candidate fecal indicators to signify a health risk from enteric pathogens in sewage-impacted waters. We extend the QMRA approach to model mixtures of sewage at different ages using genetic marker concentrations for human-associated crAssphage, Bacteroides spp., and polyomavirus in sewage samples from 49 wastewater facilities across the contiguous United States. Risk-based threshold (RBT) estimates varied across different mixture and sewage age scenarios. Fresh sewage RBT estimates were not always protective when aged sewage was present, and aged sewage RBT estimates often fell below the marker lower limit of quantification. Conservative RBT estimates of 9.3 × 102 and 9.1 × 103 (copies/100 mL) for HF183/BacR287 and CPQ_056, respectively, were predicted when fresh sewage was greater (by volume) than aged at the time of measurement. Conversely, genetic markers may not be effective indicators when aged sewage contributes the majority of pathogens, relative to fresh contamination, but minimal marker levels. Results highlight the utility of QMRA that incorporates pollutant age and mixture scenarios, the potential advantages of a crAssphage fecal indicator, and the potential influence of site-specific factors on estimating RBT values.
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Affiliation(s)
- Mary E Schoen
- Soller Environmental, LLC, 3022 King St., Berkeley, California 94703, United States
| | - Alexandria B Boehm
- Department of Civil and Environmental Engineering, Stanford University, Stanford, California 94305, United States
| | - Jeffrey Soller
- Soller Environmental, LLC, 3022 King St., Berkeley, California 94703, United States
| | - Orin C Shanks
- U.S. Environmental Protection Agency, Office of Research and Development, Martin Luther King Drive, Cincinnati, Ohio 45268, United States
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Gilpin BJ, Walker T, Paine S, Sherwood J, Mackereth G, Wood T, Hambling T, Hewison C, Brounts A, Wilson M, Scholes P, Robson B, Lin S, Cornelius A, Rivas L, Hayman DT, French NP, Zhang J, Wilkinson DA, Midwinter AC, Biggs PJ, Jagroop A, Eyre R, Baker MG, Jones N. A large scale waterborne Campylobacteriosis outbreak, Havelock North, New Zealand. J Infect 2020; 81:390-395. [DOI: 10.1016/j.jinf.2020.06.065] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 06/19/2020] [Accepted: 06/26/2020] [Indexed: 12/17/2022]
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Noroviruses are highly infectious but there is strong variation in host susceptibility and virus pathogenicity. Epidemics 2020; 32:100401. [PMID: 32721875 DOI: 10.1016/j.epidem.2020.100401] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 06/18/2020] [Accepted: 07/14/2020] [Indexed: 02/06/2023] Open
Abstract
Noroviruses are a major public health concern: their high infectivity and environmental persistence have been documented in several studies. Genetic sequencing shows that noroviruses are highly variable, and exhibit rapid evolution. A few human challenge studies have been performed with norovirus, leading to estimates of their infectivity. However, such incidental estimates do not provide insight into the biological variation of the virus and the interaction with its human host. To study the variation in infectivity and pathogenicity of norovirus, multiple challenge studies must be analysed jointly, to compare their differences and describe how virus infectivity and host susceptibility vary. Since challenge studies can only provide a small sample of the diversity in the natural norovirus population, outbreaks should be exploited as an additional source of information. The present study shows how challenge studies and 'natural experiments' can be combined in a multilevel dose response framework. Infectivity and pathogenicity are analysed by secretor status as a host factor, and genogroup as a pathogen factor. Infectivity, characterized as the estimated mean infection risk when exposed to 1 genomic copy (qPCR unit)is 0.28 for GI norovirus, and 0.076 for GII virus, both in Se+ subjects. The corresponding risks of acute enteric illness are somewhat lower, about 0.2 (GI) and 0.035 (GII), in outbreaks. Se- subjects are protected, with substantially lower risks of infection (0.00007 and 0.015 at a dose of 1 GC of GI and GII virus, respectively). The present study shows there is considerable variability in risk of infection and especially risk of acute symptoms following infection with norovirus. These challenge and outbreak data consistently indicate high infectivity among secretor positives and protection in secretor negatives.
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Bottari B, Bancalari E, Barera A, Ghidini S, Gatti M. Evaluating the presence of human pathogens in commercially frozen, biologically appropriate raw pet food sold in Italy. Vet Rec 2020; 187:e50. [PMID: 32430390 DOI: 10.1136/vr.105893] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 04/01/2020] [Accepted: 04/17/2020] [Indexed: 11/04/2022]
Abstract
BACKGROUND Biologically appropriate raw food (BARF) diet is becoming more and more popular among pet owners in Europe. However, there are documented microbiological risks associated with raw feeding, and this study aimed to determine the presence of human pathogens in commercially frozen BARF products sold in Italy. METHODS Salmonella species, Escherichia coli O157:H7, Listeria monocytogenes and Campylobacter species were identified. The general microbiological quality of BARF products and hygiene were also evaluated. Sample size was limited and therefore the study may not be representative of a larger sample. RESULTS None of the tested samples showed total bacterial count (TBC) higher than the limit set to consider a sample unacceptable. However, 14 out of 21 samples showed TBC higher than the limit set to consider a sample marginally acceptable. A high percentage of samples were contaminated by the aforementioned pathogens, highlighting the need for pet owners to be aware of the risks of this feeding strategy both to themselves and to their pets. CONCLUSIONS Considering that BARF diet meals can be prepared at home using the hands, as well as tools and spaces that could be shared, guidelines on safer handling of these pet food products should be recommended by veterinarians and nutritionists.
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Affiliation(s)
| | - Elena Bancalari
- Food and Drug, University of Parma, Parma, Emilia-Romagna, Italy
| | - Annalisa Barera
- Food and Drug, University of Parma, Parma, Emilia-Romagna, Italy
| | - Sergio Ghidini
- Food and Drug, University of Parma, Parma, Emilia-Romagna, Italy
| | - Monica Gatti
- Food and Drug, University of Parma, Parma, Emilia-Romagna, Italy
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Human Health Risks Associated with Recreational Waters: Preliminary Approach of Integrating Quantitative Microbial Risk Assessment with Microbial Source Tracking. WATER 2020. [DOI: 10.3390/w12020327] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Gastrointestinal (GI) illness risks associated with exposure to waters impacted by human and nonhuman fecal sources were estimated using quantitative microbial risk assessment (QMRA). Microbial source tracking (MST) results had identified Escherichia coli (E. coli) contributors to the waterbody as human and unidentified (10%), cattle and domestic animals (25%), and wildlife (65%) in a rural watershed. The illness risks associated with ingestion during recreation were calculated by assigning reference pathogens for each contributing source and using pathogen dose–response relationships. The risk of GI illness was calculated for a specific sampling site with a geometric mean of E. coli of 163 colony forming units (cfu) 100 mL−1, and the recreational standard of E. coli, 126 cfu 100 mL−1. While the most frequent sources of fecal indicator bacteria at the sampling site were nonhuman, the risk of illness from norovirus, the reference pathogen representing human waste, contributed the greatest risk to human health. This study serves as a preliminary review regarding the potential for incorporating results from library-dependent MST to inform a QMRA for recreational waters. The simulations indicated that identifying the sources contributing to the bacterial impairment is critical to estimate the human health risk associated with recreation in a waterbody.
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25
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Boehm AB. Risk-based water quality thresholds for coliphages in surface waters: effect of temperature and contamination aging. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2019; 21:2031-2041. [PMID: 31612888 DOI: 10.1039/c9em00376b] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Coliphages, viruses that infect Escherichia coli, have been used for decades to assess surface water quality yet there is no guideline for interpreting their concentrations. The present study uses a quantitative microbial risk assessment (QMRA) framework to derive risk-based surface water quality thresholds for somatic and F+ or male-specific coliphages. The risk-based threshold is the concentration at which the risk of gastro-intestinal illness is simulated to be 32/1000. The framework specifically investigates a simplified hazard scenario where recreational swimmers come into contact with water contaminated with untreated sewage containing coliphages and enteric pathogens. The framework considers exposure to sewage of diverse ages and thus accounts for the decay of coliphages and pathogens over time. As decay rate constants depend on temperature, the model considers the effect of temperature on the risk-based threshold. When exposure to fresh, unaged sewage contamination occurs, the risk-based water quality threshold for somatic and F+ coliphages is 60 PFU per 100 mL and 30 PFU per 100 mL, respectively, and temperature independent. The risk-based threshold decreases as the contamination ages because, on average, coliphages decay more quickly than norovirus, the pathogen that contributes the most to risk. The decrease in the risk-based threshold with contaminant age is equal to the difference in the first order decay rate constants of coliphages and norovirus. Since coliphage decay rate constants are larger at 25 °C than at 15 °C, and norovirus decay rate constants are a weak function of temperature, risk-based thresholds decrease more quickly with age at 25 °C than at 15 °C. For the common case where the age of contamination is unknown, the risk-based threshold for both coliphages is between ∼1 PFU per 100 mL and ∼10 PFU per 100 mL, depending on model assumptions. Future work can apply this QMRA framework for identifying risk-based thresholds for coliphages from different hazards (treated wastewater or animal feces) or from mixtures of contamination of different ages and sources.
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Affiliation(s)
- Alexandria B Boehm
- Department of Civil & Environmental Engineering, Stanford University, Stanford, California, USA 94305-4020.
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Sunger N, Hamilton KA, Morgan PM, Haas CN. Comparison of pathogen-derived 'total risk' with indicator-based correlations for recreational (swimming) exposure. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2019; 26:30614-30624. [PMID: 29644614 DOI: 10.1007/s11356-018-1881-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Accepted: 03/26/2018] [Indexed: 05/03/2023]
Abstract
Typical recreational water risk to swimmers is assessed using epidemiologically derived correlations by means of fecal indicator bacteria (FIB). It has been documented that concentrations of FIB do not necessarily correlate well with protozoa and viral pathogens, which pose an actual threat of illness and thus sometimes may not adequately assess the overall microbial risks from water resources. Many of the known pathogens have dose-response relationships; however, measuring water quality for all possible pathogens is impossible. In consideration of a typical freshwater receiving secondarily treated effluent, we investigated the level of consistency between the indicator-derived correlations and the sum of risks from six reference pathogens using a quantitative microbial risk assessment (QMRA) approach. Enterococci and E. coli were selected as the benchmark FIBs, and norovirus, human adenovirus (HAdV), Campylobacter jejuni, Salmonella enterica, Cryptosporidium spp., and Giardia spp. were selected as the reference pathogens. Microbial decay rates in freshwater and uncertainties in exposure relationships were considered in developing our analysis. Based on our exploratory assessment, the total risk was found within the range of risk estimated by the indicator organisms, with viral pathogens as dominant risk agents, followed by protozoan and bacterial pathogens. The risk evaluated in this study captured the likelihood of gastrointestinal illnesses only, and did not address the overall health risk potential of recreational waters with respect to other disease endpoints. Since other highly infectious pathogens like hepatitis A and Legionella spp. were not included in our analysis, these estimates should be interpreted with caution.
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Affiliation(s)
- Neha Sunger
- Department of Health, West Chester University, 855 South New Street, West Chester, PA, 19383, USA.
| | - Kerry A Hamilton
- Department of Civil, Architectural, and Environmental Engineering, Drexel University, 251 Curtis Hall, 3141 Chestnut St, Philadelphia, PA, 19104, USA
| | - Paula M Morgan
- Department of Health, West Chester University, 855 South New Street, West Chester, PA, 19383, USA
| | - Charles N Haas
- Department of Civil, Architectural, and Environmental Engineering, Drexel University, 251 Curtis Hall, 3141 Chestnut St, Philadelphia, PA, 19104, USA
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Lunn TJ, Restif O, Peel AJ, Munster VJ, de Wit E, Sokolow S, van Doremalen N, Hudson P, McCallum H. Dose-response and transmission: the nexus between reservoir hosts, environment and recipient hosts. Philos Trans R Soc Lond B Biol Sci 2019; 374:20190016. [PMID: 31401955 PMCID: PMC6711301 DOI: 10.1098/rstb.2019.0016] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/26/2019] [Indexed: 01/11/2023] Open
Abstract
Dose is the nexus between exposure and all upstream processes that determine pathogen pressure, and is thereby an important element underlying disease dynamics. Understanding the relationship between dose and disease is particularly important in the context of spillover, where nonlinearities in the dose-response could determine the likelihood of transmission. There is a need to explore dose-response models for directly transmitted and zoonotic pathogens, and how these interactions integrate within-host factors to consider, for example, heterogeneity in host susceptibility and dose-dependent antagonism. Here, we review the dose-response literature and discuss the unique role dose-response models have to play in understanding and predicting spillover events. We present a re-analysis of dose-response experiments for two important zoonotic pathogens (Middle East respiratory syndrome coronavirus and Nipah virus), to exemplify potential difficulties in differentiating between appropriate models with small exposure experiment datasets. We also discuss the data requirements needed for robust selection between dose-response models. We then suggest how these processes could be modelled to gain more realistic predictions of zoonotic transmission outcomes and highlight the exciting opportunities that could arise with increased collaboration between the virology and epidemiology disciplines. This article is part of the theme issue 'Dynamic and integrative approaches to understanding pathogen spillover'.
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Affiliation(s)
- Tamika J. Lunn
- Environmental Futures Research Institute, Griffith University, Kessels Road, Nathan, Queensland 4111, Australia
| | - Olivier Restif
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, UK
| | - Alison J. Peel
- Environmental Futures Research Institute, Griffith University, Kessels Road, Nathan, Queensland 4111, Australia
| | - Vincent J. Munster
- Laboratory of Virology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, MT 59840, USA
| | - Emmie de Wit
- Laboratory of Virology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, MT 59840, USA
| | - Sanna Sokolow
- Stanford Woods Institute for the Environment, Stanford University, Serra Mall, Stanford, CA 94305, USA
| | - Neeltje van Doremalen
- Laboratory of Virology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, MT 59840, USA
| | - Peter Hudson
- Center for Infectious Disease Dynamics, Pennsylvania State University, State College, Pennsylvania, PA 16801, USA
| | - Hamish McCallum
- Environmental Futures Research Institute, Griffith University, Kessels Road, Nathan, Queensland 4111, Australia
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Federigi I, Verani M, Donzelli G, Cioni L, Carducci A. The application of quantitative microbial risk assessment to natural recreational waters: A review. MARINE POLLUTION BULLETIN 2019; 144:334-350. [PMID: 31180003 DOI: 10.1016/j.marpolbul.2019.04.073] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 04/26/2019] [Accepted: 04/28/2019] [Indexed: 06/09/2023]
Abstract
This review examines the aims of and approaches to the Quantitative Microbial Risk Assessment (QMRA) of untreated recreational waters. The literature search was conducted on four databases and yielded 54 papers, which were analyzed on a quantitative (time-trend, geographical distribution, water type) and qualitative (aims, source of microbial data, pathogens and their measurement or estimation, ways to address variability and uncertainty, sensitivity analysis) basis. In addition, the parameters, implications, and limitations were discussed for each QMRA step. Since 2003, the number of papers has greatly increased, highlighting the importance of QMRA for the risk management of recreational waters. Nevertheless, QMRA still exhibits critical issues, above all regarding contamination data and dose-response relationships. To our knowledge, this is the first review to give a wide panoramic view on QMRA in relation to recreational exposure to untreated waters. This could be useful in identifying the current knowledge gaps and research needs.
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Affiliation(s)
- Ileana Federigi
- QMRA Lab, Department of Biology, University of Pisa, Via S. Zeno 35/39, Pisa 56127, Italy.
| | - Marco Verani
- QMRA Lab, Department of Biology, University of Pisa, Via S. Zeno 35/39, Pisa 56127, Italy.
| | - Gabriele Donzelli
- QMRA Lab, Department of Biology, University of Pisa, Via S. Zeno 35/39, Pisa 56127, Italy.
| | - Lorenzo Cioni
- Scuola Normale Superiore, Piazza dei Cavalieri 7, 56123 Pisa, Italy.
| | - Annalaura Carducci
- QMRA Lab, Department of Biology, University of Pisa, Via S. Zeno 35/39, Pisa 56127, Italy.
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Bivins A, Beetsch N, Majuru B, Montgomery M, Sumner T, Brown J. Selecting Household Water Treatment Options on the Basis of World Health Organization Performance Testing Protocols. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:5043-5051. [PMID: 30998325 DOI: 10.1021/acs.est.8b05682] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The World Health Organization's International Scheme to Evaluate Household Water Treatment Technologies serves to benchmark microbiological performance of existing and novel technologies and processes for small-scale drinking water treatment according to a tiered system. There is widespread uncertainty around which tiers of performance are most appropriate for technology selection and recommendation in humanitarian response or for routine safe water programming. We used quantitative microbial risk assessment (QMRA) to evaluate attributable reductions in diarrheal disease burden associated with water treatment technologies meeting the three tiers of performance under this Scheme, across a range of conditions. According to mean estimates and under most modeling conditions, potential health gains attributable to microbiologically improved drinking water are realized at the middle tier of performance: "comprehensive protection: high pathogen removal (★★)" for each reference pathogen. The highest tier of performance may yield additional marginal health gains where untreated water is especially contaminated and where adherence is 100%. Our results highlight that health gains from improved efficacy of household water treatment technology remain marginal when adherence is less than 90%. While selection of water treatment technologies that meet minimum WHO efficacy recommendations for comprehensive protection against waterborne pathogens is critical, additional criteria for technology choice and recommendation should focus on potential for correct, consistent, and sustained use.
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Affiliation(s)
- Aaron Bivins
- School of Civil and Environmental Engineering , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
| | - Nikki Beetsch
- World Health Organization , Geneva 1211 , Switzerland
- NSF-International , Ann Arbor , Michigan 48105 , United States
| | | | | | - Trent Sumner
- School of Civil and Environmental Engineering , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
| | - Joe Brown
- School of Civil and Environmental Engineering , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
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Owusu-Ansah EDGJ, Barnes B, Abaidoo R, Tine H, Dalsgaard A, Permin A, Schou TW. Probabilistic modeling for an integrated temporary acquired immunity with norovirus epidemiological data. Infect Dis Model 2019; 4:99-114. [PMID: 31080934 PMCID: PMC6503004 DOI: 10.1016/j.idm.2019.04.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 04/22/2019] [Indexed: 11/28/2022] Open
Abstract
Integration of acquired immunity into microbial risk assessment for illness incidence is of no doubt essential for the study of susceptibility to illness. In this study, a probabilistic model was set up as dose response for infection and a mathematical derivation was carried out by integrating immunity to obtain probability of illness models. Temporary acquire immunity from epidemiology studies which includes six different Norovirus transmission scenarios such as symptomatic individuals infectious, pre- and post-symptomatic infectiousness (low and high), innate genetic resistance, genogroup 2 type 4 and those with no immune boosting by asymptomatic infection were evaluated. Simulated results on illness inflation factor as a function of dose and exposure indicated that high frequency exposures had immense immunity build up even at high dose levels; hence minimized the probability of illness. Using Norovirus transmission dynamics data, results showed, and immunity included models had a reduction of 2-6 logs of magnitude difference in disease burden for both population and individual probable illness incidence. Additionally, the magnitude order of illness for each dose response remained largely the same for all transmission scenarios; symptomatic infectiousness and no immune boosting after asymptomatic infectiousness also remained the same throughout. With integration of epidemiological data on acquired immunity into the risk assessment, more realistic results were achieved signifying an overestimation of probable risk of illness when epidemiological immunity data are not included. This finding supported the call for rigorous integration of temporary acquired immunity in dose-response in all microbial risk assessments.
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Affiliation(s)
- Emmanuel de-Graft Johnson Owusu-Ansah
- Department of Mathematics, Faculty of Physical and Computational Science, College of Science, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.,Laboratory of Integrated Statistical Applications (LISA), Faculty of Physical and Computational Sciences, College of Science, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.,Regional Water and Environmental Sanitation Center-Kumasi, College of Engineering, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Benedict Barnes
- Department of Mathematics, Faculty of Physical and Computational Science, College of Science, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Robert Abaidoo
- Department of Theoretical and Applied Biology, Faculty of Bio Science, College of Science, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Hald Tine
- Research Group of Genomic Epidemiology, National Food Institute, Technical University of Denmark, Kgs Lyngby, Denmark
| | - Anders Dalsgaard
- Food Safety and Zoonoses, Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Stigböjlen 4, 1870 Frederiksberg C, Denmark
| | - Anders Permin
- Office for Innovation and Sector Services, Administration, Technical University of Denmark, Anker Engelunds Vej, 2800 Kgs Lyngby, Denmark
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Longitudinal Study of Shiga Toxin-Producing Escherichia coli and Campylobacter jejuni on Finnish Dairy Farms and in Raw Milk. Appl Environ Microbiol 2019; 85:AEM.02910-18. [PMID: 30709824 PMCID: PMC6585499 DOI: 10.1128/aem.02910-18] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 01/28/2019] [Indexed: 01/12/2023] Open
Abstract
Shiga toxin-producing Escherichia coli (STEC) and Campylobacter jejuni are notable health hazards associated with the consumption of raw milk. These bacteria may colonize the intestines of asymptomatic cattle and enter bulk tank milk via fecal contamination during milking. We studied the frequency of STEC O157:H7 and C. jejuni contamination in tank milk (n = 785) and the in-line milk filters of milking machines (n = 631) versus the frequency of isolation from cattle feces (n = 257) on three Finnish dairy farms for 1 year. Despite simultaneous isolation of STEC O157:H7 (17%) or C. jejuni (53%) from cattle, these bacteria were rarely isolated from milk filters (2% or <1%, respectively) and milk (0%). As revealed by phylogenomics, one STEC O157:H7 strain at a time was detected on each farm and persisted for ≤12 months despite rigorous hygienic measures. C. jejuni strains of a generalist sequence type (ST-883 and ST-1080) persisted in the herds for ≥11 months, and several other C. jejuni types were detected sporadically. The stx gene carried by STEC was detected more frequently from milk filters (37%) than from milk (7%), suggesting that milk filters are more suitable sampling targets for monitoring than milk. A questionnaire of on-farm practices suggested lower stx contamination of milk when major cleansing in the barn, culling, or pasturing of dairy cows was applied, while a higher average outdoor temperature was associated with higher stx contamination. Because pathogen contamination occurred despite good hygiene and because pathogen detection from milk and milk filters proved challenging, we recommend heat treatment for raw milk before consumption.IMPORTANCE The increased popularity of raw milk consumption has created demand for relaxing legislation, despite the risk of contamination by pathogenic bacteria, notably STEC and C. jejuni However, the epidemiology of these milk-borne pathogens on the herd level is still poorly understood, and data are lacking on the frequency of milk contamination on farms with cattle shedding these bacteria in their feces. This study suggests (i) that STEC contamination in milk can be reduced, but not prevented, by on-farm hygienic measures while fecal shedding is observable, (ii) that milk filters are more suitable sampling targets for monitoring than milk although pathogen detection from both sample matrices may be challenging, and (iii) that STEC and C. jejuni genotypes may persist in cattle herds for several months. The results can be utilized in developing and targeting pathogen monitoring and risk management on the farm level and contributed to the revision of Finnish legislation in 2017.
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Determination of Removal Efficiencies for Escherichia coli, Clostridial Spores, and F-Specific Coliphages in Unit Processes of Surface Waterworks for QMRA Applications. WATER 2018. [DOI: 10.3390/w10111525] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The removal efficiencies of bacteria, bacterial spores, and viruses after a change in source water and water pH in coagulation were studied at pilot scale in coagulation with flotation, rapid sand filtration, and disinfection with UV and chlorine. The results were compared to the treatment efficiencies of full-scale waterworks and data from literature. A quantitative microbial risk assessment (QMRA)-method was applied to estimate the numbers of illness cases caused by Campylobacter and norovirus after simulation of six operational malfunction scenarios. Coagulation with flotation and disinfection were more efficient in removing Clostridium spp. spores and MS2 coliphages than sand filtration in the pilot scale experiments (p < 0.001–0.008). The removal of E. coli was more efficient in sand filtration and in disinfection compared to coagulation with flotation (p = 0.006 and 0.01). Source water or pH change in coagulation had not significant effects on the removal efficiency of microbes. In QMRA, when disinfection was not in use, an increase in the number of illness cases compared to the normal situation was noticed. The variability in the number of illness cases demonstrated the importance of site-specific data in QMRA. This study provides new information on applying QMRA in both pilot and full-scale waterworks.
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Boehm AB, Graham KE, Jennings WC. Can We Swim Yet? Systematic Review, Meta-Analysis, and Risk Assessment of Aging Sewage in Surface Waters. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:9634-9645. [PMID: 30080397 DOI: 10.1021/acs.est.8b01948] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
This study investigated the risk of gastrointestinal illness associated with swimming in surface waters with aged sewage contamination. First, a systematic review compiled 333 first order decay rate constants ( k) for human norovirus and its surrogates feline calicivirus and murine norovirus, Salmonella, Campylobacter, Escherichia coli O157:H7, Giardia, and Cryptosporidium, and human-associated indicators in surface water. A meta-analysis investigated effects of sunlight, temperature, and water matrix on k. There was a relatively large number of k for bacterial pathogens and some human-associated indicators ( n > 40), fewer for protozoans ( n = 14-22), and few for human norovirus and its Caliciviridae surrogates ( n = 2-4). Average k ranked: Campylobacter > human-associated markers > Salmonella> E. coli O157:H7 > norovirus and its surrogates > Giardia > Cryptosporidium. Compiled k values were used in a quantitative microbial risk assessment (QMRA) to simulate gastrointestinal illness risk associated with swimming in water with aged sewage contamination. The QMRA used human-associated fecal indicator HF183 as an index for the amount of sewage present and thereby provided insight into how risk relates to HF183 concentrations in surface water. Because exposure to norovirus contributed the majority of risk, and HF183 k is greater than norovirus k, the risk associated with exposure to a fixed HF183 concentration increases with the age of contamination. Swimmer exposure to sewage after it has aged ∼3 days results in median risks less than 30/1000. A risk-based water quality threshold for HF183 in surface waters that takes into account uncertainty in contamination age is derived to be 4100 copies/100 mL.
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Affiliation(s)
- Alexandria B Boehm
- Department of Civil and Environmental Engineering , Stanford University , Stanford , California 94305 , United States
| | - Katherine E Graham
- Department of Civil and Environmental Engineering , Stanford University , Stanford , California 94305 , United States
| | - Wiley C Jennings
- Department of Civil and Environmental Engineering , Stanford University , Stanford , California 94305 , United States
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Monge S, Teunis P, Friesema I, Franz E, Ang W, van Pelt W, Mughini-Gras L. Immune response-eliciting exposure to Campylobacter vastly exceeds the incidence of clinically overt campylobacteriosis but is associated with similar risk factors: A nationwide serosurvey in the Netherlands. J Infect 2018; 77:171-177. [PMID: 29746943 DOI: 10.1016/j.jinf.2018.04.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 02/23/2018] [Accepted: 04/05/2018] [Indexed: 11/18/2022]
Abstract
BACKGROUND We aimed to estimate population-level exposure to Campylobacter and associated risk factors, using three approaches for serological data analysis. METHODS Nationwide, population-based serosurvey in the Netherlands (Feb 2006-Jun 2007). Anti-Campylobacter IgG, IgM and IgA were measured using ELISA, and analysed via: a) seroincidence estimation, using reference values of antibody peak levels and decay rates over-time after Campylobacter exposure; b) two normal distributions of true positives/negatives fitted to the IgG distribution to derive seroprevalence and individual probability of being positive/negative; and c) IgG levels. Risk factors were analysed using multiple linear regressions. RESULTS From 1559 respondents, seroincidence was estimated at 1.61 infections/person-year (95%CI:1.58-1.64) and seroprevalence at 68.1% (65.4-70.9). The three approaches identified similar risk factors, although seroincidence had higher power and results were interpretable as risk: seroincidence was higher in females [exp(b) = 1.07(1.04-1.11)], older ages [vs. 15-34 years; for < 5, 5-14, 35-54 and 55-70 years: 0.60(0.58-0.63), 0.74(0.71-0.78), 1.08(1.03-1.13) and 1.08(1.01-1.16), respectively], non-Dutch background [Moroccan/Turkish: 1.25(1.14-1.37); Caribbean: 1.14(1.03-1.25)], low socioeconomic status [1.05(1.01-1.10)], traveling outside Europe [1.05(1.01-1.09)], and eating undercooked meat [1.04(1.01-1.08)]. CONCLUSION Campylobacter exposure is much higher than clinical infection rates, but risk factors are similar to those previously described.Seroincidence is a powerful measure to study Campylobacter epidemiology, and is preferred over other methods.
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Affiliation(s)
- Susana Monge
- Centre for Infectious Disease Control Netherlands (CIb), National Institute for Public Health and the Environment (RIVM), Antonie van Leeuwenhoeklaan 9, 3721 MA Bilthoven, the Netherlands; European Programme for Intervention Epidemiology Training (EPIET), European Centre for Disease Prevention and Control, (ECDC), Stockholm, Sweden.
| | - Peter Teunis
- Centre for Infectious Disease Control Netherlands (CIb), National Institute for Public Health and the Environment (RIVM), Antonie van Leeuwenhoeklaan 9, 3721 MA Bilthoven, the Netherlands
| | - Ingrid Friesema
- Centre for Infectious Disease Control Netherlands (CIb), National Institute for Public Health and the Environment (RIVM), Antonie van Leeuwenhoeklaan 9, 3721 MA Bilthoven, the Netherlands
| | - Eelco Franz
- Centre for Infectious Disease Control Netherlands (CIb), National Institute for Public Health and the Environment (RIVM), Antonie van Leeuwenhoeklaan 9, 3721 MA Bilthoven, the Netherlands
| | - Wim Ang
- Department of Medical Microbiology and Infection Control, VU University Medical Center Amsterdam, the Netherlands
| | - Wilfrid van Pelt
- Centre for Infectious Disease Control Netherlands (CIb), National Institute for Public Health and the Environment (RIVM), Antonie van Leeuwenhoeklaan 9, 3721 MA Bilthoven, the Netherlands
| | - Lapo Mughini-Gras
- Centre for Infectious Disease Control Netherlands (CIb), National Institute for Public Health and the Environment (RIVM), Antonie van Leeuwenhoeklaan 9, 3721 MA Bilthoven, the Netherlands; Utrecht University, Faculty of Veterinary Medicine, Department of Infectious Diseases and Immunology, Utrecht, The Netherlands
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Bergion V, Lindhe A, Sokolova E, Rosén L. Risk-based cost-benefit analysis for evaluating microbial risk mitigation in a drinking water system. WATER RESEARCH 2018; 132:111-123. [PMID: 29316514 DOI: 10.1016/j.watres.2017.12.054] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 10/31/2017] [Accepted: 12/22/2017] [Indexed: 06/07/2023]
Abstract
Waterborne outbreaks of gastrointestinal diseases can cause large costs to society. Risk management needs to be holistic and transparent in order to reduce these risks in an effective manner. Microbial risk mitigation measures in a drinking water system were investigated using a novel approach combining probabilistic risk assessment and cost-benefit analysis. Lake Vomb in Sweden was used to exemplify and illustrate the risk-based decision model. Four mitigation alternatives were compared, where the first three alternatives, A1-A3, represented connecting 25, 50 and 75%, respectively, of on-site wastewater treatment systems in the catchment to the municipal wastewater treatment plant. The fourth alternative, A4, represented installing a UV-disinfection unit in the drinking water treatment plant. Quantitative microbial risk assessment was used to estimate the positive health effects in terms of quality adjusted life years (QALYs), resulting from the four mitigation alternatives. The health benefits were monetised using a unit cost per QALY. For each mitigation alternative, the net present value of health and environmental benefits and investment, maintenance and running costs was calculated. The results showed that only A4 can reduce the risk (probability of infection) below the World Health Organization guidelines of 10-4 infections per person per year (looking at the 95th percentile). Furthermore, all alternatives resulted in a negative net present value. However, the net present value would be positive (looking at the 50th percentile using a 1% discount rate) if non-monetised benefits (e.g. increased property value divided evenly over the studied time horizon and reduced microbial risks posed to animals), estimated at 800-1200 SEK (€100-150) per connected on-site wastewater treatment system per year, were included. This risk-based decision model creates a robust and transparent decision support tool. It is flexible enough to be tailored and applied to local settings of drinking water systems. The model provides a clear and holistic structure for decisions related to microbial risk mitigation. To improve the decision model, we suggest to further develop the valuation and monetisation of health effects and to refine the propagation of uncertainties and variabilities between the included methods.
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Affiliation(s)
- Viktor Bergion
- Chalmers University of Technology, Department of Architecture and Civil Engineering, SE-41296 Gothenburg, Sweden.
| | - Andreas Lindhe
- Chalmers University of Technology, Department of Architecture and Civil Engineering, SE-41296 Gothenburg, Sweden
| | - Ekaterina Sokolova
- Chalmers University of Technology, Department of Architecture and Civil Engineering, SE-41296 Gothenburg, Sweden
| | - Lars Rosén
- Chalmers University of Technology, Department of Architecture and Civil Engineering, SE-41296 Gothenburg, Sweden
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Teunis PFM, Bonačić Marinović A, Tribble DR, Porter CK, Swart A. Acute illness from Campylobacter jejuni may require high doses while infection occurs at low doses. Epidemics 2018; 24:1-20. [PMID: 29456072 DOI: 10.1016/j.epidem.2018.02.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 01/08/2018] [Accepted: 02/04/2018] [Indexed: 11/29/2022] Open
Abstract
Data from a set of different studies on the infectivity and pathogenicity of Campylobacter jejuni were analyzed with a multilevel model, allowing for effects of host species (nonhuman primates and humans) and different strains of the pathogen. All challenge studies involved high doses of the pathogen, resulting in all exposed subjects to become infected. In only one study a dose response effect (increasing trend with dose) for infection was observed. High susceptibility to infection with C. jejuni was found in a joint analysis of outbreaks and challenge studies. For that reason four outbreaks, associated with raw milk consumption, were also included in the present study. The high doses used for inoculation did not cause all infected subjects to develop acute enteric symptoms. The observed outcomes are consistent with a dose response effect for acute symptoms among infected subjects: a conditional illness dose response relation. Nonhuman primates and human volunteers did not appear to have different susceptibilities for developing enteric symptoms, but exposure in outbreaks (raw milk) did lead to a higher probability of symptomatic campylobacteriosis.
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Affiliation(s)
- Peter F M Teunis
- Center for Global Safe WASH, Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA.
| | - Axel Bonačić Marinović
- Centre for Infectious Disease Control, National Institute of Public Health and the Environment (RIVM), Bilthoven, Netherlands
| | - David R Tribble
- Infectious Disease Clinical Research Program, Department of Preventive Medicine and Biostatistics, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Chad K Porter
- Naval Medical Research Center, Enteric Diseases Department, Silver Spring, MD, USA
| | - Arno Swart
- Centre for Infectious Disease Control, National Institute of Public Health and the Environment (RIVM), Bilthoven, Netherlands
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Jones AK, Rigby D, Burton M, Millman C, Williams NJ, Jones TR, Wigley P, O'Brien SJ, Cross P. Restaurant Cooking Trends and Increased Risk for Campylobacter Infection. Emerg Infect Dis 2018; 22:1208-15. [PMID: 27314748 PMCID: PMC4918174 DOI: 10.3201/eid2207.151775] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Perceived consumer preferences for rare chicken liver are increasing risk for campylobacteriosis. In the United Kingdom, outbreaks of Campylobacter infection are increasingly attributed to undercooked chicken livers, yet many recipes, including those of top chefs, advocate short cooking times and serving livers pink. During 2015, we studied preferences of chefs and the public in the United Kingdom and investigated the link between liver rareness and survival of Campylobacter. We used photographs to assess chefs’ ability to identify chicken livers meeting safe cooking guidelines. To investigate the microbiological safety of livers chefs preferred to serve, we modeled Campylobacter survival in infected chicken livers cooked to various temperatures. Most chefs correctly identified safely cooked livers but overestimated the public’s preference for rareness and thus preferred to serve them more rare. We estimated that 19%–52% of livers served commercially in the United Kingdom fail to reach 70°C and that predicted Campylobacter survival rates are 48%–98%. These findings indicate that cooking trends are linked to increasing Campylobacter infections.
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Soller JA, Eftim SE, Nappier SP. Direct potable reuse microbial risk assessment methodology: Sensitivity analysis and application to State log credit allocations. WATER RESEARCH 2018; 128:286-292. [PMID: 29107913 PMCID: PMC6816270 DOI: 10.1016/j.watres.2017.10.034] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 10/12/2017] [Accepted: 10/17/2017] [Indexed: 05/03/2023]
Abstract
Understanding pathogen risks is a critically important consideration in the design of water treatment, particularly for potable reuse projects. As an extension to our published microbial risk assessment methodology to estimate infection risks associated with Direct Potable Reuse (DPR) treatment train unit process combinations, herein, we (1) provide an updated compilation of pathogen density data in raw wastewater and dose-response models; (2) conduct a series of sensitivity analyses to consider potential risk implications using updated data; (3) evaluate the risks associated with log credit allocations in the United States; and (4) identify reference pathogen reductions needed to consistently meet currently applied benchmark risk levels. Sensitivity analyses illustrated changes in cumulative annual risks estimates, the significance of which depends on the pathogen group driving the risk for a given treatment train. For example, updates to norovirus (NoV) raw wastewater values and use of a NoV dose-response approach, capturing the full range of uncertainty, increased risks associated with one of the treatment trains evaluated, but not the other. Additionally, compared to traditional log-credit allocation approaches, our results indicate that the risk methodology provides more nuanced information about how consistently public health benchmarks are achieved. Our results indicate that viruses need to be reduced by 14 logs or more to consistently achieve currently applied benchmark levels of protection associated with DPR. The refined methodology, updated model inputs, and log credit allocation comparisons will be useful to regulators considering DPR projects and design engineers as they consider which unit treatment processes should be employed for particular projects.
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Affiliation(s)
- Jeffrey A Soller
- Soller Environmental, LLC, 3022 King St, Berkeley, CA, 94703, USA
| | | | - Sharon P Nappier
- U.S. Environmental Protection Agency, Office of Water, Office of Science and Technology, 1200 Pennsylvania Avenue, NW, Washington, DC, 20460, USA.
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Brown KI, Graham KE, Soller JA, Boehm AB. Estimating the probability of illness due to swimming in recreational water with a mixture of human- and gull-associated microbial source tracking markers. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2017; 19:1528-1541. [PMID: 29114693 DOI: 10.1039/c7em00316a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Beaches often receive fecal contamination from more than one source. Human sources include untreated sewage as well as treated wastewater effluent, and animal sources include wildlife such as gulls. Different contamination sources are expected to pose different health risks to swimmers. Genetic microbial source tracking (MST) markers can be used to detect bacteria that are associated with different animal sources, but the health risks associated with a mixture of MST markers are unknown. This study presents a method for predicting these health risks, using human- and gull-associated markers as an example. Quantitative Microbial Risk Assessment (QMRA) is conducted with MST markers as indicators. We find that risks associated with exposure to a specific concentration of a human-associated MST marker (HF) are greater if the HF source is untreated sewage rather than treated wastewater effluent. We also provide a risk-based threshold of HF from untreated sewage at a beach, to stay below a predicted illness risk of 3 per 100 swimmers, that is a function of gull-associated MST marker (CAT) concentration.
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Affiliation(s)
- Kendra I Brown
- Department of Civil and Environmental Engineering, Environmental Engineering and Science, Stanford University, 94305-4020, USA.
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40
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Juntunen J, Meriläinen P, Simola A. Public health and economic risk assessment of waterborne contaminants and pathogens in Finland. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 599-600:873-882. [PMID: 28501011 DOI: 10.1016/j.scitotenv.2017.05.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 04/28/2017] [Accepted: 05/01/2017] [Indexed: 06/07/2023]
Abstract
This study shows that a variety of mathematical modeling techniques can be applied in a comprehensive assessment of the risks involved in drinking water production. In order to track the effects from water sources to the end consumers, we employed four models from different fields of study. First, two models of the physical environment, which track the movement of harmful substances from the sources to the water distribution. Second, a statistical quantitative microbial risk assessment (QMRA) to assess the public health risks of the consumption of such water. Finally, a regional computable general equilibrium (CGE) model to assess the economic effects of increased illnesses. In order to substantiate our analysis, we used an illustrative case of a recently built artificial recharge system in Southern Finland that provides water for a 300,000 inhabitant area. We examine the effects of various chemicals and microbes separately. Our economic calculations allow for direct effects on labor productivity due to absenteeism, increased health care expenditures and indirect effects for local businesses. We found that even a considerable risk has no notable threat to public health and thus barely measurable economic consequences. Any epidemic is likely to spread widely in the urban setting we examined, but is also going to be short-lived in both public health and economic terms. Our estimate for the ratio of total and direct effects is 1.4, which indicates the importance of general equilibrium effects. Furthermore, the total welfare loss is 2.4 times higher than the initial productivity loss. The major remaining uncertainty in the economic assessment is the indirect effects.
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Affiliation(s)
- Janne Juntunen
- Finnish Environment Institute, Survontie 9A, FI-40500 Jyväskylä, Finland.
| | - Päivi Meriläinen
- National Institute for Health and Welfare, P.O. Box 95, FI-70701 Kuopio, Finland.
| | - Antti Simola
- VATT Institute for Economic Research, P.O. Box 1279, FI-00101 Helsinki, Finland.
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Murphy HM, Meng Z, Henry R, Deletic A, McCarthy DT. Current Stormwater Harvesting Guidelines Are Inadequate for Mitigating Risk from Campylobacter During Nonpotable Reuse Activities. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:12498-12507. [PMID: 29035523 DOI: 10.1021/acs.est.7b03089] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Campylobacter is a pathogen frequently detected in urban stormwater worldwide. It is one of the leading causes of enteric disease in many developed countries and is the leading cause of enteric disease in Australia. Prior to harvesting stormwater, adequate treatment is necessary to mitigate risks derived from such harmful pathogens. The goal of this research was to estimate the health risks associated with the exposure to Campylobacter when harvesting urban stormwater for toilet flushing and irrigation activities, and the role treatment options play in limiting risks. Campylobacter data collected from several urban stormwater systems in Victoria, Australia, were the inputs of a Quantitative Microbial Risk Assessment model. The model included seven treatment scenarios, spanning wetlands, biofilters, and more traditional treatment trains including those recommended by the Australian Guidelines for Water Recycling. According to our modeling and acceptable risk thresholds, only two treatment scenarios could supply water of sufficient quality for toilet flushing and irrigation end-uses: (1) using stormwater biofilters coupled with UV-treatment and (2) a more conventional coagulation, filtration, UV, and chlorination treatment plant. Importantly, our modeling results suggest that current guidelines in place for stormwater reuse are not adequate for protecting against exposure to Campylobacter. However, more research is required to better define whether the Campylobacter detectable in stormwater are pathogenic to humans.
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Affiliation(s)
- Heather M Murphy
- Division of Environmental Health, College of Public Health, Temple University , Philadelphia, Pennsylvania 19122, United States
| | - Ze Meng
- Environmental and Public Health Microbiology Laboratory (EPHM Lab), Department of Civil Engineering, Monash Infrastructure Institute, Monash University , Clayton, Victoria 3800, Australia
| | - Rebekah Henry
- Environmental and Public Health Microbiology Laboratory (EPHM Lab), Department of Civil Engineering, Monash Infrastructure Institute, Monash University , Clayton, Victoria 3800, Australia
| | - Ana Deletic
- Environmental and Public Health Microbiology Laboratory (EPHM Lab), Department of Civil Engineering, Monash Infrastructure Institute, Monash University , Clayton, Victoria 3800, Australia
| | - David T McCarthy
- Environmental and Public Health Microbiology Laboratory (EPHM Lab), Department of Civil Engineering, Monash Infrastructure Institute, Monash University , Clayton, Victoria 3800, Australia
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Soller JA, Schoen M, Steele JA, Griffith JF, Schiff KC. Incidence of gastrointestinal illness following wet weather recreational exposures: Harmonization of quantitative microbial risk assessment with an epidemiologic investigation of surfers. WATER RESEARCH 2017; 121:280-289. [PMID: 28558279 DOI: 10.1016/j.watres.2017.05.017] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 05/02/2017] [Accepted: 05/08/2017] [Indexed: 05/26/2023]
Abstract
We modeled the risk of gastrointestinal (GI) illness associated with recreational exposures to marine water following storm events in San Diego County, California. We estimated GI illness risks via quantitative microbial risk assessment (QMRA) techniques by consolidating site specific pathogen monitoring data of stormwater, site specific dilution estimates, literature-based water ingestion data, and literature based pathogen dose-response and morbidity information. Our water quality results indicated that human sources of contamination contribute viral and bacterial pathogens to streams draining an urban watershed during wet weather that then enter the ocean and affect nearshore water quality. We evaluated a series of approaches to account for uncertainty in the norovirus dose-response model selection and compared our model results to those from a concurrently conducted epidemiological study that provided empirical estimates for illness risk following ocean exposure. The preferred norovirus dose-response approach yielded median risk estimates for water recreation-associated illness (15 GI illnesses per 1000 recreation events) that closely matched the reported epidemiological results (12 excess GI illnesses per 1000 wet weather recreation events). The results are consistent with norovirus, or other pathogens associated with norovirus, as an important cause of gastrointestinal illness among surfers in this setting. This study demonstrates the applicability of QMRA for recreational water risk estimation, even under wet weather conditions and describes a process that might be useful in developing site-specific water quality criteria in this and other locations.
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Affiliation(s)
- Jeffrey A Soller
- Soller Environmental, LLC, 3022 King St., Berkeley, CA 94703, USA.
| | - Mary Schoen
- Soller Environmental, LLC, 3022 King St., Berkeley, CA 94703, USA
| | - Joshua A Steele
- Southern California Coastal Water Research Project, 3535 Harbor Blvd #110, Costa Mesa, CA 92626, USA
| | - John F Griffith
- Southern California Coastal Water Research Project, 3535 Harbor Blvd #110, Costa Mesa, CA 92626, USA
| | - Kenneth C Schiff
- Southern California Coastal Water Research Project, 3535 Harbor Blvd #110, Costa Mesa, CA 92626, USA
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J.M.K.J.K. P, New C, A. U, Nakaguchi Y, Nishibuchi M, R. S. Risk of Escherichia coli O157:H7 infection linked to the consumption of beef. FOOD RESEARCH 2017. [DOI: 10.26656/fr.2017.3.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Sarjit A, Dykes GA. Transfer of Campylobacter and Salmonella from Poultry Meat onto Poultry Preparation Surfaces. J Food Prot 2017; 80:750-757. [PMID: 28358259 DOI: 10.4315/0362-028x.jfp-16-414] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 01/09/2017] [Indexed: 11/11/2022]
Abstract
Thermophilic Campylobacter and Salmonella enterica are major causes of gastrointestinal foodborne infection. Survival of these pathogens on food-associated surfaces is a risk contributing to their spread through the food system. This study examined the transfer of two strains each of C. jejuni, C. coli, Salmonella Enteritidis, and Salmonella Typhimurium from chicken meat to a knife or scissors used on either a plastic or wooden cutting board. Each strain of Campylobacter and Salmonella at ∼108 CFU mL-1 was inoculated (5 mL) onto 25 g of chicken meat with skin and allowed to attach (for 10 min). The meat was then cut (20 times per implement) into 1-cm2 pieces with either a knife or scissors on either a plastic or wooden cutting board. The numbers of pathogens transferred from meat onto cutting implements and cutting board surfaces were enumerated. The surfaces were subsequently either rinsed with water or rinsed with water and wiped with a kitchen towel to mimic commonly used superficial cleaning practices for these implements, and the numbers of pathogens were enumerated again. The bacterial numbers for both pathogens were determined on thin-layer agar. The attachment of the Salmonella strains to chicken meat (∼7.0 to 7.8 log CFU cm-2) was higher than the attachment of the Campylobacter strains (∼4.6 to 6.6 log CFU cm-2). All four Salmonella strains transferred in higher numbers (∼1.9 to 6.3 log CFU cm-2) to all surfaces than did the Campylobacter strains (∼1.1 to 3.9 log CFU cm-2). The transfer rates of both pathogens from the chicken meat to all the surfaces examined varied substantially between ∼0 and 21.1%. The highest rate of transfer (∼21.1%) observed was for C. coli 2875 when transferred from the chicken meat to the scissors. Most cleaning treatments reduced the numbers of both pathogens (∼0.3 to 4.1 log CFU cm-2) transferred to all the surfaces. Our study gives insights into the risks associated with the transfer of Campylobacter and Salmonella from poultry to the surfaces used in poultry preparation.
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Affiliation(s)
- Amreeta Sarjit
- School of Science, Monash University, Jalan Lagoon Selatan, Bandar Sunway 46150, Selangor, Malaysia; and
| | - Gary A Dykes
- School of Public Health, Curtin University, Bentley 6102, Western Australia, Australia (ORCID: http://orcid.org/0000-0001-5014-9282)
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Schoen ME, Ashbolt NJ, Jahne MA, Garland J. Risk-based enteric pathogen reduction targets for non-potable and direct potable use of roof runoff, stormwater, and greywater. MICROBIAL RISK ANALYSIS 2017; 5:32-43. [PMID: 31534999 PMCID: PMC6750756 DOI: 10.1016/j.mran.2017.01.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
This paper presents risk-based enteric pathogen log reduction targets for non-potable and potable uses of a variety of alternative source waters (i.e., locally-collected greywater, roof runoff, and stormwater). A probabilistic Quantitative Microbial Risk Assessment (QMRA) was used to derive the pathogen log10 reduction targets (LRTs) that corresponded with an infection risk of either 10-4 per person per year (ppy) or 10-2 ppy. The QMRA accounted for variation in pathogen concentration and sporadic pathogen occurrence (when data were available) in source waters for reference pathogens in the genera Rotavirus, Mastadenovirus(human adenoviruses), Norovirus, Campylobacter, Salmonella, Giardia and Cryptosporidium. Non-potable uses included indoor use (for toilet flushing and clothes washing) with occasional accidental ingestion of treated non-potable water (or cross-connection with potable water), and unrestricted irrigation for outdoor use. Various exposure scenarios captured the uncertainty from key inputs, i.e., the pathogen concentration in source water; the volume of water ingested; and for the indoor use, the frequency of and the fraction of the population exposed to accidental ingestion. Both potable and non-potable uses required pathogen treatment for the selected waters and the LRT was generally greater for potable use than non-potable indoor use and unrestricted irrigation. The difference in treatment requirements among source waters was driven by the microbial quality of the water - both the density and occurrence of reference pathogens. Greywater from collection systems with 1000 people had the highest LRTs; however, those for greywater collected from a smaller population (~ 5 people), which have less frequent pathogen occurrences, were lower. Stormwater had highly variable microbial quality, which resulted in a range of possible treatment requirements. The microbial quality of roof runoff, and thus the resulting LRTs, remains uncertain due to lack of relevant pathogen data.
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Affiliation(s)
- Mary E Schoen
- Soller Environmental, Inc., 3022 King St., Berkeley, CA 94703, USA
| | - Nicholas J Ashbolt
- Rm. 3-57D South Academic Building, School of Public Health, University of Alberta, Edmonton AB T6G 2G7, Canada
| | - Michael A Jahne
- U.S. Environmental Protection Agency, 26 W. Martin Luther King Drive, Cincinnati OH 45268, USA
| | - Jay Garland
- U.S. Environmental Protection Agency, 26 W. Martin Luther King Drive, Cincinnati OH 45268, USA
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Teunis P, Figueras MJ. Reassessment of the Enteropathogenicity of Mesophilic Aeromonas Species. Front Microbiol 2016; 7:1395. [PMID: 27708621 PMCID: PMC5030306 DOI: 10.3389/fmicb.2016.01395] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 08/23/2016] [Indexed: 12/11/2022] Open
Abstract
Cases of Aeromonas diarrhea have been described all over the world. The genus Aeromonas includes ca. 30 species, of which 10 have been isolated in association with gastroenteritis. The dominating species that account for ca. 96% of the identified strains are Aeromonas caviae, A. veronii, A. dhakensis, and A. hydrophila. However, the role of Aeromonas as a true enteropathogen has been questioned on the basis of the lack of outbreaks, the non-fulfillment of Koch's postulates and the low numbers of acute illnesses in the only existing human challenge study. In the present study we reassess the enteropathogenicity of Aeromonas using dose response models for microbial infection and acute illness. The analysis uses the data from the human challenge study and additional data from selected outbreak investigations where the numbers exposed and the dose were reported, allowing their inclusion as "natural experiments". In the challenge study several cases of asymptomatic shedding were found (26.3%, 15/57), however, only 3.5% (2/57) of those challenged with Aeromonas developed acute enteric symptoms (i.e., diarrhea). The "natural experiments" showed a much higher risk of illness associated with exposure to Aeromonas, even at moderate to low doses. The median dose required for 1% illness risk, was ~1.4 × 104 times higher in the challenge study (1.24 × 104 cfu) compared to natural exposure events (0.9 cfu). The dose response assessment presented in this study shows that the combined challenge and outbreak data are consistent with high infectivity of Aeromonas, and a wide range of susceptibility to acute enteric illness. To illustrate the outcomes, we simulate the risk associated with concentrations of Aeromonas found in different water and food matrices, indicating the disease burden potentially associated with these bacteria. In conclusion this study showed that Aeromonas is highly infectious, and that human susceptibility to illness may be high, similar to undisputed enteropathogens like Campylobacter or Salmonella.
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Affiliation(s)
- Peter Teunis
- Centre for Zoonoses and Environmental Microbiology, Centre for Infectious Disease Control, National Institute for Public Health and the Environment, BilthovenNetherlands
- Center for Global Safe WASH, Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, GAUSA
| | - Maria J. Figueras
- Unitat de Microbiologia, Departament de Ciènces Médiques Bàsiques, Facultat de Medicina i Ciències de la Salut, Pere Virgili Institute for Health Research, Universitat Rovira i Virgili, ReusSpain
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Survival and Risk Comparison of Campylobacter jejuni on Various Processed Meat Products. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2016; 13:ijerph13060580. [PMID: 27294947 PMCID: PMC4924037 DOI: 10.3390/ijerph13060580] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Revised: 05/30/2016] [Accepted: 06/07/2016] [Indexed: 11/17/2022]
Abstract
The objective of this study was to investigate survival kinetics of Campylobacter jejuni on various processed meat products (dry-cured ham, round ham with/without sodium nitrite, garlic seasoned ham with/without sodium nitrite, and sausage without sodium nitrite). Additionally, a semi-quantitative risk assessment of C. jejuni on various processed meat products was conducted using FDA-iRISK 1.0. Inoculated processed meat products with 6.0 ± 0.5 log CFU/g of C. jejuni were vacuum packed and stored at 4, 10, 17, 24, 30, and 36 °C. Survival curves were fitted to the Weibull model to obtain the delta values of C. jejuni on various processed meat products. The most rapid death of C. jejuni was observed on dry-cured ham, followed by sausage without sodium nitrite. The results of semi-quantitative risk assessment indicate that dry-cured ham represented the lowest risk among all samples. C. jejuni on processed meats presented a greater risk at 4 °C than at 10 °C. The risk of ham was greater than the risk of sausage, regardless of type. Among all samples, the highest risk of C. jejuni was observed in round ham without sodium nitrite. Overall, our data indicates that risk of processed meat products due to C. jejuni is relatively low.
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Giacometti F, Serraino A, Finazzi G, Daminelli P, Losio MN, Tamba M, Garigliani A, Mattioli R, Riu R, Zanoni RG. Field handling conditions of raw milk sold in vending machines: experimental evaluation of the behaviour ofListeria monocytogenes, Escherichia coliO157:H7,Salmonella TyphimuriumandCampylobacter jejuni. ITALIAN JOURNAL OF ANIMAL SCIENCE 2016. [DOI: 10.4081/ijas.2012.e24] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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49
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Petterson SR, Mitchell VG, Davies CM, O'Connor J, Kaucner C, Roser D, Ashbolt N. Evaluation of three full-scale stormwater treatment systems with respect to water yield, pathogen removal efficacy and human health risk from faecal pathogens. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 543:691-702. [PMID: 26615487 DOI: 10.1016/j.scitotenv.2015.11.056] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Revised: 11/10/2015] [Accepted: 11/10/2015] [Indexed: 05/20/2023]
Abstract
In this study, three full-scale, operational stormwater harvesting systems located in Melbourne, Australia were evaluated with respect to water yields; pathogen removal performance by analysis of native surrogate data (Escherichiacoli, somatic coliphages and Clostridium perfringens); and potential human health risk associated with exposures to faecal pathogens using Quantitative Microbial Risk Assessment (QMRA). The water yield assessment confirmed variation between design and measured yields. Faecal contamination of urban stormwater was site specific and variable. Different treatment removal performance was observed between each of the microbial surrogates and varied between event and baseline conditions, with negligible removal of viruses during event conditions. Open storages that provide a habitat for waterfowl may lead to elevated risk due to the potential for zoonotic transmission. Nevertheless, in the Australian urban setting studied, the potential for human faecal contamination of the separated stormwater system was a critical driver of risk. If the integrity of the sewerage system can be ensured, then predicted health risks are dramatically reduced.
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Affiliation(s)
- Susan R Petterson
- Water & Health Pty Ltd, P.O. Box 648, Salamander Bay 2317, Australia.
| | | | | | | | - Christine Kaucner
- Water Research Centre, School of Civil and Environmental Engineering, University of NSW, Australia
| | - David Roser
- Water Research Centre, School of Civil and Environmental Engineering, University of NSW, Australia
| | - Nicholas Ashbolt
- Water Research Centre, School of Civil and Environmental Engineering, University of NSW, Australia; School of Public Health, University of Alberta, Alberta T6G 2G7, Canada
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50
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Petterson SR. Application of a QMRA Framework to Inform Selection of Drinking Water Interventions in the Developing Context. RISK ANALYSIS : AN OFFICIAL PUBLICATION OF THE SOCIETY FOR RISK ANALYSIS 2016; 36:203-214. [PMID: 26178619 DOI: 10.1111/risa.12452] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The aim of this study was to develop a modified quantitative microbial risk assessment (QMRA) framework that could be applied as a decision support tool to choose between alternative drinking water interventions in the developing context. The impact of different household water treatment (HWT) interventions on the overall incidence of diarrheal disease and disability adjusted life years (DALYs) was estimated, without relying on source water pathogen concentration as the starting point for the analysis. A framework was developed and a software tool constructed and then implemented for an illustrative case study for Nepal based on published scientific data. Coagulation combined with free chlorine disinfection provided the greatest estimated health gains in the short term; however, when long-term compliance was incorporated into the calculations, the preferred intervention was porous ceramic filtration. The model demonstrates how the QMRA framework can be used to integrate evidence from different studies to inform management decisions, and in particular to prioritize the next best intervention with respect to estimated reduction in diarrheal incidence. This study only considered HWT interventions; it is recognized that a systematic consideration of sanitation, recreation, and drinking water pathways is important for effective management of waterborne transmission of pathogens, and the approach could be expanded to consider the broader water-related context.
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