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Denissen J, Reyneke B, Waso-Reyneke M, Havenga B, Barnard T, Khan S, Khan W. Prevalence of ESKAPE pathogens in the environment: Antibiotic resistance status, community-acquired infection and risk to human health. Int J Hyg Environ Health 2022; 244:114006. [PMID: 35841823 DOI: 10.1016/j.ijheh.2022.114006] [Citation(s) in RCA: 80] [Impact Index Per Article: 40.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 06/30/2022] [Accepted: 06/30/2022] [Indexed: 01/10/2023]
Abstract
The ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) pathogens are characterised by increased levels of resistance towards multiple classes of first line and last-resort antibiotics. Although these pathogens are frequently isolated from clinical environments and are implicated in a variety of life-threatening, hospital-associated infections; antibiotic resistant ESKAPE strains have been isolated from environmental reservoirs such as surface water, wastewater, food, and soil. Literature on the persistence and subsequent health risks posed by the ESKAPE isolates in extra-hospital settings is however, limited and the current review aims to elucidate the primary reservoirs of these pathogens in the environment, their antibiotic resistance profiles, and the link to community-acquired infections. Additionally, information on the current state of research regarding health-risk assessments linked to exposure of the ESKAPE pathogens in the natural environment, is outlined.
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Affiliation(s)
- Julia Denissen
- Department of Microbiology, Faculty of Science, Stellenbosch University, Private Bag X1, Stellenbosch, 7602, South Africa
| | - Brandon Reyneke
- Department of Microbiology, Faculty of Science, Stellenbosch University, Private Bag X1, Stellenbosch, 7602, South Africa
| | - Monique Waso-Reyneke
- Faculty of Health Sciences, University of Johannesburg, PO Box 17011, Doornfontein, 2028, South Africa
| | - Benjamin Havenga
- Department of Microbiology, Faculty of Science, Stellenbosch University, Private Bag X1, Stellenbosch, 7602, South Africa
| | - Tobias Barnard
- Water and Health Research Centre, University of Johannesburg, PO Box 17011, Doornfontein, 7305, South Africa
| | - Sehaam Khan
- Faculty of Health Sciences, University of Johannesburg, PO Box 17011, Doornfontein, 2028, South Africa
| | - Wesaal Khan
- Department of Microbiology, Faculty of Science, Stellenbosch University, Private Bag X1, Stellenbosch, 7602, South Africa.
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2
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Zadoks RN, Barker GC, Benschop J, Allan KJ, Chaters G, Cleaveland S, Crump JA, Davis MA, Mmbaga BT, Prinsen G, Thomas KM, Waldman L, French NP. Spread of Nontyphoidal Salmonella in the Beef Supply Chain in Northern Tanzania: Sensitivity in a Probabilistic Model Integrating Microbiological Data and Data from Stakeholder Interviews. RISK ANALYSIS : AN OFFICIAL PUBLICATION OF THE SOCIETY FOR RISK ANALYSIS 2022; 42:989-1006. [PMID: 34590330 DOI: 10.1111/risa.13826] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 08/22/2021] [Accepted: 08/27/2021] [Indexed: 06/13/2023]
Abstract
East Africa is a hotspot for foodborne diseases, including infection by nontyphoidal Salmonella (NTS), a zoonotic pathogen that may originate from livestock. Urbanization and increased demand for animal protein drive intensification of livestock production and food processing, creating risks and opportunities for food safety. We built a probabilistic mathematical model, informed by prior beliefs and dedicated stakeholder interviews and microbiological research, to describe sources and prevalence of NTS along the beef supply chain in Moshi, Tanzania. The supply chain was conceptualized using a bow tie model, with terminal livestock markets as pinch point, and a forked pathway postmarket to compare traditional and emerging supply chains. NTS was detected in 36 (7.7%) of 467 samples throughout the supply chain. After combining prior belief and observational data, marginal estimates of true NTS prevalence were 4% in feces of cattle entering the beef supply and 20% in raw meat at butcheries. Based on our model and sensitivity analyses, true NTS prevalence was not significantly different between supply chains. Environmental contamination, associated with butchers and vendors, was estimated to be the most likely source of NTS in meat for human consumption. The model provides a framework for assessing the origin and propagation of NTS along meat supply chains. It can be used to inform decision making when economic factors cause changes in beef production and consumption, such as where to target interventions to reduce risks to consumers. Through sensitivity and value of information analyses, the model also helps to prioritize investment in additional research.
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Affiliation(s)
- Ruth N Zadoks
- Institute of Biodiversity Animal Health and Comparative Medicine, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
- Sydney School of Veterinary Science, University of Sydney, Sydney, Australia
| | | | - Jackie Benschop
- mEpiLab, School of Veterinary Science, Massey University, Palmerston North, New Zealand
| | - Kathryn J Allan
- Institute of Biodiversity Animal Health and Comparative Medicine, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
- School of Veterinary Medicine, University of Glasgow, Glasgow, UK
| | - Gemma Chaters
- Institute of Biodiversity Animal Health and Comparative Medicine, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
| | - Sarah Cleaveland
- Institute of Biodiversity Animal Health and Comparative Medicine, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - John A Crump
- Centre for International Health, University of Otago, Dunedin, New Zealand
| | - Margaret A Davis
- Paul G. Allen School for Global Animal Health, Washington State University, Pullman, Washington, USA
| | - Blandina T Mmbaga
- Kilimanjaro Christian Medical University College and Kilimanjaro Clinical Research Institute, Moshi, United Republic of Tanzania
| | - Gerard Prinsen
- School of People, Environment and Planning, Massey University, Palmerston North, New Zealand
| | - Kate M Thomas
- Centre for International Health, University of Otago, Dunedin, New Zealand
- Ministry of Primary Industries, Wellington, New Zealand
| | - Linda Waldman
- Institute for Development Studies, University of Sussex, Brighton, UK
| | - Nigel P French
- The New Zealand Food Safety Science and Research Centre, Massey University, Palmerston North, New Zealand
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3
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Sosa-Moreno A, Lee GO, Van Engen A, Sun K, Uruchima J, Kwong LH, Ludwig-Borycz E, Caruso BA, Cevallos W, Levy K, Eisenberg JNS. Characterizing Behaviors Associated with Enteric Pathogen Exposure among Infants in Rural Ecuador through Structured Observations. Am J Trop Med Hyg 2022; 106:tpmd211099. [PMID: 35405653 PMCID: PMC9209906 DOI: 10.4269/ajtmh.21-1099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 01/31/2022] [Indexed: 11/07/2022] Open
Abstract
The relative importance of environmental pathways that results in enteropathogen transmission may vary by context. However, measurement of contact events between individuals and the environment remains a challenge, especially for infants and young children who may use their mouth and hands to explore their environment. Using a mixed-method approach, we combined 1) semistructured observations to characterize key behaviors associated with enteric pathogen exposure and 2) structured observations using Livetrak, a customized software application, to quantify the frequency and duration of contacts events among infants in rural Ecuador. After developing and iteratively piloting the structured observation instrument, we loaded the final list of prompts onto a LiveTrak pallet to assess environmental exposures of 6-month infants (N = 19) enrolled in a prospective cohort study of diarrheal disease. Here we provide a detailed account of the lessons learned. For example, in our field site, 1) most mothers reported washing their hands after diaper changes (14/18, 77.8%); however only a third (4/11, 36.4%) were observed washing their hands; 2) the observers noted that animal ownership differed from observed animal exposure because animals owned by neighboring households were reported during the observation; and 3) using Livetrak, we found that infants frequently mouthed their hands (median = 1.9 episodes/hour, median duration: 1.6 min) and mouthed surroundings objects (1.8 episodes/hour, 1.9 min). Structured observations that track events in real time, can complement environmental sampling, quantitative survey data and qualitative interviews. Customizing these observations enabled us to quantify enteric exposures most relevant to our rural Ecuadorian context.
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Affiliation(s)
| | - Gwenyth O. Lee
- School of Public Health, University of Michigan, Ann Arbor, Michigan
| | - Amanda Van Engen
- School of Public Health, University of Michigan, Ann Arbor, Michigan
| | - Kelly Sun
- School of Public Health, University of Michigan, Ann Arbor, Michigan
| | - Jessica Uruchima
- School of Public Health, University of Michigan, Ann Arbor, Michigan
| | - Laura H. Kwong
- School of Public Health, University of California Berkeley, Berkeley, California
| | | | - Bethany A. Caruso
- Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, Georgia
| | | | - Karen Levy
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington
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4
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Wilson AM, Weir MH, King MF, Jones RM. Comparing approaches for modelling indirect contact transmission of infectious diseases. J R Soc Interface 2021; 18:20210281. [PMID: 34465207 PMCID: PMC8437226 DOI: 10.1098/rsif.2021.0281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 08/02/2021] [Indexed: 11/12/2022] Open
Abstract
Mathematical models describing indirect contact transmission are an important component of infectious disease mitigation and risk assessment. A model that tracks microorganisms between compartments by coupled ordinary differential equations or a Markov chain is benchmarked against a mechanistic interpretation of the physical transfer of microorganisms from surfaces to fingers and subsequently to a susceptible person's facial mucosal membranes. The primary objective was to compare these models in their estimates of doses and changes in microorganism concentrations on hands and fomites over time. The abilities of the models to capture the impact of episodic events, such as hand hygiene, and of contact patterns were also explored. For both models, greater doses were estimated for the asymmetrical scenarios in which a more contaminated fomite was touched more often. Differing representations of hand hygiene in the Markov model did not notably impact estimated doses but affected pathogen concentration dynamics on hands. When using the Markov model, losses due to hand hygiene should be handled as separate events as opposed to time-averaging expected losses. The discrete event model demonstrated the effect of hand-to-mouth contact timing on the dose. Understanding how model design influences estimated doses is important for advancing models as reliable risk assessment tools.
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Affiliation(s)
- Amanda M. Wilson
- Department of Family and Preventive Medicine, School of Medicine, University of Utah, Salt Lake City, UT, USA
- Rocky Mountain Center for Occupational and Environmental Health, University of Utah, Salt Lake City, UT, USA
- Department of Community, Environment and Policy, Mel and Enid Zuckerman College of Public Health, University of Arizona, Tucson, AZ, USA
| | - Mark H. Weir
- Division of Environmental Health Sciences, School of Public Health, The Ohio State University, Columbus, OT, USA
| | - Marco-Felipe King
- School of Civil Engineering, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, UK
| | - Rachael M. Jones
- Department of Family and Preventive Medicine, School of Medicine, University of Utah, Salt Lake City, UT, USA
- Rocky Mountain Center for Occupational and Environmental Health, University of Utah, Salt Lake City, UT, USA
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5
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Reyneke B, Hamilton KA, Fernández-Ibáñez P, Polo-López MI, McGuigan KG, Khan S, Khan W. EMA-amplicon-based sequencing informs risk assessment analysis of water treatment systems. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 743:140717. [PMID: 32679496 DOI: 10.1016/j.scitotenv.2020.140717] [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: 03/25/2020] [Revised: 06/29/2020] [Accepted: 07/01/2020] [Indexed: 06/11/2023]
Abstract
Illumina amplicon-based sequencing was coupled with ethidium monoazide bromide (EMA) pre-treatment to monitor the total viable bacterial community and subsequently identify and prioritise the target organisms for the health risk assessment of the untreated rainwater and rainwater treated using large-volume batch solar reactor prototypes installed in an informal settlement and rural farming community. Taxonomic assignments indicated that Legionella and Pseudomonas were the most frequently detected genera containing opportunistic bacterial pathogens in the untreated and treated rainwater at both sites. Additionally, Mycobacterium, Clostridium sensu stricto and Escherichia/Shigella displayed high (≥80%) detection frequencies in the untreated and/or treated rainwater samples at one or both sites. Numerous exposure scenarios (e.g. drinking, cleaning) were subsequently investigated and the health risk of using untreated and solar reactor treated rainwater in developing countries was quantified based on the presence of L. pneumophila, P. aeruginosa and E. coli. The solar reactor prototypes were able to reduce the health risk associated with E. coli and P. aeruginosa to below the 1 × 10-4 annual benchmark limit for all the non-potable uses of rainwater within the target communities (exception of showering for E. coli). However, the risk associated with intentional drinking of untreated or treated rainwater exceeded the benchmark limit (E. coli and P. aeruginosa). Additionally, while the solar reactor treatment reduced the risk associated with garden hosing and showering based on the presence of L. pneumophila, the risk estimates for both activities still exceeded the annual benchmark limit. The large-volume batch solar reactor prototypes were thus able to reduce the risk posed by the target bacteria for non-potable activities rainwater is commonly used for in water scarce regions of sub-Saharan Africa. This study highlights the need to assess water treatment systems in field trials using QMRA.
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Affiliation(s)
- B Reyneke
- Department of Microbiology, Faculty of Science, Stellenbosch University, Private Bag X1, Stellenbosch 7602, South Africa
| | - K A Hamilton
- School for Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ 85281, United States; The Biodesign Institute Center for Environmental Health Engineering, Arizona State University, Tempe, AZ 85281, United States
| | - P Fernández-Ibáñez
- Plataforma Solar de Almeria-CIEMAT, P.O. Box 22, Tabernas, Almería, Spain; Nanotechnology and Integrated BioEngineering Centre, School of Engineering, University of Ulster, Newtownabbey, Northern Ireland, United Kingdom
| | - M I Polo-López
- Plataforma Solar de Almeria-CIEMAT, P.O. Box 22, Tabernas, Almería, Spain
| | - K G McGuigan
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - S Khan
- Faculty of Health Sciences, University of Johannesburg, PO Box 17011, Doornfontein 2028, South Africa
| | - W Khan
- Department of Microbiology, Faculty of Science, Stellenbosch University, Private Bag X1, Stellenbosch 7602, South Africa.
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6
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Goddard FB, Ban R, Barr DB, Brown J, Cannon J, Colford JM, Eisenberg JNS, Ercumen A, Petach H, Freeman MC, Levy K, Luby SP, Moe C, Pickering AJ, Sarnat JA, Stewart J, Thomas E, Taniuchi M, Clasen T. Measuring Environmental Exposure to Enteric Pathogens in Low-Income Settings: Review and Recommendations of an Interdisciplinary Working Group. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:11673-11691. [PMID: 32813503 PMCID: PMC7547864 DOI: 10.1021/acs.est.0c02421] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 08/18/2020] [Accepted: 08/19/2020] [Indexed: 05/06/2023]
Abstract
Infections with enteric pathogens impose a heavy disease burden, especially among young children in low-income countries. Recent findings from randomized controlled trials of water, sanitation, and hygiene interventions have raised questions about current methods for assessing environmental exposure to enteric pathogens. Approaches for estimating sources and doses of exposure suffer from a number of shortcomings, including reliance on imperfect indicators of fecal contamination instead of actual pathogens and estimating exposure indirectly from imprecise measurements of pathogens in the environment and human interaction therewith. These shortcomings limit the potential for effective surveillance of exposures, identification of important sources and modes of transmission, and evaluation of the effectiveness of interventions. In this review, we summarize current and emerging approaches used to characterize enteric pathogen hazards in different environmental media as well as human interaction with those media (external measures of exposure), and review methods that measure human infection with enteric pathogens as a proxy for past exposure (internal measures of exposure). We draw from lessons learned in other areas of environmental health to highlight how external and internal measures of exposure can be used to more comprehensively assess exposure. We conclude by recommending strategies for advancing enteric pathogen exposure assessments.
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Affiliation(s)
- Frederick
G. B. Goddard
- Gangarosa
Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia 30322, United States
| | - Radu Ban
- Bill and
Melinda Gates Foundation, Seattle, Washington 98109, United States
| | - Dana Boyd Barr
- Gangarosa
Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia 30322, United States
| | - Joe Brown
- School of
Civil and Environmental Engineering, Georgia
Institute of Technology, Atlanta, Georgia 30332, United States
| | - Jennifer Cannon
- Centers
for Disease Control and Prevention Foundation, Atlanta, Georgia 30308, United States
| | - John M. Colford
- Division
of Epidemiology and Biostatistics, School of Public Health, University of California−Berkeley, Berkeley, California 94720, United States
| | - Joseph N. S. Eisenberg
- Department
of Epidemiology, University of Michigan
School of Public Health, Ann Arbor, Michigan 48109, United States
| | - Ayse Ercumen
- Department
of Forestry and Environmental Resources, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Helen Petach
- U.S. Agency
for International Development, Washington, DC 20004, United States
| | - Matthew C. Freeman
- Gangarosa
Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia 30322, United States
| | - Karen Levy
- Department
of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington 98105, United States
| | - Stephen P. Luby
- Division
of Infectious Diseases and Geographic Medicine, Stanford University, California 94305, United States
| | - Christine Moe
- Center
for
Global Safe Water, Sanitation and Hygiene, Rollins School of Public
Health, Emory University, Atlanta, Georgia 30322, United States
| | - Amy J. Pickering
- Department
of Civil and Environmental Engineering, School of Engineering, Tufts University, Medford, Massachusetts 02155, United States
| | - Jeremy A. Sarnat
- Gangarosa
Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia 30322, United States
| | - Jill Stewart
- Department
of Environmental Sciences and Engineering, Gillings School of Global
Public Health, University of North Carolina, Chapel Hill, North Carolina 27599, United States
| | - Evan Thomas
- Mortenson
Center in Global Engineering, University
of Colorado Boulder, Boulder, Colorado 80303, United States
| | - Mami Taniuchi
- Division
of Infectious Diseases and International Health, Department of Medicine, University of Virginia, Charlottesville, Virginia 22903, United States
| | - Thomas Clasen
- Gangarosa
Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia 30322, United States
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7
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Scotoni M, Koch J, Julian TR, Clack L, Pitol AK, Wolfensberger A, Grass RN, Sax H. Silica nanoparticles with encapsulated DNA (SPED) - a novel surrogate tracer for microbial transmission in healthcare. Antimicrob Resist Infect Control 2020; 9:152. [PMID: 32938493 PMCID: PMC7493369 DOI: 10.1186/s13756-020-00813-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Accepted: 08/28/2020] [Indexed: 12/20/2022] Open
Abstract
Background The increase in antimicrobial resistance is of worldwide concern. Surrogate tracers attempt to simulate microbial transmission by avoiding the infectious risks associated with live organisms. We evaluated silica nanoparticles with encapsulated DNA (SPED) as a new promising surrogate tracer in healthcare. Methods SPED and Escherichia coli were used to implement three experiments in simulation rooms and a microbiology laboratory in 2017–2018. Experiment 1 investigated the transmission behaviour of SPED in a predefined simulated patient-care scenario. SPED marked with 3 different DNA sequences (SPED1-SPED3) were introduced at 3 different points of the consecutive 13 touch sites of a patient-care scenario that was repeated 3 times, resulting in a total of 288 values. Experiment 2 evaluated SPED behaviour following hand cleaning with water and soap and alcohol-based handrub. Experiment 3 compared transfer dynamics of SPED versus E. coli in a laboratory using a gloved finger touching two consecutive sites on a laminate surface after a first purposefully contaminated site. Results Experiment 1: SPED adhesiveness on bare skin after a hand-to-surface exposure was high, leading to a dissemination of SPED1–3 on all consecutive surface materials with a trend of decreasing recovery rates, also reflecting touching patterns in concordance with contaminated fingers versus palms. Experiment 2: Hand washing with soap and water resulted in a SPED reduction of 96%, whereas hand disinfection led to dispersal of SPED from the palm to the back of the hand. Experiment 3: SPED and E. coli concentration decreased in parallel with each transmission step – with SPED showing a trend for less reduction and variability. Conclusions SPED represent a convenient and safe instrument to simulate pathogen spread by contact transmission simultaneously from an infinite number of sites. They can be further developed as a central asset for successful infection prevention in healthcare.
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Affiliation(s)
- Manuela Scotoni
- Department of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, University of Zurich, Raemistrasse 100, HAL14, 8091, Zurich, Switzerland
| | - Julian Koch
- Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich, Switzerland
| | - Timothy R Julian
- Department of Environmental Microbiology, Eawag, Swiss Federal Institute of Aquatic Science and Technology, Duebendorf, Switzerland
| | - Lauren Clack
- Department of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, University of Zurich, Raemistrasse 100, HAL14, 8091, Zurich, Switzerland
| | - Ana K Pitol
- Department of Environmental Microbiology, Eawag, Swiss Federal Institute of Aquatic Science and Technology, Duebendorf, Switzerland
| | - Aline Wolfensberger
- Department of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, University of Zurich, Raemistrasse 100, HAL14, 8091, Zurich, Switzerland
| | - Robert N Grass
- Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich, Switzerland
| | - Hugo Sax
- Department of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, University of Zurich, Raemistrasse 100, HAL14, 8091, Zurich, Switzerland.
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8
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King MF, López-García M, Atedoghu KP, Zhang N, Wilson AM, Weterings M, Hiwar W, Dancer SJ, Noakes CJ, Fletcher LA. Bacterial transfer to fingertips during sequential surface contacts with and without gloves. INDOOR AIR 2020; 30:993-1004. [PMID: 32329918 DOI: 10.1111/ina.12682] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 03/26/2020] [Accepted: 04/14/2020] [Indexed: 05/05/2023]
Abstract
Bacterial transmission from contaminated surfaces via hand contact plays a critical role in disease spread. However, the fomite-to-finger transfer efficiency of microorganisms during multiple sequential surface contacts with and without gloves has not been formerly investigated. We measured the quantity of Escherichia coli on fingertips of participants after 1-8 sequential contacts with inoculated plastic coupons with and without nitrile gloves. A Bayesian approach was used to develop a mechanistic model of pathogen accretion to examine finger loading as a function of the difference between E coli on surfaces and fingers. We used the model to determine the coefficient of transfer efficiency (λ), and influence of swabbing efficiency and finger area. Results showed that λ for bare skin was higher (49%, 95% CI = 32%-72%) than for gloved hands (30%, CI = 17%-49%). Microbial load tended toward a dynamic equilibrium after four and six contacts for gloved hands and bare skin, respectively. Individual differences between volunteers' hands had a negligible effect compared with use of gloves (P < .01). Gloves reduced loading by 4.7% (CI = -12%-21%) over bare skin contacts, while 20% of participants accrued more microorganisms on gloved hands. This was due to poor fitting, which created a larger finger surface area than bare hands.
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Affiliation(s)
| | | | | | - Nan Zhang
- Department of Mechanical Engineering, The University of Hong Kong, Hong Kong, China, SAR
| | - Amanda M Wilson
- Department of Community, Environment and Policy, Mel and Enid Zuckerman College of Public Health, University of Arizona, Tucson, Arizona, USA
| | - Martijn Weterings
- Institute of Life Technologies, University of Applied Sciences and Arts Western, Sion, Valais-Wallis, Switzerland
| | - Waseem Hiwar
- School of Civil Engineering, University of Leeds, Leeds, UK
| | - Stephanie J Dancer
- School of Applied Sciences, Edinburgh Napier University, Edinburgh, UK
- Department of Microbiology, Hairmyres Hospital, NHS Lanarkshire, Glasgow, UK
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9
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Bischel HN, Caduff L, Schindelholz S, Kohn T, Julian TR. Health Risks for Sanitation Service Workers along a Container-Based Urine Collection System and Resource Recovery Value Chain. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:7055-7067. [PMID: 31082211 PMCID: PMC6587154 DOI: 10.1021/acs.est.9b01092] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 05/10/2019] [Accepted: 05/13/2019] [Indexed: 05/24/2023]
Abstract
Container-based sanitation (CBS) within a comprehensive service system value chain offers a low-cost sanitation option with potential for revenue generation but may increase microbial health risks to sanitation service workers. This study assessed occupational exposure to rotavirus and Shigella spp. during CBS urine collection and subsequent struvite fertilizer production in eThekwini, South Africa. Primary data included high resolution sequences of hand-object contacts from annotated video and measurement of fecal contamination from urine and surfaces likely to be contacted. A stochastic model incorporated chronological surface contacts, pathogen concentrations in urine, and literature data on transfer efficiencies of pathogens to model pathogen concentrations on hands and risk of infection from hand-to-mouth contacts. The probability of infection was highest from exposure to rotavirus during urine collection (∼10-1) and struvite production (∼10-2), though risks from Shigella spp. during urine collection (∼10-3) and struvite production (∼10-4) were non-negligible. Notably, risk of infection was higher during urine collection than during struvite production due to contact with contaminated urine transport containers. In the scale-up of CBS, disinfection of urine transport containers is expected to reduce pathogen transmission. Exposure data from this study can be used to evaluate the effectiveness of measures to protect sanitation service workers.
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Affiliation(s)
- Heather N. Bischel
- School
of Architecture, Civil, and Environmental Engineering (ENAC), École Polytechnique Fédérale
de Lausanne (EPFL), CH 1015 Lausanne, Switzerland
- Department
of Civil & Environmental Engineering, University of California at Davis, Davis, California 95616, United States
| | - Lea Caduff
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, CH 8600 Dübendorf, Switzerland
| | - Simon Schindelholz
- School
of Architecture, Civil, and Environmental Engineering (ENAC), École Polytechnique Fédérale
de Lausanne (EPFL), CH 1015 Lausanne, Switzerland
| | - Tamar Kohn
- School
of Architecture, Civil, and Environmental Engineering (ENAC), École Polytechnique Fédérale
de Lausanne (EPFL), CH 1015 Lausanne, Switzerland
| | - Timothy R. Julian
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, CH 8600 Dübendorf, Switzerland
- Swiss
Tropical and Public Health Institute, CH 4002 Basel, Switzerland
- University
of Basel, CH 4003 Basel, Switzerland
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10
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Canales RA, Wilson AM, Sinclair RG, Soto-Beltran M, Pearce-Walker J, Molina M, Penny M, Reynolds KA. Microbial study of household hygiene conditions and associated Listeria monocytogenes infection risks for Peruvian women. Trop Med Int Health 2019; 24:899-921. [PMID: 31066175 DOI: 10.1111/tmi.13246] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
OBJECTIVES To develop an exposure and risk assessment model to estimate listeriosis infection risks for Peruvian women. METHODS A simulation model was developed utilising Listeria monocytogenes concentrations on kitchen and latrine surfaces in Peruvian homes, hand trace data from Peruvian women and behavioural data from literature. Scenarios involving varying proportions of uncontaminated, or 'clean', surfaces and non-porous surfaces were simulated. Infection risks were estimated for 4, 6 and 8 h of behaviours and interactions with surfaces. RESULTS Although infection risks were estimated across scenarios for various time points (e.g. 4, 6, 8 h), overall mean estimated infection risks for all scenarios were ≥ 0.31. Infection risks increased as the proportions of clean surfaces decreased. Hand-to-general surface contacts accounted for the most cumulative change in L. monocytogenes concentration on hands. CONCLUSIONS In addition to gaining insights on how human behaviours affect exposure and infection risk, this model addressed uncertainties regarding the influence of household surface contamination levels. Understanding the influence of surface contamination in preventing pathogen transmission in households could help to develop intervention strategies to reduce L. monocytogenes infection and associated health risks.
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Affiliation(s)
- Robert A Canales
- Mel and Enid Zuckerman College of Public Health, University of Arizona, Tucson, AZ, USA
| | - Amanda M Wilson
- Mel and Enid Zuckerman College of Public Health, University of Arizona, Tucson, AZ, USA
| | - Ryan G Sinclair
- Loma Linda University School of Public Health, Loma Linda, CA, USA
| | - Marcela Soto-Beltran
- Facultad Ciencias Químico Biológicas, Universidad Autónoma de Sinaloa, Culiacan, Mexico
| | | | | | - Mary Penny
- Instituto de Investigación Nutricional, Lima, Peru
| | - Kelly A Reynolds
- Mel and Enid Zuckerman College of Public Health, University of Arizona, Tucson, AZ, USA
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11
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The landscape of enteric pathogen exposure of young children in public domains of low-income, urban Kenya: The influence of exposure pathway and spatial range of play on multi-pathogen exposure risks. PLoS Negl Trop Dis 2019; 13:e0007292. [PMID: 30917117 PMCID: PMC6453472 DOI: 10.1371/journal.pntd.0007292] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 04/08/2019] [Accepted: 03/12/2019] [Indexed: 11/19/2022] Open
Abstract
Young children are infected by a diverse variety of enteric pathogens in low-income, high-burden countries. Little is known about which conditions pose the greatest risk for enteric pathogen exposure and infection. Young children frequently play in residential public areas around their household, including areas contaminated by human and animal feces, suggesting these exposures are particularly hazardous. The objective of this study was to examine how the dose of six types of common enteric pathogens, and the probability of exposure to one or multiple enteric pathogens for young children playing at public play areas in Kisumu, Kenya is influenced by the type and frequency of child play behaviors that result in ingestion of soil or surface water. Additionally, we examine how pathogen doses and multi-pathogen exposure are modified by spatial variability in the number of public areas children are exposed to in their neighborhood. A Bayesian framework was employed to obtain the posterior distribution of pathogen doses for a certain number of contacts. First, a multivariate mixed effects tobit model was used to obtain the posterior distribution of pathogen concentrations, and their interdependencies, in soil and surface water, based upon empirical data of enteric pathogen contamination in three neighborhoods of Kisumu. Then, exposure doses were estimated using behavioral contact parameters from previous studies and contrasted under different exposure conditions. Pathogen presence and concentration in soil varied widely across local (< 25 meter radius area) and neighborhood-level scales, but pathogens were correlated among distinct surface water samples collected near to each other. Multi-pathogen exposure of children at public play areas was common. Pathogen doses and the probability of multi-pathogen ingestion increased with: higher frequency of environmental contact, especially for surface water; larger volume of soil or water ingested; and with play at multiple sites in the neighborhood versus single site play. Child contact with surface water and soil at public play areas in their neighborhood is an important cause of exposure to enteric pathogens in Kisumu, and behavioral, environmental, and spatial conditions are determinants of exposure.
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12
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Stephens B, Azimi P, Thoemmes MS, Heidarinejad M, Allen JG, Gilbert JA. Microbial Exchange via Fomites and Implications for Human Health. CURRENT POLLUTION REPORTS 2019; 5:198-213. [PMID: 34171005 PMCID: PMC7149182 DOI: 10.1007/s40726-019-00123-6] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
PURPOSE OF REVIEW Fomites are inanimate objects that become colonized with microbes and serve as potential intermediaries for transmission to/from humans. This review summarizes recent literature on fomite contamination and microbial survival in the built environment, transmission between fomites and humans, and implications for human health. RECENT FINDINGS Applications of molecular sequencing techniques to analyze microbial samples have increased our understanding of the microbial diversity that exists in the built environment. This growing body of research has established that microbial communities on surfaces include substantial diversity, with considerable dynamics. While many microbial taxa likely die or lay dormant, some organisms survive, including those that are potentially beneficial, benign, or pathogenic. Surface characteristics also influence microbial survival and rates of transfer to and from humans. Recent research has combined experimental data, mechanistic modeling, and epidemiological approaches to shed light on the likely contributors to microbial exchange between fomites and humans and their contributions to adverse (and even potentially beneficial) human health outcomes. SUMMARY In addition to concerns for fomite transmission of potential pathogens, new analytical tools have uncovered other microbial matters that can be transmitted indirectly via fomites, including entire microbial communities and antibiotic-resistant bacteria. Mathematical models and epidemiological approaches can provide insight on human health implications. However, both are subject to limitations associated with study design, and there is a need to better understand appropriate input model parameters. Fomites remain an important mechanism of transmission of many microbes, along with direct contact and short- and long-range aerosols.
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Affiliation(s)
- Brent Stephens
- Department of Civil, Architectural, and Environmental Engineering, Illinois Institute of Technology, Alumni Memorial Hall 228E, 3201 South Dearborn Street, Chicago, IL 60616 USA
| | - Parham Azimi
- Environmental Health Department, Harvard T.H. Chan School of Public Health, Boston, MA USA
| | - Megan S. Thoemmes
- Department of Pediatrics, University of California San Diego School of Medicine, San Diego, CA USA
| | - Mohammad Heidarinejad
- Department of Civil, Architectural, and Environmental Engineering, Illinois Institute of Technology, Alumni Memorial Hall 228E, 3201 South Dearborn Street, Chicago, IL 60616 USA
| | - Joseph G. Allen
- Environmental Health Department, Harvard T.H. Chan School of Public Health, Boston, MA USA
| | - Jack A. Gilbert
- Department of Pediatrics, University of California San Diego School of Medicine, San Diego, CA USA
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Julian TR, Vithanage HSK, Chua ML, Kuroda M, Pitol AK, Nguyen PHL, Canales RA, Fujii S, Harada H. High time-resolution simulation of E. coli on hands reveals large variation in microbial exposures amongst Vietnamese farmers using human excreta for agriculture. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 635:120-131. [PMID: 29660716 DOI: 10.1016/j.scitotenv.2018.04.100] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 04/06/2018] [Accepted: 04/06/2018] [Indexed: 05/16/2023]
Abstract
Infectious disease transmission is frequently mediated by the environment, where people's movements through and interactions with the environment dictate risks of infection and/or illness. Capturing these interactions, and quantifying their importance, offers important insights into effective interventions. In this study, we capture high time-resolution activity data for twenty-five Vietnamese farmers during collection and land application of human excreta for agriculture. Although human excreta use improves productivity, the use increases risks of enteric infections for both farmers and end users. In our study, the activity data are integrated with environmental microbial sampling data into a stochastic-mechanistic simulation of E. coli contamination on hands and E. coli ingested. Results from the study include frequent and variable contact rates for farmers' hands (from 34 to 1344 objects contacted per hour per hand), including highly variable hand-to-mouth contact rates (from 0 to 9 contacts per hour per hand). The frequency of hand-to-mouth contacts was substantially lower than the widely-used frequency previously reported for U.S. Office Workers. Environmental microbial contamination data highlighted ubiquitous E. coli contamination in the environment, including excreta, hands, toilet pit, handheld tools, soils, surfaces, and water. Results from the simulation suggest dynamic changes in E. coli contamination on hands, and wide variation in hand contamination and E. coli ingested amongst the farmers studied. Sensitivity analysis suggests that E. coli contamination on hands and ingested doses are most influenced by contamination of handheld tools, excreta, and the toilet pit as well as by frequency of hand-to-mouth contacts. The study findings are especially relevant given the context: no farmers reported adequate storage time of human excreta, and personal protective mask availability did not prevent hand-to-mouth contacts. Integrating high time-resolution activity data into exposure assessments highlights variation in exposures amongst farmers, and offers greater insight into effective interventions and their potential impacts.
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Affiliation(s)
- Timothy R Julian
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Überlandstrasse 133, CH-8600 Dübendorf, Switzerland; Swiss Tropical and Public Health Institute, Socinstrasse 57, P.O. Box, CH-4002 Basel, Switzerland; University of Basel, P.O. Box, CH-4003 Basel, Switzerland.
| | - Hasitha S K Vithanage
- UNESCO-IHE Institute for Water Education, 2601 Delft, The Netherlands; Sri Lanka National Water Supply and Drainage Board, Dehiwala-Mount Lavinia, Sri Lanka
| | - Min Li Chua
- Graduate School of Global Environmental Studies, Kyoto University, Yoshida-honmachi, Sakyo-ku 606-8501, Kyoto, Japan
| | - Matasaka Kuroda
- Graduate School of Engineering, Katsura Campus, Kyoto University, Nisikyo-ku, 615-8510, Kyoto, Japan
| | - Ana K Pitol
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Überlandstrasse 133, CH-8600 Dübendorf, Switzerland; Laboratory of Environmental Chemistry, School of Architecture, Civil, and Environmental Engineering (ENAC), École Polytechnique FÉdÉrale de Lausanne (EPFL), CH 1015 Lausanne, Switzerland
| | - Pham Hong Lien Nguyen
- School of Environmental Science and Technology, Hanoi University of Science and Technology, Viet Nam
| | - Robert A Canales
- Community, Environment & Policy Department, Mel and Enid Zuckerman College of Public Health, The University of Arizona, 1295 N. Martin Avenue, Campus PO Box 245210, Drachman Hall A229, Tucson, AZ 85724, USA
| | - Shigeo Fujii
- Graduate School of Global Environmental Studies, Kyoto University, Yoshida-honmachi, Sakyo-ku 606-8501, Kyoto, Japan
| | - Hidenori Harada
- Graduate School of Global Environmental Studies, Kyoto University, Yoshida-honmachi, Sakyo-ku 606-8501, Kyoto, Japan; Research Institute for Humanity and Nature, 457-4 Kamigamo Motoyama, Kita-ku 603-8047, Kyoto, Japan.
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14
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Where Children Play: Young Child Exposure to Environmental Hazards during Play in Public Areas in a Transitioning Internally Displaced Persons Community in Haiti. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2018; 15:ijerph15081646. [PMID: 30081490 PMCID: PMC6122025 DOI: 10.3390/ijerph15081646] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 07/31/2018] [Accepted: 07/31/2018] [Indexed: 12/17/2022]
Abstract
Globally, gastrointestinal (GI) infections by enteric pathogens are the second-leading cause of morbidity and mortality in children under five years of age (≤5 years). While GI pathogen exposure in households has been rigorously examined, there is little data about young children's exposure in public domains. Moreover, public areas in low-income settings are often used for other waste disposal practices in addition to human feces, such as trash dumping in areas near households. If young children play in public domains, they might be exposed to interrelated and highly concentrated microbial, chemical, and physical hazards. This study performed structured observations at 36 public areas in an internally displaced persons community that has transitioned into a formal settlement in Haiti. We documented how often young children played in public areas and quantified behaviors that might lead to illness and injury. Children ≤5 years played at all public sites, which included infants who played at 47% of sites. Children touched and mouthed plastic, metal and glass trash, food and other objects from the ground, ate soil (geophagia) and drank surface water. They also touched latrines, animals, animal feces and open drainage canals. Hand-to-mouth contact was one of the most common behaviors observed and the rate of contact significantly differed among developmental stages (infants: 18/h, toddlers: 11/h and young children: 9/h), providing evidence that children could ingest trace amounts of animal/human feces on hands that may contain GI pathogens. These findings demonstrate that water, sanitation and hygiene interventions could be more effective if they consider exposure risks to feces in public domains. Furthermore, this research highlights the need for waste-related interventions to address the broader set of civil conditions that create unsafe, toxic and contaminated public environments where young children play.
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15
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Navab-Daneshmand T, Friedrich MND, Gächter M, Montealegre MC, Mlambo LS, Nhiwatiwa T, Mosler HJ, Julian TR. Escherichia coli Contamination across Multiple Environmental Compartments (Soil, Hands, Drinking Water, and Handwashing Water) in Urban Harare: Correlations and Risk Factors. Am J Trop Med Hyg 2018; 98:803-813. [PMID: 29363444 PMCID: PMC5930891 DOI: 10.4269/ajtmh.17-0521] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 11/27/2017] [Indexed: 12/21/2022] Open
Abstract
Escherichia coli pathotypes (i.e., enteropathogenic and enterotoxigenic) have been identified among the pathogens most responsible for moderate-to-severe diarrhea in low- and middle-income countries (LMICs). Pathogenic E. coli are transmitted from infected human or animal feces to new susceptible hosts via environmental reservoirs such as hands, water, and soil. Commensal E. coli, which includes nonpathogenic E. coli strains, are widely used as fecal bacteria indicator, with their presence associated with increased likelihood of enteric pathogens and/or diarrheal disease. In this study, we investigated E. coli contamination in environmental reservoirs within households (N = 142) in high-population density communities of Harare, Zimbabwe. We further assessed the interconnectedness of the environmental compartments by investigating associations between, and household-level risk factors for, E. coli contamination. From the data we collected, the source and risk factors for E. coli contamination are not readily apparent. One notable exception is the presence of running tap water on the household plot, which is associated with significantly less E. coli contamination of drinking water, handwashing water, and hands after handwashing. In addition, E. coli levels on hands after washing are significantly associated with handwashing water contamination, hand contamination before washing, and diarrhea incidence. Finally, we observed that animal ownership increases E. coli contamination in soil, and E. coli in soil are correlated with contamination on hands before washing. This study highlights the complexity of E. coli contamination in household environments within LMICs. More, larger, studies are needed to better identify sources and exposure pathways of E. coli-and enteric pathogens generally-to identify effective interventions.
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Affiliation(s)
- Tala Navab-Daneshmand
- School of Chemical, Biological, and Environmental Engineering, Oregon State University, Corvallis, Oregon
- Department of Environmental Microbiology, Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland
| | - Max N. D. Friedrich
- Department of Environmental Social Sciences, Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland
| | - Marja Gächter
- Department of Environmental Microbiology, Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland
| | - Maria Camila Montealegre
- Department of Environmental Microbiology, Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland
| | - Linn S. Mlambo
- Department of Biological Sciences, University of Zimbabwe, Harare, Zimbabwe
| | - Tamuka Nhiwatiwa
- Department of Biological Sciences, University of Zimbabwe, Harare, Zimbabwe
| | - Hans-Joachim Mosler
- Department of Environmental Social Sciences, Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland
| | - Timothy R. Julian
- Department of Environmental Microbiology, Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland
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Julian TR. Environmental transmission of diarrheal pathogens in low and middle income countries. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2016; 18:944-955. [PMID: 27384220 DOI: 10.1039/c6em00222f] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Every year, more than half a million children die due to diarrheal diseases. Recent studies have identified the most important etiologies of diarrheal disease are enterotoxigenic and enteropathogenic E. coli, Shigella spp., rotavirus, norovirus and Cryptosporidium spp. These etiologies are unsurprisingly characterized by a combination of high shedding, high infectivity, and transmissibility through multiple environmental reservoirs. The relative importance of the transmission routes is likely site-specific. So the impact of interventions, which typically target only one or two environmental reservoirs, is likely also site-specific. The factors influencing the transmission routes most important for diarrheal disease are complex, including - at a minimum - etiology of endemic disease; and water, sanitation, and hygiene infrastructure and practices. The site-specific nature - and complexity of transmission - helps explain the observed variation in impacts of water, sanitation, and hygiene interventions. It may also render efforts to estimate or quantify global means for interventions' impacts irrelevant. The theme of this Perspective is that greater reductions in diarrheal disease transmission in LMICs can be achieved by designing interventions to interrupt the most important environmental transmission pathways. Intervention choice should be informed by site-specific conditions, most notably: diarrheal etiology and existing water, sanitation, and hygiene infrastructure and practices. The theme is discussed through the lens of the characteristics of the most important diarrheal diseases (shedding, infectivity, growth, and persistence) and the general characteristics of environmental reservoirs (exposure pathways and fecal contamination). The discussion highlights when interventions - and combinations of interventions - will be most effective at reducing diarrheal disease burden.
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Affiliation(s)
- Timothy R Julian
- Pathogens and Human Health, Department of Environmental Microbiology, Swiss Federal Research Institute of Aquatic Science and Technology, Eawag, BU-F08, Überlandstrasse 133, 8600 Dübendorf, Switzerland.
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Teunis PFM, Reese HE, Null C, Yakubu H, Moe CL. Quantifying Contact with the Environment: Behaviors of Young Children in Accra, Ghana. Am J Trop Med Hyg 2016; 94:920-931. [PMID: 26880773 PMCID: PMC4824240 DOI: 10.4269/ajtmh.15-0417] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 12/18/2015] [Indexed: 11/18/2022] Open
Abstract
To better understand the risks of exposure for young children to fecal contamination in their environment, we systematically characterized and quantified behaviors of 154 children, 0–5 years old, in four high-density, low-income neighborhoods in Accra, Ghana. A repertoire of six different activities and five different compartments (categories of locations within the household) was developed, and about 500 hours of ordered structured observations of activities and locations of individual children were collected. These records were analyzed using a competing hazards model, estimating (Weibull) hazard rates for each state (activity/compartment combination), dependent on the present state and the preceding state. The estimated rates were used to simulate sequences of behavior and describe days in the life of a child in low-income, urban Africa. Children younger than 1 year spent most time playing or sleeping off the ground, older children frequently played on floors. Relatively little time was spent in drains or wet trash areas. Critical combinations of activities, like handwashing after defecation or before eating were estimated to occur rarely. These quantitative behavior estimates can inform future risk assessments that examine the relative roles of various fecal–oral exposure pathways in low-income urban settings.
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Bokulich NA, Lewis ZT, Boundy-Mills K, Mills DA. A new perspective on microbial landscapes within food production. Curr Opin Biotechnol 2016; 37:182-189. [PMID: 26773388 PMCID: PMC4913695 DOI: 10.1016/j.copbio.2015.12.008] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 12/10/2015] [Accepted: 12/15/2015] [Indexed: 01/01/2023]
Abstract
High-throughput, 'next-generation' sequencing tools offer many exciting new possibilities for food research. From investigating microbial dynamics within food fermentations to the ecosystem of the food-processing built environment, amplicon sequencing, metagenomics, and transcriptomics present novel applications for exploring microbial communities in, on, and around our foods. This review discusses the many uses of these tools for food-related and food facility-related research and highlights where they may yield nuanced insight into the microbial world of food production systems.
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Affiliation(s)
- Nicholas A Bokulich
- Department of Viticulture and Enology, University of California, Davis, CA 95616,United States; Department of Food Science and Technology, University of California, Davis, CA 95616,United States; Foods for Health Institute, University of California, Davis, CA 95616, United States
| | - Zachery T Lewis
- Department of Food Science and Technology, University of California, Davis, CA 95616,United States; Foods for Health Institute, University of California, Davis, CA 95616, United States
| | - Kyria Boundy-Mills
- Department of Food Science and Technology, University of California, Davis, CA 95616,United States
| | - David A Mills
- Department of Viticulture and Enology, University of California, Davis, CA 95616,United States; Department of Food Science and Technology, University of California, Davis, CA 95616,United States; Foods for Health Institute, University of California, Davis, CA 95616, United States.
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