1
|
Hemsley CM, Essex-Lopresti A, Chisnall T, Millar M, Neale S, Reichel R, Norville IH, Titball RW. MLVA and com1 genotyping of Coxiella burnetii in farmed ruminants in Great Britain. Vet Microbiol 2023; 277:109629. [PMID: 36535174 DOI: 10.1016/j.vetmic.2022.109629] [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: 04/29/2022] [Revised: 09/15/2022] [Accepted: 12/07/2022] [Indexed: 12/13/2022]
Abstract
Coxiella burnetii, the causative agent of the zoonotic disease Q fever, has been shown to be endemic in Great Britain, but information on the prevailing genomic lineages or Genomic Groups (GGs) of Coxiella burnetii is limited. The aim of this study was to genotype C. burnetii isolates from infected farmed ruminants by Multiple Locus Variable Number Tandem Repeat Analysis (MLVA) and identify their associated Genomic Group. A total of 51 Coxiella-containing abortion samples from farmed ruminants (sheep, goats, and cattle), which were collected in Great Britain during 2013-2018, were included in the study, 34 of which returned a C. burnetii MLVA genotype. All bovine samples (n = 18), 5/7 of the ovine samples, and 3/9 of the caprine samples belonged to an MLVA cluster which we could link to the MST20 genotype of GG III, whereas 6/9 of the caprine samples and 2/7 of the ovine samples belonged to MLVA clusters which we could link to the MST33 or MST32 genotypes of GG II (7 vs 1 sample(s), respectively). We also noted that the Coxiella-specific com1 gene contained unique mutations that could genomotype isolates, i.e. assign them to a Genomic Group. In conclusion, both goats and sheep in Great Britain (from 2014 onward) were found to carry the same MLVA genotypes (MST33-like; GG II) that were linked to a human Q fever outbreak in the Netherlands. This knowledge in combination with the usage of genotyping/genomotyping methods should prove useful in future surveillance programs and in the management of outbreaks.
Collapse
Affiliation(s)
- Claudia M Hemsley
- College of Life and Environmental Sciences, Biosciences, University of Exeter, Exeter, UK.
| | | | | | | | - Sue Neale
- Animal and Plant Health Agency, Penrith, UK.
| | | | - Isobel H Norville
- College of Life and Environmental Sciences, Biosciences, University of Exeter, Exeter, UK; Defence Science and Technology Laboratory, Porton Down, Salisbury, UK.
| | - Richard W Titball
- College of Life and Environmental Sciences, Biosciences, University of Exeter, Exeter, UK.
| |
Collapse
|
2
|
Performance Evaluation and Validation of Air Samplers To Detect Aerosolized Coxiella burnetii. Microbiol Spectr 2022; 10:e0065522. [PMID: 36073825 PMCID: PMC9602806 DOI: 10.1128/spectrum.00655-22] [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] [Indexed: 12/30/2022] Open
Abstract
Coxiella burnetii, the etiological agent of Q fever, is an intracellular zoonotic pathogen transmitted via the respiratory route. Once released from infected animals, C. burnetii can travel long distances through air before infecting another host. As such, the ability to detect the presence of C. burnetii in air is important. In this study, three air samplers, AirPort MD8, BioSampler, and the Coriolis Micro, were assessed against a set of predetermined criteria in the presence of three different aerosolized C. burnetii concentrations. Two liquid collection media, phosphate-buffered saline (PBS) and alkaline polyethylene glycol (Alk PEG), were tested with devices requiring a collection liquid. Samples were tested by quantitative polymerase chain reaction assay (qPCR) targeting the single-copy com1 gene or multicopy insertion element IS1111. All air samplers performed well at detecting airborne C. burnetii across the range of concentrations tested. At high nebulized concentrations, AirPort MD8 showed higher, but variable, recovery probabilities. While the BioSampler and Coriolis Micro recovered C. burnetii at lower concentrations, the replicates were far more repeatable. At low and intermediate nebulized concentrations, results were comparable in the trials between air samplers, although the AirPort MD8 had consistently higher recovery probabilities. In this first study validating air samplers for their ability to detect aerosolized C. burnetii, we found that while all samplers performed well, not all samplers were equal. It is important that these results are further validated under field conditions. These findings will further inform efforts to detect airborne C. burnetii around known point sources of infection. IMPORTANCE Coxiella burnetii causes Q fever in humans and coxiellosis in animals. It is important to know if C. burnetii is present in the air around putative sources as it is transmitted via inhalation. This study assessed air samplers (AirPort MD8, BioSampler, and Coriolis Micro) for their efficacy in detecting C. burnetii. Our results show that all three devices could detect aerosolized bacteria effectively; however, at high concentrations the AirPort performed better than the other two devices, showing higher percent recovery. At intermediate and low concentrations AirPort detected at a level higher than or similar to that of other samplers. Quantification of samples was hindered by the limit of quantitation of the qPCR assay. Compared with the other two devices, the AirPort was easier to handle and clean in the field. Testing air around likely sources (e.g., farms, abattoirs, and livestock saleyards) using validated sampling devices will help better estimate the risk of Q fever to nearby communities.
Collapse
|
3
|
Zhang X, Ji Z, Yue Y, Liu H, Wang J. Infection Risk Assessment of COVID-19 through Aerosol Transmission: a Case Study of South China Seafood Market. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:4123-4133. [PMID: 32543176 PMCID: PMC7323058 DOI: 10.1021/acs.est.0c02895] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 06/15/2020] [Accepted: 06/16/2020] [Indexed: 05/18/2023]
Abstract
The Corona Virus Disease 2019 (COVID-19) is rapidly spreading throughout the world. Aerosol is a potential transmission route. We conducted the quantitative microbial risk assessment (QMRA) to evaluate the aerosol transmission risk by using the South China Seafood Market as an example. The key processes were integrated, including viral shedding, dispersion, deposition in air, biologic decay, lung deposition, and the infection risk based on the dose-response model. The available hospital bed for COVID-19 treatment per capita (1.17 × 10-3) in Wuhan was adopted as a reference for manageable risk. The median risk of a customer to acquire SARS-CoV-2 infection via the aerosol route after 1 h of exposure in the market with one infected shopkeeper was about 2.23 × 10-5 (95% confidence interval: 1.90 × 10-6 to 2.34 × 10-4). The upper bound could increase and become close to the manageable risk with multiple infected shopkeepers. More detailed risk assessment should be conducted in poorly ventilated markets with multiple infected cases. The uncertainties were mainly due to the limited information on the dose-response relation and the viral shedding which need further studies. The risk rapidly decreased outside the market due to the dilution by ambient air and became below 10-6 at 5 m away from the exit.
Collapse
Affiliation(s)
- Xiaole Zhang
- Institute of Environmental Engineering
(IfU), ETH Zürich, Zürich,
CH-8093, Switzerland
- Laboratory for Advanced Analytical
Technologies, Empa, Dübendorf,
CH-8600, Switzerland
| | - Zheng Ji
- Institute of Environmental Engineering
(IfU), ETH Zürich, Zürich,
CH-8093, Switzerland
- School of Geography and Tourism,
Shaanxi Normal University,
Xi’an, Shaanxi 710119, China
- International Joint
Research Centre of Shaanxi Province for Pollutant Exposure and
Eco-Environmental Health, Xi’an, Shaanxi
710119, China
| | - Yang Yue
- Institute of Environmental Engineering
(IfU), ETH Zürich, Zürich,
CH-8093, Switzerland
- Laboratory for Advanced Analytical
Technologies, Empa, Dübendorf,
CH-8600, Switzerland
| | - Huan Liu
- Institute of Environmental Engineering
(IfU), ETH Zürich, Zürich,
CH-8093, Switzerland
- Department of Environmental
Engineering, Zhejiang University, Hangzhou,
310058, China
| | - Jing Wang
- Institute of Environmental Engineering
(IfU), ETH Zürich, Zürich,
CH-8093, Switzerland
- Laboratory for Advanced Analytical
Technologies, Empa, Dübendorf,
CH-8600, Switzerland
| |
Collapse
|
4
|
Gladding TL, Rolph CA, Gwyther CL, Kinnersley R, Walsh K, Tyrrel S. Concentration and composition of bioaerosol emissions from intensive farms: Pig and poultry livestock. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2020; 272:111052. [PMID: 32669254 DOI: 10.1016/j.jenvman.2020.111052] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 06/29/2020] [Accepted: 07/03/2020] [Indexed: 06/11/2023]
Abstract
Intensive farming is widespread throughout the UK and yet the health effects of bioaerosols which may be generated by these sites are currently not well researched. A scoping study was established to measure bioaerosols emitted from intensive pig (n = 3) and poultry farms (n = 3) during the period 2014-2015. The concentration of culturable mesophilic bacteria, Gram-negative bacteria, Staphylococcus spp., and fungi selecting for presumptive Aspergillus fumigatus were measured using single-stage impaction Andersen samplers, whilst endotoxin and (1 → 3)-β-D-glucan was undertaken using inhalable personal samplers. Particulate matter concentration was determined using an optical particulate monitor. Results showed that culturable bacteria, fungi, presumptive Staphylococcus aureus (confirmed only as Staphylococcus spp.) and endotoxin concentrations were elevated above background concentrations for distances of up to 250 m downwind of the source. Of all the culturable bioaerosols measured, bacteria and Staphylococcus spp. were identified as the most significant, exceeding published or proposed bioaerosol guidelines in the UK. In particular, culturable Staphylococcus spp. downwind was at least 61 times higher than background at the boundary and at least 8 times higher 70m downwind on the four farms tested. This research represents a novel dataset of intensive farm emissions within the UK. Future research should exploit the use of innovative culture-independent methods such as next generation sequencing to develop deeper insights into the make-up of microbial communities emitted from intensive farming facilities and which would better inform species of interest from a public health perspective.
Collapse
Affiliation(s)
- T L Gladding
- The Open University, Walton Hall, Milton Keynes, MK7 6AA, UK.
| | - C A Rolph
- The Open University, Walton Hall, Milton Keynes, MK7 6AA, UK
| | - C L Gwyther
- The Open University, Walton Hall, Milton Keynes, MK7 6AA, UK
| | - R Kinnersley
- The Environment Agency, Horizon House, Deanery Road, Bristol, BS1 5AH, UK
| | - K Walsh
- The Environment Agency, Horizon House, Deanery Road, Bristol, BS1 5AH, UK
| | - S Tyrrel
- School of Water, Energy and Environment, Cranfield University, Bedfordshire, MK43 0AL, UK
| |
Collapse
|
5
|
Guinat C, Rouchy N, Camy F, Guérin JL, Paul MC. Exploring the Wind-Borne Spread of Highly Pathogenic Avian Influenza H5N8 During the 2016-2017 Epizootic in France. Avian Dis 2020; 63:246-248. [PMID: 31131582 DOI: 10.1637/11881-042718-resnote.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 09/18/2018] [Indexed: 11/05/2022]
Abstract
In winter 2016-2017, highly pathogenic avian influenza (HPAI) H5N8 virus spread in France, causing an unprecedented epizootic. During the epidemic, southwest France, where most outbreaks were reported, experienced severe weather, with three consecutive storms (Leiv, Kurt, and Marcel) from 3 to 5 February 2017. Although little information is available, one hypothesis is that the spread of HPAI-H5N8 from an infected poultry holding could have been passively facilitated by prevailing wind during the risk period. The aim of this study was therefore to assess the contribution of the wind-borne route to the spatial distribution of HPAI H5N8 outbreaks during the risk period at the beginning of February 2017. The PERLE model, an atmospheric dispersion model (ADM) developed by Météo-France, the French meteorological agency, was used to generate the predicted area at risk of infection from a suspected point source. Model outputs show that the spatial pattern of dust-particle deposition was directed east-southeast in accordance with wind direction. This contrasted with the spatial distribution of HPAI H5N8 outbreaks, which spread westward. These observations suggest that the wind-borne route alone was insufficient to explain the spatial distribution of outbreaks over large distances in southwest France at the beginning of February 2017. Finally, this study illustrates the relevance of close collaboration between governmental authorities, veterinary research institutes, and meteorological agencies involving interdisciplinary research for successful outbreak investigations.
Collapse
Affiliation(s)
- C Guinat
- IHAP, University of Toulouse, INRA, ENVT, Toulouse, France,
| | - N Rouchy
- Météo-France, DSM/EC, Toulouse, France
| | - F Camy
- Météo-France, DSM/EC, Toulouse, France
| | - J L Guérin
- IHAP, University of Toulouse, INRA, ENVT, Toulouse, France
| | - M C Paul
- IHAP, University of Toulouse, INRA, ENVT, Toulouse, France
| |
Collapse
|
6
|
De Rooij MMT, Van Leuken JPG, Swart A, Kretzschmar MEE, Nielen M, De Koeijer AA, Janse I, Wouters IM, Heederik DJJ. A systematic knowledge synthesis on the spatial dimensions of Q fever epidemics. Zoonoses Public Health 2018; 66:14-25. [PMID: 30402920 PMCID: PMC7379662 DOI: 10.1111/zph.12534] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Accepted: 10/08/2018] [Indexed: 01/07/2023]
Abstract
From 2007 through 2010, the Netherlands experienced the largest Q fever epidemic ever reported. This study integrates the outcomes of a multidisciplinary research programme on spatial airborne transmission of Coxiella burnetii and reflects these outcomes in relation to other scientific Q fever studies worldwide. We have identified lessons learned and remaining knowledge gaps. This synthesis was structured according to the four steps of quantitative microbial risk assessment (QMRA): (a) Rapid source identification was improved by newly developed techniques using mathematical disease modelling; (b) source characterization efforts improved knowledge but did not provide accurate C. burnetii emission patterns; (c) ambient air sampling, dispersion and spatial modelling promoted exposure assessment; and (d) risk characterization was enabled by applying refined dose–response analyses. The results may support proper and timely risk assessment and risk management during future outbreaks, provided that accurate and structured data are available and exchanged readily between responsible actors.
Collapse
Affiliation(s)
- Myrna M T De Rooij
- Institute for Risk Assessment Sciences (IRAS), Utrecht University, Utrecht, The Netherlands
| | - Jeroen P G Van Leuken
- Centre for Infectious Disease Control (CIb), National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | - Arno Swart
- Centre for Infectious Disease Control (CIb), National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | - Mirjam E E Kretzschmar
- Centre for Infectious Disease Control (CIb), National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands.,Julius Centre, University Medical Centre Utrecht (UMCU), Utrecht, The Netherlands
| | - Mirjam Nielen
- Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Aline A De Koeijer
- Central Veterinary Institute, Wageningen University and Research Centre, Lelystad, The Netherlands
| | - Ingmar Janse
- Centre for Infectious Disease Control (CIb), National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | - Inge M Wouters
- Institute for Risk Assessment Sciences (IRAS), Utrecht University, Utrecht, The Netherlands
| | - Dick J J Heederik
- Institute for Risk Assessment Sciences (IRAS), Utrecht University, Utrecht, The Netherlands
| |
Collapse
|
7
|
Plummer PJ, McClure JT, Menzies P, Morley PS, Van den Brom R, Van Metre DC. Management of Coxiella burnetii infection in livestock populations and the associated zoonotic risk: A consensus statement. J Vet Intern Med 2018; 32:1481-1494. [PMID: 30084178 PMCID: PMC6189356 DOI: 10.1111/jvim.15229] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 04/30/2018] [Accepted: 05/02/2018] [Indexed: 01/02/2023] Open
Abstract
Infections caused by Coxiella burnetii, commonly referred to as coxiellosis when occurring in animals and Query fever when occurring in humans, are an important cause of abortions, decreased reproductive efficiency, and subclinical infections in ruminants. The organism also represents an important zoonotic concern associated with its ability to aerosolize easily and its low infectious dose. Available diagnostic tests have limited sensitivity, which combined with the absence of treatment options in animals and limited approaches to prevention, result in difficulty managing this agent for optimal animal health and zoonotic disease outcomes. The purpose of this consensus statement is to provide veterinarians and public health officials with a summary of the available information regarding management of C. burnetii infection in livestock populations. A discussion of currently available testing options and their interpretation is provided, along with recommendations on management practices that can be implemented on‐farm in the face of an outbreak to mitigate losses. Emphasis is placed on biosecurity measures that can be considered for minimizing the zoonotic transmission risk in both field and veterinary facilities.
Collapse
Affiliation(s)
- Paul J Plummer
- Department of Veterinary Diagnostic and Production Animal Medicine and the Department of Veterinary Microbiology and Preventative Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa
| | - J Trenton McClure
- Dpeartment of Health Management, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward, Canada
| | - Paula Menzies
- Department Population Medicine, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada
| | - Paul S Morley
- Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado.,Colorado School of Public Health, Fort Collins, Colorado
| | | | - David C Van Metre
- Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado
| |
Collapse
|
8
|
Heppell CW, Egan JR, Hall I. A human time dose response model for Q fever. Epidemics 2017; 21:30-38. [PMID: 28666604 PMCID: PMC5729200 DOI: 10.1016/j.epidem.2017.06.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 05/30/2017] [Accepted: 06/07/2017] [Indexed: 12/16/2022] Open
Abstract
The causative agent of Q fever, Coxiella burnetii, has the potential to be developed for use in biological warfare and it is classified as a bioterrorism threat agent by the Centers for Disease Control and Prevention (CDC) and as a category B select agent by the National Institute of Allergy and Infectious Diseases (NIAID). In this paper we focus on the in-host properties that arise when an individual inhales a dose of C. burnetii and establish a human time-dose response model. We also propagate uncertainty throughout the model allowing us to robustly estimate key properties including the infectious dose and incubation period. Using human study data conducted in the 1950's we conclude that the dose required for a 50% probability of infection is about 15 organisms, and that one inhaled organism of C. burnetti can cause infection in 5% of the exposed population. In addition, we derive a low dose incubation period of 17.6 days and an extracellular doubling time of half a day. In conclusion this paper provides a framework for detailing the parameters and approaches that would be required for risk assessments associated with exposures to C. burnetii that might cause human infection.
Collapse
Affiliation(s)
| | - Joseph R Egan
- University of Southampton, Hampshire SO17 1BJ, United Kingdom.
| | - Ian Hall
- Public Health England, Porton, Wiltshire SP4 0JG, United Kingdom.
| |
Collapse
|
9
|
Pandit P, Hoch T, Ezanno P, Beaudeau F, Vergu E. Spread of Coxiella burnetii between dairy cattle herds in an enzootic region: modelling contributions of airborne transmission and trade. Vet Res 2016; 47:48. [PMID: 27048416 PMCID: PMC4822316 DOI: 10.1186/s13567-016-0330-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 02/04/2016] [Indexed: 11/10/2022] Open
Abstract
Q fever, a worldwide zoonotic disease caused by Coxiella burnetii, is a looming concern for livestock and public health. Epidemiological features of inter-herd transmission of C. burnetii in cattle herds by wind and trade of cows are poorly understood. We present a novel dynamic spatial model describing the inter-herd regional spread of C. burnetii in dairy cattle herds, quantifying the ability of airborne transmission and animal trade in C. burnetii propagation in an enzootic region. Among all the new herd infections, 92% were attributed to airborne transmission and the rest to cattle trade. Infections acquired following airborne transmission were shown to cause relatively small and ephemeral intra-herd outbreaks. On the contrary, disease-free herds purchasing an infectious cow experienced significantly higher intra-herd prevalence. The results also indicated that, for short duration, both transmission routes were independent from each other without any synergistic effect. The model outputs applied to the Finistère department in western France showed satisfactory sensitivity (0.71) and specificity (0.80) in predicting herd infection statuses at the end of one year in a neighbourhood of 3 km around expected incident herds, when compared with data. The model developed here thus provides important insights into the spread of C. burnetii between dairy cattle herds and paves the way for implementation and assessment of control strategies.
Collapse
Affiliation(s)
- Pranav Pandit
- INRA, LUNAM Université, Oniris, UMR1300 BioEpAR, CS40706, 44307, Nantes, France.
| | - Thierry Hoch
- INRA, LUNAM Université, Oniris, UMR1300 BioEpAR, CS40706, 44307, Nantes, France
| | - Pauline Ezanno
- INRA, LUNAM Université, Oniris, UMR1300 BioEpAR, CS40706, 44307, Nantes, France
| | - François Beaudeau
- INRA, LUNAM Université, Oniris, UMR1300 BioEpAR, CS40706, 44307, Nantes, France
| | - Elisabeta Vergu
- MaIAGE, INRA, Université Paris-Saclay, 78350, Jouy-en-Josas, France
| |
Collapse
|
10
|
Smith CM, Le Comber SC, Fry H, Bull M, Leach S, Hayward AC. Spatial methods for infectious disease outbreak investigations: systematic literature review. ACTA ACUST UNITED AC 2016; 20:30026. [PMID: 26536896 DOI: 10.2807/1560-7917.es.2015.20.39.30026] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Accepted: 09/02/2015] [Indexed: 12/28/2022]
Abstract
Investigations of infectious disease outbreaks are conventionally framed in terms of person, time and place. Although geographic information systems have increased the range of tools available, spatial analyses are used relatively infrequently. We conducted a systematic review of published reports of outbreak investigations worldwide to estimate the prevalence of spatial methods, describe the techniques applied and explore their utility. We identified 80 reports using spatial methods published between 1979 and 2013, ca 0.4% of the total number of published outbreaks. Environmental or waterborne infections were the most commonly investigated, and most reports were from the United Kingdom. A range of techniques were used, including simple dot maps, cluster analyses and modelling approaches. Spatial tools were usefully applied throughout investigations, from initial confirmation of the outbreak to describing and analysing cases and communicating findings. They provided valuable insights that led to public health actions, but there is scope for much wider implementation and development of new methods.
Collapse
Affiliation(s)
- Catherine M Smith
- UCL Department of Infectious Disease Informatics, Farr Institute of Health Informatics Research, University College London, London, United Kingdom
| | | | | | | | | | | |
Collapse
|
11
|
Egan JR, Hall IM. A review of back-calculation techniques and their potential to inform mitigation strategies with application to non-transmissible acute infectious diseases. J R Soc Interface 2016; 12. [PMID: 25977955 DOI: 10.1098/rsif.2015.0096] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Back-calculation is a process whereby generally unobservable features of an event leading to a disease outbreak can be inferred either in real-time or shortly after the end of the outbreak. These features might include the time when persons were exposed and the source of the outbreak. Such inferences are important as they can help to guide the targeting of mitigation strategies and to evaluate the potential effectiveness of such strategies. This article reviews the process of back-calculation with a particular emphasis on more recent applications concerning deliberate and naturally occurring aerosolized releases. The techniques can be broadly split into two themes: the simpler temporal models and the more sophisticated spatio-temporal models. The former require input data in the form of cases' symptom onset times, whereas the latter require additional spatial information such as the cases' home and work locations. A key aspect in the back-calculation process is the incubation period distribution, which forms the initial topic for consideration. Links between atmospheric dispersion modelling, within-host dynamics and back-calculation are outlined in detail. An example of how back-calculation can inform mitigation strategies completes the review by providing improved estimates of the duration of antibiotic prophylaxis that would be required in the response to an inhalational anthrax outbreak.
Collapse
|
12
|
Van Leuken J, Swart A, Havelaar A, Van Pul A, Van der Hoek W, Heederik D. Atmospheric dispersion modelling of bioaerosols that are pathogenic to humans and livestock - A review to inform risk assessment studies. MICROBIAL RISK ANALYSIS 2016; 1:19-39. [PMID: 32289056 PMCID: PMC7104230 DOI: 10.1016/j.mran.2015.07.002] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Revised: 06/25/2015] [Accepted: 07/17/2015] [Indexed: 05/21/2023]
Abstract
In this review we discuss studies that applied atmospheric dispersion models (ADM) to bioaerosols that are pathogenic to humans and livestock in the context of risk assessment studies. Traditionally, ADMs have been developed to describe the atmospheric transport of chemical pollutants, radioactive matter, dust, and particulate matter. However, they have also enabled researchers to simulate bioaerosol dispersion. To inform risk assessment, the aims of this review were fourfold, namely (1) to describe the most important physical processes related to ADMs and pathogen transport, (2) to discuss studies that focused on the application of ADMs to pathogenic bioaerosols, (3) to discuss emission and inactivation rate parameterisations, and (4) to discuss methods for conversion of concentrations to infection probabilities (concerning quantitative microbial risk assessment). The studies included human, livestock, and industrial sources. Important factors for dispersion included wind speed, atmospheric stability, topographic effects, and deposition. Inactivation was mainly governed by humidity, temperature, and ultraviolet radiation. A majority of the reviewed studies, however, lacked quantitative analyses and application of full quantitative microbial risk assessments (QMRA). Qualitative conclusions based on geographical dispersion maps and threshold doses were encountered frequently. Thus, to improve risk assessment for future outbreaks and releases, we recommended determining well-quantified emission and inactivation rates and applying dosimetry and dose-response models to estimate infection probabilities in the population at risk.
Collapse
Affiliation(s)
- J.P.G. Van Leuken
- Centre for Infectious Disease Control (CIb), National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
- Institute for Risk Assessment Sciences (IRAS), Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
- Corresponding author: Centre for Infectious Disease Control, National Institute for Public Health and the Environment, P.O. Box 1, 3720 BA Bilthoven, The Netherlands. Tel.: +31 30 274 2003.
| | - A.N. Swart
- Centre for Infectious Disease Control (CIb), National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | - A.H. Havelaar
- Centre for Infectious Disease Control (CIb), National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
- Institute for Risk Assessment Sciences (IRAS), Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
- Emerging Pathogens Institute and Animal Sciences Department, University of Florida, Gainesville, FL, United States of America
| | - A. Van Pul
- Environment & Safety (M&V), National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | - W. Van der Hoek
- Centre for Infectious Disease Control (CIb), National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | - D. Heederik
- Institute for Risk Assessment Sciences (IRAS), Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| |
Collapse
|
13
|
Nusinovici S, Hoch T, Brahim ML, Joly A, Beaudeau F. The Effect of Wind onCoxiella burnetiiTransmission Between Cattle Herds: a Mechanistic Approach. Transbound Emerg Dis 2015; 64:585-592. [DOI: 10.1111/tbed.12423] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Indexed: 11/28/2022]
Affiliation(s)
- S. Nusinovici
- INRA; UMR1300 Biology, Epidemiology and Risk Analysis (BioEpAR); Nantes France
- LUNAM Université; Oniris; UMR BioEpAR; Nantes France
| | - T. Hoch
- INRA; UMR1300 Biology, Epidemiology and Risk Analysis (BioEpAR); Nantes France
- LUNAM Université; Oniris; UMR BioEpAR; Nantes France
| | - M. L. Brahim
- INRA; UMR1300 Biology, Epidemiology and Risk Analysis (BioEpAR); Nantes France
- LUNAM Université; Oniris; UMR BioEpAR; Nantes France
| | - A. Joly
- GDS Bretagne; Vannes Cedex France
| | - F. Beaudeau
- INRA; UMR1300 Biology, Epidemiology and Risk Analysis (BioEpAR); Nantes France
- LUNAM Université; Oniris; UMR BioEpAR; Nantes France
| |
Collapse
|
14
|
Ladbury GAF, Van Leuken JPG, Swart A, Vellema P, Schimmer B, Ter Schegget R, Van der Hoek W. Integrating interdisciplinary methodologies for One Health: goat farm re-implicated as the probable source of an urban Q fever outbreak, the Netherlands, 2009. BMC Infect Dis 2015; 15:372. [PMID: 26336097 PMCID: PMC4558730 DOI: 10.1186/s12879-015-1083-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Accepted: 08/04/2015] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND In spring 2008, a goat farm experiencing Q fever abortions ("Farm A") was identified as the probable source of a human Q fever outbreak in a Dutch town. In 2009, a larger outbreak with 347 cases occurred in the town, despite no clinical Q fever being reported from any local farm. METHODS Our study aimed to identify the source of the 2009 outbreak by applying a combination of interdisciplinary methods, using data from several sources and sectors, to investigate seventeen farms in the area: namely, descriptive epidemiology of notified cases; collation of veterinary data regarding the seventeen farms; spatial attack rate and relative risk analyses; and GIS mapping of farms and smooth incidence of cases. We conducted further spatio-temporal analyses that integrated temporal data regarding date of onset with spatial data from an atmospheric dispersion model with the most highly suspected source at the centre. RESULTS Our analyses indicated that Farm A was again the most likely source of infection, with persons living within 1 km of the farm at a 46 times larger risk of being a case compared to those living within 5-10 km. The spatio-temporal analyses demonstrated that about 60 - 65 % of the cases could be explained by aerosol transmission from Farm A assuming emission from week 9; these explained cases lived significantly closer to the farm than the unexplained cases (p = 0.004). A visit to Farm A revealed that there had been no particular changes in management during the spring/summer of 2009, nor any animal health problems around the time of parturition or at any other time during the year. CONCLUSIONS We conclude that the probable source of the 2009 outbreak was the same farm implicated in 2008, despite animal health indicators being absent. Veterinary and public health professionals should consider farms with past as well as current history of Q fever as potential sources of human outbreaks.
Collapse
Affiliation(s)
- Georgia A F Ladbury
- Centre for Infectious Disease Control, National Institute for Public Health and the Environment (RIVM), PO Box 1, , 3720 BA, Bilthoven, The Netherlands.
- European Programme for Intervention Epidemiology Training (EPIET), European Centre for Disease Prevention and Control, Tomtebodavägen 11a, 171 83, Stockholm, Sweden.
| | - Jeroen P G Van Leuken
- Centre for Infectious Disease Control, National Institute for Public Health and the Environment (RIVM), PO Box 1, , 3720 BA, Bilthoven, The Netherlands.
- Institute for Risk Assessment Sciences (IRAS), Utrecht University, Domplein 29, 3512 JE, Utrecht, The Netherlands.
| | - Arno Swart
- Centre for Infectious Disease Control, National Institute for Public Health and the Environment (RIVM), PO Box 1, , 3720 BA, Bilthoven, The Netherlands.
| | - Piet Vellema
- Department of Small Ruminant Health, Animal Health Service (GD), Arnsbergstraat 7, 7418 EZ, Deventer, The Netherlands.
| | - Barbara Schimmer
- Centre for Infectious Disease Control, National Institute for Public Health and the Environment (RIVM), PO Box 1, , 3720 BA, Bilthoven, The Netherlands.
| | - Ronald Ter Schegget
- Municipal Health Service Brabant-Zuidoost, Clausplein 10, 5611 XP, Eindhoven, The Netherlands.
| | - Wim Van der Hoek
- Centre for Infectious Disease Control, National Institute for Public Health and the Environment (RIVM), PO Box 1, , 3720 BA, Bilthoven, The Netherlands.
| |
Collapse
|
15
|
Serological survey using ELISA to determine the prevalence of Coxiella burnetii infection (Q fever) in sheep and goats in Great Britain. Epidemiol Infect 2015; 144:19-24. [DOI: 10.1017/s0950268815000874] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
SUMMARYA survey of Coxiella burnetii infection (Q fever) in sheep flocks and goat herds in Great Britain was undertaken. A total of 5791 sheep (384 flocks) and 522 goats (145 herds) were examined for C. burnetii antibodies using an ELISA. Overall, 53 sheep (37 flocks), and four goats (four herds), tested positive. Estimates of individual animal, between-flock/-herd and within-flock/-herd crude prevalences were 0·9%, 10·2% and 9·0%, respectively, for sheep, and 0·8%, 3% and 26·3%, respectively, for goats. With sheep, the likelihood of an animal testing positive increased with total flock size (P = 0·002) and number of breeding ewes in the flock (P = 0·021). It also increased with number of goats within a 10 km radius (P = 0·038). There was no evidence for spatial clustering of positive herds above that expected by chance alone. No analysis of risk factors was attempted for goats because of the paucity of positives.
Collapse
|
16
|
Jonges M, van Leuken J, Wouters I, Koch G, Meijer A, Koopmans M. Wind-Mediated Spread of Low-Pathogenic Avian Influenza Virus into the Environment during Outbreaks at Commercial Poultry Farms. PLoS One 2015; 10:e0125401. [PMID: 25946115 PMCID: PMC4422664 DOI: 10.1371/journal.pone.0125401] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 03/23/2015] [Indexed: 02/06/2023] Open
Abstract
Avian influenza virus-infected poultry can release a large amount of virus-contaminated droppings that serve as sources of infection for susceptible birds. Much research so far has focused on virus spread within flocks. However, as fecal material or manure is a major constituent of airborne poultry dust, virus-contaminated particulate matter from infected flocks may be dispersed into the environment. We collected samples of suspended particulate matter, or the inhalable dust fraction, inside, upwind and downwind of buildings holding poultry infected with low-pathogenic avian influenza virus, and tested them for the presence of endotoxins and influenza virus to characterize the potential impact of airborne influenza virus transmission during outbreaks at commercial poultry farms. Influenza viruses were detected by RT-PCR in filter-rinse fluids collected up to 60 meters downwind from the barns, but virus isolation did not yield any isolates. Viral loads in the air samples were low and beyond the limit of RT-PCR quantification except for one in-barn measurement showing a virus concentration of 8.48 x 10(4) genome copies/m(3). Air samples taken outside poultry barns had endotoxin concentrations of ~50 EU/m(3) that declined with increasing distance from the barn. Atmospheric dispersion modeling of particulate matter, using location-specific meteorological data for the sampling days, demonstrated a positive correlation between endotoxin measurements and modeled particulate matter concentrations, with an R(2) varying from 0.59 to 0.88. Our data suggest that areas at high risk for human or animal exposure to airborne influenza viruses can be modeled during an outbreak to allow directed interventions following targeted surveillance.
Collapse
Affiliation(s)
- Marcel Jonges
- Centre for Infectious Disease Control, National Institute for Public Health and the Environment, Bilthoven, The Netherlands
- Department of Viroscience, Erasmus MC, Rotterdam, The Netherlands
| | - Jeroen van Leuken
- Centre for Infectious Disease Control, National Institute for Public Health and the Environment, Bilthoven, The Netherlands
- Institute for Risk Assessment Sciences, Faculty of Veterinary Sciences, Utrecht University, Utrecht, The Netherlands
| | - Inge Wouters
- Institute for Risk Assessment Sciences, Faculty of Veterinary Sciences, Utrecht University, Utrecht, The Netherlands
| | - Guus Koch
- Central Veterinary Institute, Wageningen University & Research Center, Lelystad, The Netherlands
| | - Adam Meijer
- Centre for Infectious Disease Control, National Institute for Public Health and the Environment, Bilthoven, The Netherlands
| | - Marion Koopmans
- Centre for Infectious Disease Control, National Institute for Public Health and the Environment, Bilthoven, The Netherlands
- Department of Viroscience, Erasmus MC, Rotterdam, The Netherlands
| |
Collapse
|
17
|
van Leuken JPG, van de Kassteele J, Sauter FJ, van der Hoek W, Heederik D, Havelaar AH, Swart AN. Improved correlation of human Q fever incidence to modelled C. burnetii concentrations by means of an atmospheric dispersion model. Int J Health Geogr 2015; 14:14. [PMID: 25888858 PMCID: PMC4440286 DOI: 10.1186/s12942-015-0003-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 02/09/2015] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Atmospheric dispersion models (ADMs) may help to assess human exposure to airborne pathogens. However, there is as yet limited quantified evidence that modelled concentrations are indeed associated to observed human incidence. METHODS We correlated human Q fever (caused by the bacterium Coxiella burnetii) incidence data in the Netherlands to modelled concentrations from three spatial exposure models: 1) a NULL model with a uniform concentration distribution, 2) a DISTANCE model with concentrations proportional to the distance between the source and residential addresses of patients, and 3) concentrations modelled by an ADM using three simple emission profiles. We used a generalized linear model to correlate the observed incidences to modelled concentrations and validated it using cross-validation. RESULTS ADM concentrations generally correlated the best to the incidence data. The DISTANCE model always performed significantly better than the NULL model. ADM concentrations based on wind speeds exceeding threshold values of 0 and 2 m/s performed better than those based on 4 or 6 m/s. This might indicate additional exposure to bacteria originating from a contaminated environment. CONCLUSIONS By adding meteorological information the correlation between modelled concentration and observed incidence improved, despite using three simple emission profiles. Although additional information is needed - especially regarding emission data - these results provide a basis for the use of ADMs to predict and to visualize the spread of airborne pathogens during livestock, industry and even bio-terroristic related outbreaks or releases to a surrounding human population.
Collapse
Affiliation(s)
- Jeroen P G van Leuken
- Institute for Risk Assessment Sciences (IRAS), Faculty of Veterinary Medicine, Utrecht University, P.O. Box 80163, 3508, TD, Utrecht, The Netherlands.
- Centre for Infectious Disease Control (CIb), National Institute for Public Health and the Environment (RIVM), P.O. Box 1, 3720, BA, Bilthoven, The Netherlands.
| | - Jan van de Kassteele
- Centre for Infectious Disease Control (CIb), National Institute for Public Health and the Environment (RIVM), P.O. Box 1, 3720, BA, Bilthoven, The Netherlands.
| | - Ferd J Sauter
- Environmental Safety (M&V), National Institute for Public Health and the Environment (RIVM), P.O. Box 1, 3720, BA, Bilthoven, The Netherlands.
| | - Wim van der Hoek
- Centre for Infectious Disease Control (CIb), National Institute for Public Health and the Environment (RIVM), P.O. Box 1, 3720, BA, Bilthoven, The Netherlands.
| | - Dick Heederik
- Institute for Risk Assessment Sciences (IRAS), Faculty of Veterinary Medicine, Utrecht University, P.O. Box 80163, 3508, TD, Utrecht, The Netherlands.
| | - Arie H Havelaar
- Institute for Risk Assessment Sciences (IRAS), Faculty of Veterinary Medicine, Utrecht University, P.O. Box 80163, 3508, TD, Utrecht, The Netherlands.
- Centre for Infectious Disease Control (CIb), National Institute for Public Health and the Environment (RIVM), P.O. Box 1, 3720, BA, Bilthoven, The Netherlands.
- Emerging Pathogens Institute, University of Floriday, Gainesville, Florida, USA.
| | - Arno N Swart
- Centre for Infectious Disease Control (CIb), National Institute for Public Health and the Environment (RIVM), P.O. Box 1, 3720, BA, Bilthoven, The Netherlands.
| |
Collapse
|
18
|
Detection of Coxiella burnetii by PCR in bulk tank milk samples from dairy caprine herds in southeast of Iran. ASIAN PACIFIC JOURNAL OF TROPICAL DISEASE 2015. [DOI: 10.1016/s2222-1808(14)60638-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
19
|
Ezatkhah M, Alimolaei M, Khalili M, Sharifi H. Seroepidemiological study of Q fever in small ruminants from Southeast Iran. J Infect Public Health 2014; 8:170-6. [PMID: 25270385 DOI: 10.1016/j.jiph.2014.08.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2014] [Revised: 07/23/2014] [Accepted: 08/24/2014] [Indexed: 10/24/2022] Open
Abstract
The aim of the present study was to determine the prevalence of Coxiella burnetii antibodies in small ruminants in Southeast Iran. A total of 368 small ruminant blood samples (241 caprine blood samples and 127 ovine blood samples) were collected from January to May of 2011 in Southeast Iran. A commercial ELISA test kit was employed to identify specific antibodies against C. burnetii in the sheep and goats. Seropositivity in the examined counties ranged from 17.1% to 39.2%. Of the animals tested, 97 animals (26.4%), including 43 sheep (33.9%) and 54 goats (22.4%), had antibodies to C. burnetii. The results of the current study reveal the high prevalence of antibody positivity in small ruminants in Southeast Iran. Thus, sheep and goats are important reservoirs in this area. Additionally, we performed a logistic regression to the identify risk factors for positivity and concluded that age was an important risk factor (P<0.001).
Collapse
Affiliation(s)
- Majid Ezatkhah
- Razi Vaccine and Serum Research Institute, Kerman Branch, Kerman, Iran
| | - Mojtaba Alimolaei
- Razi Vaccine and Serum Research Institute, Kerman Branch, Kerman, Iran; Department of Pathobiology, Faculty of Veterinary Medicine, Shahid Bahonar University of Kerman, Kerman, Iran.
| | - Mohammad Khalili
- Department of Pathobiology, Faculty of Veterinary Medicine, Shahid Bahonar University of Kerman, Kerman, Iran; Research Center of Tropical and Infectious Disease, Kerman University of Medical Sciences, Kerman, Iran
| | - Hamid Sharifi
- Department of Food Hygiene and Public Health, Faculty of Veterinary Medicine, Shahid Bahonar University of Kerman, Iran; Research Center for Modeling in Health, Institute for Futures Studies in Health, Kerman University of Medical Sciences, Kerman, Iran
| |
Collapse
|
20
|
Khalili M, Mosavi M, Diali HG, Mirza HN. Serologic survey for Coxiella burnetii phase II antibodies among slaughterhouse workers in Kerman, southeast of Iran. Asian Pac J Trop Biomed 2014; 4:S209-12. [PMID: 25183082 DOI: 10.12980/apjtb.4.2014c1268] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2014] [Accepted: 03/03/2014] [Indexed: 10/25/2022] Open
Abstract
OBJECTIVE To determine the presence of antibodies against phase II among slaughterhouse workers in Kerman, southeast of Iran. METHODS The antibody titers of the serum samples were measured by enzyme-linked immuno sorbent assay using phase II Coxiella burnetii as the antigen [kit (Virion\Serion, Wurzburg, Germany) according to the manufacturer's protocol]. RESULTS The positive rate of IgG antibody was 68% in the slaughterhouse workers. CONCLUSIONS Our findings suggest that slaughterhouse workers in Kerman area have a higher risk of infection and should consider potential infection with Coxiella burnetii.
Collapse
Affiliation(s)
- Mohammad Khalili
- Department of Pathobiology, School of Veterinary Medicine, Shahid Bahonar University of Kerman, Kerman, Iran
| | - Morteza Mosavi
- School of Veterinary Medicine, Shahid Bahonar University of Kerman, Kerman, Iran
| | | | | |
Collapse
|
21
|
Bellini C, Magouras I, Chapuis-Taillard C, Clerc O, Masserey E, Peduto G, Péter O, Schaerrer S, Schuepbach G, Greub G. Q fever outbreak in the terraced vineyards of Lavaux, Switzerland. New Microbes New Infect 2014; 2:93-9. [PMID: 25356353 PMCID: PMC4184577 DOI: 10.1002/nmi2.37] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2013] [Revised: 01/06/2014] [Accepted: 01/14/2014] [Indexed: 11/06/2022] Open
Abstract
Coxiella burnetii infection (Q fever) is a widespread zoonosis with low endemicity in Switzerland, therefore no mandatory public report was required. A cluster of initially ten human cases of acute Q fever infections characterized by prolonged fever, asthenia and mild hepatitis occurred in 2012 in the terraced vineyard of Lavaux. Epidemiological investigations based on patients' interviews and veterinary investigations included environmental sampling as well as Coxiella-specific serological assay and molecular examinations (real-time PCR in vaginal secretions) of suspected sheep. These investigations demonstrated that 43% of sheep carried the bacteria whereas 30% exhibited anti-Coxiella antibodies. Mitigation measures, including limiting human contacts with the flock, hygiene measures, flock vaccination and a public official alert, have permitted the detection of four additional human cases and the avoidance of a much larger outbreak. Since November 2012, mandatory reporting of Q fever to Swiss public health authorities has been reintroduced. A close follow up of human cases will be necessary to identify chronic Q fever.
Collapse
Affiliation(s)
- C Bellini
- Service of Infectious Diseases, Riviera Regional Hospital Vevey, Switzerland
| | - I Magouras
- Veterinary Public Health Institute, Vetsuisse faculty, University of Bern Bern, Switzerland
| | - C Chapuis-Taillard
- Service of Infectious Diseases, Medical Centre of Vidy Lausanne, Switzerland
| | - O Clerc
- Service of Infectious Diseases, Centre Hospitalier Universitaire Vaudois and University of Lausanne Lausanne, Switzerland
| | - E Masserey
- Service of Public Health, Canton of Vaud Lausanne, Switzerland
| | - G Peduto
- Service of Consumption and Veterinary Affairs, Canton of Vaud Lausanne, Switzerland
| | - O Péter
- Service of Infectious Diseases, Central Institute of Valais Sion, Switzerland
| | - S Schaerrer
- Institute of Veterinary Bacteriology, Vetsuisse faculty, University of Zurich Zurich, Switzerland
| | - G Schuepbach
- Veterinary Public Health Institute, Vetsuisse faculty, University of Bern Bern, Switzerland
| | - G Greub
- Service of Infectious Diseases, Centre Hospitalier Universitaire Vaudois and University of Lausanne Lausanne, Switzerland ; Institute of Microbiology, Centre Hospitalier Universitaire Vaudois and University of Lausanne Lausanne, Switzerland
| |
Collapse
|
22
|
Bellini C, Magouras I, Chapuis-Taillard C, Clerc O, Masserey E, Peduto G, Péter O, Schaerrer S, Schuepbach G, Greub G. Q fever outbreak in the terraced vineyards of Lavaux, Switzerland. New Microbes New Infect 2014. [DOI: 10.1002/2052-2975.37] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- C. Bellini
- Service of Infectious Diseases; Riviera Regional Hospital; Vevey Switzerland
| | - I. Magouras
- Veterinary Public Health Institute; Vetsuisse faculty; University of Bern; Bern Switzerland
| | - C. Chapuis-Taillard
- Service of Infectious Diseases; Medical Centre of Vidy; Lausanne Switzerland
| | - O. Clerc
- Service of Infectious Diseases; Centre Hospitalier Universitaire Vaudois and University of Lausanne; Lausanne Switzerland
| | - E. Masserey
- Service of Public Health; Canton of Vaud; Lausanne Switzerland
| | - G. Peduto
- Service of Consumption and Veterinary Affairs; Canton of Vaud; Lausanne Switzerland
| | - O. Péter
- Service of Infectious Diseases; Central Institute of Valais; Sion Switzerland
| | - S. Schaerrer
- Institute of Veterinary Bacteriology; Vetsuisse faculty; University of Zurich; Zurich Switzerland
| | - G. Schuepbach
- Veterinary Public Health Institute; Vetsuisse faculty; University of Bern; Bern Switzerland
| | - G. Greub
- Service of Infectious Diseases; Centre Hospitalier Universitaire Vaudois and University of Lausanne; Lausanne Switzerland
- Institute of Microbiology; Centre Hospitalier Universitaire Vaudois and University of Lausanne; Lausanne Switzerland
| |
Collapse
|
23
|
Bjork A, Marsden-Haug N, Nett RJ, Kersh GJ, Nicholson W, Gibson D, Szymanski T, Emery M, Kohrs P, Woodhall D, Anderson AD. First Reported Multistate Human Q Fever Outbreak in the United States, 2011. Vector Borne Zoonotic Dis 2014; 14:111-7. [DOI: 10.1089/vbz.2012.1202] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Adam Bjork
- Rickettsial Zoonoses Branch, Division of Vector-Borne Diseases, Centers for Disease Control and Prevention (CDC), Atlanta, Georgia
- Epidemic Intelligence Service, CDC, Atlanta, Georgia
- Present address: Division of Global HIV/AIDS, Center for Global Health; CDC, Atlanta, Georgia
| | | | - Randall J. Nett
- Career Epidemiology Field Officer Program, Office of Public Health and Preparedness, CDC, Atlanta, Georgia
- Public Health and Safety Division, Montana Department of Public Health and Human Services, Helena, Montana
| | - Gilbert J. Kersh
- Rickettsial Zoonoses Branch, Division of Vector-Borne Diseases, Centers for Disease Control and Prevention (CDC), Atlanta, Georgia
| | - William Nicholson
- Rickettsial Zoonoses Branch, Division of Vector-Borne Diseases, Centers for Disease Control and Prevention (CDC), Atlanta, Georgia
| | - Deborah Gibson
- Public Health Laboratory, Montana Department of Public Health and Human Services, Helena, Montana
| | | | - Michelle Emery
- United States Department of Agriculture, National Veterinary Services Laboratories, Ames, Iowa
| | - Paul Kohrs
- Washington State Department of Agriculture, Olympia, Washington
| | - Dana Woodhall
- Parastitic Diseases Branch, Division of Parasitic Diseases and Malaria, CDC, Atlanta, Georgia
- Epidemic Intelligence Service, CDC, Atlanta, Georgia
| | - Alicia D. Anderson
- Rickettsial Zoonoses Branch, Division of Vector-Borne Diseases, Centers for Disease Control and Prevention (CDC), Atlanta, Georgia
| |
Collapse
|
24
|
Meredith AL, Cleaveland SC, Denwood MJ, Brown JK, Shaw DJ. Coxiella burnetii (Q-Fever) Seroprevalence in Prey and Predators in the United Kingdom: Evaluation of Infection in Wild Rodents, Foxes and Domestic Cats Using a Modified ELISA. Transbound Emerg Dis 2014; 62:639-49. [PMID: 24479951 DOI: 10.1111/tbed.12211] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Indexed: 11/30/2022]
Abstract
Coxiella burnetii, the agent of Q-fever, is recognized as a worldwide zoonosis with a wide host range and potentially complex reservoir systems. Infected ruminants are the main source of infection for humans, but cats and other mammals, including wild rodents, also represent potential sources of infection. There has been a recent upsurge of reported cases in humans, domestic ruminants and wildlife in many parts of the world, and studies have indicated that wild brown rats may act as true reservoirs for C. burnetii and be implicated in outbreaks in livestock and humans. However, investigation of reservoir systems is limited by lack of validated serological tests for wildlife or other non-target species. In this study, serum samples from 796 wild rodents (180 bank voles, 309 field voles, 307 wood mice) 102 wild foxes and 26 domestic cats from three study areas in the UK were tested for the presence of antibodies to C. burnetii using a commercial indirect ELISA kit modified for use in multiple wildlife species. Test thresholds were determined for each species in the absence of species-specific reference sera using a bi-modal latent class mixture model to discriminate between positive from negative results. Based on the thresholds determined, seroprevalence in the wild rodents ranged from 15.6% to 19.1% depending on species (overall 17.3%) and was significantly higher in both foxes (41.2%) and cats (61.5%) than in rodents. This is the first report to quantify seroprevalence to C. burnetii in bank voles, field voles, wood mice, foxes and cats in the UK and provides evidence that predator species could act as indicators for the presence of C. burnetii in rodents. The study demonstrates that wildlife species could be significant reservoirs of infection for both livestock and humans, and the high seroprevalence in domestic cats highlights the potential zoonotic risk from this species.
Collapse
Affiliation(s)
- A L Meredith
- Royal (Dick) School of Veterinary Studies & The Roslin Institute, University of Edinburgh, Roslin, UK
| | - S C Cleaveland
- Institute of Biodiversity Animal Health and Comparative Medicine, College of Veterinary Medical and Life Sciences, University of Glasgow, Glasgow, UK
| | - M J Denwood
- School of Veterinary Medicine, College of Veterinary Medical and Life Sciences, University of Glasgow, Glasgow, UK
| | - J K Brown
- MRC Centre for Reproductive Health, The Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - D J Shaw
- Royal (Dick) School of Veterinary Studies & The Roslin Institute, University of Edinburgh, Roslin, UK
| |
Collapse
|
25
|
van Leuken JPG, Havelaar AH, van der Hoek W, Ladbury GAF, Hackert VH, Swart AN. A model for the early identification of sources of airborne pathogens in an outdoor environment. PLoS One 2013; 8:e80412. [PMID: 24324598 PMCID: PMC3850919 DOI: 10.1371/journal.pone.0080412] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Accepted: 10/03/2013] [Indexed: 11/19/2022] Open
Abstract
Background Source identification in areas with outbreaks of airborne pathogens is often time-consuming and expensive. We developed a model to identify the most likely location of sources of airborne pathogens. Methods As a case study, we retrospectively analyzed three Q fever outbreaks in the Netherlands in 2009, each with suspected exposure from a single large dairy goat farm. Model input consisted only of case residential addresses, day of first clinical symptoms, and human population density data. We defined a spatial grid and fitted an exponentially declining function to the incidence-distance data of each grid point. For any grid point with a fit significant at the 95% confidence level, we calculated a measure of risk. For validation, we used results from abortion notifications, voluntary (2008) and mandatory (2009) bulk tank milk sampling at large (i.e. >50 goats and/or sheep) dairy farms, and non-systematic vaginal swab sampling at large and small dairy and non-dairy goat/sheep farms. In addition, we performed a two-source simulation study. Results Hotspots – areas most likely to contain the actual source – were identified at early outbreak stages, based on the earliest 2–10% of the case notifications. Distances between the hotspots and suspected goat farms varied from 300–1500 m. In regional likelihood rankings including all large dairy farms, the suspected goat farms consistently ranked first. The two-source simulation study showed that detection of sources is most clear if the distance between the sources is either relatively small or relatively large. Conclusions Our model identifies the most likely location of sources in an airborne pathogen outbreak area, even at early stages. It can help to reduce the number of potential sources to be investigated by microbial testing and to allow rapid implementation of interventions to limit the number of human infections and to reduce the risk of source-to-source transmission.
Collapse
Affiliation(s)
- Jeroen P. G. van Leuken
- Institute for Risk Assessment Sciences (IRAS), Utrecht University, Utrecht, The Netherlands
- Centre for Infectious Disease Control (CIb), National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
- * E-mail:
| | - Arie H. Havelaar
- Institute for Risk Assessment Sciences (IRAS), Utrecht University, Utrecht, The Netherlands
- Centre for Infectious Disease Control (CIb), National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | - Wim van der Hoek
- Centre for Infectious Disease Control (CIb), National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | | | - Volker H. Hackert
- Municipal Health Service Zuid-Limburg, Sittard-Geleen, The Netherlands
| | - Arno N. Swart
- Centre for Infectious Disease Control (CIb), National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| |
Collapse
|
26
|
Tozer SJ, Lambert SB, Strong CL, Field HE, Sloots TP, Nissen MD. Potential Animal and Environmental Sources of Q Fever Infection for Humans in Queensland. Zoonoses Public Health 2013; 61:105-12. [DOI: 10.1111/zph.12051] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Indexed: 11/30/2022]
Affiliation(s)
- S. J. Tozer
- Queensland Paediatric Infectious Diseases Laboratory; Queensland Children's Medical Research Institute; Children's Health Queensland Hospitals and Health Service ; The University of Queensland; Brisbane Qld Australia
| | - S. B. Lambert
- Queensland Children's Medical Research Institute; Children's Health Queensland Hospitals and Health Service; The University of Queensland; Brisbane Qld Australia
- Immunisation Program, Communicable Diseases Branch; Queensland Health; Brisbane Qld Australia
| | - C. L. Strong
- Atmospheric Environment Research Centre; Griffith University; Brisbane Qld Australia
| | - H. E. Field
- Queensland Department of Agriculture, Fisheries & Forestry; Queensland Centre for Emerging Infectious Diseases; Biosecurity; Brisbane Qld Australia
| | - T. P. Sloots
- Queensland Paediatric Infectious Diseases Laboratory; Queensland Children's Medical Research Institute; Children's Health Queensland Hospitals and Health Service ; The University of Queensland; Brisbane Qld Australia
| | - M. D. Nissen
- Queensland Paediatric Infectious Diseases Laboratory; Queensland Children's Medical Research Institute; Children's Health Queensland Hospitals and Health Service ; The University of Queensland; Brisbane Qld Australia
- Microbiology Division; Pathology Queensland Central Laboratory; Queensland Health; Brisbane Qld Australia
| |
Collapse
|
27
|
Tostmann A, Bousema T, Oliver I. Investigation of outbreaks complicated by universal exposure. Emerg Infect Dis 2013; 18:1717-22. [PMID: 23092616 PMCID: PMC3559174 DOI: 10.3201/eid1811.111804] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Outbreaks in which most or all persons were exposed to the same suspected source of infection, so-called universal exposure, are common. They represent a challenge for public health specialists because conducting analytical studies in such investigations is complicated by the absence of a nonexposed group. We describe different strategies that can support investigations of outbreaks with universal exposure. The value of descriptive epidemiology, extensive environmental investigation, and the hypothesis-generation phase cannot be overemphasized. An exposure that seems universal may in fact not be universal when additional aspects of the exposure are taken into account. Each exposure has unique characteristics that may not be captured when investigators rely on the tools readily at hand, such as standard questionnaires. We therefore encourage field epidemiologists to be creative and consider the use of alternative data sources or original techniques in their investigations of outbreaks with universal exposure.
Collapse
Affiliation(s)
- Alma Tostmann
- Department of Primary and Community Care Medicine, Radboud University Nijmegen Medical Centre, Geert Grooteplein Zuid 10, 6525 GA Nijmegen, the Netherlands.
| | | | | |
Collapse
|
28
|
Halsby KD, Walsh AL, Smith R, Said B, Kirkbride H, Smyth B, Browning L, Larkin L, Morgan D. The Health Burden of Orphan Zoonotic Disease in the United Kingdom, 2005-2009. Zoonoses Public Health 2013; 61:39-47. [DOI: 10.1111/zph.12040] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Indexed: 11/30/2022]
Affiliation(s)
- K. D. Halsby
- Gastrointestinal, Zoonotic and Emerging Infections Department; Health Protection Agency Colindale; London UK
| | - A. L. Walsh
- Gastrointestinal, Zoonotic and Emerging Infections Department; Health Protection Agency Colindale; London UK
| | - R. Smith
- Public Health Wales Communicable Disease Surveillance Centre; Cardiff UK
| | - B. Said
- Gastrointestinal, Zoonotic and Emerging Infections Department; Health Protection Agency Colindale; London UK
| | - H. Kirkbride
- Gastrointestinal, Zoonotic and Emerging Infections Department; Health Protection Agency Colindale; London UK
| | - B. Smyth
- Public Health Agency; Belfast UK
| | - L. Browning
- Health Protection Scotland; NHS National Services Scotland; Glasgow UK
| | - L. Larkin
- Disease Mitigation and Control (Zoonoses); Department for Environment Food, and Rural Affairs; London UK
| | - D. Morgan
- Gastrointestinal, Zoonotic and Emerging Infections Department; Health Protection Agency Colindale; London UK
| |
Collapse
|
29
|
de Bruin A, Janse I, Koning M, de Heer L, van der Plaats RQJ, van Leuken JPG, van Rotterdam BJ. Detection of Coxiella burnetii DNA in the environment during and after a large Q fever epidemic in the Netherlands. J Appl Microbiol 2013; 114:1395-404. [PMID: 23398323 DOI: 10.1111/jam.12163] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Revised: 01/16/2013] [Accepted: 01/25/2013] [Indexed: 11/30/2022]
Abstract
AIM To investigate the Coxiella burnetii DNA content in environmental samples that may contribute to the transmission of C. burnetii. METHODS AND RESULTS During a large Q fever outbreak in the Netherlands, surface swabs and aerosol samples were collected inside stables and around six Q fever-affected ruminant farms, which are located in municipalities varying in Q fever incidence. After the outbreak in 2010, aerosol samples were collected in the same geographical areas. The use of an optimized multiplex qPCR for the detection of C. burnetii DNA revealed that all samples obtained inside stables were positive. In addition, the C. burnetii DNA content in aerosol samples collected in stables is significantly higher than in aerosol samples collected around the farms. Finally, the C. burnetii DNA content in aerosol samples collected in the same geographical locations was lower in 2010 in comparison with 2009. CONCLUSIONS The reduction in C. burnetii DNA content in aerosol samples between 2009 and 2010 is in agreement with the reduction in Q fever incidence in the same geographical areas. SIGNIFICANCE AND IMPACT OF THE STUDY The presence of C. burnetii DNA in environmental samples collected on and around ruminant farms supports the hypothesis that C. burnetii can be disseminated from ruminant farms to the surrounding areas.
Collapse
Affiliation(s)
- A de Bruin
- National Institute for Public Health and the Environment, Bilthoven, The Netherlands.
| | | | | | | | | | | | | |
Collapse
|
30
|
Hilbert A, Schmoock G, Lenzko H, Moog U, Diller R, Fröhlich A, Hoffmann L, Horner S, Elschner M, Tomaso H, Henning K, Neubauer H, Sprague LD. Prevalence of Coxiella burnetii in clinically healthy German sheep flocks. BMC Res Notes 2012; 5:152. [PMID: 22429653 PMCID: PMC3351016 DOI: 10.1186/1756-0500-5-152] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2011] [Accepted: 03/19/2012] [Indexed: 11/24/2022] Open
Abstract
Background Current epidemiological data on the situation of Coxiella (C.) burnetii infections in sheep are missing, making risk assessment and the implementation of counteractive measures difficult. Using the German state of Thuringia as a model example, the estimated sero-, and antigen prevalence of C. burnetii (10% and 25%, respectively) was assessed at flock level in 39/252 randomly selected clinically healthy sheep flocks with more than 100 ewes and unknown abortion rate. Results The CHECKIT™ Q-fever Test Kit identified 11 (28%) antibody positive herds, whereas real-time PCR revealed the presence of C. burnetii DNA in 2 (5%) of the flocks. Multiple-locus variable number of tandem repeats analysis of 9 isolates obtained from one flock revealed identical profiles. All isolates contained the plasmid QpH1. Conclusions The results demonstrate that C. burnetii is present in clinically inconspicuous sheep flocks and sporadic flare-ups do occur as the notifications to the German animal disease reporting system show. Although C. burnetii infections are not a primary veterinary concern due to the lack of significant clinical impact on animal health (with the exception of goats), the eminent zoonotic risk for humans should not be underestimated. Therefore, strategies combining the interests of public and veterinary public health should include monitoring of flocks, the identification and culling of shedders as well as the administration of protective vaccines.
Collapse
Affiliation(s)
- Angela Hilbert
- Institut für Epidemiologie, Friedrich-Loeffler-Institut, National Reference Laboratory for Q-fever, Wusterhausen, Germany
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Horigan MW, Bell MM, Pollard TR, Sayers AR, Pritchard GC. Q fever diagnosis in domestic ruminants: comparison between complement fixation and commercial enzyme-linked immunosorbent assays. J Vet Diagn Invest 2012; 23:924-31. [PMID: 21908348 DOI: 10.1177/1040638711416971] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Q fever is an important zoonotic disease caused by infection with the bacterium Coxiella burnetii. Veterinary diagnostic laboratories, including the Veterinary Laboratories Agency (VLA) in England and Wales, have traditionally relied on the complement fixation test (CFT) for serological diagnosis. However, Q fever has assumed greater significance in recent years following several large human outbreaks linked to exposure to infected ruminants and it is essential that more reliable tests are introduced to detect the presence of C. burnetii infection in animals. The objective of the current study was to evaluate the performance of 3 commercially available enzyme-linked immunosorbent assays (ELISAs) for detection of antibodies to C. burnetii and to compare the findings with the CFT using a sample panel of 548 sera from sheep, goats, and cattle, including animals of known disease status. The statistical analysis using TAGS (test accuracy in the absence of a gold standard) software and receiver operating characteristic techniques demonstrated that the 3 ELISAs all showed improved sensitivity over the CFT. The test based on ovine antigen demonstrated the best overall performance and therefore, the VLA has adopted this test for routine use.
Collapse
Affiliation(s)
- Mark W Horigan
- Veterinary Laboratories Agency, New Haw, Addlestone, Surrey KT15 3NB, UK.
| | | | | | | | | |
Collapse
|
32
|
Detection of Coxiella burnetii DNA on small-ruminant farms during a Q fever outbreak in the Netherlands. Appl Environ Microbiol 2012; 78:1652-7. [PMID: 22247143 DOI: 10.1128/aem.07323-11] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
During large Q fever outbreaks in the Netherlands between 2007 and 2010, dairy goat farms were implicated as the primary source of human Q fever. The transmission of Coxiella burnetii to humans is thought to occur primarily via aerosols, although available data on C. burnetii in aerosols and other environmental matrices are limited. During the outbreak of 2009, 19 dairy goat farms and one dairy sheep farm were selected nationwide to investigate the presence of C. burnetii DNA in vaginal swabs, manure, surface area swabs, milk unit filters, and aerosols. Four of these farms had a positive status during the Coxiella burnetii bulk milk monitoring program in 2009 and additionally reported abortion waves in 2008 or 2009. Eleven farms were reported as having positive bulk milk only, and five selected (control) farms had a bulk milk-negative status in 2009 and no reported Q fever history. Screening by quantitative PCR (qPCR) revealed that on farms with a history of abortions related to C. burnetii and, to a lesser extent, on farms positive by bulk milk monitoring, generally higher proportions of positive samples and higher levels of C. burnetii DNA within positive samples were observed than on the control farms. The relatively high levels of C. burnetii DNA in surface area swabs and aerosols sampled in stables of bulk milk-positive farms, including farms with a Q fever-related abortion history, support the hypothesis that these farms can pose a risk for the transmission of C. burnetii to humans.
Collapse
|
33
|
Abstract
To assess Q fever in France, we analyzed data for 1985–2009 from the French National Reference Center. A total of 179,794 serum samples were analyzed; 3,723 patients (one third female patients) had acute Q fever. Yearly distribution of acute Q fever showed a continuous increase. Periodic variations were observed in monthly distribution during January 2000–December 2009; cases peaked during April–September. Q fever was diagnosed more often in patients in southeastern France, where our laboratory is situated, than in other areas. Reevaluation of the current positive predictive value of serologic analysis for endocarditis was performed. We propose a change in the phase I (virulent bacteria) immunoglobulin G cutoff titer to >1,600. Annual incidences of acute Q fever and endocarditis were 2.5/100,000 persons and 0.1/100,000 persons, respectively. Cases and outbreaks of Q fever have increased in France.
Collapse
|
34
|
Courcoul A, Monod H, Nielen M, Klinkenberg D, Hogerwerf L, Beaudeau F, Vergu E. Modelling the effect of heterogeneity of shedding on the within herd Coxiella burnetii spread and identification of key parameters by sensitivity analysis. J Theor Biol 2011; 284:130-41. [PMID: 21723294 DOI: 10.1016/j.jtbi.2011.06.017] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2010] [Revised: 04/16/2011] [Accepted: 06/16/2011] [Indexed: 10/18/2022]
Abstract
Coxiella burnetii is the bacterium responsible for Q fever, a worldwide zoonosis. Ruminants, especially cattle, are recognized as the most important source of human infections. Although a great heterogeneity between shedder cows has been described, no previous studies have determined which features such as shedding route and duration or the quantity of bacteria shed have the strongest impact on the environmental contamination and thus on the zoonotic risk. Our objective was to identify key parameters whose variation highly influences C. burnetii spread within a dairy cattle herd, especially those related to the heterogeneity of shedding. To compare the impact of epidemiological parameters on different dynamical aspects of C. burnetii infection, we performed a sensitivity analysis on an original stochastic model describing the bacterium spread and representing the individual variability of the shedding duration, routes and intensity as well as herd demography. This sensitivity analysis consisted of a principal component analysis followed by an ANOVA. Our findings show that the most influential parameters are the probability distribution governing the levels of shedding, especially in vaginal mucus and faeces, the characteristics of the bacterium in the environment (i.e. its survival and the fraction of bacteria shed reaching the environment), and some physiological parameters related to the intermittency of shedding (transition probability from a non-shedding infected state to a shedding state) or to the transition from one type of shedder to another one (transition probability from a seronegative shedding state to a seropositive shedding state). Our study is crucial for the understanding of the dynamics of C. burnetii infection and optimization of control measures. Indeed, as control measures should impact the parameters influencing the bacterium spread most, our model can now be used to assess the effectiveness of different control strategies of Q fever within dairy cattle herds.
Collapse
Affiliation(s)
- Aurélie Courcoul
- Institut National de la Recherche Agronomique, UMR1300 Biologie, Epidémiologie et Analyse de Risque, Atlanpôle La Chantrerie, Nantes, France.
| | | | | | | | | | | | | |
Collapse
|
35
|
|
36
|
Jones RM, Twomey DF, Hannon S, Errington J, Pritchard GC, Sawyer J. Detection of Coxiella burnetii in placenta and abortion samples from British ruminants using real-time PCR. Vet Rec 2011; 167:965-7. [PMID: 21262712 DOI: 10.1136/vr.c4040] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
A real-time PCR was developed to detect Coxiella burnetii (the cause of Q fever) in ruminant placentas and aborted fetuses. Primer and probe sets previously developed for human tissue studies were used to target the insertion sequence IS1111 gene for C burnetii. The assay was highly sensitive, with a limit of detection of 10 copies of template, theoretically equating to a single bacterium, and did not cross-react with a panel of other bacteria. To determine sensitivity on field samples submitted for the diagnosis of abortion, results using the IS1111 PCR assay were compared with a com1 PCR assay. When applied to ruminant abortion material, including placental cotyledons and fetal samples, the IS1111 and com1 assays yielded positive results in 23 (25 per cent) of 93 and 19 (20 per cent) of 93 samples, respectively. One infected goat herd was monitored for 31 months: 57 (92 per cent) of 62 placental cotyledon samples from aborting and non-aborting goats, and 10 (30 per cent) of 33 fetal samples were positive by the IS1111 PCR assay.
Collapse
Affiliation(s)
- R M Jones
- Veterinary Laboratories Agency (VLA) - Weybridge, New Haw, Addlestone, Surrey
| | | | | | | | | | | |
Collapse
|