1
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Carson BD, Orians CM, Crone EE. Caterpillar movement mediates spatially local interactions and determines the relationship between population density and contact. MOVEMENT ECOLOGY 2024; 12:34. [PMID: 38689374 PMCID: PMC11061915 DOI: 10.1186/s40462-024-00473-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 04/10/2024] [Indexed: 05/02/2024]
Abstract
BACKGROUND While interactions in nature are inherently local, ecological models often assume homogeneity across space, allowing for generalization across systems and greater mathematical tractability. Density-dependent disease models are a prominent example of models that assume homogeneous interactions, leading to the prediction that disease transmission will scale linearly with population density. In this study, we examined how the scale of larval butterfly movement interacts with the resource landscape to influence the relationship between larval contact and population density in the Baltimore checkerspot (Euphydryas phaeton). Our study was inspired by the recent discovery of a viral pathogen that is transmitted horizontally among Baltimore checkerspot larvae. METHODS We used multi-year larvae location data across six Baltimore checkerspot populations in the eastern U.S. to test whether larval nests are spatially clustered. We then integrated these spatial data with larval movement data in different resource contexts to investigate whether heterogeneity in spatially local interactions alters the assumed linear relationship between larval nest density and contact. We used Correlated Random Walk (CRW) models and field observations of larval movement behavior to construct Probability Distribution Functions (PDFs) of larval dispersal, and calculated the overlap in these PDFs to estimate conspecific contact within each population. RESULTS We found that all populations exhibited significant spatial clustering in their habitat use. Subsequent larval movement rates were influenced by encounters with host plants and larval age, and under many movement scenarios, the scale of predicted larval movement was not sufficient to allow for the "homogeneous mixing" assumed in density dependent disease models. Therefore, relationships between population density and larval contact were typically non-linear. We also found that observed use of available habitat patches led to significantly greater contact than would occur if habitat use were spatially random. CONCLUSIONS These findings strongly suggest that incorporating larval movement and spatial variation in larval interactions is critical to modeling disease outcomes in E. phaeton. Epidemiological models that assume a linear relationship between population density and larval contact have the potential to underestimate transmission rates, especially in small populations that are already vulnerable to extinction.
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Affiliation(s)
- Brendan D Carson
- Department of Biology, Tufts University, Medford, MA, 02155, USA.
| | - Colin M Orians
- Department of Biology, Tufts University, Medford, MA, 02155, USA
| | - Elizabeth E Crone
- Department of Biology, Tufts University, Medford, MA, 02155, USA
- Department of Evolution and Ecology, University of California, Davis, CA, 95616, USA
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2
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Kuenzi AJ, Luis AD. Food availability leads to more connected contact networks among peridomestic zoonotic reservoir hosts. ROYAL SOCIETY OPEN SCIENCE 2023; 10:230809. [PMID: 38026027 PMCID: PMC10646467 DOI: 10.1098/rsos.230809] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 10/18/2023] [Indexed: 12/01/2023]
Abstract
The North American deermouse (Peromyscus maniculatus) is a reservoir host for many zoonotic pathogens. Deermice have been well studied, but few studies have attempted to understand social interactions within the species despite these interactions being key to understanding disease transmission. We performed an experiment to determine if supplemental food or nesting material affected social interactions of deermice and tested if interactions increased with increasing population density. We constructed three simulated buildings that received one of three treatments: food, nesting material, or control. Mice were tagged with passive integrated transponder (PIT) tags, and their movement in and out of buildings was monitored with PIT tag readers. PIT tag readings were used to create contact networks, assuming a contact if two deermice were in the same building at the same time. We found that buildings with food led to contact networks that were approximately 10 times more connected than buildings with nesting material or control buildings. We also saw a significant effect of population density on the average number of contacts per individual. These results suggest that food supplementation which is common in peridomestic settings, can significantly increase contacts between reservoir hosts, potentially leading to increased transmission of zoonotic viruses within the reservoir host and from reservoir hosts to humans.
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Affiliation(s)
- Amy J. Kuenzi
- Department of Biology, Montana Technological University, 1300 Park Street, Butte, MT 59701, USA
| | - Angela D. Luis
- Department of Ecosystem and Conservation Sciences, University of Montana, Missoula, MT 59812, USA
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3
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Yang A, Wilber MQ, Manlove KR, Miller RS, Boughton R, Beasley J, Northrup J, VerCauteren KC, Wittemyer G, Pepin K. Deriving spatially explicit direct and indirect interaction networks from animal movement data. Ecol Evol 2023; 13:e9774. [PMID: 36993145 PMCID: PMC10040956 DOI: 10.1002/ece3.9774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 01/11/2023] [Indexed: 03/29/2023] Open
Abstract
Quantifying spatiotemporally explicit interactions within animal populations facilitates the understanding of social structure and its relationship with ecological processes. Data from animal tracking technologies (Global Positioning Systems ["GPS"]) can circumvent longstanding challenges in the estimation of spatiotemporally explicit interactions, but the discrete nature and coarse temporal resolution of data mean that ephemeral interactions that occur between consecutive GPS locations go undetected. Here, we developed a method to quantify individual and spatial patterns of interaction using continuous-time movement models (CTMMs) fit to GPS tracking data. We first applied CTMMs to infer the full movement trajectories at an arbitrarily fine temporal scale before estimating interactions, thus allowing inference of interactions occurring between observed GPS locations. Our framework then infers indirect interactions-individuals occurring at the same location, but at different times-while allowing the identification of indirect interactions to vary with ecological context based on CTMM outputs. We assessed the performance of our new method using simulations and illustrated its implementation by deriving disease-relevant interaction networks for two behaviorally differentiated species, wild pigs (Sus scrofa) that can host African Swine Fever and mule deer (Odocoileus hemionus) that can host chronic wasting disease. Simulations showed that interactions derived from observed GPS data can be substantially underestimated when temporal resolution of movement data exceeds 30-min intervals. Empirical application suggested that underestimation occurred in both interaction rates and their spatial distributions. CTMM-Interaction method, which can introduce uncertainties, recovered majority of true interactions. Our method leverages advances in movement ecology to quantify fine-scale spatiotemporal interactions between individuals from lower temporal resolution GPS data. It can be leveraged to infer dynamic social networks, transmission potential in disease systems, consumer-resource interactions, information sharing, and beyond. The method also sets the stage for future predictive models linking observed spatiotemporal interaction patterns to environmental drivers.
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Affiliation(s)
- Anni Yang
- Department of Geography and Environmental SustainabilityUniversity of OklahomaOklahomaNormanUSA
- Department of Fish, Wildlife and Conservation BiologyColorado State UniversityColoradoFort CollinsUSA
- United States Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife ServicesNational Wildlife Research CenterColoradoFort CollinsUSA
| | - Mark Q. Wilber
- Forestry, Wildlife, and Fisheries, Institute of AgricultureUniversity of TennesseeTennesseeKnoxvilleUSA
| | - Kezia R. Manlove
- Department of Wildland Resources and Ecology CenterUtah State UniversityUtahLoganUSA
| | - Ryan S. Miller
- Center for Epidemiology and Animal HealthUnited States Department of Agriculture, Animal and Plant Health Inspection Service, Veterinary ServiceColoradoFort CollinsUSA
| | - Raoul Boughton
- Archbold Biological StationBuck Island RanchFloridaLake PlacidUSA
| | - James Beasley
- Savannah River Ecology LaboratoryWarnell School of Forestry and Natural ResourcesUniversity of GeorgiaSouth CarolinaAikenUSA
| | - Joseph Northrup
- Wildlife Research and Monitoring SectionOntario Ministry of Natural Resources and ForestryOntarioPeterboroughCanada
| | - Kurt C. VerCauteren
- United States Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife ServicesNational Wildlife Research CenterColoradoFort CollinsUSA
| | - George Wittemyer
- Department of Fish, Wildlife and Conservation BiologyColorado State UniversityColoradoFort CollinsUSA
| | - Kim Pepin
- United States Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife ServicesNational Wildlife Research CenterColoradoFort CollinsUSA
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4
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Hulst AD, Bijma P, De Jong MCM. Can breeders prevent pathogen adaptation when selecting for increased resistance to infectious diseases? GENETICS SELECTION EVOLUTION 2022; 54:73. [DOI: 10.1186/s12711-022-00764-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 10/24/2022] [Indexed: 11/09/2022]
Abstract
Abstract
Background
Recent research shows that genetic selection has high potential to reduce the prevalence of infectious diseases in livestock. However, like all interventions that target infectious diseases, genetic selection of livestock can exert selection pressure on pathogen populations. Such selection on the pathogen may lead to escape strategies and reduce the effect of selection of livestock for disease resistance. Thus, to successfully breed livestock for lower disease prevalence, it is essential to develop strategies that prevent the invasion of pathogen mutants that escape host resistance. Here we investigate the conditions under which such “escape mutants” can replace wild-type pathogens in a closed livestock population using a mathematical model of disease transmission.
Results
Assuming a single gene that confers sufficient resistance, results show that genetic selection for resistance in livestock typically leads to an “invasion window” within which an escape mutant of the pathogen can invade. The bounds of the invasion window are determined by the frequency of resistant hosts in the population. The lower bound occurs when the escape mutant has an advantage over the wild-type pathogen in the population. The upper bound occurs when local eradication of the pathogen is expected. The invasion window is smallest when host resistance is strong and when infection with the wild-type pathogen provides cross immunity to infection with the escape mutant.
Conclusions
To minimise opportunities for pathogens to adapt, under the assumptions of our model, the aim of disease control through genetic selection should be to achieve herd-level eradication of the infection faster than the rate of emergence of escape mutants of the pathogen. Especially for microparasitic infections, this could be achieved by placing animals into herds according to their genetic resistance, such that these herds stay completely out of the invasion window. In contrast to classical breeding theory, our model suggests that multi-trait selection with gradual improvement of each trait of the breeding goal might not be the best strategy when resistance to infectious disease is part of the breeding goal. Temporally, combining genetic selection with other interventions helps to make the invasion window smaller, and thereby reduces the risk of invasion of escape mutants.
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5
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Sawyers E, Cox TE, Fleming PJS, Leung LKP, Morris S. Social interactions of juvenile rabbits (Oryctolagus cuniculus) and their potential role in lagovirus transmission. PLoS One 2022; 17:e0271272. [PMID: 35901018 PMCID: PMC9333329 DOI: 10.1371/journal.pone.0271272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 06/28/2022] [Indexed: 11/18/2022] Open
Abstract
Rabbit Haemorrhagic Disease Virus (RHDV), which is a calicivirus, is used as a biocontrol agent to suppress European wild rabbit populations in Australia. The transmission of RHDV can be influenced by social interactions of rabbits; however, there is a paucity of this knowledge about juvenile rabbits and the roles they may play in the transmission of RHDV. We aimed to quantify the social interactions of juvenile (< 900 g) and adult (> 1200 g) rabbits in a locally abundant population in the Central Tablelands of New South Wales, Australia. Twenty-six juvenile and 16 adult rabbits were fitted with VHF proximity loggers to monitor intra- and inter-group pairings. Use of multiple warrens by these rabbits was investigated using VHF base stations at nine warrens and on foot with a hand-held Yagi antenna. Juvenile rabbits were strongly interconnected with both juveniles and adults within and outside their warren of capture, and almost all juveniles were well-connected to other individuals within their own social group. Inter-group pairings were infrequent and fleeting between adults. Both juvenile and adult rabbits used multiple warrens. However, visits to warrens outside their warren of capture, particularly those within 50 m, were more common and longer in duration in juveniles than in adults. The high connectivity of juveniles within and between warrens in close proximity increases potential pathogen exchange between warrens. Therefore, juvenile rabbits could be of greater importance in lagovirus transmission than adult rabbits. The strength of juvenile rabbit inter- and intra-group pairings, and their tendency to use multiple warrens, highlight their potential to act as ‘superspreaders’ of both infection and immunity for lagoviruses and other pathogens with similar lifecycles. Confirmation of this potential is required through examination of disease progress and rabbit age-related immune responses during outbreaks.
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Affiliation(s)
- Emma Sawyers
- Vertebrate Pest Research Unit, New South Wales Department of Primary Industries, Orange, New South Wales, Australia
- School of Agriculture and Food Sciences, University of Queensland, Gatton, Queensland, Australia
- * E-mail:
| | - Tarnya E. Cox
- Vertebrate Pest Research Unit, New South Wales Department of Primary Industries, Orange, New South Wales, Australia
| | - Peter J. S. Fleming
- Vertebrate Pest Research Unit, New South Wales Department of Primary Industries, Orange, New South Wales, Australia
- School of Agriculture and Food Sciences, University of Queensland, Gatton, Queensland, Australia
- School of Environmental and Rural Science, University of New England, Armidale, New South Wales, Australia
| | - Luke K. P. Leung
- School of Agriculture and Food Sciences, University of Queensland, Gatton, Queensland, Australia
| | - Stephen Morris
- Fisheries Research, New South Wales Department of Primary Industries, Wollongbar, New South Wales, Australia
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6
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Ossi F, Focardi S, Tolhurst BA, Picco GP, Murphy AL, Molteni D, Giannini N, Gaillard J, Cagnacci F. Quantifying the errors in animal contacts recorded by proximity loggers. J Wildl Manage 2022. [DOI: 10.1002/jwmg.22151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Federico Ossi
- Department of Biodiversity and Molecular Ecology Research and Innovation Centre, Fondazione Edmund Mach Via E. Mach 1 San Michele all'Adige 38010 Italy
- C3A—Centro Agricoltura, Alimenti Ambiente—University of Trento Via E. Mach 1 San Michele all'Adige 38010 Italy
| | - Stefano Focardi
- Istituto dei Sistemi Complessi, CNR, Via Madonna del Piano 10—50019 Sesto Fiorentino (FI) Italy
| | - Bryony A. Tolhurst
- School of Applied Sciences The University of Brighton Huxley Building, Lewes Road Brighton BN2 4GJ East Sussex United Kingdom
| | - Gian Pietro Picco
- Department of Information Engineering and Computer Science (DISI) University of Trento via Sommarive 9 I‐38123 Povo (TN) Italy
| | - Amy L. Murphy
- Center for Information and Communication Technology Bruno Kessler Foundation via Sommarive 18 I‐38123 Povo (TN) Italy
| | - Davide Molteni
- Department of Information Engineering and Computer Science (DISI) University of Trento via Sommarive 9 I‐38123 Povo (TN) Italy
| | - Noemi Giannini
- Department of Biodiversity and Molecular Ecology Research and Innovation Centre, Fondazione Edmund Mach Via E. Mach 1 San Michele all'Adige 38010 Italy
| | - Jean‐Michel Gaillard
- UMR CNRS 5558 “Biometrie et Biologie Evolutive” Université Claude Bernard Lyon1 Bat G. Mendel 43 Bd du 11 Novembre 1918 Villeurbanne 69622 Cedex France
| | - Francesca Cagnacci
- Department of Biodiversity and Molecular Ecology Research and Innovation Centre, Fondazione Edmund Mach Via E. Mach 1 San Michele all'Adige 38010 Italy
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7
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Recording cattle maternal behaviour using proximity loggers and tri-axial accelerometers. Appl Anim Behav Sci 2021. [DOI: 10.1016/j.applanim.2021.105349] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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8
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Shared use of mineral supplement in extensive farming and its potential for infection transmission at the wildlife-livestock interface. EUR J WILDLIFE RES 2021. [DOI: 10.1007/s10344-021-01493-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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9
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Woodroffe R, Donnelly CA, Chapman K, Ham C, Moyes K, Stratton NG, Cartwright SJ. Successive use of shared space by badgers and cattle: implications for
Mycobacterium bovis
transmission. J Zool (1987) 2021. [DOI: 10.1111/jzo.12863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
| | - C. A. Donnelly
- MRC Centre for Outbreak Analysis and Modelling Department of Infectious Disease Epidemiology Imperial College London London UK
- Department of Statistics University of Oxford Oxford UK
| | - K. Chapman
- Institute of Zoology Regent’s Park London UK
| | - C. Ham
- Institute of Zoology Regent’s Park London UK
| | - K. Moyes
- Centre for Ecology and Conservation University of Exeter Penryn UK
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10
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Jiménez-Ruiz S, García-Bocanegra I, Acevedo P, Espunyes J, Triguero-Ocaña R, Cano-Terriza D, Torres-Sánchez MJ, Vicente J, Risalde MÁ. A survey of shared pathogens at the domestic-wild ruminants' interface in Doñana National Park (Spain). Transbound Emerg Dis 2021; 69:1568-1576. [PMID: 33900033 DOI: 10.1111/tbed.14126] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 03/19/2021] [Accepted: 04/21/2021] [Indexed: 12/26/2022]
Abstract
A cross-sectional study was carried out to evaluate shared pathogens that can be transmitted by close or non-close contact at the domestic-wild ruminants' interface. During summer-autumn 2015, a total of 138 cattle and 203 wild ruminants (red deer, Cervus elaphus, and fallow deer, Dama dama) were sampled in Doñana National Park (DNP, south-western Spain), a Mediterranean ecosystem well known for the interaction network occurring in the ungulate host community. Pestiviruses, bovine respiratory syncytial virus (BRSV; Bovine orthopneumovirus), bovine herpesvirus 1 (BoHV-1; Bovine alphaherpesvirus 1) and Mycobacterium tuberculosis complex (MTC) were assessed using serological, microbiological and molecular techniques. The overall seroprevalence against viruses in cattle was 2.2% for pestiviruses, 11.6% for BRSV and 27.5% for BoHV-1. No virus-specific antibodies were found in wildlife. MTC incidence in cattle was 15.9%, and MTC seroprevalence in wild ruminants was 14.3%. The same Mycobacterium bovis spoligotypes (SB1232, SB1230 and SB1610) were identified in cattle, red deer and fallow deer. The serological results for the selected respiratory viruses suggest epidemiological cycles only in cattle. Surveillance efforts in multi-host epidemiological scenarios are needed to better drive and prioritize control strategies for shared pathogens.
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Affiliation(s)
- Saúl Jiménez-Ruiz
- Grupo Sanidad y Biotecnología (SaBio), Instituto de Investigación en Recursos Cinegéticos IREC (UCLM-CSIC-JCCM), Ciudad Real, Spain.,Grupo de Investigación en Sanidad Animal y Zoonosis (GISAZ), Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de Córdoba (UCO), Córdoba, Spain
| | - Ignacio García-Bocanegra
- Grupo de Investigación en Sanidad Animal y Zoonosis (GISAZ), Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de Córdoba (UCO), Córdoba, Spain
| | - Pelayo Acevedo
- Grupo Sanidad y Biotecnología (SaBio), Instituto de Investigación en Recursos Cinegéticos IREC (UCLM-CSIC-JCCM), Ciudad Real, Spain
| | - Johan Espunyes
- Wildlife Conservation Medicine Research Group (WildCoM), Departament de Medicina i Cirurgia, Universitat Autònoma de Barcelona (UAB), Bellaterra, Spain.,Research and Conservation Department. Zoo de Barcelona, Barcelona, Spain
| | - Roxana Triguero-Ocaña
- Grupo Sanidad y Biotecnología (SaBio), Instituto de Investigación en Recursos Cinegéticos IREC (UCLM-CSIC-JCCM), Ciudad Real, Spain.,VISAVET Health Surveillance Centre, Universidad Complutense de Madrid (UCM), Madrid, Spain
| | - David Cano-Terriza
- Grupo de Investigación en Sanidad Animal y Zoonosis (GISAZ), Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de Córdoba (UCO), Córdoba, Spain
| | | | - Joaquín Vicente
- Grupo Sanidad y Biotecnología (SaBio), Instituto de Investigación en Recursos Cinegéticos IREC (UCLM-CSIC-JCCM), Ciudad Real, Spain
| | - María Ángeles Risalde
- Grupo de Investigación en Sanidad Animal y Zoonosis (GISAZ), Departamento de Anatomía y Anatomía Patológica Comparadas y Toxicología, Facultad de Veterinaria, Universidad de Córdoba (UCO), Córdoba, Spain.,Unidad de Enfermedades Infecciosas, Grupo de Virología Clínica y Zoonosis, Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Hospital Reina Sofía, Universidad de Córdoba (UCO), Córdoba, Spain
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11
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Hulst AD, de Jong MCM, Bijma P. Why genetic selection to reduce the prevalence of infectious diseases is way more promising than currently believed. Genetics 2021; 217:6137839. [PMID: 33734349 PMCID: PMC8049556 DOI: 10.1093/genetics/iyab024] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 02/05/2021] [Indexed: 11/12/2022] Open
Abstract
Genetic selection for improved disease resistance is an important part of strategies to combat infectious diseases in agriculture. Quantitative genetic analyses of binary disease status, however, indicate low heritability for most diseases, which restricts the rate of genetic reduction in disease prevalence. Moreover, the common liability threshold model suggests that eradication of an infectious disease via genetic selection is impossible because the observed-scale heritability goes to zero when the prevalence approaches zero. From infectious disease epidemiology, however, we know that eradication of infectious diseases is possible, both in theory and practice, because of positive feedback mechanisms leading to the phenomenon known as herd immunity. The common quantitative genetic models, however, ignore these feedback mechanisms. Here, we integrate quantitative genetic analysis of binary disease status with epidemiological models of transmission, aiming to identify the potential response to selection for reducing the prevalence of endemic infectious diseases. The results show that typical heritability values of binary disease status correspond to a very substantial genetic variation in disease susceptibility among individuals. Moreover, our results show that eradication of infectious diseases by genetic selection is possible in principle. These findings strongly disagree with predictions based on common quantitative genetic models, which ignore the positive feedback effects that occur when reducing the transmission of infectious diseases. Those feedback effects are a specific kind of Indirect Genetic Effects; they contribute substantially to the response to selection and the development of herd immunity (i.e., an effective reproduction ratio less than one).
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Affiliation(s)
- Andries D Hulst
- Quantitative Veterinary Epidemiology, Wageningen University & Research, 6700AH, Wageningen, The Netherlands.,Animal Breeding and Genomics Group, Wageningen University & Research, 6700AH, Wageningen, The Netherlands
| | - Mart C M de Jong
- Quantitative Veterinary Epidemiology, Wageningen University & Research, 6700AH, Wageningen, The Netherlands
| | - Piter Bijma
- Animal Breeding and Genomics Group, Wageningen University & Research, 6700AH, Wageningen, The Netherlands
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12
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Abstract
Ecological corridors are one of the best, and possibly only viable, management tools to maintain biodiversity at large scales and to allow species, and ecological processes, to track climate change. This document has been assembled as a summary of the best available information about managing these systems. Our aim with this paper is to provide managers with a convenient guidance document and tool to assist in applying scientific management principles to management of corridors. We do not cover issues related to corridor design or political buy in, but focus on how a corridor should be managed once it has been established. The first part of our paper outlines the history and value of ecological corridors. We next describe our methodologies for developing this guidance document. We then summarize the information about the impacts of linear features on corridors and strategies for dealing with them—specifically, we focus on the effects of roads, canals, security fences, and transmission lines. Following the description of effects, we provide a summary of the best practices for managing the impacts of linear barriers. Globally, many corridors are established in the flood plains of stream and rivers and occur in riparian areas associated with surface waters. Therefore, we next provide guidance on how to manage corridors that occur in riparian areas. We then segue into corridors and the urban/suburban environment, and summarize strategies for dealing with urban development within corridors. The final major anthropic land use that may affect corridor management is cultivation and grazing agriculture. We end this review by identifying gaps in knowledge pertaining to how best to manage corridors.
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13
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Yang A, Schlichting P, Wight B, Anderson WM, Chinn SM, Wilber MQ, Miller RS, Beasley JC, Boughton RK, VerCauteren KC, Wittemyer G, Pepin KM. Effects of social structure and management on risk of disease establishment in wild pigs. J Anim Ecol 2021; 90:820-833. [PMID: 33340089 DOI: 10.1111/1365-2656.13412] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 11/16/2020] [Indexed: 11/29/2022]
Abstract
Contact heterogeneity among hosts determines invasion and spreading dynamics of infectious disease, thus its characterization is essential for identifying effective disease control strategies. Yet, little is known about the factors shaping contact networks in many wildlife species and how wildlife management actions might affect contact networks. Wild pigs in North America are an invasive, socially structured species that pose a health concern for domestic swine given their ability to transmit numerous devastating diseases such as African swine fever (ASF). Using proximity loggers and GPS data from 48 wild pigs in Florida and South Carolina, USA, we employed a probabilistic framework to estimate weighted contact networks. We determined the effects of sex, social group and spatial distribution (monthly home-range overlap and distance) on wild pig contact. We also estimated the impacts of management-induced perturbations on contact and inferred their effects on ASF establishment in wild pigs with simulation. Social group membership was the primary factor influencing contacts. Between-group contacts depended primarily on space use characteristics, with fewer contacts among groups separated by >2 km and no contacts among groups >4 km apart within a month. Modelling ASF dynamics on the contact network demonstrated that indirect contacts resulting from baiting (a typical method of attracting wild pigs or game species to a site to enhance recreational hunting) increased the risk of disease establishment by ~33% relative to direct contact. Low-intensity population reduction (<5.9% of the population) had no detectable impact on contact structure but reduced predicted ASF establishment risk relative to no population reduction. We demonstrate an approach for understanding the relative role of spatial, social and individual-level characteristics in shaping contact networks and predicting their effects on disease establishment risk, thus providing insight for optimizing disease control in spatially and socially structured wildlife species.
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Affiliation(s)
- Anni Yang
- Department of Fish, Wildlife, and Conservation Biology, Colorado State University, Fort Collins, CO, USA.,National Wildlife Research Center, United States Department of Agriculture, Animal and Plant Health Inspection Service, Fort Collins, CO, USA
| | - Peter Schlichting
- Savannah River Ecology Laboratory, Warnell School of Forestry and Natural Resources, University of Georgia, Aiken, SC, USA
| | - Bethany Wight
- Wildlife Ecology and Conservation, Range Cattle Research and Education Center, University of Florida, Ona, FL, USA
| | - Wesley M Anderson
- Wildlife Ecology and Conservation, Range Cattle Research and Education Center, University of Florida, Ona, FL, USA
| | - Sarah M Chinn
- Savannah River Ecology Laboratory, Warnell School of Forestry and Natural Resources, University of Georgia, Aiken, SC, USA
| | - Mark Q Wilber
- Ecology, Evolution and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA, USA
| | - Ryan S Miller
- Center for Epidemiology and Animal Health, United States Department of Agriculture, Animal and Plant Health Inspection Service, Veterinary Service, Fort Collins, CO, USA
| | - James C Beasley
- Savannah River Ecology Laboratory, Warnell School of Forestry and Natural Resources, University of Georgia, Aiken, SC, USA
| | - Raoul K Boughton
- Wildlife Ecology and Conservation, Range Cattle Research and Education Center, University of Florida, Ona, FL, USA
| | - Kurt C VerCauteren
- National Wildlife Research Center, United States Department of Agriculture, Animal and Plant Health Inspection Service, Fort Collins, CO, USA
| | - George Wittemyer
- Department of Fish, Wildlife, and Conservation Biology, Colorado State University, Fort Collins, CO, USA
| | - Kim M Pepin
- National Wildlife Research Center, United States Department of Agriculture, Animal and Plant Health Inspection Service, Fort Collins, CO, USA
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14
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Evaluation of a Fecal Shedding Test To Detect Badger Social Groups Infected with Mycobacterium bovis. J Clin Microbiol 2020; 59:JCM.01226-20. [PMID: 33055185 PMCID: PMC7771468 DOI: 10.1128/jcm.01226-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 10/02/2020] [Indexed: 11/20/2022] Open
Abstract
Bovine tuberculosis (bTB) is an economically important disease affecting the cattle industry in England and Wales. bTB, caused by Mycobacterium bovis, also causes disease in the Eurasian badger (Meles meles), a secondary maintenance host. Disease transmission between these two species is bidirectional. Infected badgers shed M. bovis in their feces. The Animal and Plant Health Agency (APHA) of the United Kingdom organized a comparative trial to determine the performance of tests in detecting M. bovis in badger feces for the Department for Environment, Food, and Rural Affairs (DEFRA). Here, we assessed the performance of the existing Warwick Fast24-qPCR test and its modified version based on a high-throughput DNA extraction method (Fast96-qPCR). We found Fast24-qPCR to have a sensitivity of 96.7% (95% confidence interval [CI], 94.5 to 99%; n = 244) and a specificity of 99% (95% CI, 97.8 to 100%; n = 292). Fast96-qPCR requires further optimization. Determining the disease status of badger social groups requires multiple tests per group. Therefore, to increase specificity further, we independently repeated the Fast24-qPCR test on positive samples, increasing stringency by requiring a second positive result. Fast24-qPCR with repeat testing had a sensitivity of 87.3% (95% CI, 83.1 to 91.5%; n = 244), and a specificity of 100% (95% CI, 100 to 100; n = 201) on an individual-sample level. At the social-group level, this repeat testing gives Fast24-qPCR high herd specificity, while testing multiple samples per group provides high herd sensitivity. With Fast24-qPCR, we provide a social-group-level test with sufficient specificity and sensitivity to monitor shedding in badgers via latrine sampling, delivering a potentially valuable tool to measure the impacts of bTB control measures.
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Bacigalupo SA, Dixon LK, Gubbins S, Kucharski AJ, Drewe JA. Towards a unified generic framework to define and observe contacts between livestock and wildlife: a systematic review. PeerJ 2020; 8:e10221. [PMID: 33173619 PMCID: PMC7594637 DOI: 10.7717/peerj.10221] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 09/29/2020] [Indexed: 11/25/2022] Open
Abstract
Wild animals are the source of many pathogens of livestock and humans. Concerns about the potential transmission of economically important and zoonotic diseases from wildlife have led to increased surveillance at the livestock-wildlife interface. Knowledge of the types, frequency and duration of contacts between livestock and wildlife is necessary to identify risk factors for disease transmission and to design possible mitigation strategies. Observing the behaviour of many wildlife species is challenging due to their cryptic nature and avoidance of humans, meaning there are relatively few studies in this area. Further, a consensus on the definition of what constitutes a 'contact' between wildlife and livestock is lacking. A systematic review was conducted to investigate which livestock-wildlife contacts have been studied and why, as well as the methods used to observe each species. Over 30,000 publications were screened, of which 122 fulfilled specific criteria for inclusion in the analysis. The majority of studies examined cattle contacts with badgers or with deer; studies involving wild pig contacts with cattle or with domestic pigs were the next most frequent. There was a range of observational methods including motion-activated cameras and global positioning system collars. As a result of the wide variation and lack of consensus in the definitions of direct and indirect contacts, we developed a unified framework to define livestock-wildlife contacts that is sufficiently flexible to be applied to most wildlife and livestock species for non-vector-borne diseases. We hope this framework will help standardise the collection and reporting of contact data; a valuable step towards being able to compare the efficacy of wildlife-livestock observation methods. In doing so, it may aid the development of better disease transmission models and improve the design and effectiveness of interventions to reduce or prevent disease transmission.
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Affiliation(s)
| | | | - Simon Gubbins
- The Pirbright Institute, Woking, Surrey, United Kingdom
| | - Adam J. Kucharski
- London School of Hygiene & Tropical Medicine, University of London, London, United Kingdom
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16
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Smith JE, Pinter-Wollman N. Observing the unwatchable: Integrating automated sensing, naturalistic observations and animal social network analysis in the age of big data. J Anim Ecol 2020; 90:62-75. [PMID: 33020914 DOI: 10.1111/1365-2656.13362] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 09/15/2020] [Indexed: 12/11/2022]
Abstract
In the 4.5 decades since Altmann (1974) published her seminal paper on the methods for the observational study of behaviour, automated detection and analysis of social interaction networks have fundamentally transformed the ways that ecologists study social behaviour. Methodological developments for collecting data remotely on social behaviour involve indirect inference of associations, direct recordings of interactions and machine vision. These recent technological advances are improving the scale and resolution with which we can dissect interactions among animals. They are also revealing new intricacies of animal social interactions at spatial and temporal resolutions as well as in ecological contexts that have been hidden from humans, making the unwatchable seeable. We first outline how these technological applications are permitting researchers to collect exquisitely detailed information with little observer bias. We further recognize new emerging challenges from these new reality-mining approaches. While technological advances in automating data collection and its analysis are moving at an unprecedented rate, we urge ecologists to thoughtfully combine these new tools with classic behavioural and ecological monitoring methods to place our understanding of animal social networks within fundamental biological contexts.
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Affiliation(s)
| | - Noa Pinter-Wollman
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, Los Angeles, CA, USA
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17
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Triguero-Ocaña R, Laguna E, Jiménez-Ruiz S, Fernández-López J, García-Bocanegra I, Barasona JÁ, Risalde MÁ, Montoro V, Vicente J, Acevedo P. The wildlife-livestock interface on extensive free-ranging pig farms in central Spain during the "montanera" period. Transbound Emerg Dis 2020; 68:2066-2078. [PMID: 32979253 DOI: 10.1111/tbed.13854] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 09/18/2020] [Accepted: 09/18/2020] [Indexed: 12/14/2022]
Abstract
The effective management of shared pathogens between wild ungulates and livestock requires the understanding of the processes of interaction between them. In this work, we studied the interspecific frequency of interaction (ifreq) and its spatiotemporal pattern between wild and domestic ungulates that coexist in free-ranging farms. For this purpose, 6 red deer, 6 wild boar, 8 Iberian pigs and 3 cattle were monitored using GPS devices during the "montanera" period (the period in which Iberian pigs are maintained in extensive conditions to feed on acorn). The ifreq was quantified for two spatiotemporal windows: 30 m - 10 min, for inferring potential direct interactions (short window), and 30 m - 12 days for indirect interactions (large window). Secondly, the variation in the ifreq was modelled with regard to 2 temporal (time of the day and week of the year) and 4 environmental factors (distance to water, distance to vegetation cover, Quercus density and distance to feeding points). The interactions at the short window were scarce (N = 13); however, they were very frequent at the large one (N = 37,429), with the red deer as the species with the greatest involvement in the interactions. Models showed that the time of the day and distance to water were the variables that best predicted the ifreq and they were conditioned by differences in the activity pattern of the targeted species. Food resource availability also predicted the ifreq, especially at the short window and between wild species. The results presented here highlight the role that wild ungulates may play in the transmission of pathogens to extensive livestock in general and pigs in particular and show the epidemiological risk of certain areas, periods of time and management practices (for wildlife and livestock) as well as providing useful information in the prevention of the transmission of shared pathogens.
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Affiliation(s)
- Roxana Triguero-Ocaña
- Instituto de Investigación en Recursos Cinegéticos (IREC), UCLM-CSIC-JCCM, Ciudad Real, Spain.,VISAVET Health Surveillance Centre, Universidad Complutense de Madrid, Madrid, Spain
| | - Eduardo Laguna
- Instituto de Investigación en Recursos Cinegéticos (IREC), UCLM-CSIC-JCCM, Ciudad Real, Spain
| | - Saúl Jiménez-Ruiz
- Instituto de Investigación en Recursos Cinegéticos (IREC), UCLM-CSIC-JCCM, Ciudad Real, Spain.,Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de Córdoba-Campus de Excelencia Internacional Agroalimentario (ceiA3), Córdoba, Spain
| | - Javier Fernández-López
- Instituto de Investigación en Recursos Cinegéticos (IREC), UCLM-CSIC-JCCM, Ciudad Real, Spain
| | - Ignacio García-Bocanegra
- Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de Córdoba-Campus de Excelencia Internacional Agroalimentario (ceiA3), Córdoba, Spain
| | - Jose Ángel Barasona
- VISAVET Health Surveillance Centre, Universidad Complutense de Madrid, Madrid, Spain
| | - Maria Ángeles Risalde
- Departamento de Anatomía y Anatomía Patológica Comparadas, Facultad de Veterinaria, Universidad de Córdoba, Córdoba, Spain
| | - Vidal Montoro
- Instituto de Investigación en Recursos Cinegéticos (IREC), UCLM-CSIC-JCCM, Ciudad Real, Spain.,Escuela Técnica Superior de Ingenieros Agrónomos, UCLM, Ciudad Real, Spain
| | - Joaquín Vicente
- Instituto de Investigación en Recursos Cinegéticos (IREC), UCLM-CSIC-JCCM, Ciudad Real, Spain.,Escuela Técnica Superior de Ingenieros Agrónomos, UCLM, Ciudad Real, Spain
| | - Pelayo Acevedo
- Instituto de Investigación en Recursos Cinegéticos (IREC), UCLM-CSIC-JCCM, Ciudad Real, Spain.,Escuela Técnica Superior de Ingenieros Agrónomos, UCLM, Ciudad Real, Spain
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18
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Lekko YM, Ooi PT, Omar S, Mazlan M, Ramanoon SZ, Jasni S, Jesse FFA, Che-Amat A. Mycobacterium tuberculosis complex in wildlife: Review of current applications of antemortem and postmortem diagnosis. Vet World 2020; 13:1822-1836. [PMID: 33132593 PMCID: PMC7566238 DOI: 10.14202/vetworld.2020.1822-1836] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Accepted: 07/16/2020] [Indexed: 12/31/2022] Open
Abstract
Tuberculosis (TB) is a chronic inflammatory and zoonotic disease caused by Mycobacterium tuberculosis complex (MTBC) members, which affects various domestic animals, wildlife, and humans. Some wild animals serve as reservoir hosts in the transmission and epidemiology of the disease. Therefore, the monitoring and surveillance of both wild and domestic hosts are critical for prevention and control strategies. For TB diagnosis, the single intradermal tuberculin test or the single comparative intradermal tuberculin test, and the gamma-interferon test, which is regarded as an ancillary test, are used. Postmortem examination can identify granulomatous lesions compatible with a diagnosis of TB. In contrast, smears of the lesions can be stained for acid-fast bacilli, and samples of the affected organs can be subjected to histopathological analyses. Culture is the gold standard test for isolating mycobacterial bacilli because it has high sensitivity and specificity compared with other methods. Serology for antibody detection allows the testing of many samples simply, rapidly, and inexpensively, and the protocol can be standardized in different laboratories. Molecular biological analyses are also applicable to trace the epidemiology of the disease. In conclusion, reviewing the various techniques used in MTBC diagnosis can help establish guidelines for researchers when choosing a particular diagnostic method depending on the situation at hand, be it disease outbreaks in wildlife or for epidemiological studies. This is because a good understanding of various diagnostic techniques will aid in monitoring and managing emerging pandemic threats of infectious diseases from wildlife and also preventing the potential spread of zoonotic TB to livestock and humans. This review aimed to provide up-to-date information on different techniques used for diagnosing TB at the interfaces between wildlife, livestock, and humans.
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Affiliation(s)
- Yusuf Madaki Lekko
- Department of Veterinary Clinical Studies, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.,Department of Veterinary Medicine, Faculty of Veterinary Medicine, University of Maiduguri, 1069 PMB, Maiduguri, Borno State, Nigeria
| | - Peck Toung Ooi
- Department of Veterinary Clinical Studies, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia
| | - Sharina Omar
- Department of Veterinary Pathology and Microbiology, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia
| | - Mazlina Mazlan
- Department of Veterinary Pathology and Microbiology, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia
| | - Siti Zubaidah Ramanoon
- Department of Farm and Exotic Animal Medicine and Surgery, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia
| | - Sabri Jasni
- Department of Paraclinical, Faculty of Veterinary Medicine, Universiti Malaysia Kelantan, Pengkalan Chepa, 16100 Kota Bharu, Kelantan, Malaysia
| | - Faez Firdaus Abdullah Jesse
- Department of Veterinary Clinical Studies, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia
| | - Azlan Che-Amat
- Department of Veterinary Clinical Studies, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia
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Milne G, Allen A, Graham J, Kirke R, McCormick C, Presho E, Skuce R, Byrne AW. Mycobacterium bovis Population Structure in Cattle and Local Badgers: Co-Localisation and Variation by Farm Type. Pathogens 2020; 9:pathogens9070592. [PMID: 32708155 PMCID: PMC7400278 DOI: 10.3390/pathogens9070592] [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: 05/25/2020] [Revised: 07/03/2020] [Accepted: 07/08/2020] [Indexed: 11/16/2022] Open
Abstract
Bovine tuberculosis surveillance in Northern Ireland includes Multiple-Locus Variable number tandem repeat Analysis (MLVA) to determine the Mycobacterium bovis genetic type present in both cattle and the predominant wildlife host, the European badger (Meles meles). These data are useful for investigating clusters of infection and understanding the scale at which interspecific transmission may occur. We utilised a comprehensive dataset of routinely sampled isolates from infected cattle and from badgers killed in road-traffic accidents to investigate the spatial co-location of MLVA types in, and between, the badger and cattle populations. Furthermore, we investigated the hypothesis that the type of farming enterprise might explain some variation in this relationship. MLVA types were spatially co-localised in cattle and road-traffic accident (RTA) badger hosts, indicative of a shared epidemic. Dairy herds were more likely to have at least one MLVA type in common with nearby RTA badgers, compared to non-dairy herd types. Marginally more MLVA spatial clustering was observed in non-dairy herds, which may be a consequence of relatively more between-herd movements. For the cattle population, local transmission mechanisms such as infection from contiguous herds, infectious wildlife and short-range between-herd cattle movements appear primarily to drive the epidemic: there appears to be a more limited role for long-range movements. Animal management practices are likely to be the driving force behind this observation, as beef rearing is associated with elevated numbers of animal movements compared to dairy herds.
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Affiliation(s)
- Georgina Milne
- Veterinary Sciences Division, Agri-Food and Biosciences Institute (AFBI), Belfast BT4 3SD, UK; (A.A.); (J.G.); (E.P.); (R.S.)
- Correspondence:
| | - Adrian Allen
- Veterinary Sciences Division, Agri-Food and Biosciences Institute (AFBI), Belfast BT4 3SD, UK; (A.A.); (J.G.); (E.P.); (R.S.)
| | - Jordon Graham
- Veterinary Sciences Division, Agri-Food and Biosciences Institute (AFBI), Belfast BT4 3SD, UK; (A.A.); (J.G.); (E.P.); (R.S.)
| | - Raymond Kirke
- Veterinary Epidemiology Unit, Department of Agriculture, Environment and Rural Affairs, Belfast BT4 3SB, UK;
| | - Carl McCormick
- Department of Agriculture, Environment and Rural Affairs, Veterinary Service Animal Health, Coleraine BT52 2AJ, UK;
| | - Eleanor Presho
- Veterinary Sciences Division, Agri-Food and Biosciences Institute (AFBI), Belfast BT4 3SD, UK; (A.A.); (J.G.); (E.P.); (R.S.)
| | - Robin Skuce
- Veterinary Sciences Division, Agri-Food and Biosciences Institute (AFBI), Belfast BT4 3SD, UK; (A.A.); (J.G.); (E.P.); (R.S.)
- School of Biological Sciences, Queen’s University Belfast, Belfast BT9 5DL, UK;
| | - Andrew W. Byrne
- School of Biological Sciences, Queen’s University Belfast, Belfast BT9 5DL, UK;
- One-Health Unit, Department of Agriculture, Food and the Marine, Agriculture House, Dublin, Ireland
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20
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Milne G, Allen A, Graham J, Lahuerta-Marin A, McCormick C, Presho E, Reid N, Skuce R, Byrne AW. Bovine tuberculosis breakdown duration in cattle herds: an investigation of herd, host, pathogen and wildlife risk factors. PeerJ 2020; 8:e8319. [PMID: 32117602 PMCID: PMC7003687 DOI: 10.7717/peerj.8319] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 11/29/2019] [Indexed: 11/20/2022] Open
Abstract
Background Despite rigorous controls placed on herds which disclose ante-mortem test positive cattle to bovine tuberculosis, caused by the infection of Mycobacterium bovis, many herds in Northern Ireland (NI) experience prolonged breakdowns. These herds represent a considerable administrative and financial burden to the State and farming community. Methods A retrospective observational study was conducted to better understand the factors associated with breakdown duration, which was modelled using both negative binomial and ordinal regression approaches. Results Six explanatory variables were important predictors of breakdown length in both models; herd size, the number of reactors testing positive in the initial SICCT test, the presence of a lesioned animal at routine slaughter (LRS), the count of M. bovis genotypes during the breakdown (MLVA richness), the local herd-level bTB prevalence, and the presence of herds linked via management factors (associated herds). We report that between 2008 and 2014, mean breakdown duration in NI was 226 days (approx. seven months; median: 188 days). In the same period, however, more than 6% of herds in the region remained under movement restriction for more than 420 days (13 months); almost twice as long as the mean. The MLVA richness variable was a particularly important predictor of breakdown duration. We contend that this variable primarily represents a proxy for beef fattening herds, which can operate by purchasing cattle and selling animals straight to slaughter, despite prolonged trading restrictions. For other herd types, the model supports the hypothesis that prolonged breakdowns are a function of both residual infection within the herd, and infection from the environment (e.g. infected wildlife, contiguous herds and/or a contaminated environment). The impact of badger density on breakdown duration was assessed by including data on main sett (burrow) density. Whilst a positive association was observed in the univariate analysis, confounding with other variables means that the contribution of badgers to prolonged breakdowns was not clear from our study. We do not fully reject the hypothesis that badgers are implicated in prolonging bTB breakdowns via spillback infection, but given our results, we posit that increased disease risk from badgers is unlikely to simply be a function of increasing badger density measured using sett metrics.
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Affiliation(s)
- Georgina Milne
- Veterinary Sciences Division, Agri-food and Biosciences Institute, Belfast, United Kingdom
| | - Adrian Allen
- Veterinary Sciences Division, Agri-food and Biosciences Institute, Belfast, United Kingdom
| | - Jordon Graham
- Veterinary Sciences Division, Agri-food and Biosciences Institute, Belfast, United Kingdom
| | - Angela Lahuerta-Marin
- Veterinary Sciences Division, Agri-food and Biosciences Institute, Belfast, United Kingdom
| | - Carl McCormick
- Veterinary Sciences Division, Agri-food and Biosciences Institute, Belfast, United Kingdom.,Department of Agriculture, Environment, and Rural Affairs, Coleraine, United Kingdom
| | - Eleanor Presho
- Veterinary Sciences Division, Agri-food and Biosciences Institute, Belfast, United Kingdom
| | - Neil Reid
- School of Biological Sciences, Queen's University Belfast, Belfast, United Kingdom
| | - Robin Skuce
- Veterinary Sciences Division, Agri-food and Biosciences Institute, Belfast, United Kingdom
| | - Andrew W Byrne
- Veterinary Sciences Division, Agri-food and Biosciences Institute, Belfast, United Kingdom.,School of Biological Sciences, Queen's University Belfast, Belfast, United Kingdom.,One-Health Scientific Support Unit, Department of Agriculture, Food and the Marine, Dublin, Ireland
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21
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Powell SN, Wallen MM, Miketa ML, Krzyszczyk E, Foroughirad V, Bansal S, Mann J. Sociality and tattoo skin disease among bottlenose dolphins in Shark Bay, Australia. Behav Ecol 2019. [DOI: 10.1093/beheco/arz207] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Abstract
Social behavior is an important driver of infection dynamics, though identifying the social interactions that foster infectious disease transmission is challenging. Here we examine how social behavior impacts disease transmission in Indo-Pacific bottlenose dolphins (Tursiops aduncus) using an easily identifiable skin disease and social network data. We analyzed tattoo skin disease (TSD) lesions based on photographs collected as part of a 34-year longitudinal study in relation to the sociality of T. aduncus using three metrics (degree, time spent socializing, and time in groups) and network structure, using the k-test. We show that calves with TSD in the second year of life associated more with TSD-positive individuals in the first year of life compared with calves that did not have TSD. Additionally, the network k-test showed that the social network links are epidemiologically relevant for transmission. However, degree, time spent in groups, and time spent socializing were not significantly different between infected and uninfected groups. Our findings indicate that association with infected individuals is predictive of an individual’s risk for TSD and that the social association network can serve as a proxy for studying the epidemiology of skin diseases in bottlenose dolphins.
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Affiliation(s)
- Sarah N Powell
- Department of Biology, Georgetown University, Washington, DC, USA
| | - Megan M Wallen
- Department of Biology, Georgetown University, Washington, DC, USA
| | - Madison L Miketa
- Department of Biology, Georgetown University, Washington, DC, USA
| | - Ewa Krzyszczyk
- Department of Biology, Georgetown University, Washington, DC, USA
| | | | - Shweta Bansal
- Department of Biology, Georgetown University, Washington, DC, USA
| | - Janet Mann
- Department of Biology, Georgetown University, Washington, DC, USA
- Department of Psychology, Georgetown University, Washington, DC, USA
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22
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Gaughran A, MacWhite T, Mullen E, Maher P, Kelly DJ, Good M, Marples NM. Dispersal patterns in a medium-density Irish badger population: Implications for understanding the dynamics of tuberculosis transmission. Ecol Evol 2019; 9:13142-13152. [PMID: 31871635 PMCID: PMC6912907 DOI: 10.1002/ece3.5753] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 07/26/2019] [Accepted: 09/15/2019] [Indexed: 11/12/2022] Open
Abstract
European badgers (Meles meles) are group-living mustelids implicated in the spread of bovine tuberculosis (TB) to cattle and act as a wildlife reservoir for the disease. In badgers, only a minority of individuals disperse from their natal social group. However, dispersal may be extremely important for the spread of TB, as dispersers could act as hubs for disease transmission. We monitored a population of 139 wild badgers over 7 years in a medium-density population (1.8 individuals/km2). GPS tracking collars were applied to 80 different individuals. Of these, we identified 25 dispersers, 14 of which were wearing collars as they dispersed. This allowed us to record the process of dispersal in much greater detail than ever before. We show that dispersal is an extremely complex process, and measurements of straight-line distance between old and new social groups can severely underestimate how far dispersers travel. Assumptions of straight-line travel can also underestimate direct and indirect interactions and the potential for disease transmission. For example, one female disperser which eventually settled 1.5 km from her natal territory traveled 308 km and passed through 22 different territories during dispersal. Knowledge of badgers' ranging behavior during dispersal is crucial to understanding the dynamics of TB transmission, and for designing appropriate interventions, such as vaccination.
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Affiliation(s)
- Aoibheann Gaughran
- Department of ZoologySchool of Natural SciencesTrinity College DublinDublinIreland
- Trinity Centre for Biodiversity ResearchTrinity College DublinDublinIreland
| | | | - Enda Mullen
- Department of Culture, Heritage and the GaeltachtNational Parks and Wildlife ServiceDublinIreland
| | - Peter Maher
- Department of Agriculture, Food and the MarineDublinIreland
| | - David J. Kelly
- Department of ZoologySchool of Natural SciencesTrinity College DublinDublinIreland
- Trinity Centre for Biodiversity ResearchTrinity College DublinDublinIreland
| | - Margaret Good
- Department of ZoologySchool of Natural SciencesTrinity College DublinDublinIreland
- Trinity Centre for Biodiversity ResearchTrinity College DublinDublinIreland
| | - Nicola M. Marples
- Department of ZoologySchool of Natural SciencesTrinity College DublinDublinIreland
- Trinity Centre for Biodiversity ResearchTrinity College DublinDublinIreland
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23
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Ham C, Donnelly CA, Astley KL, Jackson SYB, Woodroffe R. Effect of culling on individual badger Meles meles behaviour: Potential implications for bovine tuberculosis transmission. J Appl Ecol 2019; 56:2390-2399. [PMID: 34565831 PMCID: PMC8447922 DOI: 10.1111/1365-2664.13512] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 07/30/2019] [Indexed: 11/27/2022]
Abstract
Culling wildlife as a form of disease management can have unexpected and sometimes counterproductive outcomes. In the UK, badgers Meles meles are culled in efforts to reduce badger-to-cattle transmission of Mycobacterium bovis, the causative agent of bovine tuberculosis (TB). However, culling has previously been associated with both increased and decreased incidence of M. bovis infection in cattle.The adverse effects of culling have been linked to cull-induced changes in badger ranging, but such changes are not well-documented at the individual level. Using GPS-collars, we characterized individual badger behaviour within an area subjected to widespread industry-led culling, comparing it with the same area before culling and with three unculled areas.Culling was associated with a 61% increase (95% CI 27%-103%) in monthly home range size, a 39% increase (95% CI 28%-51%) in nightly maximum distance from the sett, and a 17% increase (95% CI 11%-24%) in displacement between successive GPS-collar locations recorded at 20-min intervals. Despite travelling further, we found a 91.2 min (95% CI 67.1-115.3 min) reduction in the nightly activity time of individual badgers associated with culling. These changes became apparent while culls were ongoing and persisted after culling ended.Expanded ranging in culled areas was associated with individual badgers visiting 45% (95% CI 15%-80%) more fields each month, suggesting that surviving individuals had the opportunity to contact more cattle. Moreover, surviving badgers showed a 19.9-fold increase (95% CI 10.8-36.4-fold increase) in the odds of trespassing into neighbouring group territories, increasing opportunities for intergroup contact.Synthesis and applications. Badger culling was associated with behavioural changes among surviving badgers which potentially increased opportunities for both badger-to-badger and badger-to-cattle transmission of Mycobacterium bovis. Furthermore, by reducing the time badgers spent active, culling may have reduced badgers' accessibility to shooters, potentially undermining subsequent population control efforts. Our results specifically illustrate the challenges posed by badger behaviour to cull-based TB control strategies and furthermore, they highlight the negative impacts culling can have on integrated disease control strategies.
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Affiliation(s)
- Cally Ham
- Department of Infectious Disease EpidemiologyScience and Solutions for a Changing Planet DTPMRC Centre for Global Infectious Disease AnalysisImperial College LondonLondonUK
- Institute of ZoologyRegent's Park, LondonUK
| | - Christl A. Donnelly
- Department of Infectious Disease EpidemiologyMRC Centre for Global Infectious Disease AnalysisImperial College LondonLondonUK
- Department of StatisticsUniversity of OxfordOxfordUK
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Murphy D, Mumby HS, Henley MD. Age differences in the temporal stability of a male African elephant (Loxodonta africana) social network. Behav Ecol 2019. [DOI: 10.1093/beheco/arz152] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Social animals live in complex and variable socio-ecological environments where individuals adapt their behavior to local conditions. Recently, there have been calls for studies of animal social networks to take account of temporal dynamics in social relationships as these have implications for the spread of information and disease, group cohesion, and the drivers of sociality, and there is evidence that maintaining stable social relationships has fitness benefits. It has recently been recognized that male elephants form strong social bonds with other males. The nature of these relationships, and thus network structure, may vary over time in response to varying environmental conditions and as individuals age. Using social network analysis, we examine the stability of relationships and network centrality in a population of male African elephants. Our results suggest that males may maintain stable social relationships with others over time. Older males show greater stability in network centrality than younger males, suggesting younger males face uncertainty in transitioning to adult society. For elephants, where older individuals function as social repositories of knowledge, maintaining a social network underpinned by older males could be of particular importance.
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Affiliation(s)
- Derek Murphy
- Department of Zoology, University of Cambridge, Cambridge, UK
| | - Hannah S Mumby
- Department of Zoology, University of Cambridge, Cambridge, UK
- College for Life Sciences, Wissenschaftskolleg zu Berlin, Wallotstraße, Berlin, Germany
- Centre for African Ecology, School of Animal, Plant and Environmental Sciences, University of Witwatersrand, Wits, South Africa
- School of Biological Sciences, University of Hong Kong, Pok Fu Lam, Hong Kong
| | - Michelle D Henley
- Elephants Alive, Hoedspruit, South Africa
- Applied Ecosystem and Conservation Research Unit, University of South Africa, Johannesburg, South Africa
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Saleetid N, Green DM. Network structure and risk-based surveillance algorithms for live shrimp movements in Thailand. Transbound Emerg Dis 2019; 66:2450-2461. [PMID: 31389195 DOI: 10.1111/tbed.13303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 06/19/2019] [Accepted: 06/27/2019] [Indexed: 11/29/2022]
Abstract
Live shrimp movements pose a potential route for site-to-site transmission of acute hepatopancreatic necrosis disease (AHPND) and other shrimp diseases. We present the first application of network theory to study shrimp epizootiology, providing quantitative information about the live shrimp movement network of Thailand (LSMN), and supporting practical and policy implementations of disease surveillance and control measures. We examined the LSMN over a 13-month period from March 2013 to March 2014, with data obtained from the Thailand Department of Fisheries. The LSMN had a mixture of characteristics both limiting and facilitating disease spread. Importantly, the LSMN exhibited power-law distributions of in and out degrees with exponents of 2.87 and 2.17, respectively. This characteristic indicates that the LSMN behaves like a scale-free network and suggests that an effective strategy to control disease spread in the Thai shrimp farming sector can be achieved by removing a small number of targeted inter-site connections (arcs between nodes). Specifically, a disease-control algorithm based on betweenness centrality (defined as the number of shortest paths between node pairs that traverse a given arc) is proposed here to prioritize targets for disease surveillance and control measures.
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Affiliation(s)
- Nattakan Saleetid
- Department of Fisheries, Kasetsart University Campus, Bangkok, Thailand
| | - Darren Michael Green
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, UK
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26
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Sanchez JN, Hudgens BR. Impacts of Heterogeneous Host Densities and Contact Rates on Pathogen Transmission in the Channel Island Fox ( Urocyon littoralis). BIOLOGICAL CONSERVATION 2019; 236:593-603. [PMID: 32831352 PMCID: PMC7441459 DOI: 10.1016/j.biocon.2019.05.045] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Diseases threaten wildlife populations worldwide and have caused severe declines resulting in host species being listed as threatened or endangered. The risk of a widespread epidemic is especially high when pathogens are introduced to naive host populations, often leading to high morbidity and mortality. Prevention and control of these epidemics is based on knowledge of what drives pathogen transmission among hosts. Previous disease outbreaks suggest the spread of directly transmitted pathogens is determined by host contact rates and local host density. While theoretical models of disease spread typically assume a constant host density, most wildlife populations occur at a variety of densities across the landscape. We explored how spatial heterogeneity in host density influences pathogen spread by simulating the introduction and spread of rabies and canine distemper in a spatially heterogeneous population of Channel Island foxes (Urocyon littoralis), coupling fox density and contact rates with probabilities of viral transmission. For both diseases, the outcome of pathogen introductions varied widely among simulation iterations and depended on the density of hosts at the site of pathogen introduction. Introductions into areas of higher fox densities resulted in more rapid pathogen transmission and greater impact on the host population than if the pathogen was introduced at lower densities. Both pathogens were extirpated in a substantial fraction of iterations. Rabies was over five times more likely to go locally extinct when introduced at low host density sites than at high host-density sites, leaving an average of >99% of foxes uninfected. Canine distemper went extinct in >98% of iterations regardless of introduction site, but only after >90% of foxes had become infected. Our results highlight the difficulty in predicting the course of an epidemic, in part due to complex interactions between pathogen biology and host behavior, exacerbated by the spatial variation of most host populations.
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Affiliation(s)
- Jessica N Sanchez
- Institute for Wildlife Studies, P.O. Box 1104, Arcata, California 95518, USA
| | - Brian R Hudgens
- Institute for Wildlife Studies, P.O. Box 1104, Arcata, California 95518, USA
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Campbell EL, Byrne AW, Menzies FD, McBride KR, McCormick CM, Scantlebury M, Reid N. Interspecific visitation of cattle and badgers to fomites: A transmission risk for bovine tuberculosis? Ecol Evol 2019; 9:8479-8489. [PMID: 31410255 PMCID: PMC6686281 DOI: 10.1002/ece3.5282] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 04/04/2019] [Accepted: 04/23/2019] [Indexed: 01/10/2023] Open
Abstract
In Great Britain and Ireland, badgers (Meles meles) are a wildlife reservoir of Mycobacterium bovis and implicated in bovine tuberculosis transmission to domestic cattle. The route of disease transmission is unknown with direct, so-called "nose-to-nose," contact between hosts being extremely rare. Camera traps were deployed for 64,464 hr on 34 farms to quantify cattle and badger visitation rates in space and time at six farm locations. Badger presence never coincided with cattle presence at the same time, with badger and cattle detection at the same location but at different times being negatively correlated. Badgers were never recorded within farmyards during the present study. Badgers utilized cattle water troughs in fields, but detections were infrequent (equivalent to one badger observed drinking every 87 days). Cattle presence at badger-associated locations, for example, setts and latrines, were three times more frequent than badger presence at cattle-associated locations, for example, water troughs. Preventing cattle access to badger setts and latrines and restricting badger access to cattle water troughs may potentially reduce interspecific bTB transmission through reduced indirect contact.
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Affiliation(s)
- Emma L. Campbell
- School of Biological SciencesQueen's University BelfastBelfastUK
- Veterinary Sciences DivisionAgri‐Food and Biosciences Institute (AFBI)BelfastUK
| | - Andrew W. Byrne
- School of Biological SciencesQueen's University BelfastBelfastUK
- Veterinary Sciences DivisionAgri‐Food and Biosciences Institute (AFBI)BelfastUK
- Present address:
Department of AgricultureFood and the Marine (DAFM), Agriculture HouseDublin 2Ireland
| | - Fraser D. Menzies
- Veterinary Epidemiology Unit, Department of AgricultureEnvironment and Rural Affairs (DAERA)BelfastUK
| | - Kathryn R. McBride
- Veterinary Epidemiology Unit, Department of AgricultureEnvironment and Rural Affairs (DAERA)BelfastUK
| | - Carl M. McCormick
- Veterinary Sciences DivisionAgri‐Food and Biosciences Institute (AFBI)BelfastUK
- Veterinary Epidemiology Unit, Department of AgricultureEnvironment and Rural Affairs (DAERA)BelfastUK
| | - Michael Scantlebury
- School of Biological SciencesQueen's University BelfastBelfastUK
- Institute for Global Food Security (IGFS)Queen's University BelfastBelfastUK
| | - Neil Reid
- School of Biological SciencesQueen's University BelfastBelfastUK
- Institute for Global Food Security (IGFS)Queen's University BelfastBelfastUK
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Chaters GL, Johnson PCD, Cleaveland S, Crispell J, de Glanville WA, Doherty T, Matthews L, Mohr S, Nyasebwa OM, Rossi G, Salvador LCM, Swai E, Kao RR. Analysing livestock network data for infectious disease control: an argument for routine data collection in emerging economies. Philos Trans R Soc Lond B Biol Sci 2019; 374:20180264. [PMID: 31104601 PMCID: PMC6558568 DOI: 10.1098/rstb.2018.0264] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/13/2019] [Indexed: 11/12/2022] Open
Abstract
Livestock movements are an important mechanism of infectious disease transmission. Where these are well recorded, network analysis tools have been used to successfully identify system properties, highlight vulnerabilities to transmission, and inform targeted surveillance and control. Here we highlight the main uses of network properties in understanding livestock disease epidemiology and discuss statistical approaches to infer network characteristics from biased or fragmented datasets. We use a 'hurdle model' approach that predicts (i) the probability of movement and (ii) the number of livestock moved to generate synthetic 'complete' networks of movements between administrative wards, exploiting routinely collected government movement permit data from northern Tanzania. We demonstrate that this model captures a significant amount of the observed variation. Combining the cattle movement network with a spatial between-ward contact layer, we create a multiplex, over which we simulated the spread of 'fast' ( R0 = 3) and 'slow' ( R0 = 1.5) pathogens, and assess the effects of random versus targeted disease control interventions (vaccination and movement ban). The targeted interventions substantially outperform those randomly implemented for both fast and slow pathogens. Our findings provide motivation to encourage routine collection and centralization of movement data to construct representative networks. This article is part of the theme issue 'Modelling infectious disease outbreaks in humans, animals and plants: epidemic forecasting and control'. This theme issue is linked with the earlier issue 'Modelling infectious disease outbreaks in humans, animals and plants: approaches and important themes'.
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Affiliation(s)
- G. L. Chaters
- Boyd Orr Centre for Population and Ecosystem Health, Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, UK
| | - P. C. D. Johnson
- Boyd Orr Centre for Population and Ecosystem Health, Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, UK
| | - S. Cleaveland
- Boyd Orr Centre for Population and Ecosystem Health, Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, UK
| | - J. Crispell
- School of Veterinary Medicine, University College Dublin, Dublin, Ireland
| | - W. A. de Glanville
- Boyd Orr Centre for Population and Ecosystem Health, Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, UK
| | - T. Doherty
- Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Easter Bush Campus, Midlothian EH25 9RG, UK
| | - L. Matthews
- Boyd Orr Centre for Population and Ecosystem Health, Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, UK
| | - S. Mohr
- Boyd Orr Centre for Population and Ecosystem Health, Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, UK
| | - O. M. Nyasebwa
- Department of Veterinary Services, Ministry of Livestock and Fisheries, Nelson Mandela Road, Dar Es Salaam, Tanzania
| | - G. Rossi
- Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Easter Bush Campus, Midlothian EH25 9RG, UK
| | - L. C. M. Salvador
- Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Easter Bush Campus, Midlothian EH25 9RG, UK
- Department of Infectious Diseases, University of Georgia, Athens, GA 30602, USA
- Institute of Bioinformatics, University of Georgia, Athens, GA 30602, USA
| | - E. Swai
- Department of Veterinary Services, Ministry of Livestock and Fisheries, Nelson Mandela Road, Dar Es Salaam, Tanzania
| | - R. R. Kao
- Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Easter Bush Campus, Midlothian EH25 9RG, UK
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29
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Use of social network analysis to improve the understanding of social behaviour in dairy cattle and its impact on disease transmission. Appl Anim Behav Sci 2019. [DOI: 10.1016/j.applanim.2019.01.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Wilber MQ, Pepin KM, Campa H, Hygnstrom SE, Lavelle MJ, Xifara T, VerCauteren KC, Webb CT. Modelling multi‐species and multi‐mode contact networks: Implications for persistence of bovine tuberculosis at the wildlife–livestock interface. J Appl Ecol 2019. [DOI: 10.1111/1365-2664.13370] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Mark Q. Wilber
- Department of BiologyColorado State University Fort Collins Colorado
- United States Department of Agriculture, Animal and Plant Health Inspection ServiceWildlife ServicesNational Wildlife Research Center Fort Collins Colorado
| | - Kim M. Pepin
- United States Department of Agriculture, Animal and Plant Health Inspection ServiceWildlife ServicesNational Wildlife Research Center Fort Collins Colorado
| | - Henry Campa
- Department of Fisheries and WildlifeMichigan State University East Lansing Minnesota
| | - Scott E. Hygnstrom
- Wisconsin Center for WildlifeCollege of Natural ResourcesUniversity of Wisconsin‐Stevens Point Stevens Point Wisconsin
| | - Michael J. Lavelle
- United States Department of Agriculture, Animal and Plant Health Inspection ServiceWildlife ServicesNational Wildlife Research Center Fort Collins Colorado
| | - Tatiana Xifara
- Department of BiologyColorado State University Fort Collins Colorado
- United States Department of Agriculture, Animal and Plant Health Inspection ServiceWildlife ServicesNational Wildlife Research Center Fort Collins Colorado
| | - Kurt C. VerCauteren
- United States Department of Agriculture, Animal and Plant Health Inspection ServiceWildlife ServicesNational Wildlife Research Center Fort Collins Colorado
| | - Colleen T. Webb
- Department of BiologyColorado State University Fort Collins Colorado
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Triguero-Ocaña R, Barasona JA, Carro F, Soriguer RC, Vicente J, Acevedo P. Spatio-temporal trends in the frequency of interspecific interactions between domestic and wild ungulates from Mediterranean Spain. PLoS One 2019; 14:e0211216. [PMID: 30682123 PMCID: PMC6347242 DOI: 10.1371/journal.pone.0211216] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Accepted: 01/09/2019] [Indexed: 01/22/2023] Open
Abstract
Controlling infections shared by wildlife and livestock requires the understanding and quantification of interspecific interactions between the species involved. This is particularly important in extensive multi-host systems, in which controlled domestic animals interact with uncontrolled, abundant and expanding wild species, such as wild ungulates. We have, therefore, quantified the interspecific interactions between wild boar (Sus scrofa) and free-ranging cattle in Mediterranean Spain, along with their spatio-temporal variability. GPS-GSM-collars were used to monitor 12 cows and 14 wild boar in the Doñana National Park between 2011 and 2013. Interactions were defined as encounters between cattle and wild boar within a spatio-temporal window of 52 m and 1 hour. On average, each wild boar interacted with one cow 1.5 ± (SE) 0.5 times per day, while each cow interacted with one wild boar 1.3 ± 0.4 times per day. The frequency of interaction was significantly higher during crepuscular hours owing to the overlap of both species’ activity, and also during spring and autumn, probably owing to a higher individual aggregation around shared resources. Finally, the frequency of interaction was higher near the most significant shared resources (e.g. water points) but was lower in areas with dense vegetation. The results presented here show the usefulness of GPS monitoring as regards quantifying interactions and helping to clarify the process of pathogen transmission at the wildlife-livestock interface in Mediterranean Spain, along with the main spatio-temporal risk factors. In a changing scenario in which European populations of wild ungulates are increasing, more efficient measures with which to control interactions are required to meet the demands of farmers and managers. Our results, therefore, provide directional hypotheses that could be used to design disease control programmes.
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Affiliation(s)
- Roxana Triguero-Ocaña
- Instituto de Investigación en Recursos Cinegéticos, IREC (UCLM-CSIC-JCCM), Ciudad Real, Spain
- * E-mail:
| | - José A. Barasona
- VISAVET Centre, Animal Health Department, Complutense University of Madrid, Madrid, Spain
| | | | | | - Joaquín Vicente
- Instituto de Investigación en Recursos Cinegéticos, IREC (UCLM-CSIC-JCCM), Ciudad Real, Spain
- Escuela Técnica Superior de Ingenieros Agrónomos, UCLM, Ciudad Real, Spain
| | - Pelayo Acevedo
- Instituto de Investigación en Recursos Cinegéticos, IREC (UCLM-CSIC-JCCM), Ciudad Real, Spain
- Escuela Técnica Superior de Ingenieros Agrónomos, UCLM, Ciudad Real, Spain
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32
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Huyvaert KP, Russell RE, Patyk KA, Craft ME, Cross PC, Garner MG, Martin MK, Nol P, Walsh DP. Challenges and Opportunities Developing Mathematical Models of Shared Pathogens of Domestic and Wild Animals. Vet Sci 2018; 5:E92. [PMID: 30380736 PMCID: PMC6313884 DOI: 10.3390/vetsci5040092] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 10/04/2018] [Accepted: 10/18/2018] [Indexed: 01/19/2023] Open
Abstract
Diseases that affect both wild and domestic animals can be particularly difficult to prevent, predict, mitigate, and control. Such multi-host diseases can have devastating economic impacts on domestic animal producers and can present significant challenges to wildlife populations, particularly for populations of conservation concern. Few mathematical models exist that capture the complexities of these multi-host pathogens, yet the development of such models would allow us to estimate and compare the potential effectiveness of management actions for mitigating or suppressing disease in wildlife and/or livestock host populations. We conducted a workshop in March 2014 to identify the challenges associated with developing models of pathogen transmission across the wildlife-livestock interface. The development of mathematical models of pathogen transmission at this interface is hampered by the difficulties associated with describing the host-pathogen systems, including: (1) the identity of wildlife hosts, their distributions, and movement patterns; (2) the pathogen transmission pathways between wildlife and domestic animals; (3) the effects of the disease and concomitant mitigation efforts on wild and domestic animal populations; and (4) barriers to communication between sectors. To promote the development of mathematical models of transmission at this interface, we recommend further integration of modern quantitative techniques and improvement of communication among wildlife biologists, mathematical modelers, veterinary medicine professionals, producers, and other stakeholders concerned with the consequences of pathogen transmission at this important, yet poorly understood, interface.
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Affiliation(s)
- Kathryn P Huyvaert
- Department of Fish, Wildlife, and Conservation Biology, Colorado State University, Fort Collins, CO 80523, USA.
| | - Robin E Russell
- U.S. Geological Survey, National Wildlife Health Center, Madison, WI 53711, USA.
| | - Kelly A Patyk
- Center for Epidemiology and Animal Health, United States Department of Agriculture, Animal and Plant Health Inspection Service, Fort Collins, CO 80526, USA.
| | - Meggan E Craft
- Department of Veterinary Population Medicine, University of Minnesota, St. Paul, MN 55108, USA.
| | - Paul C Cross
- U.S. Geological Survey, Northern Rocky Mountain Science Center, Bozeman, MT 59715, USA.
| | - M Graeme Garner
- European Commission for the Control of Foot-and-Mouth Disease-Food and Agriculture Organization of the United Nations, 00153 Roma RM, Italy.
| | - Michael K Martin
- Livestock Poultry Health Division, Clemson University, Columbia, SC 29224, USA.
| | - Pauline Nol
- Center for Epidemiology and Animal Health, United States Department of Agriculture, Animal and Plant Health Inspection Service, Fort Collins, CO 80526, USA.
| | - Daniel P Walsh
- U.S. Geological Survey, National Wildlife Health Center, Madison, WI 53711, USA.
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Bouchez-Zacria M, Courcoul A, Durand B. The Distribution of Bovine Tuberculosis in Cattle Farms Is Linked to Cattle Trade and Badger-Mediated Contact Networks in South-Western France, 2007-2015. Front Vet Sci 2018; 5:173. [PMID: 30094243 PMCID: PMC6071575 DOI: 10.3389/fvets.2018.00173] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2018] [Accepted: 07/04/2018] [Indexed: 11/13/2022] Open
Abstract
Bovine tuberculosis (bTB), mainly caused by Mycobacterium bovis, can affect domestic and wild animals as well as humans. Identifying the major transmission mechanisms in an area is necessary for disease control and management. In this study, we aimed to evaluate the involvement of different types of contact in M. bovis transmission between cattle farms of south-western France between 2007 and 2015. We analyzed an empirical contact network of cattle farms as nodes, with known infection status and molecular types (16 circulated during the study period of which 14 affected only cattle and two both badgers and cattle). Edges were based on cattle trade data (T-edges) and on spatial neighborhood relationships between farms, either direct (P-edges) or badger-mediated, when two farms neighbored the same badger home range (B-edges), or two distinct but neighboring badger home ranges (D-edges). Edge types were aggregated so that the contact network contained only unique edges labeled by one or several edge types. The association between the contact network structure and bTB infection status was assessed using a non-parametric test, each molecular type being considered a marker of an independent epidemic. Using a logistic regression model, we estimated the contribution of each edge type to the probability for an edge originating from an infected farm to end at another infected farm. A total number of 1946 cattle farms were included in the study and were linked by 54,243 edges. Within this contact network, infected farms (whatever the molecular type) always belonged to the same component, suggesting the contact network may have supported bTB spread among those farms. A significant association between the pattern of bTB-infected farms and the structure of the contact network was observed when all the molecular types were simultaneously considered. The logistic regression model showed a significant association between M. bovis infection in direct neighbors of infected farms and the connection by T-, B- and D-edges, with odds-ratios of 7.4, 1.9, and 10.4, respectively. These results indicate a multifactorial M. bovis transmission between cattle farms of the studied area, with varying implication levels of the trade, pasture and badger networks according to the molecular type.
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Affiliation(s)
- Malika Bouchez-Zacria
- Epidemiology Unit, Paris-Sud University, Laboratory for Animal Health, French Agency for FoodEnvironment and Occupational Health and Safety (ANSES), Maisons-Alfort, France
| | - Aurélie Courcoul
- Epidemiology Unit, Paris-Est University, Laboratory for Animal Health, French Agency for FoodEnvironment and Occupational Health and Safety (ANSES), Maisons-Alfort, France
| | - Benoit Durand
- Epidemiology Unit, Paris-Est University, Laboratory for Animal Health, French Agency for FoodEnvironment and Occupational Health and Safety (ANSES), Maisons-Alfort, France
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Allen AR, Skuce RA, Byrne AW. Bovine Tuberculosis in Britain and Ireland - A Perfect Storm? the Confluence of Potential Ecological and Epidemiological Impediments to Controlling a Chronic Infectious Disease. Front Vet Sci 2018; 5:109. [PMID: 29951489 PMCID: PMC6008655 DOI: 10.3389/fvets.2018.00109] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 05/03/2018] [Indexed: 12/17/2022] Open
Abstract
Successful eradication schemes for bovine tuberculosis (bTB) have been implemented in a number of European and other countries over the last 50 years. However, the islands of Britain and Ireland remain a significant aberration to this trend, with the recent exception of Scotland. Why have eradication schemes failed within these countries, while apparently similar programs have been successful elsewhere? While significant socio-economic and political factors have been discussed elsewhere as key determinants of disease eradication, here we review some of the potential ecological and epidemiological constraints that are present in these islands relative to other parts of Europe. We argue that the convergence of these potential factors may interact additively to diminish the potential of the present control programs to achieve eradication. Issues identified include heterogeneity of diagnostic testing approaches, the presence of an abundant wildlife reservoir of infection and the challenge of sustainably managing this risk effectively; the nature, size, density and network structure of cattle farming; potential effects of Mycobacterium bovis strain heterogeneity on disease transmission dynamics; possible impacts of concurrent endemic infections on the disclosure of truly infected animals; climatological differences and change coupled with environmental contamination. We further argue that control and eradication of this complex disease may benefit from an ecosystem level approach to management. We hope that this perspective can stimulate a new conversation about the many factors potentially impacting bTB eradication schemes in Britain and Ireland and possibly stimulate new research in the areas identified.
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Affiliation(s)
| | - R. A. Skuce
- Veterinary Science Division, Agri-Food and Biosciences Institute, Belfast, United Kingdom
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Gaughran A, Kelly DJ, MacWhite T, Mullen E, Maher P, Good M, Marples NM. Super-ranging. A new ranging strategy in European badgers. PLoS One 2018; 13:e0191818. [PMID: 29444100 PMCID: PMC5812585 DOI: 10.1371/journal.pone.0191818] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2017] [Accepted: 01/11/2018] [Indexed: 11/18/2022] Open
Abstract
We monitored the ranging of a wild European badger (Meles meles) population over 7 years using GPS tracking collars. Badger range sizes varied seasonally and reached their maximum in June, July and August. We analysed the summer ranging behaviour, using 83 home range estimates from 48 individuals over 6974 collar-nights. We found that while most adult badgers (males and females) remained within their own traditional social group boundaries, several male badgers (on average 22%) regularly ranged beyond these traditional boundaries. These adult males frequently ranged throughout two (or more) social group’s traditional territories and had extremely large home ranges. We therefore refer to them as super-rangers. While ranging across traditional boundaries has been recorded over short periods of time for extraterritorial mating and foraging forays, or for pre-dispersal exploration, the animals in this study maintained their super-ranges from 2 to 36 months. This study represents the first time such long-term extra-territorial ranging has been described for European badgers. Holding a super-range may confer an advantage in access to breeding females, but could also affect local interaction networks. In Ireland & the UK, badgers act as a wildlife reservoir for bovine tuberculosis (TB). Super-ranging may facilitate the spread of disease by increasing both direct interactions between conspecifics, particularly across social groups, and indirect interactions with cattle in their shared environment. Understanding super-ranging behaviour may both improve our understanding of tuberculosis epidemiology and inform future control strategies.
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Affiliation(s)
- Aoibheann Gaughran
- Department of Zoology, School of Natural Sciences, Trinity College, Dublin, Ireland
- * E-mail:
| | - David J. Kelly
- Department of Zoology, School of Natural Sciences, Trinity College, Dublin, Ireland
| | - Teresa MacWhite
- Department of Agriculture, Food and the Marine, Kildare Street, Dublin, Ireland
| | - Enda Mullen
- National Parks and Wildlife Service, Department of Culture, Heritage and the Gaeltacht, Wicklow Mountains National Park, Kilafin, Laragh, Wicklow, Ireland
| | - Peter Maher
- Department of Agriculture, Food and the Marine, Kildare Street, Dublin, Ireland
| | - Margaret Good
- Department of Agriculture, Food and the Marine, Kildare Street, Dublin, Ireland
| | - Nicola M. Marples
- Department of Zoology, School of Natural Sciences, Trinity College, Dublin, Ireland
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Russell RE, Katz RA, Richgels KLD, Walsh DP, Grant EHC. A Framework for Modeling Emerging Diseases to Inform Management. Emerg Infect Dis 2018; 23:1-6. [PMID: 27983501 PMCID: PMC5176225 DOI: 10.3201/eid2301.161452] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The rapid emergence and reemergence of zoonotic diseases requires the ability to rapidly evaluate and implement optimal management decisions. Actions to control or mitigate the effects of emerging pathogens are commonly delayed because of uncertainty in the estimates and the predicted outcomes of the control tactics. The development of models that describe the best-known information regarding the disease system at the early stages of disease emergence is an essential step for optimal decision-making. Models can predict the potential effects of the pathogen, provide guidance for assessing the likelihood of success of different proposed management actions, quantify the uncertainty surrounding the choice of the optimal decision, and highlight critical areas for immediate research. We demonstrate how to develop models that can be used as a part of a decision-making framework to determine the likelihood of success of different management actions given current knowledge.
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Robinson SJ, Barbieri MM, Murphy S, Baker JD, Harting AL, Craft ME, Littnan CL. Model recommendations meet management reality: implementation and evaluation of a network-informed vaccination effort for endangered Hawaiian monk seals. Proc Biol Sci 2018; 285:20171899. [PMID: 29321294 PMCID: PMC5784189 DOI: 10.1098/rspb.2017.1899] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 12/04/2017] [Indexed: 11/23/2022] Open
Abstract
Where disease threatens endangered wildlife populations, substantial resources are required for management actions such as vaccination. While network models provide a promising tool for identifying key spreaders and prioritizing efforts to maximize efficiency, population-scale vaccination remains rare, providing few opportunities to evaluate performance of model-informed strategies under realistic scenarios. Because the endangered Hawaiian monk seal could be heavily impacted by disease threats such as morbillivirus, we implemented a prophylactic vaccination programme. We used contact networks to prioritize vaccinating animals with high contact rates. We used dynamic network models to simulate morbillivirus outbreaks under real and idealized vaccination scenarios. We then evaluated the efficacy of model recommendations in this real-world vaccination project. We found that deviating from the model recommendations decreased the efficiency; requiring 44% more vaccinations to achieve a given decrease in outbreak size. However, we gained protection more quickly by vaccinating available animals rather than waiting to encounter priority seals. This work demonstrates the value of network models, but also makes trade-offs clear. If vaccines were limited but time was ample, vaccinating only priority animals would maximize herd protection. However, where time is the limiting factor, vaccinating additional lower-priority animals could more quickly protect the population.
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Affiliation(s)
- Stacie J Robinson
- NOAA National Marine Fisheries Service, Pacific Islands Fisheries Science Center, 1845 Wasp Boulevard, Honolulu, HI, USA
| | - Michelle M Barbieri
- NOAA National Marine Fisheries Service, Pacific Islands Fisheries Science Center, 1845 Wasp Boulevard, Honolulu, HI, USA
| | | | - Jason D Baker
- NOAA National Marine Fisheries Service, Pacific Islands Fisheries Science Center, 1845 Wasp Boulevard, Honolulu, HI, USA
| | | | - Meggan E Craft
- College of Veterinary Medicine, University of Minnesota, St Paul, MN, USA
| | - Charles L Littnan
- NOAA National Marine Fisheries Service, Pacific Islands Fisheries Science Center, 1845 Wasp Boulevard, Honolulu, HI, USA
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Jones K, Thompson R, Godfrey S. Social networks: a tool for assessing the impact of perturbations on wildlife behaviour and implications for pathogen transmission. BEHAVIOUR 2018. [DOI: 10.1163/1568539x-00003485] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Abstract
Wildlife are increasingly subject to perturbations, which can impact pathogen transmission and lead to disease emergence. While a myriad of factors influence disease dynamics in wildlife, behaviour is emerging as a major influence. In this review, we examine how perturbations alter the behaviour of individuals and how, in turn, disease transmission may be impacted, with a focus on the use of network models as a powerful tool. There are emerging hypotheses as to how networks respond to different types of perturbations. The broad effects of perturbations make predicting potential outcomes and identifying mitigation opportunities for disease emergence critical; yet, the current paucity of data makes identification of underlying trends difficult. Social network analysis facilitates a mechanistic approach to how perturbation-induced behavioural changes result in shifts in pathogen transmission. However, the field is still developing, and future work should strive to address current deficits. There is particular need for empirical data to support modelling predictions and increased inclusion of pathogen monitoring in network studies.
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Affiliation(s)
- K.L. Jones
- aSchool of Veterinary and Life Sciences, Murdoch University, Murdoch, WA 6150, Australia
| | - R.C.A. Thompson
- aSchool of Veterinary and Life Sciences, Murdoch University, Murdoch, WA 6150, Australia
| | - S.S. Godfrey
- aSchool of Veterinary and Life Sciences, Murdoch University, Murdoch, WA 6150, Australia
- bDepartment of Zoology, University of Otago, Dunedin, New Zealand
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Leu ST, Godfrey SS. Advances from the nexus of animal behaviour and pathogen transmission: new directions and opportunities using contact networks. BEHAVIOUR 2018. [DOI: 10.1163/1568539x-00003507] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Abstract
Contact network models have enabled significant advances in understanding the influence of behaviour on parasite and pathogen transmission. They are an important tool that links variation in individual behaviour, to epidemiological consequences at the population level. Here, in our introduction to this special issue, we highlight the importance of applying network approaches to disease ecological and epidemiological questions, and how this has provided a much deeper understanding of these research areas. Recent advances in tracking host behaviour (bio-logging: e.g., GPS tracking, barcoding) and tracking pathogens (high-resolution sequencing), as well as methodological advances (multi-layer networks, computational techniques) started producing exciting new insights into disease transmission through contact networks. We discuss some of the exciting directions that the field is taking, some of the challenges, and importantly the opportunities that lie ahead. For instance, we suggest to integrate multiple transmission pathways, multiple pathogens, and in some systems, multiple host species, into the next generation of network models. Corresponding opportunities exist in utilising molecular techniques, such as high-resolution sequencing, to establish causality in network connectivity and disease outcomes. Such novel developments and the continued integration of network tools offers a more complete understanding of pathogen transmission processes, their underlying mechanisms and their evolutionary consequences.
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Affiliation(s)
- Stephan T. Leu
- aDepartment of Biological Sciences, Macquarie University, Sydney, Australia. E-mail:
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40
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Silk M, Drewe J, Delahay R, Weber N, Steward L, Wilson-Aggarwal J, Boots M, Hodgson D, Croft D, McDonald R. Quantifying direct and indirect contacts for the potential transmission of infection between species using a multilayer contact network. BEHAVIOUR 2018. [DOI: 10.1163/1568539x-00003493] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Abstract
Detecting opportunities for between-species transmission of pathogens can be challenging, particularly if rare behaviours or environmental transmission are involved. We present a multilayer network framework to quantify transmission potential in multi-host systems, incorporating environmental transmission, by using empirical data on direct and indirect contacts between European badgers Meles meles and domestic cattle. We identify that indirect contacts via the environment at badger latrines on pasture are likely to be important for transmission within badger populations and between badgers and cattle. We also find a positive correlation between the role of individual badgers within the badger social network, and their role in the overall badger-cattle-environment network, suggesting that the same behavioural traits contribute to the role of individual badgers in within- and between-species transmission. These findings have implications for disease management interventions in this system, and our novel network approach can provide general insights into transmission in other multi-host disease systems.
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Affiliation(s)
- Matthew J. Silk
- aEnvironment and Sustainability Institute, University of Exeter, Penryn, Cornwall, UK
| | - Julian A. Drewe
- bThe Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire, UK
| | - Richard J. Delahay
- cNational Wildlife Management Centre, Animal and Plant Health Agency, Gloucestershire, UK
| | - Nicola Weber
- dCentre for Ecology and Conservation, University of Exeter, Penryn, Cornwall, UK
| | - Lucy C. Steward
- aEnvironment and Sustainability Institute, University of Exeter, Penryn, Cornwall, UK
| | - Jared Wilson-Aggarwal
- aEnvironment and Sustainability Institute, University of Exeter, Penryn, Cornwall, UK
| | - Mike Boots
- dCentre for Ecology and Conservation, University of Exeter, Penryn, Cornwall, UK
- eIntegrative Biology, University of California, Berkeley, CA, USA
| | - David J. Hodgson
- dCentre for Ecology and Conservation, University of Exeter, Penryn, Cornwall, UK
| | - Darren P. Croft
- fCentre for Research in Animal Behaviour, University of Exeter, Exeter, UK
| | - Robbie A. McDonald
- aEnvironment and Sustainability Institute, University of Exeter, Penryn, Cornwall, UK
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Berg SS, Forester JD, Craft ME. Infectious Disease in Wild Animal Populations: Examining Transmission and Control with Mathematical Models. ADVANCES IN ENVIRONMENTAL MICROBIOLOGY 2018. [PMCID: PMC7123867 DOI: 10.1007/978-3-319-92373-4_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The mathematical modeling of ecological interactions is an essential tool in predicting the behavior of complex systems across landscapes. The scientific literature is growing with examples of models used to explore predator-prey interactions, resource selection, population growth, and dynamics of disease transmission. These models provide managers with an efficient alternative means of testing new management and control strategies without resorting to empirical testing that is often costly, time-consuming, and impractical. This chapter presents a review of four types of mathematical models used to understand and predict the spread of infectious diseases in wild animals: compartmental, metapopulation, spatial, and contact network models. Descriptions of each model’s uses and limitations are used to provide a look at the complexities involved in modeling the spread of diseases and the trade-offs that accompany selecting one modeling approach over another. Potential avenues for the improvement and use of these models in future studies are also discussed, as are specific examples of how each type of model has improved our understanding of infectious diseases in populations of wild animals.
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Rasambainarivo F, Farris ZJ, Andrianalizah H, Parker PG. Interactions Between Carnivores in Madagascar and the Risk of Disease Transmission. ECOHEALTH 2017; 14:691-703. [PMID: 29038989 DOI: 10.1007/s10393-017-1280-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 09/19/2017] [Accepted: 09/22/2017] [Indexed: 06/07/2023]
Abstract
Introduced carnivores exert considerable pressure on native predators through predation, competition and disease transmission. Recent research shows that exotic carnivores negatively affect the distribution and abundance of the native and endangered carnivores of Madagascar. In this study, we provide information about the frequency and distribution of interactions between exotic (dogs and cats) and native carnivores (Eupleridae) in the Betampona Natural Reserve (BNR), Madagascar, using noninvasive camera trap surveys. Domestic dogs (Canis familiaris) were the most frequently detected carnivore species within the BNR, and we found that indirect interactions between exotic and native carnivores were frequent (n = 236). Indirect interactions were more likely to occur near the research station (incidence rate ratio = 0.91), which may constitute a disease transmission hot spot for carnivores at BNR. The intervals between capture of native and exotic carnivores suggest that there is potential for pathogen transmission between species in BNR. These capture intervals were significantly shorter near the edge of the reserve (P = 0.04). These data could be used to implement biosecurity measures to monitor interactions and prevent disease transmission between species at the domestic animal and wildlife interface.
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Affiliation(s)
- Fidisoa Rasambainarivo
- Department of Biology and Whitney R. Harris World Ecology Center, University of Missouri-Saint Louis, One University Blvd, Saint Louis, MO, 63121, USA.
- Departement d'Enseignement des Sciences et Medecine Vétérinaires, University of Antananarivo, Antananarivo, Madagascar.
- Madagascar Fauna and Flora Group, c/o Saint Louis Zoo, One Government Dr., Saint Louis, MO, USA.
| | - Zach J Farris
- Department of Fish and Wildlife Conservation, Virginia Tech, Blacksburg, VA, USA
| | - Hertz Andrianalizah
- Departement d'Enseignement des Sciences et Medecine Vétérinaires, University of Antananarivo, Antananarivo, Madagascar
| | - Patricia G Parker
- Department of Biology and Whitney R. Harris World Ecology Center, University of Missouri-Saint Louis, One University Blvd, Saint Louis, MO, 63121, USA
- Saint Louis Zoo, One Government Dr., Saint Louis, MO, USA
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43
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Fisher DN, McAdam AG. Social traits, social networks and evolutionary biology. J Evol Biol 2017; 30:2088-2103. [DOI: 10.1111/jeb.13195] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 10/08/2017] [Accepted: 10/12/2017] [Indexed: 01/20/2023]
Affiliation(s)
- D. N. Fisher
- Department for Integrative Biology; University of Guelph; Guelph Ontario Canada
| | - A. G. McAdam
- Department for Integrative Biology; University of Guelph; Guelph Ontario Canada
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44
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White LA, Forester JD, Craft ME. Dynamic, spatial models of parasite transmission in wildlife: Their structure, applications and remaining challenges. J Anim Ecol 2017; 87:559-580. [PMID: 28944450 DOI: 10.1111/1365-2656.12761] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2017] [Accepted: 09/07/2017] [Indexed: 01/26/2023]
Abstract
Individual differences in contact rate can arise from host, group and landscape heterogeneity and can result in different patterns of spatial spread for diseases in wildlife populations with concomitant implications for disease control in wildlife of conservation concern, livestock and humans. While dynamic disease models can provide a better understanding of the drivers of spatial spread, the effects of landscape heterogeneity have only been modelled in a few well-studied wildlife systems such as rabies and bovine tuberculosis. Such spatial models tend to be either purely theoretical with intrinsic limiting assumptions or individual-based models that are often highly species- and system-specific, limiting the breadth of their utility. Our goal was to review studies that have utilized dynamic, spatial models to answer questions about pathogen transmission in wildlife and identify key gaps in the literature. We begin by providing an overview of the main types of dynamic, spatial models (e.g., metapopulation, network, lattice, cellular automata, individual-based and continuous-space) and their relation to each other. We investigate different types of ecological questions that these models have been used to explore: pathogen invasion dynamics and range expansion, spatial heterogeneity and pathogen persistence, the implications of management and intervention strategies and the role of evolution in host-pathogen dynamics. We reviewed 168 studies that consider pathogen transmission in free-ranging wildlife and classify them by the model type employed, the focal host-pathogen system, and their overall research themes and motivation. We observed a significant focus on mammalian hosts, a few well-studied or purely theoretical pathogen systems, and a lack of studies occurring at the wildlife-public health or wildlife-livestock interfaces. Finally, we discuss challenges and future directions in the context of unprecedented human-mediated environmental change. Spatial models may provide new insights into understanding, for example, how global warming and habitat disturbance contribute to disease maintenance and emergence. Moving forward, better integration of dynamic, spatial disease models with approaches from movement ecology, landscape genetics/genomics and ecoimmunology may provide new avenues for investigation and aid in the control of zoonotic and emerging infectious diseases.
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Affiliation(s)
- Lauren A White
- Department of Ecology, Evolution & Behavior, University of Minnesota, St. Paul, MN, USA
| | - James D Forester
- Department of Fisheries, Wildlife, and Conservation Biology, University of Minnesota, St. Paul, MN, USA
| | - Meggan E Craft
- Department of Veterinary Population Medicine, University of Minnesota, St. Paul, MN, USA
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45
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VanderWaal K, Enns EA, Picasso C, Packer C, Craft ME. Evaluating empirical contact networks as potential transmission pathways for infectious diseases. J R Soc Interface 2017; 13:rsif.2016.0166. [PMID: 27488249 DOI: 10.1098/rsif.2016.0166] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Accepted: 07/07/2016] [Indexed: 12/19/2022] Open
Abstract
Networks are often used to incorporate heterogeneity in contact patterns in mathematical models of pathogen spread. However, few tools exist to evaluate whether potential transmission pathways in a population are adequately represented by an observed contact network. Here, we describe a novel permutation-based approach, the network k-test, to determine whether the pattern of cases within the observed contact network are likely to have resulted from transmission processes in the network, indicating that the network represents potential transmission pathways between nodes. Using simulated data of pathogen spread, we compare the power of this approach to other commonly used analytical methods. We test the robustness of this technique across common sampling constraints, including undetected cases, unobserved individuals and missing interaction data. We also demonstrate the application of this technique in two case studies of livestock and wildlife networks. We show that the power of the k-test to correctly identify the epidemiologic relevance of contact networks is substantially greater than other methods, even when 50% of contact or case data are missing. We further demonstrate that the impact of missing data on network analysis depends on the structure of the network and the type of missing data.
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Affiliation(s)
- Kimberly VanderWaal
- Department of Veterinary Population Medicine, University of Minnesota, St Paul, MN, USA
| | - Eva A Enns
- Division of Health Policy and Management, School of Public Health, University of Minnesota, Minneapolis, MN, USA
| | - Catalina Picasso
- Department of Veterinary Population Medicine, University of Minnesota, St Paul, MN, USA
| | - Craig Packer
- Department of Ecology, Evolution, and Behavior, University of Minnesota, St Paul, MN, USA
| | - Meggan E Craft
- Department of Veterinary Population Medicine, University of Minnesota, St Paul, MN, USA
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46
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Bouchez-Zacria M, Courcoul A, Jabert P, Richomme C, Durand B. Environmental determinants of the Mycobacterium bovis concomitant infection in cattle and badgers in France. EUR J WILDLIFE RES 2017. [DOI: 10.1007/s10344-017-1131-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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47
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Pilosof S, Greenbaum G, Krasnov BR, Zelnik YR. Asymmetric disease dynamics in multihost interconnected networks. J Theor Biol 2017; 430:237-244. [PMID: 28735858 DOI: 10.1016/j.jtbi.2017.07.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 07/18/2017] [Accepted: 07/20/2017] [Indexed: 12/23/2022]
Abstract
Epidemic spread in single-host systems strongly depends on the population's transmission network. However, little is known regarding the spread of epidemics across networks representing populations of multiple hosts. We explored cross-species transmission in a multilayer network where layers represent populations of two distinct hosts, and disease can spread across intralayer (within-host) and interlayer (between-host) edges. We developed an analytic framework for the SIR epidemic model to examine the effect of (i) source of infection and (ii) between-host asymmetry in infection probabilities, on disease risk. We measured risk as outbreak probability and outbreak size in a focal host, represented by one network layer. Numeric simulations were used to validate the analytic formulations. We found that outbreak probability is determined by a complex interaction between source of infection and between-host infection probabilities, whereas outbreak size is mainly affected by the non-focal host to focal host infection probability. Hence, inter-specific asymmetry in infection probabilities shapes disease dynamics in multihost networks. These results highlight the importance of considering multiple measures of disease risk and advance our understanding of disease spread in multihost systems. The study provides a flexible way to model disease dynamics in multiple hosts while considering contact heterogeneity within and between species. We strongly encourage empirical studies that include information on both cross-species infection rates and network structure of multiple hosts. Such studies are necessary to corroborate our theoretical results and to improve our understanding of multihost epidemiology.
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Affiliation(s)
- Shai Pilosof
- Department of Ecology and Evolution, University of Chicago, 1103 E 57 st, Chicago, 60637, USA.
| | - Gili Greenbaum
- Mitrani Department of Desert Ecology, Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, 84990, Israel; Department of Solar Energy and Environmental Physics, Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, 84990, Israel
| | - Boris R Krasnov
- Mitrani Department of Desert Ecology, Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, 84990, Israel
| | - Yuval R Zelnik
- Department of Solar Energy and Environmental Physics, Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, 84990, Israel
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Ellwood SA, Newman C, Montgomery RA, Nicosia V, Buesching CD, Markham A, Mascolo C, Trigoni N, Pasztor B, Dyo V, Latora V, Baker SE, Macdonald DW. An active‐radio‐frequency‐identification system capable of identifying co‐locations and social‐structure: Validation with a wild free‐ranging animal. Methods Ecol Evol 2017. [DOI: 10.1111/2041-210x.12839] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Stephen A. Ellwood
- Wildlife Conservation Research UnitDepartment of ZoologyUniversity of OxfordThe Recanati‐Kaplan Centre Abingdon Oxfordshire UK
| | - Chris Newman
- Wildlife Conservation Research UnitDepartment of ZoologyUniversity of OxfordThe Recanati‐Kaplan Centre Abingdon Oxfordshire UK
| | - Robert A. Montgomery
- Wildlife Conservation Research UnitDepartment of ZoologyUniversity of OxfordThe Recanati‐Kaplan Centre Abingdon Oxfordshire UK
- Department of Fisheries and WildlifeMichigan State University East Lansing MI USA
| | - Vincenzo Nicosia
- School of Mathematical SciencesQueen Mary University of London London UK
| | - Christina D. Buesching
- Wildlife Conservation Research UnitDepartment of ZoologyUniversity of OxfordThe Recanati‐Kaplan Centre Abingdon Oxfordshire UK
| | - Andrew Markham
- Sensor Networks GroupDepartment of Computer SciencesUniversity of Oxford Oxford UK
| | | | - Niki Trigoni
- Sensor Networks GroupDepartment of Computer SciencesUniversity of Oxford Oxford UK
| | - Bence Pasztor
- Computer LaboratoryUniversity of Cambridge Cambridge UK
| | - Vladimir Dyo
- Department of Computer Science and TechnologyUniversity of BedfordshireUniversity Square Luton UK
| | - Vito Latora
- School of Mathematical SciencesQueen Mary University of London London UK
| | - Sandra E. Baker
- Wildlife Conservation Research UnitDepartment of ZoologyUniversity of OxfordThe Recanati‐Kaplan Centre Abingdon Oxfordshire UK
| | - David W. Macdonald
- Wildlife Conservation Research UnitDepartment of ZoologyUniversity of OxfordThe Recanati‐Kaplan Centre Abingdon Oxfordshire UK
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49
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Effect of host diversity and species assemblage composition on bovine tuberculosis (bTB) risk in Ethiopian cattle. Parasitology 2017; 144:783-792. [PMID: 28134065 DOI: 10.1017/s0031182016002511] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Current theories on diversity-disease relationships describe host species diversity and species identity as important factors influencing disease risk, either diluting or amplifying disease prevalence in a community. Whereas the simple term 'diversity' embodies a set of animal community characteristics, it is not clear how different measures of species diversity are correlated with disease risk. We therefore tested the effects of species richness, Pielou's evenness and Shannon's diversity on bovine tuberculosis (bTB) risk in cattle in the Afar Region and Awash National Park between November 2013 and April 2015. We also analysed the identity effect of a particular species and the effect of host habitat use overlap on bTB risk. We used the comparative intradermal tuberculin test to assess the number of bTB-infected cattle. Our results suggested a dilution effect through species evenness. We found that the identity effect of greater kudu - a maintenance host - confounded the dilution effect of species diversity on bTB risk. bTB infection was positively correlated with habitat use overlap between greater kudu and cattle. Different diversity indices have to be considered together for assessing diversity-disease relationships, for understanding the underlying causal mechanisms. We posit that unpacking diversity metrics is also relevant for formulating disease control strategies to manage cattle in ecosystems characterized by seasonally limited resources and intense wildlife-livestock interactions.
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50
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How Behaviour and the Environment Influence Transmission in Mobile Groups. TEMPORAL NETWORK EPIDEMIOLOGY 2017. [PMCID: PMC7123459 DOI: 10.1007/978-981-10-5287-3_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The movement of individuals living in groups leads to the formation of physical interaction networks over which signals such as information or disease can be transmitted. Direct contacts represent the most obvious opportunities for a signal to be transmitted. However, because signals that persist after being deposited into the environment may later be acquired by other group members, indirect environmentally-mediated transmission is also possible. To date, studies of signal transmission within groups have focused on direct physical interactions and ignored the role of indirect pathways. Here, we use an agent-based model to study how the movement of individuals and characteristics of the signal being transmitted modulate transmission. By analysing the dynamic interaction networks generated from these simulations, we show that the addition of indirect pathways speeds up signal transmission, while the addition of physically-realistic collisions between individuals in densely packed environments hampers it. Furthermore, the inclusion of spatial biases that induce the formation of individual territories, reveals the existence of a trade-off such that optimal signal transmission at the group level is only achieved when territories are of intermediate sizes. Our findings provide insight into the selective pressures guiding the evolution of behavioural traits in natural groups, and offer a means by which multi-agent systems can be engineered to achieve desired transmission capabilities.
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