1
|
Medlock JM, Vaux AGC, Gandy S, Cull B, McGinley L, Gillingham E, Catton M, Pullan ST, Hansford KM. Spatial and temporal heterogeneity of the density of Borrelia burgdorferi-infected Ixodes ricinus ticks across a landscape: A 5-year study in southern England. MEDICAL AND VETERINARY ENTOMOLOGY 2022; 36:356-370. [PMID: 35521893 PMCID: PMC9545817 DOI: 10.1111/mve.12574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 03/17/2022] [Accepted: 03/22/2022] [Indexed: 06/14/2023]
Abstract
The density of Borrelia burgdorferi-infected Ixodes ricinus nymphs (DIN) was investigated during 2013-2017 across a Lyme disease-endemic landscape in southern England. The density of nymphs (DON), nymph infection prevalence (NIP), and DIN varied across five different natural habitats, with the highest DIN in woodland edge and high biodiversity woodlands. DIN was significantly lower in scrub grassland compared to the woodland edge, with low DON and no evidence of infection in ticks in non-scrub grassland. Over the 5 years, DON, NIP and DIN were comparable within habitats, except in 2014, with NIP varying three-fold and DIN significantly lower compared to 2015-2017. Borrelia garinii was most common, with bird-associated Borrelia (B. garinii/valaisiana) accounting for ~70% of all typed sequences. Borrelia burgdorferi sensu stricto was more common than B. afzelii. Borrelia afzelii was more common in scrub grassland than woodland and absent in some years. The possible impact of scrub on grazed grassland, management of ecotonal woodland margins with public access, and the possible role of birds/gamebirds impacting NIP are discussed. Mean NIP was 7.6%, highlighting the potential risk posed by B. burgdorferi in this endemic area. There is a need for continued research to understand its complex ecology and identify strategies for minimizing risk to public health, through habitat/game management and public awareness.
Collapse
Affiliation(s)
- Jolyon M. Medlock
- Medical Entomology & Zoonoses Ecology GroupUK Health Security AgencySalisburyWiltshireUK
| | - Alexander G. C. Vaux
- Medical Entomology & Zoonoses Ecology GroupUK Health Security AgencySalisburyWiltshireUK
| | - Sara Gandy
- Medical Entomology & Zoonoses Ecology GroupUK Health Security AgencySalisburyWiltshireUK
| | - Benjamin Cull
- Medical Entomology & Zoonoses Ecology GroupUK Health Security AgencySalisburyWiltshireUK
| | - Liz McGinley
- Medical Entomology & Zoonoses Ecology GroupUK Health Security AgencySalisburyWiltshireUK
| | - Emma Gillingham
- Medical Entomology & Zoonoses Ecology GroupUK Health Security AgencySalisburyWiltshireUK
| | - Matthew Catton
- Medical Entomology & Zoonoses Ecology GroupUK Health Security AgencySalisburyWiltshireUK
| | - Steven T. Pullan
- Diagnostic & Genomic TechnologiesUK Health Security AgencySalisburyWiltshireUK
| | - Kayleigh M. Hansford
- Medical Entomology & Zoonoses Ecology GroupUK Health Security AgencySalisburyWiltshireUK
| |
Collapse
|
2
|
Occhibove F, Kenobi K, Swain M, Risley C. An eco-epidemiological modeling approach to investigate dilution effect in two different tick-borne pathosystems. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2022; 32:e2550. [PMID: 35092122 PMCID: PMC9286340 DOI: 10.1002/eap.2550] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 10/20/2021] [Accepted: 10/27/2021] [Indexed: 05/05/2023]
Abstract
Disease (re)emergence appears to be driven by biodiversity decline and environmental change. As a result, it is increasingly important to study host-pathogen interactions within the context of their ecology and evolution. The dilution effect is the concept that higher biodiversity decreases pathogen transmission. It has been observed especially in zoonotic vector-borne pathosystems, yet evidence against it has been found. In particular, it is still debated how the community (dis)assembly assumptions and the degree of generalism of vectors and pathogens affect the direction of the biodiversity-pathogen transmission relationship. The aim of this study was to use empirical data and mechanistic models to investigate dilution mechanisms in two rodent-tick-pathogen systems differing in their vector degree of generalism. A community was assembled to include ecological interactions that expand from purely additive to purely substitutive. Such systems are excellent candidates to analyze the link between vector ecology, community (dis)assembly dynamics, and pathogen transmission. To base our mechanistic models on empirical data, rodent live-trapping, including tick sampling, was conducted in Wales across two seasons for three consecutive years. We have developed a deterministic single-vector, multi-host compartmental model that includes ecological relationships with non-host species, uniquely integrating theoretical and observational approaches. To describe pathogen transmission across a gradient of community diversity, the model was populated with parameters describing five different scenarios differing in ecological complexity; each based around one of the pathosystems: Ixodes ricinus (generalist tick)-Borrelia burgdorferi and I. trianguliceps (small mammals specialist tick)-Babesia microti. The results suggested that community composition and interspecific dynamics affected pathogen transmission with different dilution outcomes depending on the vector degree of generalism. The model provides evidence that dilution and amplification effects are not mutually exclusive in the same community but depend on vector ecology and the epidemiological output considered (i.e., the "risk" of interest). In our scenarios, more functionally diverse communities resulted in fewer infectious rodents, supporting the dilution effect. In the pathosystem with generalist vector we identified a hump shaped relationship between diversity and infections in hosts, while for that characterized by specialist tick, this relationship was more complex and more dependent upon specific parameter values.
Collapse
Affiliation(s)
- Flavia Occhibove
- IBERS, Aberystwyth UniversityAberystwythUK
- UK Centre for Ecology & HydrologyWallingfordUK
| | - Kim Kenobi
- Department of MathematicsAberystwyth UniversityAberystwythUK
| | | | | |
Collapse
|
3
|
Edwards CD, Campbell H. Sampling implications of variation in daily activity of the sheep tick, Ixodes ricinus at a coastal grassland site in the U.K. MEDICAL AND VETERINARY ENTOMOLOGY 2022; 36:127-132. [PMID: 34338344 DOI: 10.1111/mve.12543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 06/22/2021] [Accepted: 07/05/2021] [Indexed: 06/13/2023]
Abstract
The sheep tick, Ixodes ricinus L. (Acari: Ixodidae), is an important vector of many pathogens of medical and veterinary significance. Determining vector abundance is a requisite of assessing potential vector-borne disease risk. Estimation of tick abundance is often conducted by blanket drag sampling a site, conducted at one time point during the day. The time of day chosen for sampling can vary, is not widely standardized and is often unreported by the investigator. This study investigated whether the time of day chosen for sampling had an effect on tick collection at an open grassland coastal site in North Devon, U.K., during May 2019 to July 2019. Tick abundance for both adults and nymphs in the evening period was more than twice that found in the mid-day sampling period. Overall abundance differed with site aspect, ground temperature and relative humidity. This study shows that for this open grassland recreational site, the time of day chosen for sampling has important implications for tick collection and the assessment of the relative risk of human exposure to ticks and tick-borne infections.
Collapse
Affiliation(s)
- C D Edwards
- Department of Agriculture and Environment, Harper Adams University, Newport, Shropshire, U.K
- The Wain House, Chetwynd, Newport, Shropshire, TF10 8AE, U.K
| | - H Campbell
- Department of Agriculture and Environment, Harper Adams University, Newport, Shropshire, U.K
| |
Collapse
|
4
|
Lihou K, Rose Vineer H, Wall R. Distribution and prevalence of ticks and tick-borne disease on sheep and cattle farms in Great Britain. Parasit Vectors 2020; 13:406. [PMID: 32778148 PMCID: PMC7419194 DOI: 10.1186/s13071-020-04287-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 08/03/2020] [Indexed: 11/10/2022] Open
Abstract
INTRODUCTION The most abundant and widespread tick species in Great Britain, Ixodes ricinus, is responsible for the transmission of a range of pathogens that cause disease in livestock. Empirical data on tick distribution and prevalence are required to inform farm management strategies. However, such data are largely unavailable; previous surveys have been rare and are usually relatively localised. METHODS A retrospective questionnaire survey of farmers was used to assess the reported prevalence of ticks on livestock across Great Britain. Spatial scan statistics and kernel density maps were used to assess spatial clustering and identify areas of significantly elevated risk, independent of the underlying distribution of respondents. Logistic regression models were used to identify risk factors for tick presence. RESULTS Tick infection risk to livestock is shown to be spatially aggregated, with areas of significantly elevated risk in north Wales, northwest England and western Scotland. Overall, the prevalence of farms reporting tick presence was 13% for sheep farms and 6% for cattle farms, but in "hot spot" clusters prevalence ranged between 48-100%. The prevalence of farms reporting tick-borne disease overall was 6% for sheep and 2% for cattle, but on farms reporting ticks, prevalence was 44% and 33% for sheep and cattle farms, respectively. Upland farming, larger flock sizes, region and the presence of sheep on cattle farms were all significant risk factors for tick presence. CONCLUSIONS These data have important implications for assessing both the risk of tick-borne disease in livestock and optimising approaches to disease management. In particular, the study highlights the need for effective livestock tick control in upland regions and the southwest, and provides evidence for the importance of sheep as tick maintenance hosts.
Collapse
Affiliation(s)
- Katie Lihou
- School of Biological Sciences, University of Bristol, Bristol, BS8 1TQ, UK.
| | - Hannah Rose Vineer
- Department of Infection and Microbiome, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
| | - Richard Wall
- School of Biological Sciences, University of Bristol, Bristol, BS8 1TQ, UK
| |
Collapse
|
5
|
Jaenson TGT, Petersson EH, Jaenson DGE, Kindberg J, Pettersson JHO, Hjertqvist M, Medlock JM, Bengtsson H. The importance of wildlife in the ecology and epidemiology of the TBE virus in Sweden: incidence of human TBE correlates with abundance of deer and hares. Parasit Vectors 2018; 11:477. [PMID: 30153856 PMCID: PMC6114827 DOI: 10.1186/s13071-018-3057-4] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 08/10/2018] [Indexed: 02/06/2023] Open
Abstract
Background Tick-borne encephalitis (TBE) is one tick-transmitted disease where the human incidence has increased in some European regions during the last two decades. We aim to find the most important factors causing the increasing incidence of human TBE in Sweden. Based on a review of published data we presume that certain temperature-related variables and the population densities of transmission hosts, i.e. small mammals, and of primary tick maintenance hosts, i.e. cervids and lagomorphs, of the TBE virus vector Ixodes ricinus, are among the potentially most important factors affecting the TBE incidence. Therefore, we compare hunting data of the major tick maintenance hosts and two of their important predators, and four climatic variables with the annual numbers of human cases of neuroinvasive TBE. Data for six Swedish regions where human TBE incidence is high or has recently increased are examined by a time-series analysis. Results from the six regions are combined using a meta-analytical method. Results With a one-year time lag, the roe deer (Capreolus capreolus), red deer (Cervus elaphus), mountain hare (Lepus timidus) and European hare (Lepus europaeus) showed positive covariance; the Eurasian elk (moose, Alces alces) and fallow deer (Dama dama) negative covariance; whereas the wild boar (Sus scrofa), lynx (Lynx lynx), red fox (Vulpes vulpes) and the four climate parameters showed no significant covariance with TBE incidence. All game species combined showed positive covariance. Conclusions The epidemiology of TBE varies with time and geography and depends on numerous factors, i.a. climate, virus genotypes, and densities of vectors, tick maintenance hosts and transmission hosts. This study suggests that the increased availability of deer to I. ricinus over large areas of potential tick habitats in southern Sweden increased the density and range of I. ricinus and created new TBEV foci, which resulted in increased incidence of human TBE. New foci may be established by TBE virus-infected birds, or by birds or migrating mammals infested with TBEV-infected ticks. Generally, persistence of TBE virus foci appears to require presence of transmission-competent small mammals, especially mice (Apodemus spp.) or bank voles (Myodes glareolus). Electronic supplementary material The online version of this article (10.1186/s13071-018-3057-4) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Thomas G T Jaenson
- Department of Organismal Biology, Uppsala University, Norbyvägen 18d, SE-752 36, Uppsala, Sweden.
| | - Erik H Petersson
- Department of Aquatic Resources, Division of Freshwater Research, Swedish University of Agricultural Sciences, Stångholmsvägen 2, SE-178 93, Drottningholm, Sweden
| | - David G E Jaenson
- Department of Automatic Control, Lund University, SE-221 00, Lund, Sweden
| | - Jonas Kindberg
- Department of Wildlife, Fish and Environmental Studies, Swedish University of Agricultural Sciences, SE-901 83, Umeå, Sweden
| | - John H-O Pettersson
- Department of Infectious Disease Epidemiology and Modelling, Norwegian Institute of Public Health, Lovisenberggata 8, N-0456, Oslo, Norway.,Department of Medical Biochemistry and Microbiology (IMBIM), Zoonosis Science Center, Uppsala University, Uppsala, Sweden.,Marie Bashir Institute for Infectious Diseases and Biosecurity, Charles Perkins Centre, School of Life and Environmental Sciences and Sydney Medical School, the University of Sydney, Sydney, New South Wales, 2006, Australia.,Public Health Agency of Sweden, Nobels väg 18, SE-171 82, Solna, Sweden
| | - Marika Hjertqvist
- Public Health Agency of Sweden, Nobels väg 18, SE-171 82, Solna, Sweden
| | - Jolyon M Medlock
- Medical Entomology Group, Emergency Response Department, Public Health England, Porton Down, Salisbury, UK.,Health Protection Research Unit in Emerging Infections & Zoonoses, Porton Down, Salisbury, UK
| | - Hans Bengtsson
- Swedish Meteorological and Hydrological Institute (SMHI), Gothenburg, Sweden
| |
Collapse
|
6
|
Goldstein V, Boulanger N, Schwartz D, George JC, Ertlen D, Zilliox L, Schaeffer M, Jaulhac B. Factors responsible for Ixodes ricinus nymph abundance: Are soil features indicators of tick abundance in a French region where Lyme borreliosis is endemic? Ticks Tick Borne Dis 2018; 9:938-944. [PMID: 29606622 DOI: 10.1016/j.ttbdis.2018.03.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 03/11/2018] [Accepted: 03/12/2018] [Indexed: 10/17/2022]
Abstract
In Europe, the hard tick Ixodes ricinus (Acari: Ixodidae) is the main vector of Lyme borreliosis spirochetes (Borrelia burgdorferi sensu lato group). A field study was conducted to evaluate the abundance of Ixodes nymphs in the French region of Alsace, where Lyme borreliosis is endemic, and to determine whether environmental factors such as soil moisture and composition may be associated with nymph abundance. In the ten sites studied, ticks were collected by drag sampling from March to October in 2013 and 2014. Temperature, relative humidity, saturation deficit, soil pH, humus composition and type of vegetation were recorded at each site. The abundance of I. ricinus was highly variable from one site to another. Inter-annual variations were also observed, since the nymph abundance were higher in 2013 than in 2014. This study shows that humus type can be indicative of nymph abundance. Three types of humus were observed: (1) moder, (2) mull, and (3) mull-moder humus. One of them, moder humus, which is characterized by a thick layer of fragmented leaves, was found in multivariate analyses to be strongly associated with the nymph abundance. This study demonstrates that factors such as saturation deficit do not suffice to explain the differences in nymph abundance among sites. The composition of the soil and especially the type of humus should also be taken into consideration when assessing acarological risk.
Collapse
Affiliation(s)
- Valérie Goldstein
- EA 7290: Virulence bactérienne précoce: groupe Borréliose de Lyme, Facultés de pharmacie et de médecine, Université de Strasbourg, 3 rue Koeberlé, 67097, Strasbourg, France
| | - Nathalie Boulanger
- EA 7290: Virulence bactérienne précoce: groupe Borréliose de Lyme, Facultés de pharmacie et de médecine, Université de Strasbourg, 3 rue Koeberlé, 67097, Strasbourg, France; Centre National de Référence des Borrelia, Centre hospitalier universitaire, Strasbourg, 3 rue Koeberlé, 67097, Strasbourg, France.
| | - Dominique Schwartz
- UMR 7362, Laboratoire Image, Ville et Environnement, Faculté de géographie, Université de Strasbourg, 3 rue de l'Argonne, 67000, Strasbourg, France
| | - Jean-Claude George
- Centre National de Référence des Borrelia, Centre hospitalier universitaire, Strasbourg, 3 rue Koeberlé, 67097, Strasbourg, France
| | - Damien Ertlen
- UMR 7362, Laboratoire Image, Ville et Environnement, Faculté de géographie, Université de Strasbourg, 3 rue de l'Argonne, 67000, Strasbourg, France
| | - Laurence Zilliox
- Centre National de Référence des Borrelia, Centre hospitalier universitaire, Strasbourg, 3 rue Koeberlé, 67097, Strasbourg, France
| | - Mickaël Schaeffer
- Département d'Information Médicale, Centre hospitalier universitaire, 1 place de l'Hôpital, 67000, Strasbourg, France
| | - Benoît Jaulhac
- EA 7290: Virulence bactérienne précoce: groupe Borréliose de Lyme, Facultés de pharmacie et de médecine, Université de Strasbourg, 3 rue Koeberlé, 67097, Strasbourg, France; Centre National de Référence des Borrelia, Centre hospitalier universitaire, Strasbourg, 3 rue Koeberlé, 67097, Strasbourg, France
| |
Collapse
|
7
|
Hall JL, Alpers K, Bown KJ, Martin SJ, Birtles RJ. Use of Mass-Participation Outdoor Events to Assess Human Exposure to Tickborne Pathogens. Emerg Infect Dis 2018; 23:463-467. [PMID: 28221107 PMCID: PMC5382723 DOI: 10.3201/eid2303.161397] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
Mapping the public health threat of tickborne pathogens requires quantification of not only the density of infected host-seeking ticks but also the rate of human exposure to these ticks. To efficiently sample a high number of persons in a short time, we used a mass-participation outdoor event. In June 2014, we sampled ≈500 persons competing in a 2-day mountain marathon run across predominantly tick-infested habitat in Scotland. From the number of tick bites recorded and prevalence of tick infection with Borrelia burgdoferi sensu lato and B. miyamotoi, we quantified the frequency of competitor exposure to the pathogens. Mass-participation outdoor events have the potential to serve as excellent windows for epidemiologic study of tickborne pathogens; their concerted use should improve spatial and temporal mapping of human exposure to infected ticks.
Collapse
|
8
|
Millins C, Gilbert L, Medlock J, Hansford K, Thompson DB, Biek R. Effects of conservation management of landscapes and vertebrate communities on Lyme borreliosis risk in the United Kingdom. Philos Trans R Soc Lond B Biol Sci 2018; 372:rstb.2016.0123. [PMID: 28438912 PMCID: PMC5413871 DOI: 10.1098/rstb.2016.0123] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/17/2016] [Indexed: 02/01/2023] Open
Abstract
Landscape change and altered host abundance are major drivers of zoonotic pathogen emergence. Conservation and biodiversity management of landscapes and vertebrate communities can have secondary effects on vector-borne pathogen transmission that are important to assess. Here we review the potential implications of these activities on the risk of Lyme borreliosis in the United Kingdom. Conservation management activities include woodland expansion, management and restoration, deer management, urban greening and the release and culling of non-native species. Available evidence suggests that increasing woodland extent, implementing biodiversity policies that encourage ecotonal habitat and urban greening can increase the risk of Lyme borreliosis by increasing suitable habitat for hosts and the tick vectors. However, this can depend on whether deer population management is carried out as part of these conservation activities. Exclusion fencing or culling deer to low densities can decrease tick abundance and Lyme borreliosis risk. As management actions often constitute large-scale perturbation experiments, these hold great potential to understand underlying drivers of tick and pathogen dynamics. We recommend integrating monitoring of ticks and the risk of tick-borne pathogens with conservation management activities. This would help fill knowledge gaps and the production of best practice guidelines to reduce risks. This article is part of the themed issue ‘Conservation, biodiversity and infectious disease: scientific evidence and policy implications’.
Collapse
Affiliation(s)
- Caroline Millins
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, UK .,The Boyd Orr Centre for Population and Ecosystem Health, University of Glasgow, Glasgow G12 8QQ, UK.,School of Veterinary Medicine, University of Glasgow, Glasgow G61 1QH, UK
| | - Lucy Gilbert
- The James Hutton Institute, Craigiebuckler, Aberdeen AB15 8QH, UK
| | - Jolyon Medlock
- Medical Entomology Group, Emergency Response Department, Public Health England, Salisbury, SP4 0JG, UK.,Health Protection Research Unit in Environment and Health, Porton Down, Salisbury SP4 0JG, UK
| | - Kayleigh Hansford
- Medical Entomology Group, Emergency Response Department, Public Health England, Salisbury, SP4 0JG, UK
| | - Des Ba Thompson
- Scottish Natural Heritage, 231 Corstorphine Road, Edinburgh, EH12 7AT, UK
| | - Roman Biek
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, UK.,The Boyd Orr Centre for Population and Ecosystem Health, University of Glasgow, Glasgow G12 8QQ, UK
| |
Collapse
|
9
|
Zintl A, Moutailler S, Stuart P, Paredis L, Dutraive J, Gonzalez E, O'Connor J, Devillers E, Good B, OMuireagain C, De Waal T, Morris F, Gray J. Ticks and Tick-borne diseases in Ireland. Ir Vet J 2017; 70:4. [PMID: 28163889 PMCID: PMC5282849 DOI: 10.1186/s13620-017-0084-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 01/19/2017] [Indexed: 11/12/2022] Open
Abstract
Throughout Europe interest in tick-borne agents is increasing, particularly with regard to those that can cause human disease. The reason for this is the apparent rise in the incidence of many tick-borne diseases (TBD’s). While there has never been a national survey of ticks or TBD’s in Ireland, the trend here appears to be the reverse with a decline in the incidence of some agents seemingly associated with decreasing tick numbers particularly on agricultural land. In the absence of robust baseline data, however, this development cannot be confirmed. This review collates the limited information available from several dated published records on tick species and a small number of studies focused on certain TBD’s. Some pilot data on tick density and TBD agents collected in 2016 are also presented. The aim is to explore the particular situation in Ireland with regard to ticks and TBD’s and to provide a reference for future workers in the field.
Collapse
Affiliation(s)
- Annetta Zintl
- UCD School of Veterinary Medicine, University College Dublin, Belfield, Ireland
| | - Sara Moutailler
- UMR BIPAR, ANSES, INRA, ENVA, Animal Health Laboratory, 14 rue Pierre et Marie Curie, 94700 Maisons-Alfort, France
| | - Peter Stuart
- Department of Zoology, Trinity College Dublin, Dublin 2, Ireland
| | - Linda Paredis
- Department of Zoology, Trinity College Dublin, Dublin 2, Ireland
| | | | | | | | - Elodie Devillers
- UMR BIPAR, ANSES, INRA, ENVA, Animal Health Laboratory, 14 rue Pierre et Marie Curie, 94700 Maisons-Alfort, France
| | - Barbara Good
- Animal & Grassland Research and Innovation Centre, Teagasc, Athenry, Co. Galway Ireland
| | - Colm OMuireagain
- Department of Agriculture, Food and the Marine, Sligo Regional Veterinary Laboratory, Sligo, Ireland
| | - Theo De Waal
- UCD School of Veterinary Medicine, University College Dublin, Belfield, Ireland
| | | | - Jeremy Gray
- School of Biology and Environmental Science (Emeritus Professor), University College Dublin, Belfield, Ireland
| |
Collapse
|
10
|
Jennett AL, Smith FD, Wall R. Tick infestation risk for dogs in a peri-urban park. Parasit Vectors 2013; 6:358. [PMID: 24341594 PMCID: PMC3895857 DOI: 10.1186/1756-3305-6-358] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Accepted: 12/13/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Increases in the abundance and distribution of ticks and tick borne disease (TBD) within Europe have been reported extensively over the last 10-20 years. Changes in climate, habitat management, economic patterns and changes in the abundance of hosts, particularly deer, may all have influenced this change to varying extents. Increasing abundances of tick populations in urban and peri-urban environments, such as parks, are of particular concern. In these sites, suitable habitat, wildlife hosts, tick populations, people and their pets may be brought into close proximity and hence may provide foci for tick infestation and, ultimately, disease transmission. METHODS The distribution and abundance of ticks were examined in an intensively used, peri-urban park. First the seasonal and spatial distribution and abundance of ticks in various habitat types were quantified by blanket dragging. Then the pattern of pet dog movement in the park was mapped by attaching GPS recorders to the collars of dogs brought to the park for exercise, allowing their walking routes to be tracked. Information about the dog, its park use and its history of tick attachment were obtained from the dog-owners. RESULTS Ticks were found predominantly in woodland, woodland edge and deer park areas and were least abundant in mown grassland. Tick infestation of dogs was a relatively frequent occurrence with, on average, one case of tick attachment reported per year for a dog walked once per week, but for some dogs walked daily, infestation 4-5 times per week was reported. All dogs appeared to be at equal risk, regardless of walk route or duration and infestation was primarily influenced by the frequency of exposure. CONCLUSIONS In peri-urban green spaces, tick-biting risk for dogs may be high and here was shown to be related primarily to exposure frequency. While tick-biting is of direct veterinary importance for dogs, dogs also represent useful sentinels for human tick-exposure.
Collapse
Affiliation(s)
| | | | - Richard Wall
- Veterinary Parasitology and Ecology Group, School of Biological Sciences, University of Bristol, BS8 1UG Bristol, UK.
| |
Collapse
|
11
|
Tijsse-Klasen E, Hansford KM, Jahfari S, Phipps P, Sprong H, Medlock JM. Spotted fever group rickettsiae in Dermacentor reticulatus and Haemaphysalis punctata ticks in the UK. Parasit Vectors 2013; 6:212. [PMID: 23870197 PMCID: PMC3725166 DOI: 10.1186/1756-3305-6-212] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Accepted: 07/15/2013] [Indexed: 11/10/2022] Open
Abstract
Background Spotted fever group (SFG) rickettsiae have recently been identified for the first time in UK ticks. This included the findings of Rickettsia helvetica in Ixodes ricinus and Rickettsia raoultii in Dermacentor reticulatus. This paper further investigates the occurrence of SFG rickettsiae in additional geographically distinct populations of D. reticulatus, and for the first time, investigates the occurrence of SFG rickettsiae in UK populations of Haemaphysalis punctata ticks. Methods Questing D. reticulatus and H. punctata were collected at a number of sites in England and Wales. DNA from questing ticks was extracted by alkaline lysis and detection of rickettsiae DNA was performed, in addition to detection of A. phagocytophilum, N. mikurensis, C. burnetii and B. burgdorferi sensu lato. Results This paper builds on previous findings to include the detection of spotted fever Rickettsia which showed the highest homology to Rickettsia massiliae in Haemaphysalis punctata, as well as R. helvetica in D. reticulatus. The occurrence of SFG rickettsiae in D. reticulatus in the UK appears to be confined only to Welsh and Essex populations, with no evidence so far from Devon. Similarly, the occurrence of SFG rickettsiae in H. punctata appears confined to one of two farms known to be infested with this tick in North Kent, with no evidence so far from the Sussex populations. Anaplasma phagocytophilum, Neoehrlichia mikurensis, Coxiella burnetii and Borrelia burgdorferi sensu lato DNA was not detected in any of the ticks. Conclusion These two tick species are highly restricted in their distribution in England and Wales, but where they do occur they can be abundant. Following detection of these SFG rickettsiae in additional UK tick species, as well as I. ricinus, research should now be directed towards clarifying firstly the geographic distribution of SFG rickettsiae in UK ticks, and secondly to assess the prevalence rates in ticks, wild and domesticated animals and humans to identify the drivers for disease transmission and their public health significance.
Collapse
Affiliation(s)
- Ellen Tijsse-Klasen
- Laboratory for Zoonoses and Environmental Microbiology, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | | | | | | | | | | |
Collapse
|
12
|
Steigedal HH, Loe LE, Grøva L, Mysterud A. The effect of sheep ( Ovis aries) presence on the abundance of ticks ( Ixodes ricinus). ACTA AGR SCAND A-AN 2013. [DOI: 10.1080/09064702.2013.823236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
13
|
Medlock JM, Hansford KM, Bormane A, Derdakova M, Estrada-Peña A, George JC, Golovljova I, Jaenson TGT, Jensen JK, Jensen PM, Kazimirova M, Oteo JA, Papa A, Pfister K, Plantard O, Randolph SE, Rizzoli A, Santos-Silva MM, Sprong H, Vial L, Hendrickx G, Zeller H, Van Bortel W. Driving forces for changes in geographical distribution of Ixodes ricinus ticks in Europe. Parasit Vectors 2013; 6:1. [PMID: 23281838 PMCID: PMC3549795 DOI: 10.1186/1756-3305-6-1] [Citation(s) in RCA: 529] [Impact Index Per Article: 48.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Accepted: 12/10/2012] [Indexed: 11/10/2022] Open
Abstract
Many factors are involved in determining the latitudinal and altitudinal spread of the important tick vector Ixodes ricinus (Acari: Ixodidae) in Europe, as well as in changes in the distribution within its prior endemic zones. This paper builds on published literature and unpublished expert opinion from the VBORNET network with the aim of reviewing the evidence for these changes in Europe and discusses the many climatic, ecological, landscape and anthropogenic drivers. These can be divided into those directly related to climatic change, contributing to an expansion in the tick's geographic range at extremes of altitude in central Europe, and at extremes of latitude in Scandinavia; those related to changes in the distribution of tick hosts, particularly roe deer and other cervids; other ecological changes such as habitat connectivity and changes in land management; and finally, anthropogenically induced changes. These factors are strongly interlinked and often not well quantified. Although a change in climate plays an important role in certain geographic regions, for much of Europe it is non-climatic factors that are becoming increasingly important. How we manage habitats on a landscape scale, and the changes in the distribution and abundance of tick hosts are important considerations during our assessment and management of the public health risks associated with ticks and tick-borne disease issues in 21(st) century Europe. Better understanding and mapping of the spread of I. ricinus (and changes in its abundance) is, however, essential to assess the risk of the spread of infections transmitted by this vector species. Enhanced tick surveillance with harmonized approaches for comparison of data enabling the follow-up of trends at EU level will improve the messages on risk related to tick-borne diseases to policy makers, other stake holders and to the general public.
Collapse
Affiliation(s)
- Jolyon M Medlock
- Medical Entomology Group, MRA, Emergency Response Department, Health Protection Agency, Salisbury, UK.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Sherrard-Smith E, Chadwick E, Cable J. Abiotic and biotic factors associated with tick population dynamics on a mammalian host: Ixodes hexagonus infesting otters, Lutra lutra. PLoS One 2012; 7:e47131. [PMID: 23071736 PMCID: PMC3465257 DOI: 10.1371/journal.pone.0047131] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2012] [Accepted: 09/12/2012] [Indexed: 11/25/2022] Open
Abstract
The Eurasian otter, Lutra lutra, hosts several parasites with zoonotic potential. As this semiaquatic mammal has large ranges across terrestrial, freshwater and marine habitats, it has the capacity for wide dispersion of pathogens. Despite this, parasites of otters have received relatively little attention. Here, we examine their ectoparasite load and assess whether this is influenced by abiotic or biotic variables. Climatic phenomena such as the North Atlantic Oscillation (NAO) affect weather conditions in northern Europe. Consequently parasite distributions, particularly species with life stages exposed to the external environment, can be affected. We assessed the extent to which inter-annual variations in large-scale weather patterns (specifically the NAO and Central England (CE) temperatures) and host characteristics influenced tick prevalence and intensity. Ectoparasites consisted of a single species, the nidiculous tick Ixodes hexagonus (prevalence = 24.3%; mean intensity = 7.2; range = 1-122; on n = 820 otter hosts). The prevalence, but not intensity of infestation, was associated with high CE temperatures, while both prevalence and intensity were associated with positive phases of the NAO. Such associations indicate that I. hexagonus are most abundant when weather conditions are warmer and wetter. Ticks were more prevalent on juvenile than sub-adult or adult otters, which probably reflects the length of time the hosts spend in the holt where these ticks quest. High tick number was associated with poor host condition, so either poor condition hosts are more susceptible to ticks, or tick infestations negatively impact on host condition. Otters are clearly an important and common host for I. hexagonus, which has implications for vector-borne diseases. This work is the first to consider the impacts of long-term weather patterns on I. hexagonus and uses wild-animal cadavers to illustrate the importance of abiotic and biotic pressures impacting parasitic populations.
Collapse
|
15
|
Kuo CC, Huang JL, Shu PY, Lee PL, Kelt DA, Wang HC. Cascading effect of economic globalization on human risks of scrub typhus and tick-borne rickettsial diseases. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2012; 22:1803-1816. [PMID: 23092017 DOI: 10.1890/12-0031.1] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The increase in global travel and trade has facilitated the dissemination of disease vectors. Globalization can also indirectly affect vector-borne diseases through the liberalization of cross-border trade, which has far-reaching, worldwide effects on agricultural practices and may in turn influence vectors through the modification of the ecological landscape. While the cascading effect of economic globalization on vector-borne diseases, sometimes acting synergistically with regional agricultural policy, could be substantial and have significant economic, agricultural, and public health implications, research into this remains very limited. We evaluated how abandonment of rice paddies in Taiwan after joining the World Trade Organization, along with periodic plowing, an agricultural policy to reduce farm pests in abandoned fields can unexpectedly influence risks to diseases transmitted by ticks and chiggers (larval trombiculid mites), which we collected from their small-mammal hosts. Sampling was limited to abandoned (fallow) and plowed fields due to the challenge of trapping small mammals in flooded rice paddies. Striped field mice (Apodemus agrarius) are the main hosts for both vectors. They harbored six times more ticks and three times more chiggers in fallow than in plowed plots. The proportion of ticks infected with Rickettsia spp. (etiologic agent of spotted fever) was three times higher in fallow plots, while that of Orientia tsutsugamushi (scrub typhus) in chiggers was similar in both treatments. Fallow plots had more ground cover and higher vegetation than plowed ones. Moreover, ticks and chiggers in both field types were dominated by species known to infest humans. Because ticks and chiggers should exhibit very low survival in flooded rice paddies, we propose that farm abandonment in Taiwan, driven by globalization, may have inadvertently led to increased risks of spotted fever and scrub typhus. However, periodic plowing can unintentionally mitigate vector burdens. Economic globalization can have unexpected consequences on disease risk through modification of the agricultural landscape, but the outcome may also be influenced by agricultural policies, calling for further research on vector-borne diseases and their control from broader perspectives.
Collapse
Affiliation(s)
- Chi-Chien Kuo
- Department of Wildlife, Fish, and Conservation Biology, University of California, One Shields Avenue, Davis, California 95616, USA
| | | | | | | | | | | |
Collapse
|
16
|
Corrain R, Drigo M, Fenati M, Menandro ML, Mondin A, Pasotto D, Martini M. Study on ticks and tick-borne zoonoses in public parks in Italy. Zoonoses Public Health 2012; 59:468-76. [PMID: 22551055 DOI: 10.1111/j.1863-2378.2012.01490.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
A survey on tick density and on tick-borne zoonoses was carried out in four public parks in the outskirts of Imola (northern Italy) from June to October 2006. All stages of Ixodes ricinus and only larvae of Riphicephalus sanguineus were recovered by dragging, performed on 100-m transects. Almost all ticks (99%) were harvested in one park. I. ricinus density (nymphs/100 m(2) ) ranged from 0 in park L to 6.3 in park F. Nymphs and adults of I. ricinus were subjected to PCR for Anaplasma phagocytophilum, Bartonella spp., Borrelia burgdorferi s. l. and Rickettsia spp. The observed prevalences were 38.3% for Bartonella henselae, 5.2% for Bartonella clarridgeiae, 10.4% for B. burgdorferi s. l., 2.6% for Rickettsia helvetica and 13% for Rickettsia monacensis, respectively. No DNA of A. phagocytophilum was found. Acarological risks (AR) were calculated as probabilities of collecting at least one infected nymph per transect. The AR values calculated for the various zoonotic agents were 11.4% for R. helvetica, 27.7% for B. clarridgeiae, 49.7% for B. burgdorferi s. l., 57.2% for R. monacensis and 90.4% for B. henselae, respectively. In this study, B. clarridgeiae was for the first time identified in I. ricinus ticks.
Collapse
Affiliation(s)
- R Corrain
- Dipartimento di Sanità Pubblica, Patologia Comparata e Igiene Veterinaria, Università di Padova, Padova, Italy
| | | | | | | | | | | | | |
Collapse
|
17
|
Smith FD, Ballantyne R, Morgan ER, Wall R. Prevalence, distribution and risk associated with tick infestation of dogs in Great Britain. MEDICAL AND VETERINARY ENTOMOLOGY 2011; 25:377-384. [PMID: 21418263 DOI: 10.1111/j.1365-2915.2011.00954.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Current concerns over the potential impacts of climate change and the increased movement between countries of people and companion animals on the distribution of ectoparasites, highlight the need for accurate understanding of existing prevalence patterns. Without these future changes will not be detected. Here, the distribution and prevalence of tick infestations of domestic dogs in Great Britain were examined. A total of 173 veterinary practices were recruited to monitor tick attachment to dogs in their local areas between March and October 2009. Practices selected five dogs at random each week from those brought to the surgery and undertook a thorough, standardized examination for ticks. Each veterinary practice participated for 3 months before being replaced. Any ticks identified were collected and a sample sent to the investigators for identification, along with a clinical history of the dog. A total of 3534 dogs were examined; 810 dogs were found to be carrying at least one tick. Ixodes ricinus (Linnaeus) (Acari: Ixodidae) was identified in 72.1% of cases, Ixodes hexagonus Leach in 21.7% and Ixodes canisuga Johnston in 5.6% of cases. Five samples of Dermacentor reticulatus (Fabricius) (Acari: Ixodidae) were also found, adding to the growing evidence that an established population of D. reticulatus now exists in south-eastern England. Almost all the ticks found were adults. Overall, 19.2% of the veterinary practices reported no tick detections, 50% reported that ≥14.9% of the dogs seen were infested and 14.6% reported that >50% of the dogs inspected carried ticks. The estimated incidence of tick attachment was 0.013 per day in March (lowest) and 0.096 per day in June (highest). A number of risk factors affected the likelihood of tick attachment on dogs. Gundog, terrier and pastoral breed groups were more likely to carry ticks, as were non-neutered dogs. Dogs with shorter hair were less likely to have ticks, and dogs were most likely to carry a tick in June. This study is of value because, unusually, it presents the results of a randomized sample of dogs and gives a prevalence which is higher than those previously recorded in Great Britain.
Collapse
Affiliation(s)
- F D Smith
- Veterinary Parasitology and Ecology Group, School of Biological Sciences, University of Bristol, U.K.
| | | | | | | |
Collapse
|
18
|
Greenfield BPJ. Environmental parameters affecting tick (Ixodes ricinus) distribution during the summer season in Richmond Park, London. ACTA ACUST UNITED AC 2011. [DOI: 10.1093/biohorizons/hzr016] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
|
19
|
Kempf F, McCoy KD, De Meeûs T. Wahlund effects and sex-biased dispersal in Ixodes ricinus, the European vector of Lyme borreliosis: new tools for old data. INFECTION GENETICS AND EVOLUTION 2010; 10:989-97. [PMID: 20601167 DOI: 10.1016/j.meegid.2010.06.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2009] [Revised: 05/28/2010] [Accepted: 06/04/2010] [Indexed: 11/25/2022]
Abstract
Population genetics can help us better understand species microevolution and population biology, but inferences made from the genetic polymorphisms of field-collected organisms critically rely on sampling design. The population structure of the tick Ixodes ricinus L. (Acari, Ixodidae), a commonly encountered ectoparasite and the principal vector of human Lyme disease in Europe, has been the focus of some study, but many ecological aspects of this species remain poorly understood. Here, we apply a Bayesian clustering approach to observed and simulated data to examine within-population structure in I. ricinus, and to re-analyse patterns of sex-biased dispersal based on this substructure. We found between 18 and 27 distinct clusters within each of the 12 subsamples examined with a significant drop of heterozygote deficits. Parallel analyses on a comparable species, the seabird tick Ixodes uriae, indicated that these clusters can reflect important ecological features of the species (i.e., local host-associations). Analyses that considered the within-population clustering pattern of I. ricinus showed reversed patterns of sex-biased dispersal as compared to raw data (i.e., female-biased instead of male-biased dispersal). Simulated data supported the hypothesis that these scale-dependant patterns could be due to a combination of sex-specific dispersal and mortality. These different results raise new questions on the dispersal and host use strategies of I. ricinus and the potential importance of these ecological features for disease transmission. Furthermore, this work underlines the importance of taking into account patterns of genetic substructure when investigating sex-biased dispersal in natural populations.
Collapse
Affiliation(s)
- Florent Kempf
- Génétique et Evolution des Maladies Infectieuses, UMR CNRS-IRD 2724, IRD, 911 avenue Agropolis, BP 64501, 34394 Montpellier Cedex 5, France.
| | | | | |
Collapse
|
20
|
Medlock J, Jameson L. Ecological approaches to informing public health policy and risk assessments on emerging vector-borne zoonoses. EMERGING HEALTH THREATS JOURNAL 2010; 3:e1. [PMID: 22460391 PMCID: PMC3167655 DOI: 10.3134/ehtj.10.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/25/2009] [Revised: 11/27/2009] [Accepted: 12/01/2009] [Indexed: 11/18/2022]
Abstract
Pathogens associated with vector-borne zoonoses occur in enzootic cycles within nature. They are driven by a combination of vertebrate host and invertebrate vector population dynamics, which in turn respond to changes in environmental stimuli. Human involvement in these cycles, and hence the occurrence of human disease, is often to act as incidental host. From a public health perspective our ability to better predict human outbreaks of these diseases and prepare intervention and mitigation strategies relies on understanding the natural cycle of pathogen transmission. This requires consideration of, for example, invertebrate and vertebrate ecology and biology, climatology, land use and habitat change. Collectively, these can be referred to as medical entomology and medical ecology. This article reviews the importance for inclusion of such disciplines when assessing the public health risk from vector-borne zoonoses and summarizes the possible future challenges and driving forces for changes in vector status and vector-borne zoonoses emergence, with a particular focus on a UK and European context.
Collapse
Affiliation(s)
- Jm Medlock
- Medical Entomology and Zoonoses Ecology Group, Microbial Risk Assessment, Health Protection Agency, Salisbury, UK
| | | |
Collapse
|
21
|
Kempf F, De Meeûs T, Arnathau C, Degeilh B, McCoy KD. Assortative pairing in Ixodes ricinus (Acari: Ixodidae), the European vector of Lyme borreliosis. JOURNAL OF MEDICAL ENTOMOLOGY 2009; 46:471-474. [PMID: 19496415 DOI: 10.1603/033.046.0309] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
In sexual organisms, the way in which gametes associate can greatly influence the maintenance of genetic variation, the structure of this variation in space, and ultimately organismal evolution. Based on patterns of genetic structure previously found, we explicitly tested whether adults of the sheep tick Ixodes ricinus pair according to their genetic relatedness. We sampled tick pairs from the vegetation in four natural populations and genotyped individual ticks at seven microsatellite loci. Based on this data, we observed highly significant assortative mating in two of the four locations, a pattern that could not be accounted for by a spatial autocorrelation in the distribution of related ticks. One explanation for these observations may be the existence of local host associations that develop independently in different populations. Assortative mating in I. ricinus will have clear consequences for its population dynamics and, through processes of adaptation and transmission, may significantly alter the epidemiological patterns of the pathogens it carries, including the Lyme disease agent Borrelia burgdorferi s.l. Future tests will now be required to examine the mechanisms leading to this pattern and its epidemiological consequences.
Collapse
Affiliation(s)
- Florent Kempf
- Génétique et Evolution des Maladies Infectieuses, UMR CNRS-IRD 2724, Centre IRD, 911 Avenue Agropolis, BP 64501, 34394 Montpellier Cedex 5, France.
| | | | | | | | | |
Collapse
|
22
|
Haemig PD, Waldenstrom J, Olsen B. Roadside ecology and epidemiology of tick-borne diseases. ACTA ACUST UNITED AC 2009; 40:853-8. [PMID: 18618374 DOI: 10.1080/00365540802270003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
When humans, pets and livestock walk along roads, they may encounter questing ticks and tick-borne pathogens. A new field of environmental science called road ecology can help researchers study the complex epidemiology of tick-borne diseases in the unique roadside environment. This paper reviews some of the important ways that roads alter the distribution, abundance and behaviour of wildlife species that are involved in the enzootic cycles of tick-borne diseases. Compared to the surrounding landscape, roadways often constitute a different environment and hence there is no assurance that disease risk along roads will be the same as in the adjacent landscape, or that disease control measures taken in the surrounding landscape will work in the adjacent roadway. Since roadways have their own special ecological conditions, are used extensively by the human populace and play strategic roles in community security, we believe that roadways should be one of the habitats where tick-borne diseases are studied. It is amazing that at this late period of human history, epidemiological research along such important corridors has been almost completely ignored.
Collapse
Affiliation(s)
- Paul D Haemig
- Section for Zoonotic Ecology and Epidemiology, School of Pure and Applied Natural Sciences, Linne University.
| | | | | |
Collapse
|