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Kauer L, Dobler G, Schmuck HM, Chitimia‐Dobler L, Pfeffer M, Kühn R. Interrelation of the spatial and genetic structure of tick-borne encephalitis virus, its reservoir host ( Myodes glareolus), and its vector ( Ixodes ricinus) in a natural focus area. Ecol Evol 2024; 14:e70163. [PMID: 39165543 PMCID: PMC11333545 DOI: 10.1002/ece3.70163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 06/21/2024] [Accepted: 07/26/2024] [Indexed: 08/22/2024] Open
Abstract
Tick-borne encephalitis (TBE) virus is considered the medically most important arthropod-borne virus in Europe. Although TBE is endemic throughout central Europe, ticks and rodents determine its maintenance in small, difficult-to-assess, natural foci. We investigated the interrelation between the population genetics of the main TBE virus (TBEV) vector tick (Ixodes ricinus), the most important reservoir host (Myodes glareolus, syn. Clethrionomys glareolus), and TBEV. Rodents and ticks were sampled on 15 sites within an exploratory study area, which has been screened regularly for TBEV occurrence in ticks for more than 10 years. On all 15 sites, ticks and bank voles were sampled, screened for TBEV presence via serology and RT-PCR, and genetically examined. Moreover, TBEV isolates derived from these analyses were sequenced. In long-term TBEV foci bank vole populations show extraordinary genetic constitutions, leading to a particular population structure, whereas ticks revealed a panmictic genetic structure overall sampling sites. Landscape genetics and habitat connectivity modeling (analysis of isolation by resistance) showed no landscape-related barriers explaining the genetic structure of the bank vole populations. The results suggest that bank voles do not simply serve as TBEV reservoirs, but their genetic composition appears to have a significant influence on establishing and maintaining long-term natural TBEV foci, whereas the genetic structure of TBEV's main vector I. ricinus does not play an important role in the sustainability of long-term TBEV foci. A thorough investigation of how and to which extent TBEV and M. glareolus genetics are associated is needed to further unravel the underlying mechanisms.
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Affiliation(s)
- Lea Kauer
- Molecular Zoology, Department of Zoology, TUM School of Life SciencesTechnical University of MunichFreisingGermany
| | | | - Hannah M. Schmuck
- Institute of Animal Hygiene and Veterinary Public HealthUniversity of LeipzigLeipzigGermany
| | | | - Martin Pfeffer
- Institute of Animal Hygiene and Veterinary Public HealthUniversity of LeipzigLeipzigGermany
| | - Ralph Kühn
- Molecular Zoology, Department of Zoology, TUM School of Life SciencesTechnical University of MunichFreisingGermany
- Department of Fish, Wildlife and Conservation EcologyNew Mexico State UniversityLas CrucesNew MexicoUSA
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2
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Diakou A, Foucault-Simonin A, Antoniou G, Cabezas-Cruz A, Földvári G. Tick paralysis induced by Ixodes gibbosus: enigmatic cases in domestic mammals from Cyprus. Front Vet Sci 2024; 11:1416501. [PMID: 38903693 PMCID: PMC11189028 DOI: 10.3389/fvets.2024.1416501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Accepted: 05/16/2024] [Indexed: 06/22/2024] Open
Abstract
Tick paralysis is a potentially fatal condition caused by toxins produced and secreted by tick salivary glands. This survey presents clinical and epidemiological observations of tick paralysis cases in domestic animals in Cyprus. Local veterinarians report typical tick paralysis cases occurring in goats, sheep, dogs, and cats. The animals suffering from paralysis are free from other neurological diseases, have blood and biochemical parameters within normal ranges, and recover fast by simply removing the ticks found predominantly on the head and around the neck. Tick paralysis cases occur in a specific geographic area of Cyprus (Akamas peninsula), from September through March, but not every year. Instead, the phenomenon has 2 periodic cycles of occurrence, a 3- and a 7-year cycle. The 2 cycles are differentiated by severity based on the number of affected animals and the resulting losses. As described for other tick-borne diseases, these cyclic patterns may be attributed to external factors, self-oscillations of the disease system, or the combined action of these mechanisms. Ticks collected from a recent paralysis case in a goat were morphologically and molecularly identified as Ixodes gibbosus. Efforts should be made to characterize the specific toxins involved in tick paralysis and to develop a vaccine, which could prevent significant losses of small ruminants, especially in free-ranging farming systems, a prevalent management approach observed in Cyprus and various regions worldwide.
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Affiliation(s)
- Anastasia Diakou
- Laboratory of Parasitology and Parasitic Diseases, School of Veterinary Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece
- Diagnostics and Laboratory Research Task Force, Balkan Association for Vector-Borne Diseases, Novi Sad, Serbia
| | - Angelique Foucault-Simonin
- ANSES, INRAE, Ecole Nationale Vétérinaire d’Alfort, UMR BIPAR, Laboratoire de Santé Animale, Maisons-Alfort, France
| | | | - Alejandro Cabezas-Cruz
- ANSES, INRAE, Ecole Nationale Vétérinaire d’Alfort, UMR BIPAR, Laboratoire de Santé Animale, Maisons-Alfort, France
| | - Gábor Földvári
- Institute of Evolution, HUN-REN Centre for Ecological Research, Budapest, Hungary
- Centre for Eco-Epidemiology, National Laboratory for Health Security, Budapest, Hungary
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3
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Giesen C, Cifo D, Gomez-Barroso D, Estévez-Reboredo RM, Figuerola J, Herrador Z. The Role of Environmental Factors in Lyme Disease Transmission in the European Union: A Systematic Review. Trop Med Infect Dis 2024; 9:113. [PMID: 38787046 PMCID: PMC11125681 DOI: 10.3390/tropicalmed9050113] [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: 01/24/2024] [Revised: 04/01/2024] [Accepted: 05/10/2024] [Indexed: 05/25/2024] Open
Abstract
BACKGROUND Lyme disease (LD) is an emergent vector-borne disease caused by Borrelia spp. and transmitted through infected ticks, mainly Ixodes spp. Our objective was to determine meteorological and environmental factors associated with LD transmission in Europe and the effect of climate change on LD. MATERIALS AND METHODS A systematic review following the PRISMA guidelines was performed. We selected studies on LD transmission in the European Union (EU) and the European Economic Area (EEA) published between 2000 and 2022. The protocol was registered in the PROSPERO database. RESULTS We included 81 studies. The impact of environmental, meteorological or climate change factors on tick vectors was studied in 65 papers (80%), and the impact on human LD cases was studied in 16 papers (19%), whereas animal hosts were only addressed in one study (1%). A significant positive relationship was observed between temperature and precipitation and the epidemiology of LD, although contrasting results were found among studies. Other positive factors were humidity and the expansion of anthropized habitats. CONCLUSIONS The epidemiology of LD seems to be related to climatic factors that are changing globally due to ongoing climate change. Unfortunately, the complete zoonotic cycle was not systematically analyzed. It is important to adopt a One Health approach to understand LD epidemiology.
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Affiliation(s)
- Christine Giesen
- Centro de Salud Internacional Madrid Salud, Ayuntamiento de Madrid, 28006 Madrid, Spain;
| | - Daniel Cifo
- Escuela Nacional de Sanidad, Instituto de Salud Carlos III, 28029 Madrid, Spain;
| | - Diana Gomez-Barroso
- Centro Nacional de Epidemiología, Instituto de Salud Carlos III, 28029 Madrid, Spain; (D.G.-B.); (R.M.E.-R.)
- CIBER Epidemiología y Salud Pública (CIBERESP), 28029 Madrid, Spain;
| | - Rosa M. Estévez-Reboredo
- Centro Nacional de Epidemiología, Instituto de Salud Carlos III, 28029 Madrid, Spain; (D.G.-B.); (R.M.E.-R.)
| | - Jordi Figuerola
- CIBER Epidemiología y Salud Pública (CIBERESP), 28029 Madrid, Spain;
- Estación Biológica de Doñana, Consejo Superior de Investigaciones Científicas, 41092 Sevilla, Spain
| | - Zaida Herrador
- Centro Nacional de Epidemiología, Instituto de Salud Carlos III, 28029 Madrid, Spain; (D.G.-B.); (R.M.E.-R.)
- CIBER Epidemiología y Salud Pública (CIBERESP), 28029 Madrid, Spain;
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4
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Jore S, Viljugrein H, Hjertqvist M, Dub T, Mäkelä H. Outdoor recreation, tick borne encephalitis incidence and seasonality in Finland, Norway and Sweden during the COVID-19 pandemic (2020/2021). Infect Ecol Epidemiol 2023; 13:2281055. [PMID: 38187169 PMCID: PMC10769561 DOI: 10.1080/20008686.2023.2281055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 11/03/2023] [Indexed: 01/09/2024] Open
Abstract
During the pandemic outdoor activities were encouraged to mitigate transmission risk while providing safe spaces for social interactions. Human behaviour, which may favour or disfavour, contact rates between questing ticks and humans, is a key factor impacting tick-borne encephalitis (TBE) incidence. We analyzed annual and weekly TBE cases in Finland, Norway and Sweden from 2010 to 2021 to assess trend, seasonality, and discuss changes in human tick exposure imposed by COVID-19. We compared the pre-pandemic incidence (2010-2019) with the pandemic incidence (2020-2021) by fitting a generalized linear model (GLM) to incidence data. Pre-pandemic incidence was 1.0, 0.29 and 2.8 for Finland, Norway and Sweden, respectively, compared to incidence of 2.2, 1.0 and 3.9 during the pandemic years. However, there was an increasing trend for all countries across the whole study period. Therefore, we predicted the number of cases in 2020/2021 based on a model fitted to the annual cases in 2010-2019. The incidences during the pandemic were 1.3 times higher for Finland, 1.7 times higher for Norway and no difference for Sweden. When social restrictions were enforced to curb the spread of SARS-CoV-2 there were profound changes in outdoor recreational behavior. Future consideration of public health interventions that promote outdoor activities may increase exposure to vector-borne diseases.
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Affiliation(s)
- Solveig Jore
- Zoonotic, Food & Waterborne Infections, Norwegian Institute of Public Health (NIPH), Oslo, Norway
| | - Hildegunn Viljugrein
- Norwegian Veterinary Institute, Norway
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, Blindern, Norway
| | - Marika Hjertqvist
- Department of Communicable Disease Control and Health Protection, Public Health Agency of Sweden, Solna, Sweden
| | - Timothée Dub
- Infectious Disease Control and Vaccinations Unit, Department of Health Security, Finnish Institute for Health and Welfare (THL), Helsinki, Finland
| | - Henna Mäkelä
- Infectious Disease Control and Vaccinations Unit, Department of Health Security, Finnish Institute for Health and Welfare (THL), Helsinki, Finland
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Dagostin F, Tagliapietra V, Marini G, Cataldo C, Bellenghi M, Pizzarelli S, Cammarano RR, Wint W, Alexander NS, Neteler M, Haas J, Dub T, Busani L, Rizzoli A. Ecological and environmental factors affecting the risk of tick-borne encephalitis in Europe, 2017 to 2021. Euro Surveill 2023; 28:2300121. [PMID: 37855903 PMCID: PMC10588310 DOI: 10.2807/1560-7917.es.2023.28.42.2300121] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 05/11/2023] [Indexed: 10/20/2023] Open
Abstract
BackgroundTick-borne encephalitis (TBE) is a disease which can lead to severe neurological symptoms, caused by the TBE virus (TBEV). The natural transmission cycle occurs in foci and involves ticks as vectors and several key hosts that act as reservoirs and amplifiers of the infection spread. Recently, the incidence of TBE in Europe has been rising in both endemic and new regions.AimIn this study we want to provide comprehensive understanding of the main ecological and environmental factors that affect TBE spread across Europe.MethodsWe searched available literature on covariates linked with the circulation of TBEV in Europe. We then assessed the best predictors for TBE incidence in 11 European countries by means of statistical regression, using data on human infections provided by the European Surveillance System (TESSy), averaged between 2017 and 2021.ResultsWe retrieved data from 62 full-text articles and identified 31 different covariates associated with TBE occurrence. Finally, we selected eight variables from the best model, including factors linked to vegetation cover, climate, and the presence of tick hosts.DiscussionThe existing literature is heterogeneous, both in study design and covariate types. Here, we summarised and statistically validated the covariates affecting the variability of TBEV across Europe. The analysis of the factors enhancing disease emergence is a fundamental step towards the identification of potential hotspots of viral circulation. Hence, our results can support modelling efforts to estimate the risk of TBEV infections and help decision-makers implement surveillance and prevention campaigns.
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Affiliation(s)
- Francesca Dagostin
- Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige (TN), Italy
| | - Valentina Tagliapietra
- Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige (TN), Italy
| | - Giovanni Marini
- Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige (TN), Italy
| | - Claudia Cataldo
- Centre for Gender-specific Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Maria Bellenghi
- Centre for Gender-specific Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Scilla Pizzarelli
- Knowledge Unit (Documentation, Library), Istituto Superiore di Sanità, Rome, Italy
| | | | - William Wint
- Environmental Research Group Oxford Ltd, Oxford, United Kingdom
| | | | | | | | - Timothée Dub
- Department of Health Security, Finnish Institute for Health and Welfare, Helsinki, Finland
| | - Luca Busani
- Centre for Gender-specific Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Annapaola Rizzoli
- Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige (TN), Italy
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6
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Marini G, Tagliapietra V, Cristofolini F, Cristofori A, Dagostin F, Zuccali MG, Molinaro S, Gottardini E, Rizzoli A. Correlation between airborne pollen data and the risk of tick-borne encephalitis in northern Italy. Sci Rep 2023; 13:8262. [PMID: 37217780 DOI: 10.1038/s41598-023-35478-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 05/18/2023] [Indexed: 05/24/2023] Open
Abstract
Tick-borne encephalitis (TBE) is caused by a flavivirus that infects animals including humans. In Europe, the TBE virus circulates enzootically in natural foci among ticks and rodent hosts. The abundance of ticks depends on the abundance of rodent hosts, which in turn depends on the availability of food resources, such as tree seeds. Trees can exhibit large inter-annual fluctuations in seed production (masting), which influences the abundance of rodents the following year, and the abundance of nymphal ticks two years later. Thus, the biology of this system predicts a 2-year time lag between masting and the incidence of tick-borne diseases such as TBE. As airborne pollen abundance is related to masting, we investigated whether inter-annual variation in pollen load could be directly correlated with inter-annual variation in the incidence of TBE in human populations with a 2-year time lag. We focused our study on the province of Trento (northern Italy), where 206 TBE cases were notified between 1992 and 2020. We tested the relationship between TBE incidence and pollen load collected from 1989 to 2020 for 7 different tree species common in our study area. Through univariate analysis we found that the pollen quantities recorded two years prior for two tree species, hop-hornbeam (Ostrya carpinifolia) and downy oak (Quercus pubescens), were positively correlated with TBE emergence (R2 = 0.2) while a multivariate model with both tree species better explained the variation in annual TBE incidence (R2 = 0.34). To the best of our knowledge, this is the first attempt at quantifying the correlation between pollen quantities and the incidence of TBE in human populations. As pollen loads are collected by widespread aerobiological networks using standardized procedures, our study could be easily replicated to test their potential as early warning system for TBE and other tick-borne diseases.
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Affiliation(s)
- Giovanni Marini
- Research and Innovation Centre, Fondazione Edmund Mach, San Michele All'Adige, TN, Italy.
| | - Valentina Tagliapietra
- Research and Innovation Centre, Fondazione Edmund Mach, San Michele All'Adige, TN, Italy
| | - Fabiana Cristofolini
- Research and Innovation Centre, Fondazione Edmund Mach, San Michele All'Adige, TN, Italy
| | - Antonella Cristofori
- Research and Innovation Centre, Fondazione Edmund Mach, San Michele All'Adige, TN, Italy
| | - Francesca Dagostin
- Research and Innovation Centre, Fondazione Edmund Mach, San Michele All'Adige, TN, Italy
| | | | | | - Elena Gottardini
- Research and Innovation Centre, Fondazione Edmund Mach, San Michele All'Adige, TN, Italy
| | - Annapaola Rizzoli
- Research and Innovation Centre, Fondazione Edmund Mach, San Michele All'Adige, TN, Italy
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7
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Borde JP, Glaser R, Braun K, Riach N, Hologa R, Kaier K, Chitimia-Dobler L, Dobler G. Decoding the Geography of Natural TBEV Microfoci in Germany: A Geostatistical Approach Based on Land-Use Patterns and Climatological Conditions. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:11830. [PMID: 36142105 PMCID: PMC9517139 DOI: 10.3390/ijerph191811830] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/17/2022] [Revised: 09/11/2022] [Accepted: 09/11/2022] [Indexed: 06/16/2023]
Abstract
Background: Tickborne-encephalitis (TBE) is a potentially life-threating neurological disease that is mainly transmitted by ticks. The goal of the present study is to analyze the potential uniform environmental patterns of the identified TBEV microfoci in Germany. The results are used to calculate probabilities for the present distribution of TBEV microfoci in Germany based on a geostatistical model. Methods: We aim to consider the specification of environmental characteristics of locations of TBEV microfoci detected in Germany using open access epidemiological, geographical and climatological data sources. We use a two-step geostatistical approach, where in a first step, the characteristics of a broad set of environmental variables between the 56 TBEV microfoci and a control or comparator set of 3575 sampling points covering Germany are compared using Fisher's Exact Test. In the second step, we select the most important variables, which are then used in a MaxEnt distribution model to calculate a high resolution (400 × 400 m) probability map for the presence of TBEV covering the entire area of Germany. Results: The findings from the MaxEnt prediction model indicate that multi annual actual evapotranspiration (27.0%) and multi annual hot days (22.5%) have the highest contribution to our model. These two variables are followed by four additional variables with a lower, but still important, explanatory influence: Land cover classes (19.6%), multi annual minimum air temperature (14.9%), multi annual sunshine duration (9.0%), and distance to coniferous and mixed forest border (7.0%). Conclusions: Our findings are based on defined TBEV microfoci with known histories of infection and the repeated confirmation of the virus in the last years, resulting in an in-depth high-resolution model/map of TBEV microfoci in Germany. Multi annual actual evapotranspiration (27%) and multi annual hot days (22.5%) have the most explanatory power in our model. The results may be used to tailor specific regional preventive measures and investigations.
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Affiliation(s)
- Johannes P. Borde
- Division of Infectious Diseases, Department of Medicine II, Faculty of Medicine, University of Freiburg Medical Center, D-79106 Freiburg im Breisgau, Germany
- Praxis Prof. Dr. J. Borde & Kollegen, Gesundheitszentrum Oberkirch, Am Marktplatz 8, D-77704 Oberkirch, Germany
| | - Rüdiger Glaser
- Institute of Environmental Social Sciences and Geography, University of Freiburg, Schreiberstr. 20, D-79098 Freiburg im Breisgau, Germany
| | - Klaus Braun
- Institute of Environmental Social Sciences and Geography, University of Freiburg, Schreiberstr. 20, D-79098 Freiburg im Breisgau, Germany
| | - Nils Riach
- Institute of Environmental Social Sciences and Geography, University of Freiburg, Schreiberstr. 20, D-79098 Freiburg im Breisgau, Germany
| | - Rafael Hologa
- Institute of Environmental Social Sciences and Geography, University of Freiburg, Schreiberstr. 20, D-79098 Freiburg im Breisgau, Germany
| | - Klaus Kaier
- Medical Center, Faculty of Medicine, Institute of Medical Biometry and Statistics, University of Freiburg, Stefan-Meier-Straße 26, D-79104 Freiburg im Breisgau, Germany
| | - Lidia Chitimia-Dobler
- German National Reference Laboratory for TBEV, Bundeswehr Institute of Microbiology, Neuherbergstraße 11, D-80937 München, Germany
- Parasitology Unit, University of Hohenheim, Emil-Wolff-Straße 34, D-70599 Stuttgart, Germany
| | - Gerhard Dobler
- German National Reference Laboratory for TBEV, Bundeswehr Institute of Microbiology, Neuherbergstraße 11, D-80937 München, Germany
- Parasitology Unit, University of Hohenheim, Emil-Wolff-Straße 34, D-70599 Stuttgart, Germany
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8
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Hacket‐Pain A, Foest JJ, Pearse IS, LaMontagne JM, Koenig WD, Vacchiano G, Bogdziewicz M, Caignard T, Celebias P, van Dormolen J, Fernández‐Martínez M, Moris JV, Palaghianu C, Pesendorfer M, Satake A, Schermer E, Tanentzap AJ, Thomas PA, Vecchio D, Wion AP, Wohlgemuth T, Xue T, Abernethy K, Aravena Acuña M, Daniel Barrera M, Barton JH, Boutin S, Bush ER, Donoso Calderón S, Carevic FS, de Castilho CV, Manuel Cellini J, Chapman CA, Chapman H, Chianucci F, da Costa P, Croisé L, Cutini A, Dantzer B, Justin DeRose R, Dikangadissi J, Dimoto E, da Fonseca FL, Gallo L, Gratzer G, Greene DF, Hadad MA, Herrera AH, Jeffery KJ, Johnstone JF, Kalbitzer U, Kantorowicz W, Klimas CA, Lageard JGA, Lane J, Lapin K, Ledwoń M, Leeper AC, Vanessa Lencinas M, Lira‐Guedes AC, Lordon MC, Marchelli P, Marino S, Schmidt Van Marle H, McAdam AG, Momont LRW, Nicolas M, de Oliveira Wadt LH, Panahi P, Martínez Pastur G, Patterson T, Luis Peri P, Piechnik Ł, Pourhashemi M, Espinoza Quezada C, Roig FA, Peña Rojas K, Micaela Rosas Y, Schueler S, Seget B, Soler R, Steele MA, Toro‐Manríquez M, Tutin CEG, Ukizintambara T, White L, Yadok B, Willis JL, Zolles A, Żywiec M, Ascoli D. MASTREE+: Time-series of plant reproductive effort from six continents. GLOBAL CHANGE BIOLOGY 2022; 28:3066-3082. [PMID: 35170154 PMCID: PMC9314730 DOI: 10.1111/gcb.16130] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 01/21/2022] [Accepted: 01/25/2022] [Indexed: 05/31/2023]
Abstract
Significant gaps remain in understanding the response of plant reproduction to environmental change. This is partly because measuring reproduction in long-lived plants requires direct observation over many years and such datasets have rarely been made publicly available. Here we introduce MASTREE+, a data set that collates reproductive time-series data from across the globe and makes these data freely available to the community. MASTREE+ includes 73,828 georeferenced observations of annual reproduction (e.g. seed and fruit counts) in perennial plant populations worldwide. These observations consist of 5971 population-level time-series from 974 species in 66 countries. The mean and median time-series length is 12.4 and 10 years respectively, and the data set includes 1122 series that extend over at least two decades (≥20 years of observations). For a subset of well-studied species, MASTREE+ includes extensive replication of time-series across geographical and climatic gradients. Here we describe the open-access data set, available as a.csv file, and we introduce an associated web-based app for data exploration. MASTREE+ will provide the basis for improved understanding of the response of long-lived plant reproduction to environmental change. Additionally, MASTREE+ will enable investigation of the ecology and evolution of reproductive strategies in perennial plants, and the role of plant reproduction as a driver of ecosystem dynamics.
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Affiliation(s)
- Andrew Hacket‐Pain
- Department of Geography and PlanningSchool of Environmental SciencesUniversity of LiverpoolLiverpoolUK
| | - Jessie J. Foest
- Department of Geography and PlanningSchool of Environmental SciencesUniversity of LiverpoolLiverpoolUK
| | - Ian S. Pearse
- U.S. Geological SurveyFort Collins Science CenterFort CollinsColoradoUSA
| | | | - Walter D. Koenig
- Hastings ReservationUniversity of California BerkeleyCarmel ValleyCaliforniaUSA
| | - Giorgio Vacchiano
- Department of Agricultural and Environmental SciencesUniversity of MilanMilanItaly
| | - Michał Bogdziewicz
- Faculty of BiologyInstitute of Environmental BiologyAdam Mickiewicz UniversityPoznańPoland
- INRAELESSEMUniversity Grenoble AlpesGrenobleFrance
| | | | - Paulina Celebias
- Faculty of BiologyInstitute of Environmental BiologyAdam Mickiewicz UniversityPoznańPoland
| | | | | | - Jose V. Moris
- Department of Agricultural, Forest and Food Sciences (DISAFA)University of TorinoTorinoItaly
| | | | - Mario Pesendorfer
- Department of Forest and Soil SciencesInstitute of Forest EcologyUniversity of Natural Resources and Life Sciences ViennaViennaAustria
| | | | - Eliane Schermer
- Aix Marseille UnivAvignon UniversitéCNRSIRDIMBEMarseilleFrance
| | - Andrew J. Tanentzap
- Ecosystems and Global Change GroupDepartment of Plant SciencesUniversity of CambridgeCambridgeUK
| | | | - Davide Vecchio
- Department of Agricultural, Forest and Food Sciences (DISAFA)University of TorinoTorinoItaly
| | - Andreas P. Wion
- Graduate Degree Program in Ecology and The Department of Forest and Rangeland StewardshipColorado State UniversityFort CollinsColoradoUSA
| | - Thomas Wohlgemuth
- Swiss Federal Institute for Forest, Snow and Landscape Research WSLBirmensdorfSwitzerland
| | - Tingting Xue
- College of Civil and Architecture and EngineeringChuzhou UniversityChina
| | - Katharine Abernethy
- Faculty of Natural SciencesUniversity of StirlingStirlingUK
- Institut de Recherche en Ecologie TropicaleCENARESTLibrevilleGabon
| | - Marie‐Claire Aravena Acuña
- Facultad de Ciencias Forestales y de la Conservación de la Naturaleza (FCFCN)Universidad de ChileSantiagoChile
| | | | - Jessica H. Barton
- Department of Biological SciencesDePaul UniversityChicagoIllinoisUSA
| | - Stan Boutin
- Department of Biological SciencesUniversity of AlbertaEdmontonABCanada
| | | | - Sergio Donoso Calderón
- Facultad de Ciencias Forestales y de la Conservación de la Naturaleza (FCFCN)Universidad de ChileSantiagoChile
| | - Felipe S. Carevic
- Facultad de Recursos Naturales RenovablesUniversidad Arturo PratIquiqueChile
| | | | - Juan Manuel Cellini
- Facultad de Ciencias Forestales y de la Conservación de la Naturaleza (FCFCN)Universidad de ChileSantiagoChile
| | - Colin A. Chapman
- Wilson CenterWashingtonDistrict of ColumbiaUSA
- Department of AnthropologyGeorge Washington UniversityWashingtonDistrict of ColumbiaUSA
- School of Life SciencesUniversity of KwaZulu‐NatalPietermaritzburgSouth Africa
- Shaanxi Key Laboratory for Animal ConservationNorthwest UniversityXi'anChina
| | - Hazel Chapman
- School of Biological SciencesUniversity of CanterburyCanterburyNew Zealand
- Nigerian Montane Forest Project (NMFP)Yelway VillageNigeria
| | | | - Patricia da Costa
- Brazilian Agricultural Research CorporationEmbrapa Meio AmbienteJaguariúnaBrazil
| | - Luc Croisé
- Département Recherche‐Développement‐InnovationOffice National des ForêtsFontainebleauFrance
| | - Andrea Cutini
- CREA—Research Centre for Forestry and WoodArezzoItaly
| | - Ben Dantzer
- Department of PsychologyDepartment of Ecology and Evolutionary BiologyUniversity of MichiganAnn ArborMichiganUSA
| | - R. Justin DeRose
- Department of Wildland Resources and Ecology CenterUtah State UniversityLoganUtahUSA
| | | | - Edmond Dimoto
- Agence Nationale des Parcs Nationaux (ANPN)LibrevilleGabon
| | | | - Leonardo Gallo
- Instituto de Investigaciones Forestales y Agropecuarias Bariloche (IFAB) (INTA—CONICETInstituto Nacional de Tecnología Agropecuaria—Consejo Nacional de Investigaciones Científicas y TécnicasBarilocheArgentina
| | - Georg Gratzer
- Department of Forest and Soil SciencesInstitute of Forest EcologyUniversity of Natural Resources and Life Sciences ViennaViennaAustria
| | - David F. Greene
- Department of Forestry and Wildland ResourcesHumboldt State UniversityArcataCaliforniaUSA
| | - Martín A. Hadad
- Laboratorio de Dendrocronología de Zonas ÁridasCIGEOBIO (CONICET‐UNSJ)RivadaviaArgentina
| | - Alejandro Huertas Herrera
- Centro de Investigación en Ecosistemas de la Patagonia (CIEP)CoyhaiqueChile
- Ulterarius Consultores Ambientales y Científicos LtdaPunta ArenasChile
| | | | - Jill F. Johnstone
- Institute of Arctic BiologyUniversity of Alaska FairbanksFairbanksAlaskaUSA
| | - Urs Kalbitzer
- Department for the Ecology of Animal SocietiesMax Planck Institute of Animal BehaviorRadolfzellGermany
- Department of BiologyUniversity of KonstanzKonstanzGermany
| | - Władysław Kantorowicz
- Department of Silviculture and Genetics of Forest TreesForest Research InstituteRaszynPoland
| | - Christie A. Klimas
- Environmental Science and Studies DepartmentDePaul UniversityChicagoIllinoisUSA
| | | | - Jeffrey Lane
- Department of BiologyUniversity of SaskatchewanSaskatoonSaskatchewanCanada
| | | | - Mateusz Ledwoń
- Institute of Systematics and Evolution of AnimalsPolish Academy of SciencesKrakówPoland
| | - Abigail C. Leeper
- Department of Biological SciencesDePaul UniversityChicagoIllinoisUSA
| | - Maria Vanessa Lencinas
- Centro Austral de Investigaciones Científicas (CADIC)Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)UshuaiaArgentina
| | | | - Michael C. Lordon
- Department of Biological SciencesDePaul UniversityChicagoIllinoisUSA
| | - Paula Marchelli
- Instituto de Investigaciones Forestales y Agropecuarias Bariloche (IFAB) (INTA—CONICETInstituto Nacional de Tecnología Agropecuaria—Consejo Nacional de Investigaciones Científicas y TécnicasBarilocheArgentina
| | - Shealyn Marino
- Department of Biology and Institute of the EnvironmentWilkes UniversityWilkes‐BarrePennsylvaniaUSA
| | | | - Andrew G. McAdam
- Department of Ecology and Evolutionary BiologyUniversity of ColoradoBoulderColoradoUSA
| | | | - Manuel Nicolas
- Département Recherche‐Développement‐InnovationOffice National des ForêtsFontainebleauFrance
| | | | - Parisa Panahi
- Botany Research DivisionResearch Institute of Forests and RangelandsAgricultural Research, Education and Extension OrganizationTehranIran
| | - Guillermo Martínez Pastur
- Centro Austral de Investigaciones Científicas (CADIC)Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)UshuaiaArgentina
| | - Thomas Patterson
- School of Biological, Environmental, and Earth SciencesThe University of Southern MississippiHattiesburgMississippiUSA
| | - Pablo Luis Peri
- Instituto Nacional de Tecnología Agropecuaria (INTA)Universidad Nacional de la Patagonia Austral (UNPA)Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)Río GallegosArgentina
| | - Łukasz Piechnik
- W. Szafer Institute of BotanyPolish Academy of SciencesKrakówPoland
| | - Mehdi Pourhashemi
- Forest Research DivisionResearch Institute of Forests and RangelandsAgricultural Research, Education and Extension OrganizationTehranIran
| | | | - Fidel A. Roig
- Laboratorio de Dendrocronología e Historia AmbientalIANIGLA—CONICET‐Universidad Nacional de CuyoMendozaArgentina
- Facultad de CienciasHémera Centro de Observación de la TierraEscuela de Ingeniería ForestalUniversidad MayorSantiagoChile
| | | | - Yamina Micaela Rosas
- Centro Austral de Investigaciones Científicas (CADIC)Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)UshuaiaArgentina
| | | | - Barbara Seget
- W. Szafer Institute of BotanyPolish Academy of SciencesKrakówPoland
| | - Rosina Soler
- Centro Austral de Investigaciones Científicas (CADIC)Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)UshuaiaArgentina
| | - Michael A. Steele
- Department of Biology and Institute of the EnvironmentWilkes UniversityWilkes‐BarrePennsylvaniaUSA
| | - Mónica Toro‐Manríquez
- Centro de Investigación en Ecosistemas de la Patagonia (CIEP)CoyhaiqueChile
- Ulterarius Consultores Ambientales y Científicos LtdaPunta ArenasChile
| | | | | | - Lee White
- Faculty of Natural SciencesUniversity of StirlingStirlingUK
- Institut de Recherche en Ecologie TropicaleCENARESTLibrevilleGabon
- Ministère des Eaux, des Forêts, de la Mer, de l'Environnement chargé du Plan Climat, des Objectifs de Development Durable et du Plan d'Affectation des TerresBoulevard TriomphaleLibrevilleGabon
| | - Biplang Yadok
- Nigerian Montane Forest Project (NMFP)Yelway VillageNigeria
- Biosecurity NZMinistry for Primary IndustriesWellingtonNew Zealand
| | | | - Anita Zolles
- Austrian Research Centre for Forests BFWViennaAustria
| | - Magdalena Żywiec
- W. Szafer Institute of BotanyPolish Academy of SciencesKrakówPoland
| | - Davide Ascoli
- Department of Agricultural, Forest and Food Sciences (DISAFA)University of TorinoTorinoItaly
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Nolzen H, Brugger K, Reichold A, Brock J, Lange M, Thulke HH. Model-based extrapolation of ecological systems under future climate scenarios: The example of Ixodes ricinus ticks. PLoS One 2022; 17:e0267196. [PMID: 35452467 PMCID: PMC9032420 DOI: 10.1371/journal.pone.0267196] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Accepted: 04/05/2022] [Indexed: 11/29/2022] Open
Abstract
Models can be applied to extrapolate consequences of climate change for complex ecological systems in the future. The acknowledged systems' behaviour at present is projected into the future considering climate projection data. Such an approach can be used to addresses the future activity and density of the castor bean tick Ixodes ricinus, the most widespread tick species in Europe. It is an important vector of pathogens causing Lyme borreliosis and tick-borne encephalitis. The population dynamics depend on several biotic and abiotic factors. Such complexity makes it difficult to predict the future dynamics and density of I. ricinus and associated health risk for humans. The objective of this study is to force ecological models with high-resolution climate projection data to extrapolate I. ricinus tick density and activity patterns into the future. We used climate projection data of temperature, precipitation, and relative humidity for the period 1971-2099 from 15 different climate models. Tick activity was investigated using a climate-driven cohort-based population model. We simulated the seasonal population dynamics using climate data between 1971 and 2099 and observed weather data since 1949 at a specific location in southern Germany. We evaluated derived quantities of local tick ecology, e.g. the maximum questing activity of the nymphal stage. Furthermore, we predicted spatial density changes by extrapolating a German-wide tick density model. We compared the tick density of the reference period (1971-2000) with the counter-factual densities under the near-term scenario (2012-2041), mid-term scenario (2050-2079) and long-term scenario (2070-2099). We found that the nymphal questing peak would shift towards early seasons of the year. Also, we found high spatial heterogeneity across Germany, with predicted hotspots of up to 2,000 nymphs per 100 m2 and coldspots with constant density. As our results suggest extreme changes in tick behaviour and density, we discuss why caution is needed when extrapolating climate data-driven models into the distant future when data on future climate drive the model projection.
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Affiliation(s)
- Henning Nolzen
- Department of Ecological Modelling, Helmholtz-Centre for Environmental Research GmbH–UFZ, Leipzig, Germany
| | - Katharina Brugger
- Unit for Veterinary Public Health and Epidemiology, University of Veterinary Medicine Vienna, Vienna, Austria
- Competence Center for Climate and Health, Austrian Public Health Institute (Gesundheit Österreich), Vienna, Austria
| | - Adam Reichold
- Department of Ecological Modelling, Helmholtz-Centre for Environmental Research GmbH–UFZ, Leipzig, Germany
| | - Jonas Brock
- Department of Ecological Modelling, Helmholtz-Centre for Environmental Research GmbH–UFZ, Leipzig, Germany
| | - Martin Lange
- Department of Ecological Modelling, Helmholtz-Centre for Environmental Research GmbH–UFZ, Leipzig, Germany
| | - Hans-Hermann Thulke
- Department of Ecological Modelling, Helmholtz-Centre for Environmental Research GmbH–UFZ, Leipzig, Germany
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The evolving story of Borrelia burgdorferi sensu lato transmission in Europe. Parasitol Res 2022; 121:781-803. [PMID: 35122516 PMCID: PMC8816687 DOI: 10.1007/s00436-022-07445-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 01/19/2022] [Indexed: 12/13/2022]
Abstract
Beside mosquitoes, ticks are well-known vectors of different human pathogens. In the Northern Hemisphere, Lyme borreliosis (Eurasia, LB) or Lyme disease (North America, LD) is the most commonly occurring vector-borne infectious disease caused by bacteria of the genus Borrelia which are transmitted by hard ticks of the genus Ixodes. The reported incidence of LB in Europe is about 22.6 cases per 100,000 inhabitants annually with a broad range depending on the geographical area analyzed. However, the epidemiological data are largely incomplete, because LB is not notifiable in all European countries. Furthermore, not only differ reporting procedures between countries, there is also variation in case definitions and diagnostic procedures. Lyme borreliosis is caused by several species of the Borrelia (B.) burgdorferi sensu lato (s.l.) complex which are maintained in complex networks including ixodid ticks and different reservoir hosts. Vector and host influence each other and are affected by multiple factors including climate that have a major impact on their habitats and ecology. To classify factors that influence the risk of transmission of B. burgdorferi s.l. to their different vertebrate hosts as well as to humans, we briefly summarize the current knowledge about the pathogens including their astonishing ability to overcome various host immune responses, regarding the main vector in Europe Ixodes ricinus, and the disease caused by borreliae. The research shows, that a higher standardization of case definition, diagnostic procedures, and standardized, long-term surveillance systems across Europe is necessary to improve clinical and epidemiological data.
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11
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Rubel F, Brugger K. Maps of ticks (Acari: Argasidae, Ixodidae) for Austria and South Tyrol, Italy. EXPERIMENTAL & APPLIED ACAROLOGY 2022; 86:211-233. [PMID: 35050437 PMCID: PMC8858313 DOI: 10.1007/s10493-022-00688-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 01/12/2022] [Indexed: 05/21/2023]
Abstract
A first compilation of georeferenced tick locations in Austria and South Tyrol, Italy, is presented here. This allows the tick fauna to be examined in the various climatic regions of the European Alps. The dataset comprises 424 tick locations of Austria and 48 tick locations of South Tyrol, which were digitized from literature and visualized in the form of geographical maps. The tick fauna of Austria includes two species of Argasidae in the genera Argas and Carios and 15 species of Ixodidae in the genera Dermacentor, Haemaphysalis, and Ixodes, altogether 17 tick species. In addition, two species of Ixodidae in the genera Hyalomma (each spring imported by migratory birds) and Rhipicephalus (occasionally imported by dogs returning from abroad with their owners) are included in the tick atlas. Of these, the georeferenced locations of 18 tick species are depicted in maps. The occurrence of the one remaining tick species, Ixodes inopinatus, is given at the level of the federal states. The first Austrian distribution map of the long-legged bat tick Ixodes vespertilionis, which was reported from 21 caves, deserves special mention. The most common and widespread tick species is Ixodes ricinus, with records in all nine federal states of Austria, followed by Ixodes canisuga, Ixodes hexagonus, and I. vespertilionis in six federal states each. Haemaphysalis concinna and Dermacentor reticulatus are only endemic in the eastern plains, while Dermacentor marginatus only occurs in the west, in the Tyrolean Alpine valleys. Eight tick species were reported from South Tyrol, Italy. There, the most frequently flagged tick from the vegetation is also I. ricinus, while D. marginatus and Haemaphysalis punctata are often collected from sheep. The locations are shown together with those from North and East Tyrol on a separate Tyrol map. The tick atlas in Austria and South Tyrol as well as the underlying digital dataset in the supplement contribute to the closing of data gaps in global distribution maps of ticks and improve the data basis for new species distribution models.
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Affiliation(s)
- Franz Rubel
- University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria
| | - Katharina Brugger
- University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria
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12
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Abstract
AbstractEvidence climate change is impacting ticks and tick-borne infections is generally lacking. This is primarily because, in most parts of the world, there are no long-term and replicated data on the distribution and abundance of tick populations, and the prevalence and incidence of tick-borne infections. Notable exceptions exist, as in Canada where the northeastern advance of Ixodes scapularis and Lyme borreliosis in the USA prompted the establishment of tick and associated disease surveillance. As a result, the past 30 years recorded the encroachment and spread of I. scapularis and Lyme borreliosis across much of Canada concomitant with a 2-3 °C increase in land surface temperature. A similar northerly advance of I. ricinus [and associated Lyme borreliosis and tick-borne encephalitis (TBE)] has been recorded in northern Europe together with expansion of this species’ range to higher altitudes in Central Europe and the Greater Alpine Region, again concomitant with rising temperatures. Changes in tick species composition are being recorded, with increases in more heat tolerant phenotypes (such as Rhipicephalus microplus in Africa), while exotic species, such as Haemaphysalis longicornis and Hyalomma marginatum, are becoming established in the USA and Southern Europe, respectively. In the next 50 years these trends are likely to continue, whereas, at the southern extremities of temperate species’ ranges, diseases such as Lyme borreliosis and TBE may become less prevalent. Where socioeconomic conditions link livestock with livelihoods, as in Pakistan and much of Africa, a One Health approach is needed to tackling ticks and tick-borne infections under the increasing challenges presented by climate change.
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Bregnard C, Rais O, Herrmann C, Kahl O, Brugger K, Voordouw MJ. Beech tree masting explains the inter-annual variation in the fall and spring peaks of Ixodes ricinus ticks with different time lags. Parasit Vectors 2021; 14:570. [PMID: 34749794 PMCID: PMC8577035 DOI: 10.1186/s13071-021-05076-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 10/18/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The tick Ixodes ricinus is an important vector of tick-borne diseases including Lyme borreliosis. In continental Europe, the nymphal stage of I. ricinus often has a bimodal phenology with a large spring peak and a smaller fall peak. There is consensus about the origin of the spring nymphal peak, but there are two alternative hypotheses for the fall nymphal peak. In the direct development hypothesis, larvae quest as nymphs in the fall of the same year that they obtained their larval blood meal. In the developmental diapause hypothesis, larvae overwinter in the engorged state and quest as nymphs one year after they obtained their larval blood meal. These two hypotheses make different predictions about the time lags that separate the larval blood meal and the density of questing nymphs (DON) in the spring and fall. METHODS Inter-annual variation in seed production (masting) by deciduous trees is a time-lagged index for the density of vertebrate hosts (e.g., rodents) which provide blood meals for larval ticks. We used a long-term data set on the masting of the European beech tree and a 15-year study on the DON at 4 different elevation sites in western Switzerland to differentiate between the two alternative hypotheses for the origin of the fall nymphal peak. RESULTS Questing I. ricinus nymphs had a bimodal phenology at the three lower elevation sites, but a unimodal phenology at the top elevation site. At the lower elevation sites, the DON in the fall was strongly correlated with the DON in the spring of the following year. The inter-annual variation in the densities of I. ricinus nymphs in the fall and spring was best explained by a 1-year versus a 2-year time lag with the beech tree masting index. Fall nymphs had higher fat content than spring nymphs indicating that they were younger. All these observations are consistent with the direct development hypothesis for the fall peak of I. ricinus nymphs at our study site. Our study provides new insight into the complex bimodal phenology of this important disease vector. CONCLUSIONS Public health officials in Europe should be aware that following a strong mast year, the DON will increase 1 year later in the fall and 2 years later in the spring. Studies of I. ricinus populations with a bimodal phenology should consider that the spring and fall peak in the same calendar year represent different generations of ticks.
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Affiliation(s)
- Cindy Bregnard
- Laboratory of Ecology and Evolution of Parasites, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Olivier Rais
- Laboratory of Ecology and Epidemiology of Parasites, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
- Laboratory of Eco-Epidemiology of Parasites, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Coralie Herrmann
- Laboratory of Eco-Epidemiology of Parasites, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Olaf Kahl
- tick-radar GmbH, 10555 Berlin, Germany
| | - Katharina Brugger
- Unit for Veterinary Public Health and Epidemiology, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria
| | - Maarten J. Voordouw
- Laboratory of Ecology and Evolution of Parasites, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
- Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada
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Bregnard C, Rais O, Voordouw MJ. Masting by beech trees predicts the risk of Lyme disease. Parasit Vectors 2021; 14:168. [PMID: 33743800 PMCID: PMC7980658 DOI: 10.1186/s13071-021-04646-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 02/16/2021] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND The incidence of Lyme borreliosis and other tick-borne diseases is increasing in Europe and North America. There is currently much interest in identifying the ecological factors that determine the density of infected ticks as this variable determines the risk of Lyme borreliosis to vertebrate hosts, including humans. Lyme borreliosis is caused by the bacterium Borrelia burgdorferi sensu lato (s.l.) and in western Europe, the hard tick Ixodes ricinus is the most important vector. METHODS Over a 15-year period (2004-2018), we monitored the monthly abundance of I. ricinus ticks (nymphs and adults) and their B. burgdorferi s.l. infection status at four different elevations on a mountain in western Switzerland. We collected climate variables in the field and from nearby weather stations. We obtained data on beech tree seed production (masting) from the literature, as the abundance of Ixodes nymphs can increase dramatically 2 years after a masting event. We used generalized linear mixed effects models and AIC-based model selection to identify the ecological factors that influence inter-annual variation in the nymphal infection prevalence (NIP) and the density of infected nymphs (DIN). RESULTS We found that the NIP decreased by 78% over the study period. Inter-annual variation in the NIP was explained by the mean precipitation in the present year, and the duration that the DNA extraction was stored in the freezer prior to pathogen detection. The DIN decreased over the study period at all four elevation sites, and the decrease was significant at the top elevation. Inter-annual variation in the DIN was best explained by elevation site, year, beech tree masting index 2 years prior and the mean relative humidity in the present year. This is the first study in Europe to demonstrate that seed production by deciduous trees influences the density of nymphs infected with B. burgdorferi s.l. and hence the risk of Lyme borreliosis. CONCLUSIONS Public health officials in Europe should be aware that masting by deciduous trees is an important predictor of the risk of Lyme borreliosis.
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Affiliation(s)
- Cindy Bregnard
- Laboratory of Ecology and Evolution of Parasites, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Olivier Rais
- Laboratory of Ecology and Epidemiology of Parasites, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Maarten Jeroen Voordouw
- Laboratory of Ecology and Evolution of Parasites, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
- Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada
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Borde JP, Kaier K, Hehn P, Matzarakis A, Frey S, Bestehorn M, Dobler G, Chitimia-Dobler L. The complex interplay of climate, TBEV vector dynamics and TBEV infection rates in ticks-Monitoring a natural TBEV focus in Germany, 2009-2018. PLoS One 2021; 16:e0244668. [PMID: 33411799 PMCID: PMC7790265 DOI: 10.1371/journal.pone.0244668] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Accepted: 12/14/2020] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Tick-borne encephalitis (TBE) is the most important tick-borne viral disease in Eurasia and causes disease in humans and in a number of animals, among them dogs and horses. There is still no good correlation between tick numbers, weather conditions and human cases. There is the hypothesis that co-feeding due to simultaneous occurrence of larvae and nymphs may be a factor for the increased transmission of the virus in nature and for human disease. Based on long-term data from a natural TBEV focus, phylogenetic results and meteorological data we sought to challenge this hypothesis. METHODS Ticks from an identified TBE natural focus were sampled monthly from 04/2009 to 12/2018. Ticks were identified and pooled. Pools were tested by RT-qPCR. Positive pools were confirmed by virus isolation and/or sequencing of additional genes (E gene, NS2 gene). Temperature data such as the decadal (10-day) mean daily maximum air temperature (DMDMAT) were obtained from a nearby weather station and statistical correlations between tick occurrence and minimal infection rates (MIR) were calculated. RESULTS In the study period from 04/2009 to 12/2018 a total of 15,530 ticks (2,226 females, 2,268 males, 11,036 nymphs) were collected. The overall MIR in nymphs over the whole period was 77/15,530 (0.49%), ranging from 0.09% (2009) to 1.36% (2015). The overall MIR of female ticks was 0.76% (17/2,226 ticks), range 0.14% (2013) to 3.59% (2016). The overall MIR of males was 0.57% (13/2,268 ticks), range from 0.26% (2009) to 0.97% (2015). The number of nymphs was statistically associated with a later start of spring/vegetation period, indicated by the onset of forsythia flowering. CONCLUSION There was no particular correlation between DMDMAT dynamics in spring and/or autumn and the MIR of nymphs or adult ticks detected. However, there was a positive correlation between the number of nymphs and the number of reported human TBE cases in the following months, but not in the following year. The hypothesis of the importance of co-feeding of larvae and nymphs for the maintenance of transmission cycle of TBEV in nature is not supported by our findings.
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Affiliation(s)
- Johannes P. Borde
- Division of Infectious Diseases, Department of Medicine II, University of Freiburg Medical Center and Faculty of Medicine, Freiburg i.Br., Germany
- Praxis Dr. J. Borde / Gesundheitszentrum Oberkirch, Oberkirch, Germany
| | - Klaus Kaier
- Institute of Medical Biometry and Statistics, Faculty of Medicine and Medical Center – University of Freiburg, University of Freiburg, Freiburg, Germany
| | - Philip Hehn
- Institute of Medical Biometry and Statistics, Faculty of Medicine and Medical Center – University of Freiburg, University of Freiburg, Freiburg, Germany
| | - Andreas Matzarakis
- Research Centre Human Biometeorology, German Meteorological Service, Freiburg, Germany
| | - Stefan Frey
- Bundeswehr Institute of Microbiology, German National Reference Laboratory for TBEV, München, Germany
| | | | - Gerhard Dobler
- Bundeswehr Institute of Microbiology, German National Reference Laboratory for TBEV, München, Germany
- Parasitology Unit, University of Hohenheim, Stuttgart, Germany
| | - Lidia Chitimia-Dobler
- Bundeswehr Institute of Microbiology, German National Reference Laboratory for TBEV, München, Germany
- Parasitology Unit, University of Hohenheim, Stuttgart, Germany
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Disappearance of TBEV Circulation among Rodents in a Natural Focus in Alsace, Eastern France. Pathogens 2020; 9:pathogens9110930. [PMID: 33182764 PMCID: PMC7697581 DOI: 10.3390/pathogens9110930] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 11/02/2020] [Accepted: 11/07/2020] [Indexed: 12/17/2022] Open
Abstract
Tick-borne encephalitis virus (TBEV) depends mainly on a fragile mode of transmission, the co-feeding between infected nymphs and larvae on rodents, and thus persists under a limited set of biotic and abiotic conditions. If these conditions change, natural TBEV foci might be unstable over time. We conducted a longitudinal study over seven years in a mountain forest in Alsace, Eastern France, located at the western border of known TBEV distribution. The objectives were (i) to monitor the persistence of TBEV circulation between small mammals and ticks and (ii) to discuss the presence of TBEV circulation in relation to the synchronous activity of larvae and nymphs, to the densities of questing nymphs and small mammals, and to potential changes in meteorological conditions and deer densities. Small mammals were trapped five times per year from 2012 to 2018 to collect blood samples and record the presence of feeding ticks, and were then released. Questing nymphs were collected twice a year. Overall, 1344 different small mammals (Myodes glareolus and Apodemus flavicollis) were captured and 2031 serum samples were tested for the presence of antibodies against TBEV using an in-house ELISA. Seropositive rodents (2.1%) were only found from 2012 to 2015, suggesting that the virus disappeared afterwards. In parallel, we observed unusual variations in inter-annual nymph abundance and intra-annual larval activity that could be related to exceptional meteorological conditions. Changes in the densities of questing nymphs and deer associated with the natural stochastic variations in the frequency of contacts between rodents and infected ticks may have contributed to the endemic fadeout of TBEV on the study site. Further studies are needed to assess whether such events occur relatively frequently in the area, which could explain the low human incidence of TBE in Alsace and even in other areas of France.
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Rubel F, Brugger K. Operational TBE incidence forecasts for Austria, Germany, and Switzerland 2019-2021. Ticks Tick Borne Dis 2020; 12:101579. [PMID: 33080518 DOI: 10.1016/j.ttbdis.2020.101579] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 08/26/2020] [Accepted: 09/21/2020] [Indexed: 11/16/2022]
Abstract
In spring 2019, forecasts of the incidence of tick-borne encephalitis (TBE) for the next 2 years, i.e. 2019 and 2020, were made for the first time. For this purpose, negative binomial regression models with 4-5 predictors were fitted to the time series of annual human TBE incidences from Austria, Germany, and Switzerland. The most important predictor for TBE incidences is the fructification index of the European beech (Fagus sylvatica) 2 years prior as a proxi for the intensity of the TBE virus transmission cycle. These forecasts were repeated in spring 2020 after the updated predictors and the confirmed TBE cases for 2019 became available. Forecasting TBE incidences for 2020 and 2021 results in 156 ± 19 and 131 ± 23 TBE cases for Austria, 663 ± 95 and 543 ± 112 TBE cases for Germany as well as 472 ± 56 and 350 ± 62 TBE cases for Switzerland. The newly implemented operational TBE forecasts will be verified every year with confirmed TBE cases. An initial verification for 2019 demonstrates the high reliability of the forecasts.
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Affiliation(s)
- Franz Rubel
- Unit for Veterinary Public Health and Epidemiology, University of Veterinary Medicine, Vienna, Austria.
| | - Katharina Brugger
- Unit for Veterinary Public Health and Epidemiology, University of Veterinary Medicine, Vienna, Austria
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Tetens MM, Haahr R, Dessau RB, Krogfelt KA, Bodilsen J, Andersen NS, Møller JK, Roed C, Christiansen CB, Ellermann-Eriksen S, Bangsborg JM, Hansen K, Benfield TL, Andersen CØ, Obel N, Omland LH, Lebech AM. Changes in Lyme neuroborreliosis incidence in Denmark, 1996 to 2015. Ticks Tick Borne Dis 2020; 11:101549. [PMID: 32993955 DOI: 10.1016/j.ttbdis.2020.101549] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 07/31/2020] [Accepted: 08/17/2020] [Indexed: 12/18/2022]
Abstract
Lyme neuroborreliosis (LNB) has recently been added to the list of diseases under the European Union epidemiological surveillance in order to obtain updated information on incidence. The goal of this study was to identify temporal (yearly) variation, high risk geographical regions and risk groups, and seasonal variation for LNB in Denmark. This cohort-study investigated Danish patients (n = 2791) diagnosed with LNB (defined as a positive Borrelia burgdorferi sensu lato (s.l.) intrathecal antibody test) between 1996-2015. We calculated incidence and incidence ratios of LNB by comparing 4-yr groups of calendar-years, area of residency, sex and age, income and education groups, and the number of new LNB cases per month. The incidence of LNB was 2.2 per 100,000 individuals and year in 1996-1999, 2.7 in 2004-2007 and 1.1 per 100,000 individuals in 2012-2015. Yearly variations in LNB incidence were similar for most calendar-year groups. LNB incidence was highest in Eastern Denmark and among males and individuals who were 0-14 yrs old, who had a yearly income of >449,000 DKK, and who had a Master's degree or higher education. The number of LNB cases was highest from July to November (p < 0.001). In conclusion, based on Danish nationwide data of patients with positive B. burgdorferi s.l. intrathecal antibody index (1996-2015) the incidence of LNB was found to increase until 2004-2007 but thereafter to decline. European surveillance studies of Lyme borreliosis should be encouraged to monitor the incidence trend.
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Affiliation(s)
- Malte M Tetens
- Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.
| | - Rasmus Haahr
- Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Ram B Dessau
- Department of Clinical Microbiology, Slagelse Hospital, Slagelse, Denmark
| | - Karen A Krogfelt
- Department of Virus and Microbiological Special Diagnostics, Statens Serum Institut, Denmark; Department of Natural Sciences and Environment, Roskilde University, Denmark
| | - Jacob Bodilsen
- Departments of Clinical Microbiology, Aalborg University Hospital, Aalborg, Denmark; Departments of and Infectious Diseases, Aalborg University Hospital, Aalborg, Denmark
| | - Nanna S Andersen
- Clinical Centre for Emerging and Vector-borne Infections, Odense University Hospital, Odense, Denmark
| | - Jens K Møller
- Department of Clinical Microbiology, Vejle Hospital, Vejle, Denmark
| | - Casper Roed
- Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Claus B Christiansen
- Department of Clinical Microbiology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | | | - Jette M Bangsborg
- Department of Clinical Microbiology, Herlev University Hospital, Copenhagen, Denmark
| | - Klaus Hansen
- Department of Neurology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Thomas L Benfield
- Department of Infectious Diseases, Hvidovre University Hospital, Copenhagen, Denmark; Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Niels Obel
- Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark; Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Lars H Omland
- Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Anne-Mette Lebech
- Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark; Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Bregnard C, Rais O, Voordouw MJ. Climate and tree seed production predict the abundance of the European Lyme disease vector over a 15-year period. Parasit Vectors 2020; 13:408. [PMID: 32778177 PMCID: PMC7418309 DOI: 10.1186/s13071-020-04291-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 08/05/2020] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND To predict the risk of tick-borne disease, it is critical to understand the ecological factors that determine the abundance of ticks. In Europe, the sheep tick (Ixodes ricinus) transmits a number of important diseases including Lyme borreliosis. The aim of this long-term study was to determine the abiotic and biotic factors driving the annual abundance of I. ricinus at a location in Switzerland where Lyme borreliosis is endemic. METHODS Over a 15-year period (2004 to 2018), we monitored the abundance of I. ricinus ticks on a monthly basis at three different elevations on Chaumont Mountain in Neuchâtel, Switzerland. We collected climate variables in the field and from nearby weather stations. We obtained data on beech tree seed production from the literature, as the abundance of Ixodes nymphs can increase dramatically two years after a masting event. We used AIC-based model selection to determine which ecological variables drive annual variation in tick density. RESULTS We found that elevation site, year, seed production by beech trees two years prior, and mean annual relative humidity together explained 73.2% of the variation in our annual estimates of nymph density. According to the parameter estimates of our models, (i) the annual density of nymphs almost doubled over the 15-year study period, (ii) changing the beech tree seed production index from very poor mast (1) to full mast (5) increased the abundance of nymphs by 86.2% two years later, and (iii) increasing the field-collected mean annual relative humidity from 50.0 to 75.0% decreased the abundance of nymphs by 46.4% in the same year. Climate variables collected in the field were better predictors of tick abundance than those from nearby weather stations indicating the importance of the microhabitat. CONCLUSIONS From a public health perspective, the increase in nymph abundance is likely to have increased the risk of tick-borne disease in this region of Switzerland. Public health officials in Europe should be aware that seed production by deciduous trees is a critical driver of the abundance of I. ricinus, and hence the risk of tick-borne disease.
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Affiliation(s)
- Cindy Bregnard
- Laboratory of Ecology and Evolution of Parasites, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Olivier Rais
- Laboratory of Ecology and Epidemiology of Parasites, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Maarten Jeroen Voordouw
- Laboratory of Ecology and Evolution of Parasites, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
- Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada
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20
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Vogelgesang JR, Walter M, Kahl O, Rubel F, Brugger K. Long-term monitoring of the seasonal density of questing ixodid ticks in Vienna (Austria): setup and first results. EXPERIMENTAL & APPLIED ACAROLOGY 2020; 81:409-420. [PMID: 32556948 PMCID: PMC7359148 DOI: 10.1007/s10493-020-00511-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 06/04/2020] [Indexed: 05/13/2023]
Abstract
The first long-term monitoring to document both activity and density of questing ixodid ticks in Vienna, Austria, is introduced. It was started in 2017 and is planned to run over decades. Such long-term monitorings are needed to quantify possible effects of climate change or to develop tick density forecast models. The monthly questing tick density at three sites has been observed by using a standardized sampling method by dragging an area of [Formula: see text] at each occasion. Popular recreational areas were chosen as study sites. These are the Prater public park, the wooded Kahlenberg, and a wildlife garden in Klosterneuburg. First results show a 3-year time series of nymphs and adults of the Ixodes ricinus species complex and Haemaphysalis concinna for the period 2017-2019. Whereas questing nymphs of the I. ricinus species complex were collected from February to November, H. concinna nymphs were only dragged from May to October. The peak of nymphal activity of the I. ricinus species complex was in May, that of H. concinna in August. In addition, a brief overview is given about ticks and tick-borne pathogens occurring in urban and suburban areas of Vienna.
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Affiliation(s)
- Janna R Vogelgesang
- Unit for Veterinary Public Health and Epidemiology, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210, Vienna, Austria
| | - Melanie Walter
- Unit for Veterinary Public Health and Epidemiology, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210, Vienna, Austria
| | - Olaf Kahl
- tick-radar GmbH, 10555, Berlin, Germany
| | - Franz Rubel
- Unit for Veterinary Public Health and Epidemiology, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210, Vienna, Austria
| | - Katharina Brugger
- Unit for Veterinary Public Health and Epidemiology, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210, Vienna, Austria.
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21
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Tick-Borne Encephalitis Virus: Seasonal and Annual Variation of Epidemiological Parameters Related to Nymph-to-Larva Transmission and Exposure of Small Mammals. Pathogens 2020; 9:pathogens9070518. [PMID: 32605114 PMCID: PMC7400523 DOI: 10.3390/pathogens9070518] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 06/23/2020] [Accepted: 06/25/2020] [Indexed: 12/20/2022] Open
Abstract
A greater knowledge of the ecology of the natural foci of tick-borne encephalitis virus (TBEV) is essential to better assess the temporal variations of the risk of tick-borne encephalitis for humans. To describe the seasonal and inter-annual variations of the TBEV-cycle and the epidemiological parameters related to TBEV nymph-to-larva transmission, exposure of small mammals to TBEV, and tick aggregation on small mammals, a longitudinal survey in ticks and small mammals was conducted over a 3-year period in a mountain forest in Alsace, eastern France. TBEV prevalence in questing nymphs was lower in 2013 than in 2012 and 2014, probably because small mammals (Myodes glareolus and Apodemus flavicollis) were more abundant in 2012, which reduced tick aggregation and co-feeding transmission between ticks. The prevalence of TBEV in questing nymphs was higher in autumn than spring. Despite these variations in prevalence, the density of infected questing nymphs was constant over time, leading to a constant risk for humans. The seroprevalence of small mammals was also constant over time, although the proportion of rodents infested with ticks varied between years and seasons. Our results draw attention to the importance of considering the complex relationship between small mammal densities, tick aggregation on small mammals, density of infected questing nymphs, and prevalence of infected nymphs in order to forecast the risk of TBEV for humans.
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Rubel F, Walter M, Vogelgesang JR, Brugger K. Tick-borne encephalitis (TBE) cases are not random: explaining trend, low- and high-frequency oscillations based on the Austrian TBE time series. BMC Infect Dis 2020; 20:448. [PMID: 32586360 PMCID: PMC7316636 DOI: 10.1186/s12879-020-05156-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 06/12/2020] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Why human tick-borne encephalitis (TBE) cases differ from year to year, in some years more 100%, has not been clarified, yet. The cause of the increasing or decreasing trends is also controversial. Austria is the only country in Europe where a 40-year TBE time series and an official vaccine coverage time series are available to investigate these open questions. METHODS A series of generalized linear models (GLMs) has been developed to identify demographic and environmental factors associated with the trend and the oscillations of the TBE time series. Both the observed and the predicted TBE time series were subjected to spectral analysis. The resulting power spectra indicate which predictors are responsible for the trend, the high-frequency and the low-frequency oscillations, and with which explained variance they contribute to the TBE oscillations. RESULTS The increasing trend can be associated with the demography of the increasing human population. The responsible GLM explains 12% of the variance of the TBE time series. The low-frequency oscillations (10 years) are associated with the decadal changes of the large-scale climate in Central Europe. These are well described by the so-called Scandinavian index. This 10-year oscillation cycle is reinforced by the socio-economic predictor net migration. Considering the net migration and the Scandinavian index increases the explained variance of the GLM to 44%. The high-frequency oscillations (2-3 years) are associated with fluctuations of the natural TBE transmission cycle between small mammals and ticks, which are driven by beech fructification. Considering also fructification 2 years prior explains 64% of the variance of the TBE time series. Additionally, annual sunshine duration as predictor for the human outdoor activity increases the explained variance to 70%. CONCLUSIONS The GLMs presented here provide the basis for annual TBE forecasts, which were mainly determined by beech fructification. A total of 3 of the 5 years with full fructification, resulting in high TBE case numbers 2 years later, occurred after 2010. The effects of climate change are therefore not visible through a direct correlation of the TBE cases with rising temperatures, but indirectly via the increased frequency of mast seeding.
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Affiliation(s)
- Franz Rubel
- Unit for Veterinary Public Health and Epidemiology, University of Veterinary Medicine Vienna, Austria, Veterinaerplatz 1, Vienna, 1210, Austria.
| | - Melanie Walter
- Unit for Veterinary Public Health and Epidemiology, University of Veterinary Medicine Vienna, Austria, Veterinaerplatz 1, Vienna, 1210, Austria
| | - Janna R Vogelgesang
- Unit for Veterinary Public Health and Epidemiology, University of Veterinary Medicine Vienna, Austria, Veterinaerplatz 1, Vienna, 1210, Austria
| | - Katharina Brugger
- Unit for Veterinary Public Health and Epidemiology, University of Veterinary Medicine Vienna, Austria, Veterinaerplatz 1, Vienna, 1210, Austria
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Rubel F, Brugger K. Tick-borne encephalitis incidence forecasts for Austria, Germany, and Switzerland. Ticks Tick Borne Dis 2020; 11:101437. [PMID: 32723631 DOI: 10.1016/j.ttbdis.2020.101437] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 03/31/2020] [Accepted: 03/31/2020] [Indexed: 11/26/2022]
Abstract
The forecast of human tick-borne encephalitis (TBE) incidence for the next years has been on the research agenda of epidemiologists since the discovery of this tick-borne zoonosis. Based on models to explain the trend as well as the low- and high-frequency oscillations in the Austrian TBE incidence series, TBE forecasts for Austria, Germany and Switzerland are presented here. For this purpose, generalized linear models (GLMs) of type negative binomial regression were calibrated with the TBE incidences of the period 1991-2018 to forecast the TBE incidences 2019 and 2020. The GLMs require only 4-5 predictors, 2 of which are large-scale synchronized over Central Europe and used for all 3 countries. Predictors used include the demographic parameters total population and net migration rate, the Scandinavian index which describes the large-scale atmospheric circulation patterns, the fructification index of the European beech (Fagus sylvatica) 2 years prior as a proxy for the intensity of the TBE virus transmission cycle, and the national TBE vaccination coverage. Since an official time series of TBE vaccination coverage is only available for Austria, the missing TBE vaccination coverages of Germany and Switzerland were reconstructed and presented as the first results. Model verification results in explained variances of 76% for Austria, 84% for Germany, and 89% for Switzerland. Thus, the best model fit was determined for the Swiss GLM which is able to predict the TBE incidence with a root-mean-square error of RMSE = 25 cases (19% of the mean TBE incidence 1991-2018 or 7% of the TBE incidence of 2018). Forecasting TBE incidences for 2019 and 2020 results in 92 ± 12 and 142 ± 26 TBE cases for Austria, 417 ± 71 and 670 ± 168 TBE cases for Germany as well as 235 ± 30 and 465 ± 91 TBE cases for Switzerland.
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Affiliation(s)
- Franz Rubel
- Unit for Veterinary Public Health and Epidemiology, University of Veterinary Medicine Vienna, Austria.
| | - Katharina Brugger
- Unit for Veterinary Public Health and Epidemiology, University of Veterinary Medicine Vienna, Austria
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Hauck D, Springer A, Chitimia-Dobler L, Strube C. Two-year monitoring of tick abundance and influencing factors in an urban area (city of Hanover, Germany). Ticks Tick Borne Dis 2020; 11:101464. [PMID: 32723659 DOI: 10.1016/j.ttbdis.2020.101464] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 04/29/2020] [Accepted: 05/03/2020] [Indexed: 11/16/2022]
Abstract
Ticks may transmit a variety of human and animal pathogens. Prevalence of Borrelia spp., Rickettsia spp. and Anaplasma phagocytophilum in ticks has been monitored in the city of Hanover, Germany, since 2005. However, to determine the infection risk for humans and animals, not only pathogen prevalence, but also tick abundance and seasonality need to be taken into account. Therefore, the aim of this study was to investigate tick abundance at ten different collection sites in the city of Hanover, Germany. Collection of questing ticks was performed by the flagging method in the first and second half of each month during the tick season (April-October) in 2017 and 2018. At each 200 m² collection site, one of four 50 m² fields was sampled per visit on a rotational basis, resulting in 100 m² sampled per month. In addition, data on weather conditions, near-ground temperature, relative humidity and vegetation composition were noted at each collection event. In 2017, a total of 1770 ticks were collected, while 1866 ticks were collected in 2018. Ixodes ricinus was the most prevalent species (97.0 % of all ticks, 98.0 % of nymphs, 91.6 % of adults) followed by I. inopinatus (2.3 % of all ticks, 1.1 % of nymphs, 8.0 % of adults), I. frontalis (0.6 % of all ticks, 0.6 % of nymphs, 0.3 % of adults) and I. hexagonus (0.03 % of all ticks, 0.03 % of nymphs, 0.0 % of adults). Using generalized linear mixed modeling, density of I. ricinus and I. inopinatus in 2017 was significantly higher than in 2018. Regarding different landscape types, ticks were significantly more abundant in mixed forests than in parks, with more than 50 ticks/100 m² on average in both years. In urban parks, average tick density amounted to 15 ticks/100 m² in 2017 and 11 ticks/100 m² in 2018 and in broad-leaved forests average tick density was 13 and 18 ticks/100 m² in 2017 and 2018, respectively. Tick density showed a marked peak in June 2017 and in May 2018 at most sites, whereas a less pronounced peak was recognizable in September. Tick density varied considerably between collection sites. However, no statistically significant effect of (micro-)climatic variables, including near-ground temperature, relative humidity and saturation deficit, was found. Thus, further factors, such as the abundance of wildlife hosts, need to be considered in future studies to explain the differences between collection sites.
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Affiliation(s)
- Daniela Hauck
- Institute for Parasitology, Centre for Infection Medicine, University of Veterinary Medicine Hannover, Buenteweg 17, 30559, Hanover, Germany
| | - Andrea Springer
- Institute for Parasitology, Centre for Infection Medicine, University of Veterinary Medicine Hannover, Buenteweg 17, 30559, Hanover, Germany
| | | | - Christina Strube
- Institute for Parasitology, Centre for Infection Medicine, University of Veterinary Medicine Hannover, Buenteweg 17, 30559, Hanover, Germany.
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Prolongation of Tick-Borne Encephalitis Cycles in Warmer Climatic Conditions. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:ijerph16224532. [PMID: 31731822 PMCID: PMC6888212 DOI: 10.3390/ijerph16224532] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 11/12/2019] [Accepted: 11/12/2019] [Indexed: 02/03/2023]
Abstract
Tick-borne encephalitis exhibits profound inter-annual fluctuations in incidence. Previous studies showed that three-fifths of the variation can be explained in terms of four superimposed oscillations: a quasi-biennial, triennial, pentennial, and a decadal cycle. This study was conducted to determine how these cycles could be influenced by climate change. Epidemiological data, spanning from the 1970s to the present, and originating from six regions/countries bridging Scandinavia and the Mediterranean, represented a temporal/latitudinal gradient. Spectral analysis of time series was used to determine variation in the cycles’ length/amplitude with respect to these gradients. The analysis showed that—whereas the lengths of the shorter cycles do not vary substantially—cycles in the decadal band tend to be longer southwards. When comparing the disease’s oscillations before- and after the mid-1990s, a shift towards longer oscillations was detected in the pentennial–decadal band, but not in the biennial– triennial band. Simultaneously, oscillations in the latter band increased in intensity whereas the decadal oscillations weakened. In summary, the rhythm of the cycles has been altered by climate change. Lengthened cycles may be explained by prolonged survival of some animal hosts, and consequently greater inertia in herd immunity changes, slowing down a feedback loop between the herd immunity and amount of virus circulating in nature.
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Canine vector-borne disease: mapping and the accuracy of forecasting using big data from the veterinary community. Anim Health Res Rev 2019; 20:47-60. [PMID: 31895020 DOI: 10.1017/s1466252319000045] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Diagnosis, treatment, and prevention of vector-borne disease (VBD) in pets is one cornerstone of companion animal practices. Veterinarians are facing new challenges associated with the emergence, reemergence, and rising incidence of VBD, including heartworm disease, Lyme disease, anaplasmosis, and ehrlichiosis. Increases in the observed prevalence of these diseases have been attributed to a multitude of factors, including diagnostic tests with improved sensitivity, expanded annual testing practices, climatologic and ecological changes enhancing vector survival and expansion, emergence or recognition of novel pathogens, and increased movement of pets as travel companions. Veterinarians have the additional responsibility of providing information about zoonotic pathogen transmission from pets, especially to vulnerable human populations: the immunocompromised, children, and the elderly. Hindering efforts to protect pets and people is the dynamic and ever-changing nature of VBD prevalence and distribution. To address this deficit in understanding, the Companion Animal Parasite Council (CAPC) began efforts to annually forecast VBD prevalence in 2011. These forecasts provide veterinarians and pet owners with expected disease prevalence in advance of potential changes. This review summarizes the fidelity of VBD forecasts and illustrates the practical use of CAPC pathogen prevalence maps and forecast data in the practice of veterinary medicine and client education.
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Kunze U. Report of the 20th annual meeting of the International Scientific Working Group on Tick-Borne Encephalitis (ISW-TBE): ISW-TBE: 20 years of commitment and still challenges ahead. Ticks Tick Borne Dis 2018; 10:13-17. [PMID: 30172555 DOI: 10.1016/j.ttbdis.2018.08.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 08/04/2018] [Indexed: 11/26/2022]
Abstract
The 20th Meeting of the International Scientific Working Group on Tick-Borne Encephalitis (ISW-TBE) - a group of neurologists, general practitioners, clinicians, travel physicians, virologists, pediatricians, ecologists, and epidemiologists - was held under the theme "ISW-TBE: 20 years of commitment & still challenges ahead". On the occasion of the 20th anniversary of the ISW-TBE several key topics in TBE were extensively discussed, among them current epidemiological developments and investigations, expansion of risk areas, clinical aspects and cases, traveling and mobility, and latest news on TBE vaccination. The main goals that have been achieved by the ISW-TBE so far are, among others, an increased awareness in endemic and non-endemic countries, an increase of vaccination rates in various countries, getting TBE acknowledged and established as a travel-related risk, and building contact with the European Centre for Disease Prevention and Control.
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Affiliation(s)
- Ursula Kunze
- Institute for Social Medicine, Center for Public Health, Medical University of Vienna, Kinderspitalgasse 15, A-1090, Vienna, Austria.
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- Institute for Social Medicine, Center for Public Health, Medical University of Vienna, Kinderspitalgasse 15, A-1090, Vienna, Austria
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