Sample records for abundance predict tick-borne

  1. Adverse moisture events predict seasonal abundance of Lyme disease vector ticks (Ixodes scapularis)

    USGS Publications Warehouse

    Berger, Kathryn A.; Ginsberg, Howard S.; Dugas, Katherine D.; Hamel, Lutz H.; Mather, Thomas N.

    2014-01-01

    Background: Lyme borreliosis (LB) is the most commonly reported vector-borne disease in north temperate regions worldwide, affecting an estimated 300,000 people annually in the United States alone. The incidence of LB is correlated with human exposure to its vector, the blacklegged tick (Ixodes scapularis). To date, attempts to model tick encounter risk based on environmental parameters have been equivocal. Previous studies have not considered (1) the differences between relative humidity (RH) in leaf litter and at weather stations, (2) the RH threshold that affects nymphal blacklegged tick survival, and (3) the time required below the threshold to induce mortality. We clarify the association between environmental moisture and tick survival by presenting a significant relationship between the total number of tick adverse moisture events (TAMEs - calculated as microclimatic periods below a RH threshold) and tick abundance each year.Methods: We used a 14-year continuous statewide tick surveillance database and corresponding weather data from Rhode Island (RI), USA, to assess the effects of TAMEs on nymphal populations of I. scapularis. These TAMEs were defined as extended periods of time (>8 h below 82% RH in leaf litter). We fit a sigmoid curve comparing weather station data to those collected by loggers placed in tick habitats to estimate RH experienced by nymphal ticks, and compiled the number of historical TAMEs during the 14-year record.Results: The total number of TAMEs in June of each year was negatively related to total seasonal nymphal tick densities, suggesting that sub-threshold humidity episodes >8 h in duration naturally lowered nymphal blacklegged tick abundance. Furthermore, TAMEs were positively related to the ratio of tick abundance early in the season when compared to late season, suggesting that lower than average tick abundance for a given year resulted from tick mortality and not from other factors.Conclusions: Our results clarify the mechanism

  2. Cascading effects of predator activity on tick-borne disease risk.

    PubMed

    Hofmeester, Tim R; Jansen, Patrick A; Wijnen, Hendrikus J; Coipan, Elena C; Fonville, Manoj; Prins, Herbert H T; Sprong, Hein; van Wieren, Sipke E

    2017-07-26

    Predators and competitors of vertebrates can in theory reduce the density of infected nymphs (DIN)-an often-used measure of tick-borne disease risk-by lowering the density of reservoir-competent hosts and/or the tick burden on reservoir-competent hosts. We investigated this possible indirect effect of predators by comparing data from 20 forest plots across the Netherlands that varied in predator abundance. In each plot, we measured the density of questing Ixodes ricinus nymphs (DON), DIN for three pathogens, rodent density, the tick burden on rodents and the activity of mammalian predators. We analysed whether rodent density and tick burden on rodents were correlated with predator activity, and how rodent density and tick burden predicted DON and DIN for the three pathogens. We found that larval burden on two rodent species decreased with activity of two predator species, while DON and DIN for all three pathogens increased with larval burden on rodents, as predicted. Path analyses supported an indirect negative correlation of activity of both predator species with DON and DIN. Our results suggest that predators can indeed lower the number of ticks feeding on reservoir-competent hosts, which implies that changes in predator abundance may have cascading effects on tick-borne disease risk. © 2017 The Authors.

  3. Interacting effects of wildlife loss and climate on ticks and tick-borne disease.

    PubMed

    Titcomb, Georgia; Allan, Brian F; Ainsworth, Tyler; Henson, Lauren; Hedlund, Tyler; Pringle, Robert M; Palmer, Todd M; Njoroge, Laban; Campana, Michael G; Fleischer, Robert C; Mantas, John Naisikie; Young, Hillary S

    2017-09-13

    Both large-wildlife loss and climatic changes can independently influence the prevalence and distribution of zoonotic disease. Given growing evidence that wildlife loss often has stronger community-level effects in low-productivity areas, we hypothesized that these perturbations would have interactive effects on disease risk. We experimentally tested this hypothesis by measuring tick abundance and the prevalence of tick-borne pathogens ( Coxiella burnetii and Rickettsia spp . ) within long-term, size-selective, large-herbivore exclosures replicated across a precipitation gradient in East Africa. Total wildlife exclusion increased total tick abundance by 130% (mesic sites) to 225% (dry, low-productivity sites), demonstrating a significant interaction of defaunation and aridity on tick abundance. When differing degrees of exclusion were tested for a subset of months, total tick abundance increased from 170% (only mega-herbivores excluded) to 360% (all large wildlife excluded). Wildlife exclusion differentially affected the abundance of the three dominant tick species, and this effect varied strongly over time, likely due to differences among species in their host associations, seasonality, and other ecological characteristics. Pathogen prevalence did not differ across wildlife exclusion treatments, rainfall levels, or tick species, suggesting that exposure risk will respond to defaunation and climate change in proportion to total tick abundance. These findings demonstrate interacting effects of defaunation and aridity that increase disease risk, and they highlight the need to incorporate ecological context when predicting effects of wildlife loss on zoonotic disease dynamics. © 2017 The Author(s).

  4. Predictability of tick-borne encephalitis fluctuations.

    PubMed

    Zeman, P

    2017-10-01

    Tick-borne encephalitis is a serious arboviral infection with unstable dynamics and profound inter-annual fluctuations in case numbers. A dependable predictive model has been sought since the discovery of the disease. The present study demonstrates that four superimposed cycles, approximately 2·4, 3, 5·4, and 10·4 years long, can account for three-fifths of the variation in the disease fluctuations over central Europe. Using harmonic regression, these cycles can be projected into the future, yielding forecasts of sufficient accuracy for up to 4 years ahead. For the years 2016-2018, this model predicts elevated incidence levels in most parts of the region.

  5. Management of ticks and tick-borne diseases

    USGS Publications Warehouse

    Ginsberg, H.S.; Stafford, K.C.; Goodman, J.L.; Dennis, D.T.; Sonenshine, D .E.

    2005-01-01

    The mainstays of tick management and protection from tick-borne diseases have traditionally been personal precautions and the application of acaricides. These techniques maintain their value, and current innovations hold considerable promise for future improvement in effective targeting of materials for tick control. Furthermore, an explosion of research in the past few decades has resulted in the development and expansion of several novel and potentially valuable approaches to tick control, including vaccination against tick-borne pathogen transmission and against tick attachment, host management, use of natural enemies (especially entomopathogenic fungi), and pheromone-based techniques. The situations that require tick management are diverse, and occur under varied ecological conditions. Therefore, the likelihood of finding a single ?magic bullet? for tick management is low. In practical terms, the approach to tick management or to management of tick-borne disease must be tailored to the specific conditions at hand. One area that needs increased attention is the decision-making process in applying IPM to tick control. Further development of novel tick control measures, and increased efficiency in their integration and application to achieve desired goals, holds great promise for effective future management of ticks and tick-borne diseases.

  6. Identification of tick-borne pathogens in ticks feeding on humans in Turkey.

    PubMed

    Orkun, Ömer; Karaer, Zafer; Çakmak, Ayşe; Nalbantoğlu, Serpil

    2014-08-01

    The importance of tick-borne diseases is increasing all over the world, including Turkey. The tick-borne disease outbreaks reported in recent years and the abundance of tick species and the existence of suitable habitats increase the importance of studies related to the epidemiology of ticks and tick-borne pathogens in Turkey. The aim of this study was to investigate the presence of and to determine the infection rates of some tick-borne pathogens, including Babesia spp., Borrelia burgdorferi sensu lato and spotted fever group rickettsiae in the ticks removed from humans in different parts of Ankara. A total of 169 ticks belonging to the genus Haemaphysalis, Hyalomma, Ixodes and Rhipicephalus were collected by removing from humans in different parts of Ankara. Ticks were molecularly screened for Babesia spp., Borrelia burgdorferi sensu lato and spotted fever group rickettsiae by PCR and sequencing analysis. We detected 4 Babesia spp.; B. crassa, B. major, B. occultans and B. rossi, one Borrelia spp.; B. burgdorferi sensu stricto and 3 spotted fever group rickettsiae; R. aeschlimannii, R. slovaca and R. hoogstraalii in the tick specimens analyzed. This is the report showing the presence of B. rossi in a region that is out of Africa and in the host species Ha. parva. In addition, B. crassa, for which limited information is available on its distribution and vector species, and B. occultans, for which no conclusive information is available on its presence in Turkey, were identified in Ha. parva and H. marginatum, respectively. Two human pathogenic rickettsia species (R. aeschlimannii and R. slovaca) were detected with a high prevalence in ticks. Additionally, B. burgdorferi sensu stricto was detected in unusual tick species (H. marginatum, H. excavatum, Hyalomma spp. (nymph) and Ha. parva). This study investigates both the distribution of several tick-borne pathogens affecting humans and animals, and the presence of new tick-borne pathogens in Turkey. More

  7. Tick-borne protozoa

    USDA-ARS?s Scientific Manuscript database

    Tick-borne protozoa impose a significant health burden on humans and animals throughout the world. The virulence of tick-borne protozoa, and the geographic distribution of their tick vectors and vertebrate hosts remain in flux as they adapt to changing environmental and climatic conditions. Babesios...

  8. A quantitative synthesis of the role of birds in carrying ticks and tick-borne pathogens in North America.

    PubMed

    Loss, Scott R; Noden, Bruce H; Hamer, Gabriel L; Hamer, Sarah A

    2016-12-01

    Birds play a central role in the ecology of tick-borne pathogens. They expand tick populations and pathogens across vast distances and serve as reservoirs that maintain and amplify transmission locally. Research into the role of birds for supporting ticks and tick-borne pathogens has largely been descriptive and focused in small areas. To expand inference beyond these studies, we conducted a quantitative review at the scale of North America to identify avian life history correlates of tick infestation and pathogen prevalence, calculate species-level indices of importance for carrying ticks, and identify research gaps limiting understanding of tick-borne pathogen transmission. Across studies, 78 of 162 bird species harbored ticks, yielding an infestation prevalence of 1981 of 38,929 birds (5.1 %). Avian foraging and migratory strategies interacted to influence infestation. Ground-foraging species, especially non-migratory ground foragers, were disproportionately likely to have high prevalence and intensity of tick infestation. Studies largely focused on Borrelia burgdorferi, the agent of Lyme disease, and non-migratory ground foragers were especially likely to carry B. burgdorferi-infected ticks, a finding that highlights the potential importance of resident birds in local pathogen transmission. Based on infestation indices, all "super-carrier" bird species were passerines. Vast interior areas of North America, many bird and tick species, and most tick-borne pathogens, remain understudied, and research is needed to address these gaps. More studies are needed that quantify tick host preferences, host competence, and spatiotemporal variation in pathogen prevalence and vector and host abundance. This information is crucial for predicting pathogen transmission dynamics under future global change.

  9. Identification of Tick-Borne Pathogens in Ticks Feeding on Humans in Turkey

    PubMed Central

    Orkun, Ömer; Karaer, Zafer; Çakmak, Ayşe; Nalbantoğlu, Serpil

    2014-01-01

    Background The importance of tick-borne diseases is increasing all over the world, including Turkey. The tick-borne disease outbreaks reported in recent years and the abundance of tick species and the existence of suitable habitats increase the importance of studies related to the epidemiology of ticks and tick-borne pathogens in Turkey. The aim of this study was to investigate the presence of and to determine the infection rates of some tick-borne pathogens, including Babesia spp., Borrelia burgdorferi sensu lato and spotted fever group rickettsiae in the ticks removed from humans in different parts of Ankara. Methodology/Principal Findings A total of 169 ticks belonging to the genus Haemaphysalis, Hyalomma, Ixodes and Rhipicephalus were collected by removing from humans in different parts of Ankara. Ticks were molecularly screened for Babesia spp., Borrelia burgdorferi sensu lato and spotted fever group rickettsiae by PCR and sequencing analysis. We detected 4 Babesia spp.; B. crassa, B. major, B. occultans and B. rossi, one Borrelia spp.; B. burgdorferi sensu stricto and 3 spotted fever group rickettsiae; R. aeschlimannii, R. slovaca and R. hoogstraalii in the tick specimens analyzed. This is the report showing the presence of B. rossi in a region that is out of Africa and in the host species Ha. parva. In addition, B. crassa, for which limited information is available on its distribution and vector species, and B. occultans, for which no conclusive information is available on its presence in Turkey, were identified in Ha. parva and H. marginatum, respectively. Two human pathogenic rickettsia species (R. aeschlimannii and R. slovaca) were detected with a high prevalence in ticks. Additionally, B. burgdorferi sensu stricto was detected in unusual tick species (H. marginatum, H. excavatum, Hyalomma spp. (nymph) and Ha. parva). Conclusions/Significance This study investigates both the distribution of several tick-borne pathogens affecting humans and animals, and

  10. Roadside ecology and epidemiology of tick-borne diseases.

    PubMed

    Haemig, Paul D; Waldenstrom, Jonas; Olsen, Bjorn

    2008-01-01

    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.

  11. Prevention of tick-borne diseases.

    PubMed

    Piesman, Joseph; Eisen, Lars

    2008-01-01

    Tick-borne diseases are on the rise. Lyme borreliosis is prevalent throughout the Northern Hemisphere, and the same Ixodes tick species transmitting the etiologic agents of this disease also serve as vectors of pathogens causing human babesiosis, human granulocytic anaplasmosis, and tick-borne encephalitis. Recently, several novel agents of rickettsial diseases have been described. Despite an explosion of knowledge in the fields of tick biology, genetics, molecular biology, and immunology, transitional research leading to widely applied public health measures to combat tick-borne diseases has not been successful. Except for the vaccine against tick-borne encephalitis virus, and a brief campaign to reduce this disease in the former Soviet Union through widespread application of DDT, success stories in the fight against tick-borne diseases are lacking. Both new approaches to tick and pathogen control and novel ways of translating research findings into practical control measures are needed to prevent tick-borne diseases in the twenty-first century.

  12. Tick-borne disease.

    PubMed

    Bratton, Robert L; Corey, Ralph

    2005-06-15

    Tick-borne diseases in the United States include Rocky Mountain spotted fever, Lyme disease, ehrlichiosis, tularemia, babesiosis, Colorado tick fever, and relapsing fever. It is important for family physicians to consider these illnesses when patients present with influenza-like symptoms. A petechial rash initially affecting the palms and soles of the feet is associated with Rocky Mountain spotted fever, whereas erythema migrans (annular macule with central clearing) is associated with Lyme disease. Various other rashes or skin lesions accompanied by fever and influenza-like illness also may signal the presence of a tick-borne disease. Early, accurate diagnosis allows treatment that may help prevent significant morbidity and possible mortality. Because 24 to 48 hours of attachment to the host are required for infection to occur, early removal can help prevent disease. Treatment with doxycycline or tetracycline is indicated for Rocky Mountain spotted fever, Lyme disease, ehrlichiosis, and relapsing fever. In patients with clinical findings suggestive of tick-borne disease, treatment should not be delayed for laboratory confirmation. If no symptoms follow exposure to tick bites, empiric treatment is not indicated. The same tick may harbor different infectious pathogens and transmit several with one bite. Advising patients about prevention of tick bites, especially in the summer months, may help prevent exposure to dangerous vector-borne diseases.

  13. Changing geographic ranges of ticks and tick-borne pathogens: drivers, mechanisms and consequences for pathogen diversity

    PubMed Central

    Ogden, Nick H.; Mechai, Samir; Margos, Gabriele

    2013-01-01

    The geographic ranges of ticks and tick-borne pathogens are changing due to global and local environmental (including climatic) changes. In this review we explore current knowledge of the drivers for changes in the ranges of ticks and tick-borne pathogen species and strains via effects on their basic reproduction number (R0), and the mechanisms of dispersal that allow ticks and tick-borne pathogens to invade suitable environments. Using the expanding geographic distribution of the vectors and agent of Lyme disease as an example we then investigate what could be expected of the diversity of tick-borne pathogens during the process of range expansion, and compare this with what is currently being observed. Lastly we explore how historic population and range expansions and contractions could be reflected in the phylogeography of ticks and tick-borne pathogens seen in recent years, and conclude that combined study of currently changing tick and tick-borne pathogen ranges and diversity, with phylogeographic analysis, may help us better predict future patterns of invasion and diversity. PMID:24010124

  14. Changing geographic ranges of ticks and tick-borne pathogens: drivers, mechanisms and consequences for pathogen diversity.

    PubMed

    Ogden, Nick H; Mechai, Samir; Margos, Gabriele

    2013-01-01

    The geographic ranges of ticks and tick-borne pathogens are changing due to global and local environmental (including climatic) changes. In this review we explore current knowledge of the drivers for changes in the ranges of ticks and tick-borne pathogen species and strains via effects on their basic reproduction number (R 0), and the mechanisms of dispersal that allow ticks and tick-borne pathogens to invade suitable environments. Using the expanding geographic distribution of the vectors and agent of Lyme disease as an example we then investigate what could be expected of the diversity of tick-borne pathogens during the process of range expansion, and compare this with what is currently being observed. Lastly we explore how historic population and range expansions and contractions could be reflected in the phylogeography of ticks and tick-borne pathogens seen in recent years, and conclude that combined study of currently changing tick and tick-borne pathogen ranges and diversity, with phylogeographic analysis, may help us better predict future patterns of invasion and diversity.

  15. Reducing tick bite risk in Finland - combining citizen science and GIS for predictive modelling of tick occurrence

    NASA Astrophysics Data System (ADS)

    Sormunen, Jani; Kulha, Niko; Klemola, Tero

    2017-04-01

    Ticks (Acari: Ixodidae) and tick-borne diseases constitute a growing welfare problem in northern Europe and Russia. Surveys conducted in Russia, Sweden and Norway have revealed a northwards shift in distribution and an increase in tick abundance over the past few decades. In southwestern Finland, surveys have revealed a similar increase in tick abundance, as well as the presence of novel tick-borne pathogens. As avoiding risk areas and removing attached ticks as quickly as possible are the best available methods for preventing tick-borne diseases, accessible and up-to-date data on tick occurrence is essential. However, consistently tracking the nationwide distribution of ticks is impossible using traditional collection methods. Therefore, GIS-based predictive modelling for tick occurrence is required. In May 2015, a national tick collection campaign was launched by the University of Turku tick project, with the objective of mapping the current geographical distribution of the two tick species responsible for tick-borne infections in Finland, Ixodes ricinus and Ixodes persulcatus. During the collection campaign, citizens were asked to send any ticks they found to the University of Turku by letter, along with information on the collection locality. The campaign ended in September 2015 and was a great success, with nearly 7000 letters delivered to the University. These letters contained more than 20 000 individual ticks from all around Finland. The geographic data from the letters was converted into coordinate points after the campaign was concluded. Data from the national tick collection campaign revealed not only a northwards shift in the distribution of I. ricinus, but also novel foci for I. persulcatus in Finland. Strikingly, while they were otherwise found throughout Finland, I. persulcatus were absent from the south-southwestern coast, where I. ricinus is nevertheless abundant. The exact cause for this phenomenon is unclear, as I. persulcatus are found further

  16. [The ecology of ticks, tick-borne diseases and biological tick control in Baden-Württemberg].

    PubMed

    Sebastian, P; Mackenstedt, U; Wassermann, M; Wurst, E; Hartelt, K; Petney, T; Pfäffle, M; Littwin, N; Steidle, J L M; Selzer, P; Norra, S; Böhnke, D; Gebhardt, R; Kahl, O; Dautel, H; Oehme, R

    2014-05-01

    Ticks and tick-borne diseases are of great significance for the health of humans and animals. However, the factors influencing their distribution and dynamics are inadequately known. In a project financed by the Baden-Württemberg Ministry of the Environment, Climate and Energy Industry, as part of the program BWPLUS, interdisciplinary specialists work together to determine the influence of weather, (micro)climate, habitat, land use, human activities, and the population dynamics of host animals on the distribution and abundance of ticks and the diseases that they transmit in Baden-Württemberg. The project comprises four modules: the large-scale distribution of ticks in Baden-Württemberg (module 1), detailed studies of host-tick-pathogen interaction in relation to the microclimate (module 2), and the spatial occurrence of important tick-borne pathogens (module 3). The fourth module involves the comprehensive analysis and synthesis of all data in order to determine the relative importance of the factors studied and to develop a risk model. Recently, intensive investigations into tick control have been undertaken using various entomopathogenic fungi and nematodes as well as a parasitoid wasp. Our aim was to determine whether these natural enemies could be used to effectively reduce the number of free-living ticks.

  17. Ticks and tick-borne pathogens of dogs along an elevational and land-use gradient in Chiriquí province, Panamá.

    PubMed

    Ferrell, A Michelle; Brinkerhoff, R Jory; Bernal, Juan; Bermúdez, Sergio E

    2017-04-01

    Systematic acarological surveys are useful tools in assessing risk to tick-borne infections, especially in areas where consistent clinical surveillance for tick-borne disease is lacking. Our goal was to identify environmental predictors of tick burdens on dogs and tick-borne infectious agents in dog-derived ticks in the Chiriquí Province of western Panama to draw inferences about spatio-temporal variation in human risk to tick-borne diseases. We used a model-selection approach to test the relative importance of elevation, human population size, vegetative cover, and change in landuse on patterns of tick parasitism on dogs. We collected 2074 ticks, representing four species (Rhipicephalus sanguineus, R. microplus, Amblyomma ovale, and Ixodes boliviensis) from 355 dogs. Tick prevalence ranged from 0 to 74% among the sites we sampled, and abundance ranged from 0 to 20.4 ticks per dog with R. sanguineus s.l. being the most commonly detected tick species (97% of all ticks sampled). Whereas elevation was the best single determinant of tick prevalence and abundance on dogs, the top models also included predictor variables describing vegetation cover and landuse change. Specifically, low-elevation areas associated with decreasing vegetative cover were associated with highest tick occurrence on dogs, potentially because of the affinity of R. sanguineus for human dwellings. Although we found low prevalence of tick-borne pathogen genera (two Rickettsia-positive ticks, no R. rickettsia or Ehrlichia spp.) in our study, all of the tick species we collected from dogs are known vectors of zoonotic pathogens. In areas where epidemiological surveillance infrastructure is limited, field-based assessments of acarological risk can be useful and cost-effective tools in efforts to identify high-risk environments for tick-transmitted pathogens.

  18. Disease Risk in a Dynamic Environment: The Spread of Tick-Borne Pathogens in Minnesota, USA

    PubMed Central

    Robinson, Stacie J.; Neitzel, David F.; Moen, Ronald A.; Craft, Meggan E.; Hamilton, Karin E.; Johnson, Lucinda B.; Mulla, David J.; Munderloh, Ulrike G.; Redig, Patrick T.; Smith, Kirk E.; Turner, Clarence L.; Umber, Jamie K.; Pelican, Katharine M.

    2015-01-01

    As humans and climate change alter the landscape, novel disease risk scenarios emerge. Understanding the complexities of pathogen emergence and subsequent spread as shaped by landscape heterogeneity is crucial to understanding disease emergence, pinpointing high-risk areas, and mitigating emerging disease threats in a dynamic environment. Tick-borne diseases present an important public health concern and incidence of many of these diseases are increasing in the United States. The complex epidemiology of tick-borne diseases includes strong ties with environmental factors that influence host availability, vector abundance, and pathogen transmission. Here, we used 16 years of case data from the Minnesota Department of Health to report spatial and temporal trends in Lyme disease (LD), human anaplasmosis, and babesiosis. We then used a spatial regression framework to evaluate the impact of landscape and climate factors on the spread of LD. Finally, we use the fitted model, and landscape and climate datasets projected under varying climate change scenarios, to predict future changes in tick-borne pathogen risk. Both forested habitat and temperature were important drivers of LD spread in Minnesota. Dramatic changes in future temperature regimes and forest communities predict rising risk of tick-borne disease. PMID:25281302

  19. Disease risk in a dynamic environment: the spread of tick-borne pathogens in Minnesota, USA.

    PubMed

    Robinson, Stacie J; Neitzel, David F; Moen, Ronald A; Craft, Meggan E; Hamilton, Karin E; Johnson, Lucinda B; Mulla, David J; Munderloh, Ulrike G; Redig, Patrick T; Smith, Kirk E; Turner, Clarence L; Umber, Jamie K; Pelican, Katharine M

    2015-03-01

    As humans and climate change alter the landscape, novel disease risk scenarios emerge. Understanding the complexities of pathogen emergence and subsequent spread as shaped by landscape heterogeneity is crucial to understanding disease emergence, pinpointing high-risk areas, and mitigating emerging disease threats in a dynamic environment. Tick-borne diseases present an important public health concern and incidence of many of these diseases are increasing in the United States. The complex epidemiology of tick-borne diseases includes strong ties with environmental factors that influence host availability, vector abundance, and pathogen transmission. Here, we used 16 years of case data from the Minnesota Department of Health to report spatial and temporal trends in Lyme disease (LD), human anaplasmosis, and babesiosis. We then used a spatial regression framework to evaluate the impact of landscape and climate factors on the spread of LD. Finally, we use the fitted model, and landscape and climate datasets projected under varying climate change scenarios, to predict future changes in tick-borne pathogen risk. Both forested habitat and temperature were important drivers of LD spread in Minnesota. Dramatic changes in future temperature regimes and forest communities predict rising risk of tick-borne disease.

  20. Transport of ixodid ticks and tick-borne pathogens by migratory birds.

    PubMed

    Hasle, Gunnar

    2013-01-01

    Birds, particularly passerines, can be parasitized by Ixodid ticks, which may be infected with tick-borne pathogens, like Borrelia spp., Babesia spp., Anaplasma, Rickettsia/Coxiella, and tick-borne encephalitis virus. The prevalence of ticks on birds varies over years, season, locality and different bird species. The prevalence of ticks on different species depends mainly on the degree of feeding on the ground. In Europe, the Turdus spp., especially the blackbird, Turdus merula, appears to be most important for harboring ticks. Birds can easily cross barriers, like fences, mountains, glaciers, desserts and oceans, which would stop mammals, and they can move much faster than the wingless hosts. Birds can potentially transport tick-borne pathogens by transporting infected ticks, by being infected with tick-borne pathogens and transmit the pathogens to the ticks, and possibly act as hosts for transfer of pathogens between ticks through co-feeding. Knowledge of the bird migration routes and of the spatial distribution of tick species and tick-borne pathogens is crucial for understanding the possible impact of birds as spreaders of ticks and tick-borne pathogens. Successful colonization of new tick species or introduction of new tick-borne pathogens will depend on suitable climate, vegetation and hosts. Although it has never been demonstrated that a new tick species, or a new tick pathogen, actually has been established in a new locality after being seeded there by birds, evidence strongly suggests that this could occur.

  1. Transport of ixodid ticks and tick-borne pathogens by migratory birds

    PubMed Central

    Hasle, Gunnar

    2013-01-01

    Birds, particularly passerines, can be parasitized by Ixodid ticks, which may be infected with tick-borne pathogens, like Borrelia spp., Babesia spp., Anaplasma, Rickettsia/Coxiella, and tick-borne encephalitis virus. The prevalence of ticks on birds varies over years, season, locality and different bird species. The prevalence of ticks on different species depends mainly on the degree of feeding on the ground. In Europe, the Turdus spp., especially the blackbird, Turdus merula, appears to be most important for harboring ticks. Birds can easily cross barriers, like fences, mountains, glaciers, desserts and oceans, which would stop mammals, and they can move much faster than the wingless hosts. Birds can potentially transport tick-borne pathogens by transporting infected ticks, by being infected with tick-borne pathogens and transmit the pathogens to the ticks, and possibly act as hosts for transfer of pathogens between ticks through co-feeding. Knowledge of the bird migration routes and of the spatial distribution of tick species and tick-borne pathogens is crucial for understanding the possible impact of birds as spreaders of ticks and tick-borne pathogens. Successful colonization of new tick species or introduction of new tick-borne pathogens will depend on suitable climate, vegetation and hosts. Although it has never been demonstrated that a new tick species, or a new tick pathogen, actually has been established in a new locality after being seeded there by birds, evidence strongly suggests that this could occur. PMID:24058903

  2. Wild birds and urban ecology of ticks and tick-borne pathogens, Chicago, Illinois, USA, 2005-2010.

    PubMed

    Hamer, Sarah A; Goldberg, Tony L; Kitron, Uriel D; Brawn, Jeffrey D; Anderson, Tavis K; Loss, Scott R; Walker, Edward D; Hamer, Gabriel L

    2012-10-01

    Bird-facilitated introduction of ticks and associated pathogens is postulated to promote invasion of tick-borne zoonotic diseases into urban areas. Results of a longitudinal study conducted in suburban Chicago, Illinois, USA, during 2005-2010 show that 1.6% of 6,180 wild birds captured in mist nets harbored ticks. Tick species in order of abundance were Haemaphysalis leporispalustris, Ixodes dentatus, and I. scapularis, but 2 neotropical tick species of the genus Amblyomma were sampled during the spring migration. I. scapularis ticks were absent at the beginning of the study but constituted the majority of ticks by study end and were found predominantly on birds captured in areas designated as urban green spaces. Of 120 ticks, 5 were infected with Borrelia burgdorferi, spanning 3 ribotypes, but none were infected with Anaplasma phagocytophilum. Results allow inferences about propagule pressure for introduction of tick-borne diseases and emphasize the large sample sizes required to estimate this pressure.

  3. Tick-Borne Encephalitis (TBE)

    MedlinePlus

    ... virus, Siberian tick-borne encephalitis virus, and Far eastern Tick-borne encephalitis virus (formerly known as Russian ... viruses are closely related to TBEV and Far-eastern TBE, and include Omsk hemorrhagic fever virus in ...

  4. Distribution of tick-borne diseases in China

    PubMed Central

    2013-01-01

    As an important contributor to vector-borne diseases in China, in recent years, tick-borne diseases have attracted much attention because of their increasing incidence and consequent significant harm to livestock and human health. The most commonly observed human tick-borne diseases in China include Lyme borreliosis (known as Lyme disease in China), tick-borne encephalitis (known as Forest encephalitis in China), Crimean-Congo hemorrhagic fever (known as Xinjiang hemorrhagic fever in China), Q-fever, tularemia and North-Asia tick-borne spotted fever. In recent years, some emerging tick-borne diseases, such as human monocytic ehrlichiosis, human granulocytic anaplasmosis, and a novel bunyavirus infection, have been reported frequently in China. Other tick-borne diseases that are not as frequently reported in China include Colorado fever, oriental spotted fever and piroplasmosis. Detailed information regarding the history, characteristics, and current epidemic status of these human tick-borne diseases in China will be reviewed in this paper. It is clear that greater efforts in government management and research are required for the prevention, control, diagnosis, and treatment of tick-borne diseases, as well as for the control of ticks, in order to decrease the tick-borne disease burden in China. PMID:23617899

  5. Wild Birds and Urban Ecology of Ticks and Tick-borne Pathogens, Chicago, Illinois, USA, 2005–2010

    PubMed Central

    Goldberg, Tony L.; Kitron, Uriel D.; Brawn, Jeffrey D.; Anderson, Tavis K.; Loss, Scott R.; Walker, Edward D.; Hamer, Gabriel L.

    2012-01-01

    Bird-facilitated introduction of ticks and associated pathogens is postulated to promote invasion of tick-borne zoonotic diseases into urban areas. Results of a longitudinal study conducted in suburban Chicago, Illinois, USA, during 2005–2010 show that 1.6% of 6,180 wild birds captured in mist nets harbored ticks. Tick species in order of abundance were Haemaphysalis leporispalustris, Ixodes dentatus, and I. scapularis, but 2 neotropical tick species of the genus Amblyomma were sampled during the spring migration. I. scapularis ticks were absent at the beginning of the study but constituted the majority of ticks by study end and were found predominantly on birds captured in areas designated as urban green spaces. Of 120 ticks, 5 were infected with Borrelia burgdorferi, spanning 3 ribotypes, but none were infected with Anaplasma phagocytophilum. Results allow inferences about propagule pressure for introduction of tick-borne diseases and emphasize the large sample sizes required to estimate this pressure. PMID:23017244

  6. Ticks and Tick-Borne Infections: Complex Ecology, Agents, and Host Interactions.

    PubMed

    Wikel, Stephen K

    2018-06-20

    Ticks transmit the most diverse array of infectious agents of any arthropod vector. Both ticks and the microbes they transmit are recognized as significant threats to human and veterinary public health. This article examines the potential impacts of climate change on the distribution of ticks and the infections they transmit; the emergence of novel tick-borne pathogens, increasing geographic range and incidence of tick-borne infections; and advances in the characterization of tick saliva mediated modulation of host defenses and the implications of those interactions for transmission, establishment, and control of tick infestation and tick-borne infectious agents.

  7. Ticks and tick-borne diseases in Oklahoma.

    PubMed

    Moody, E K; Barker, R W; White, J L; Crutcher, J M

    1998-11-01

    Tick-borne diseases are common in Oklahoma, especially the eastern part of the state where tick prevalence is highest. Three species of hard ticks are present in Oklahoma that are known vectors of human disease--the American dog tick (Rocky Mountain spotted fever; RMSF), the lone star tick (ehrlichiosis) and the black-legged tick (Lyme disease). Oklahoma consistently ranks among the top states in numbers of reported RMSF cases, and Ehrlichiosis may be as prevalent as RMSF. Although Lyme disease is frequently reported in Oklahoma, over-diagnosing of this disease due to false-positive test results is common; positive or equivocal screening tests should be confirmed by Western immunoblot. At present, it is unclear whether the disease seen here is Lyme disease or another Lyme-like disease. If true Lyme disease is present in the state, it is probably rare. Physicians should be aware of the most recent recommendations for diagnosis, therapy and prevention of tick-borne diseases.

  8. Influence of the biotope on the tick infestation of cattle and on the tick-borne pathogen repertoire of cattle ticks in Ethiopia.

    PubMed

    Hornok, Sándor; Abichu, Getachew; Meli, Marina L; Tánczos, Balázs; Sulyok, Kinga M; Gyuranecz, Miklós; Gönczi, Enikő; Farkas, Róbert; Hofmann-Lehmann, Regina

    2014-01-01

    The majority of vector-borne infections occur in the tropics, including Africa, but molecular eco-epidemiological studies are seldom reported from these regions. In particular, most previously published data on ticks in Ethiopia focus on species distribution, and only a few molecular studies on the occurrence of tick-borne pathogens or on ecological factors influencing these. The present study was undertaken to evaluate, if ticks collected from cattle in different Ethiopian biotopes harbour (had access to) different pathogens. In South-Western Ethiopia 1032 hard ticks were removed from cattle grazing in three kinds of tick biotopes. DNA was individually extracted from one specimen of both sexes of each tick species per cattle. These samples were molecularly analysed for the presence of tick-borne pathogens. Amblyomma variegatum was significantly more abundant on mid highland, than on moist highland. Rhipicephalus decoloratus was absent from savannah lowland, where virtually only A. cohaerens was found. In the ticks Coxiella burnetii had the highest prevalence on savannah lowland. PCR positivity to Theileria spp. did not appear to depend on the biotope, but some genotypes were unique to certain tick species. Significantly more A. variegatum specimens were rickettsia-positive, than those of other tick species. The presence of rickettsiae (R. africae) appeared to be associated with mid highland in case of A. variegatum and A. cohaerens. The low level of haemoplasma positivity seemed to be equally distributed among the tick species, but was restricted to one biotope type. The tick biotope, in which cattle are grazed, will influence not only the tick burden of these hosts, but also the spectrum of pathogens in their ticks. Thus, the presence of pathogens with alternative (non-tick-borne) transmission routes, with transstadial or with transovarial transmission by ticks appeared to be associated with the biotope type, with the tick species, or both, respectively.

  9. Tick-borne pathogens in ticks collected from birds in Taiwan.

    PubMed

    Kuo, Chi-Chien; Lin, Yi-Fu; Yao, Cheng-Te; Shih, Han-Chun; Chung, Lo-Hsuan; Liao, Hsien-Chun; Hsu, Yu-Cheng; Wang, Hsi-Chieh

    2017-11-25

    A variety of human diseases transmitted by arthropod vectors, including ticks, are emerging around the globe. Birds are known to be hosts of ticks and can disperse exotic ticks and tick-borne pathogens. In Taiwan, previous studies have focused predominantly on mammals, leaving the role of birds in the maintenance of ticks and dissemination of tick-borne pathogens undetermined. Ticks were collected opportunistically when birds were studied from 1995 to 2013. Furthermore, to improve knowledge on the prevalence and mean load of tick infestation on birds in Taiwan, ticks were thoroughly searched for when birds were mist-netted at seven sites between September 2014 and April 2016 in eastern Taiwan. Ticks were identified based on both morphological and molecular information and were screened for potential tick-borne pathogens, including the genera Anaplasma, Babesia, Borrelia, Ehrlichia and Rickettsia. Finally, a list of hard tick species collected from birds in Taiwan was compiled based on past work and the current study. Nineteen ticks (all larvae) were recovered from four of the 3096 unique mist-netted bird individuals, yielding a mean load of 0.006 ticks/individual and an overall prevalence of 0.13%. A total of 139 ticks from birds, comprising 48 larvae, 35 nymphs, 55 adults and one individual of unknown life stage, were collected from 1995 to 2016, and 11 species of four genera were identified, including three newly recorded species (Haemaphysalis wellingtoni, Ixodes columnae and Ixodes turdus). A total of eight tick-borne pathogens were detected, with five species (Borrelia turdi, Anaplasma sp. clone BJ01, Ehrlichia sp. BL157-9, Rickettsia helvetica and Rickettsia monacensis) not previously isolated in Taiwan. Overall, 16 tick species of five genera have been recorded feeding on birds, including nine species first discovered in this study. Our study demonstrates the paucity of information on ticks of birds and emphasizes the need for more research on ticks of birds

  10. Climate change, biodiversity, ticks and tick-borne diseases: The butterfly effect.

    PubMed

    Dantas-Torres, Filipe

    2015-12-01

    We have killed wild animals for obtaining food and decimated forests for many reasons. Nowadays, we are burning fossil fuels as never before and even exploring petroleum in deep waters. The impact of these activities on our planet is now visible to the naked eye and the debate on climate change is warming up in scientific meetings and becoming a priority on the agenda of both scientists and policy decision makers. On the occasion of the Impact of Environmental Changes on Infectious Diseases (IECID) meeting, held in the 2015 in Sitges, Spain, I was invited to give a keynote talk on climate change, biodiversity, ticks and tick-borne diseases. The aim of the present article is to logically extend my rationale presented on the occasion of the IECID meeting. This article is not intended to be an exhaustive review, but an essay on climate change, biodiversity, ticks and tick-borne diseases. It may be anticipated that warmer winters and extended autumn and spring seasons will continue to drive the expansion of the distribution of some tick species (e.g., Ixodes ricinus) to northern latitudes and to higher altitudes. Nonetheless, further studies are advocated to improve our understanding of the complex interactions between landscape, climate, host communities (biodiversity), tick demography, pathogen diversity, human demography, human behaviour, economics, and politics, also considering all ecological processes (e.g., trophic cascades) and other possible interacting effects (e.g., mutual effects of increased greenhouse gas emissions and increased deforestation rates). The multitude of variables and interacting factors involved, and their complexity and dynamism, make tick-borne transmission systems beyond (current) human comprehension. That is, perhaps, the main reason for our inability to precisely predict new epidemics of vector-borne diseases in general.

  11. Climate change, biodiversity, ticks and tick-borne diseases: The butterfly effect

    PubMed Central

    Dantas-Torres, Filipe

    2015-01-01

    We have killed wild animals for obtaining food and decimated forests for many reasons. Nowadays, we are burning fossil fuels as never before and even exploring petroleum in deep waters. The impact of these activities on our planet is now visible to the naked eye and the debate on climate change is warming up in scientific meetings and becoming a priority on the agenda of both scientists and policy decision makers. On the occasion of the Impact of Environmental Changes on Infectious Diseases (IECID) meeting, held in the 2015 in Sitges, Spain, I was invited to give a keynote talk on climate change, biodiversity, ticks and tick-borne diseases. The aim of the present article is to logically extend my rationale presented on the occasion of the IECID meeting. This article is not intended to be an exhaustive review, but an essay on climate change, biodiversity, ticks and tick-borne diseases. It may be anticipated that warmer winters and extended autumn and spring seasons will continue to drive the expansion of the distribution of some tick species (e.g., Ixodes ricinus) to northern latitudes and to higher altitudes. Nonetheless, further studies are advocated to improve our understanding of the complex interactions between landscape, climate, host communities (biodiversity), tick demography, pathogen diversity, human demography, human behaviour, economics, and politics, also considering all ecological processes (e.g., trophic cascades) and other possible interacting effects (e.g., mutual effects of increased greenhouse gas emissions and increased deforestation rates). The multitude of variables and interacting factors involved, and their complexity and dynamism, make tick-borne transmission systems beyond (current) human comprehension. That is, perhaps, the main reason for our inability to precisely predict new epidemics of vector-borne diseases in general. PMID:26835253

  12. Tick-borne disease risk in a forest food web.

    PubMed

    Ostfeld, Richard S; Levi, Taal; Keesing, Felicia; Oggenfuss, Kelly; Canham, Charles D

    2018-05-08

    Changes to the community ecology of hosts for zoonotic pathogens, particularly rodents, are likely to influence the emergence and prevalence of zoonotic diseases worldwide. However, the complex interactions between abiotic factors, pathogens, vectors, hosts, and both food resources and predators of hosts are difficult to disentangle. Here we (1) use 19 years of data from six large field plots in southeastern New York to compare the effects of hypothesized drivers of interannual variation in Lyme disease risk, including the abundance of acorns, rodents, and deer, as well as a series of climate variables; and (2) employ landscape epidemiology to explore how variation in predator community structure and forest cover influences spatial variation in the infection prevalence of ticks for the Lyme disease bacterium, Borrelia burgdorferi, and two other important tick-borne pathogens, Anaplasma phagocytophilum and Babesia microti. Acorn-driven increases in the abundance of mice were correlated with a lagged increase in the abundance of questing nymph-stage Ixodes scapularis ticks infected with Lyme disease bacteria. Abundance of white-tailed deer two years prior also correlated with increased density of infected nymphal ticks, although the effect was weak. Density of rodents in the current year was a strong negative predictor of nymph density, apparently because high current abundance of these hosts can remove nymphs from the host-seeking population. Warm, dry spring or winter weather was associated with reduced density of infected nymphs. At the landscape scale, the presence of functionally diverse predator communities or of bobcats, the only obligate carnivore, was associated with reduced infection prevalence of I. scapularis nymphs with all three zoonotic pathogens. In the case of Lyme disease, infection prevalence increased where coyotes were present but smaller predators were displaced or otherwise absent. For all pathogens, infection prevalence was lowest when forest

  13. Cross-neutralisation of viruses of the tick-borne encephalitis complex following tick-borne encephalitis vaccination and/or infection.

    PubMed

    McAuley, Alexander J; Sawatsky, Bevan; Ksiazek, Thomas; Torres, Maricela; Korva, Miša; Lotrič-Furlan, Stanka; Avšič-Županc, Tatjana; von Messling, Veronika; Holbrook, Michael R; Freiberg, Alexander N; Beasley, David W C; Bente, Dennis A

    2017-01-01

    The tick-borne encephalitis complex contains a number of flaviviruses that share close genetic homology, and are responsible for significant human morbidity and mortality with widespread geographical range. Although many members of this complex have been recognised for decades, licenced human vaccines with broad availability are only available for tick-borne encephalitis virus. While tick-borne encephalitis virus vaccines have been demonstrated to induce significant protective immunity, as determined by virus-neutralisation titres, vaccine breakthrough (clinical infection following complete vaccination), has been described. The aim of this study was to confirm the cross-neutralisation of tick-borne flaviviruses using mouse immune ascitic fluids, and to determine the magnitude of cross-neutralising antibody titres in sera from donors following tick-borne encephalitis vaccination, infection, and vaccine breakthrough. The results demonstrate that there is significant cross-neutralisation of representative members of the tick-borne encephalitis complex following vaccination and/or infection, and that the magnitude of immune responses varies based upon the exposure type. Donor sera successfully neutralised most of the viruses tested, with 85% of vaccinees neutralising Kyasanur forest disease virus and 73% of vaccinees neutralising Alkhumra virus. By contrast, only 63% of vaccinees neutralised Powassan virus, with none of these neutralisation titres exceeding 1:60. Taken together, the data suggest that tick-borne encephalitis virus vaccination may protect against most of the members of the tick-borne encephalitis complex including Kyasanur forest disease virus and Alkhumra virus, but that the neutralisation of Powassan virus following tick-borne encephalitis vaccination is minimal.

  14. Tick-borne pathogens and associated co-infections in ticks collected from domestic animals in central China.

    PubMed

    Chen, Zhuo; Liu, Qin; Liu, Ji-Qi; Xu, Bian-Li; Lv, Shan; Xia, Shang; Zhou, Xiao-Nong

    2014-05-22

    Ticks can transmit a number of pathogens to humans and domestic animals. Tick borne diseases (TBDs), which may lead to organ failure and death have been recently reported in China. 98.75% of the total cases (>1000) in Henan provinces have been reported in Xinyang city. Therefore, the aims of this study were to investigate the fauna of ticks and detect the potential pathogens in ticks in Xinyang, the region of central China. Ticks were collected from 10 villages of Xinyang from April to December 2012, from domestic animals including sheep, cattle and dogs. Then identification of ticks and detection of tick-borne pathogens, including Babesia spp., Theileria spp., Anaplasma spp., Ehrlichia spp., Rickettsia spp., tick-borne encephalitis virus (TBEV), Borrelia burgdorferi sensu lato, Leishmania infantum, were undertaken by using polymerase chain reaction assay (PCR) and sequence analysis. Moreover, the co-infection patterns of various pathogens were compared among locations where ticks were collected. A total of 308 ticks were collected. Two species of Ixodidae were found, namely Haemaphysalis longicornis (96.75%) and Rhipicephalus microplus (3.25%). Five genera of pathogens, namely Theileria spp. (3.25%), Anaplasma spp. (2.92%), Babesia spp. (1.95%), Ehrlichia spp. (2.92%) and Rickettsia spp. (0.65%), were detected in 7 villages. Co-infections by two pathogens were diagnosed in 11.11% of all infected ticks. Both human and animal pathogens were abundant in ticks in the study areas. Humans and animals in these regions were at a high risk of exposure to piroplasmosis, since piroplasm had the highest rates of infection and co-infection in positive ticks.

  15. The ecology of ticks and epidemiology of tick-borne viral diseases.

    PubMed

    Estrada-Peña, Agustín; de la Fuente, José

    2014-08-01

    A number of tick-borne diseases of humans have increased in incidence and geographic range over the past few decades, and there is concern that they will pose an even greater threat to public health in future. Although global warming is often cited as the underlying mechanism favoring the spread of tick-borne diseases, climate is just one of many factors that determine which tick species are found in a given geographic region, their population density, the likelihood that they will be infected with microbes pathogenic for humans and the frequency of tick-human contact. This article provides basic information needed for microbiologists to understand the many factors that affect the geographic range and population density of ticks and the risk of human exposure to infected ticks. It first briefly summarizes the life cycle and basic ecology of ticks and how ticks and vertebrate hosts interact, then reviews current understanding of the role of climate, sociodemographic factors, agricultural development and changes in human behavior that affect the incidence of tick-borne diseases. These concepts are then illustrated in specific discussions of tick-borne encephalitis and Crimean-Congo hemorrhagic fever. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Tick-borne pathogens and the vector potential of ticks in China.

    PubMed

    Yu, Zhijun; Wang, Hui; Wang, Tianhong; Sun, Wenying; Yang, Xiaolong; Liu, Jingze

    2015-01-14

    Ticks, as obligate blood-sucking ectoparasites, attack a broad range of vertebrates and transmit a great diversity of pathogenic microorganisms. They are considered second only to mosquitoes as vectors of human disease, and the most important vector of pathogens of domestic and wild animals. Of the 117 described species in the Chinese tick fauna, 60 are known to transmit one or more diseases: 36 species isolated within China and 24 species isolated outside China. Moreover, 38 of these species carry multiple pathogens, indicating the potentially vast role of these vectors in transmitting pathogens. Spotted fever is the most common tick-borne disease, and is carried by at least 27 tick species, with Lyme disease and human granulocytic anaplasmosis ranked as the second and third most widespread tick-borne diseases, carried by 13 and 10 species, respectively. Such knowledge provides us with clues for the identification of tick-associated pathogens and suggests ideas for the control of tick-borne diseases in China. However, the numbers of tick-associated pathogens and tick-borne diseases in China are probably underestimated because of the complex distribution and great diversity of tick species in this country.

  17. Assessing the abundance, seasonal questing activity, and Borrelia and tick-borne encephalitis virus (TBEV) prevalence of Ixodes ricinus ticks in a Lyme borreliosis endemic area in Southwest Finland.

    PubMed

    Sormunen, Jani J; Klemola, Tero; Vesterinen, Eero J; Vuorinen, Ilppo; Hytönen, Jukka; Hänninen, Jari; Ruohomäki, Kai; Sääksjärvi, Ilari E; Tonteri, Elina; Penttinen, Ritva

    2016-02-01

    Studies have revealed that Ixodes ricinus (Acari: Ixodidae) have become more abundant and their geographical distribution extended northwards in some Nordic countries during the past few decades. However, ecological data of tick populations in Finland are sparse. In the current study, I. ricinus abundance, seasonal questing activity, and their Borrelia spp. and tick-borne encephalitis virus (TBEV) prevalence were evaluated in a Lyme borreliosis endemic area in Southwest Finland, Seili Island, where a previous study mapping tick densities was conducted 12 years earlier. A total of 1940 ticks were collected from five different biotopes by cloth dragging during May-September 2012. The overall tick density observed was 5.2 ticks/100m(2) for nymphs and adults. Seasonal questing activity of ticks differed between biotopes and life stages: bimodal occurrences were observed especially for nymphal and adult ticks in forested biotopes, while larvae in pastures exhibited mostly unimodal occurrence. Prevalence of Borrelia and TBEV in ticks was evaluated using conventional and real-time PCR. All samples were negative for TBEV. Borrelia prevalence was 25.0% for adults (n=44) and the minimum infection rate (MIR) 5.6% for pooled nymph samples (191 samples, 1-14 individuals per sample; 30/191 positive). No Borrelia were detected in pooled larval samples (63 samples, 1-139 individuals per sample). Five species of Borrelia were identified from the samples: B. afzelii, B. burgdorferi s.s., B. garinii, B. valaisiana and B. miyamotoi. In Finland, B. valaisiana and B. miyamotoi have previously been reported from the Åland Islands but not from the mainland or inner archipelago. The results of the present study suggest an increase in I. ricinus abundance on the island. Copyright © 2015 Elsevier GmbH. All rights reserved.

  18. Ticks and tick-borne diseases: a One Health perspective.

    PubMed

    Dantas-Torres, Filipe; Chomel, Bruno B; Otranto, Domenico

    2012-10-01

    Tick-borne diseases are common occurrences in both the medical and veterinary clinical settings. In addition to the constraints related to their diagnosis and clinical management, the control and prevention of these diseases is often difficult, because it requires the disruption of a complex transmission chain, involving vertebrate hosts and ticks, which interact in a constantly changing environment. We provide a contemporary review of representative tick-borne diseases of humans and discuss aspects linked to their medical relevance worldwide. Finally, we emphasize the importance of a One Health approach to tick-borne diseases, calling physicians and veterinarians to unify their efforts in the management of these diseases, several of which are zoonoses. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Transmission of tick-borne pathogens between co-feeding ticks: Milan Labuda's enduring paradigm.

    PubMed

    Randolph, Sarah E

    2011-12-01

    During the 1990s, Milan Labuda's experimental results established a new paradigm for the study of tick-borne viruses that has since been strengthened by its demonstrated effectiveness in explaining the epidemiology of tick-borne encephalitis (TBE). This brief review summarizes the essential features of the transmission of tick-borne pathogens such as TBE virus. Leukocytes migrate between tick feeding sites, bearing infective virions and providing a transport route for the virus between co-feeding ticks independent of a systemic viraemia. Such tick-borne pathogens are thus transmitted from tick to tick via vertebrates; the ticks are the reservoirs as well as the vectors, while the vertebrate is the transient bridge. The aim is to bring the related but non-synonymous terms (co-feeding and non-systemic) to the attention of workers who use simple PCR screening to identify additional vertebrate reservoir hosts of vector-borne pathogens that are not in fact maintained in nature through systemic transmission. Copyright © 2011 Elsevier GmbH. All rights reserved.

  20. Borrelia Diversity and Co-infection with Other Tick Borne Pathogens in Ticks.

    PubMed

    Raileanu, Cristian; Moutailler, Sara; Pavel, Ionuţ; Porea, Daniela; Mihalca, Andrei D; Savuta, Gheorghe; Vayssier-Taussat, Muriel

    2017-01-01

    Identifying Borrelia burgdorferi as the causative agent of Lyme disease in 1981 was a watershed moment in understanding the major impact that tick-borne zoonoses can have on public health worldwide, particularly in Europe and the USA. The medical importance of tick-borne diseases has long since been acknowledged, yet little is known regarding the occurrence of emerging tick-borne pathogens such as Borrelia spp., Anaplasma phagocytophilum, Rickettsia spp., Bartonella spp., " Candidatus Neoehrlichia mikurensis", and tick-borne encephalitis virus in questing ticks in Romania, a gateway into Europe. The objective of our study was to identify the infection and co-infection rates of different Borrelia genospecies along with other tick-borne pathogens in questing ticks collected from three geographically distinct areas in eastern Romania. We collected 557 questing adult and nymph ticks of three different species (534 Ixodes ricinus , 19 Haemaphysalis punctata , and 4 Dermacentor reticulatus ) from three areas in Romania. We analyzed ticks individually for the presence of eight different Borrelia genospecies with high-throughput real-time PCR. Ticks with Borrelia were then tested for possible co-infections with A. phagocytophilum, Rickettsia spp., Bartonella spp., " Candidatus Neoehrlichia mikurensis", and tick-borne encephalitis virus. Borrelia spp. was detected in I. ricinus ticks from all sampling areas, with global prevalence rates of 25.8%. All eight Borrelia genospecies were detected in I. ricinus ticks: Borrelia garinii (14.8%), B. afzelii (8.8%), B. valaisiana (5.1%), B. lusitaniae (4.9%), B. miyamotoi (0.9%), B. burgdorferi s.s (0.4%), and B. bissettii (0.2%). Regarding pathogen co-infection 64.5% of infected I. ricinus were positive for more than one pathogen. Associations between different Borrelia genospecies were detected in 9.7% of ticks, and 6.9% of I. ricinus ticks tested positive for co-infection of Borrelia spp. with other tick-borne pathogens. The most

  1. Borrelia Diversity and Co-infection with Other Tick Borne Pathogens in Ticks

    PubMed Central

    Raileanu, Cristian; Moutailler, Sara; Pavel, Ionuţ; Porea, Daniela; Mihalca, Andrei D.; Savuta, Gheorghe; Vayssier-Taussat, Muriel

    2017-01-01

    Identifying Borrelia burgdorferi as the causative agent of Lyme disease in 1981 was a watershed moment in understanding the major impact that tick-borne zoonoses can have on public health worldwide, particularly in Europe and the USA. The medical importance of tick-borne diseases has long since been acknowledged, yet little is known regarding the occurrence of emerging tick-borne pathogens such as Borrelia spp., Anaplasma phagocytophilum, Rickettsia spp., Bartonella spp., “Candidatus Neoehrlichia mikurensis”, and tick-borne encephalitis virus in questing ticks in Romania, a gateway into Europe. The objective of our study was to identify the infection and co-infection rates of different Borrelia genospecies along with other tick-borne pathogens in questing ticks collected from three geographically distinct areas in eastern Romania. We collected 557 questing adult and nymph ticks of three different species (534 Ixodes ricinus, 19 Haemaphysalis punctata, and 4 Dermacentor reticulatus) from three areas in Romania. We analyzed ticks individually for the presence of eight different Borrelia genospecies with high-throughput real-time PCR. Ticks with Borrelia were then tested for possible co-infections with A. phagocytophilum, Rickettsia spp., Bartonella spp., “Candidatus Neoehrlichia mikurensis”, and tick-borne encephalitis virus. Borrelia spp. was detected in I. ricinus ticks from all sampling areas, with global prevalence rates of 25.8%. All eight Borrelia genospecies were detected in I. ricinus ticks: Borrelia garinii (14.8%), B. afzelii (8.8%), B. valaisiana (5.1%), B. lusitaniae (4.9%), B. miyamotoi (0.9%), B. burgdorferi s.s (0.4%), and B. bissettii (0.2%). Regarding pathogen co-infection 64.5% of infected I. ricinus were positive for more than one pathogen. Associations between different Borrelia genospecies were detected in 9.7% of ticks, and 6.9% of I. ricinus ticks tested positive for co-infection of Borrelia spp. with other tick-borne pathogens. The

  2. Distribution of Ixodes ricinus ticks and prevalence of tick-borne encephalitis virus among questing ticks in the Arctic Circle region of northern Norway.

    PubMed

    Soleng, A; Edgar, K S; Paulsen, K M; Pedersen, B N; Okbaldet, Y B; Skjetne, I E B; Gurung, D; Vikse, R; Andreassen, Å K

    2018-01-01

    This study investigated the geographical distribution of Ixodes ricinus and prevalence of the tick-borne encephalitis virus (TBEV) in northern Norway. Flagging for questing I. ricinus ticks was performed in areas ranging from Vikna in Nord-Trøndelag County, located 190km south of the Arctic Circle (66.3°N), to Steigen in Nordland County, located 155km north of the Arctic Circle. We found that ticks were abundant in both Vikna (64.5°N) and Brønnøy (65.1°N). Only a few ticks were found at locations ∼66°N, and no ticks were found at several locations up to 67.5°N. Real-time PCR (RT-PCR) analyses of the collected ticks (nymphs and adults) for the presence of TBEV revealed a low prevalence (0.1%) of TBEV among the nymphs collected in Vikna, while a prevalence of 0% to 3% was found among nymphs collected at five locations in Brønnøy. Adult ticks collected in Vikna and Brønnøy had higher rates of TBEV infection (8.6% and 0%-9.0%, respectively) than the nymphs. No evidence of TBEV was found in the few ticks collected further north of Brønnøy. This is the first report of TBEV being detected at locations up to 65.1°N. It remains to be verified whether viable populations of I. ricinus exist at locations north of 66°N. Future studies are warranted to increase our knowledge concerning tick distribution, tick abundance, and tick-borne pathogens in northern Norway. Copyright © 2017 Elsevier GmbH. All rights reserved.

  3. Knowledge, attitudes, and practices regarding ticks and tick-borne diseases, Finland.

    PubMed

    Zöldi, Viktor; Turunen, Topi; Lyytikäinen, Outi; Sane, Jussi

    2017-10-01

    Tick-borne encephalitis (TBE) and Lyme borreliosis (LB) are endemic in Finland, with tens and thousands of cases, respectively, reported annually. We performed a field survey to investigate people's knowledge, attitudes and practices (KAP) regarding ticks, tick-borne diseases, and prevention strategies. The KAP were assessed using a pre-validated anonymous questionnaire consisting of 39 questions and statements. On two consecutive days in July 2016, convenience sampling was used in the cities of Parainen and Kotka, located in high-risk areas of tick-borne diseases, particularly of TBE. In attitudes and practices sections, each question was scored and analysed with ordered logistic regression model. In total, 101 individuals responded. The TBE vaccination rate among respondents was 40%. The best known preventive measures were having vaccination against TBE (88%), and wearing long sleeves and pants against ticks (81%). Two-thirds incorrectly identified the ring-like rash as a symptom of TBE. Of all respondents, 78% could not exclude that TBE can be treated with antibiotics; 55% that vaccine protects against LB; and 46% that it protects against ticks. The minority (14%) believed tick repellents to be effective. Among preventive behaviour, the quick removal of an attached tick was most frequently applied (97%). Repellents were used by 21% when visiting tick-infested areas. Significant associations were found between the vaccination status and having a correct belief that the vaccine protects against TBE (P<0.001) but not against ticks (P<0.05), or LB (P<0.001). KAP is a quick and easy tool to get a rough estimation on people's awareness regarding ticks and tick-borne diseases. We identified gaps in knowledge and misbeliefs. Our results can be used in public health communication tools on tick-borne diseases, especially those on intervention strategies. Copyright © 2017 Elsevier GmbH. All rights reserved.

  4. Molecular Detection and Characterization of Tick-borne Pathogens in Dogs and Ticks from Nigeria

    PubMed Central

    Kamani, Joshua; Baneth, Gad; Mumcuoglu, Kosta Y.; Waziri, Ndadilnasiya E.; Eyal, Osnat; Guthmann, Yifat; Harrus, Shimon

    2013-01-01

    Background Only limited information is currently available on the prevalence of vector borne and zoonotic pathogens in dogs and ticks in Nigeria. The aim of this study was to use molecular techniques to detect and characterize vector borne pathogens in dogs and ticks from Nigeria. Methodology/Principal Findings Blood samples and ticks (Rhipicephalus sanguineus, Rhipicephalus turanicus and Heamaphysalis leachi) collected from 181 dogs from Nigeria were molecularly screened for human and animal vector-borne pathogens by PCR and sequencing. DNA of Hepatozoon canis (41.4%), Ehrlichia canis (12.7%), Rickettsia spp. (8.8%), Babesia rossi (6.6%), Anaplasma platys (6.6%), Babesia vogeli (0.6%) and Theileria sp. (0.6%) was detected in the blood samples. DNA of E. canis (23.7%), H. canis (21.1%), Rickettsia spp. (10.5%), Candidatus Neoehrlichia mikurensis (5.3%) and A. platys (1.9%) was detected in 258 ticks collected from 42 of the 181 dogs. Co- infections with two pathogens were present in 37% of the dogs examined and one dog was co-infected with 3 pathogens. DNA of Rickettsia conorii israelensis was detected in one dog and Rhipicephalus sanguineus tick. DNA of another human pathogen, Candidatus N. mikurensis was detected in Rhipicephalus sanguineus and Heamaphysalis leachi ticks, and is the first description of Candidatus N. mikurensis in Africa. The Theileria sp. DNA detected in a local dog in this study had 98% sequence identity to Theileria ovis from sheep. Conclusions/Significance The results of this study indicate that human and animal pathogens are abundant in dogs and their ticks in Nigeria and portray the potential high risk of human exposure to infection with these agents. PMID:23505591

  5. The occurrence of Ixodes ricinus ticks and important tick-borne pathogens in areas with high tick-borne encephalitis prevalence in different altitudinal levels of the Czech Republic Part I. Ixodes ricinus ticks and tick-borne encephalitis virus.

    PubMed

    Daniel, M; Danielová, V; Kříž, B; Růžek, D; Fialová, A; Malý, M; Materna, J; Pejčoch, M; Erhart, J

    The aim of the three-year study (2011-2013) was to monitor population density of Ixodes ricinus ticks and its infection rate with the tick-borne encephalitis virus in areas with a high incidence of tick-borne encephalitis as reported in the previous decade 2001-2010. Such a comprehensive and long-term study based on existing epidemiolo-gical findings has not previously been conducted in Europe. In the areas of the Ústí nad Labem Region, Olomouc Region, South Bohemian Region, and Highlands Region, 600 m2 plots were selected in the local optimal I. ricinus habitats where tick flagging was performed every year in the spring-summer and autumn seasons of the questing activity. In total, 18,721 I. ricinus ticks (1448 females, 1425 males, and 15,848 nymphs) were collected and investigated. The results have shown that the differences in the infection rate of I. ricinus observed between regions are driven by variation in the density of the local I. ricinus populations which is influenced by the characteris-tics of the whole local biocenosis. The overall prevalence estimate of TBE virus in Ixodes ricinus ticks at the altitudes below 600 m a.s.l. was 0.096 % (95% CI 0.055-0.156) for nymphs, and 0.477 % (95% CI 0.272-0.773) for adults. The dynamics of the seasonal variation in I. ricinus populations, depending primarily on the climatic factors, are behind the interyear differences in the infection rate of ticks and, consequently, in the epidemiological situation of tick-borne encephalitis. The nymph to adult ratio was 5.5 on average but showed great interregional variability (from 10.3 in the Ústí nad Labem Region to 1.8 in the Highlands Region). It might be used in the future as one of the indicators of the composition of the local I. ricinus population and of the level of the circulation of tick-borne pathogens in zoonotic sphere and also for use in the health risk assessment in a given area. Despite the permanent expansion of ticks and tick-borne pathogens in higher

  6. Tick-borne infections in human and animal population worldwide

    PubMed Central

    Brites-Neto, José; Duarte, Keila Maria Roncato; Martins, Thiago Fernandes

    2015-01-01

    The abundance and activity of ectoparasites and its hosts are affected by various abiotic factors, such as climate and other organisms (predators, pathogens and competitors) presenting thus multiples forms of association (obligate to facultative, permanent to intermittent and superficial to subcutaneous) developed during long co-evolving processes. Ticks are ectoparasites widespread globally and its eco epidemiology are closely related to the environmental conditions. They are obligatory hematophagous ectoparasites and responsible as vectors or reservoirs at the transmission of pathogenic fungi, protozoa, viruses, rickettsia and others bacteria during their feeding process on the hosts. Ticks constitute the second vector group that transmit the major number of pathogens to humans and play a role primary for animals in the process of diseases transmission. Many studies on bioecology of ticks, considering the information related to their population dynamics, to the host and the environment, comes possible the application and efficiency of tick control measures in the prevention programs of vector-borne diseases. In this review were considered some taxonomic, morphological, epidemiological and clinical fundamental aspects related to the tick-borne infections that affect human and animal populations. PMID:27047089

  7. Advancing integrated tick management to mitigate burden of tick-borne diseases

    USDA-ARS?s Scientific Manuscript database

    More than half of the world’s population is at risk of exposure to vector-borne pathogens. Annually, more than 1 billion people are infected and more than 1 million die from vector-borne diseases, including those caused by pathogens transmitted by ticks. The problem with tick borne diseases (TBD) is...

  8. Immunological control of ticks and tick-borne diseases that impact cattle health and production.

    PubMed

    Almazan, Consuelo; Tipacamu, Gabriela Aguilar; Rodriguez, Sergio; Mosqueda, Juan; Perez de Leon, Adalberto

    2018-03-01

    The cattle industry is one of the most important agroeconomic activities in Mexico. The national herd is estimated to include approximately 33.5. million head of cattle. Ticks and tick-borne diseases are principal factors with a negative impact on cattle health and production. The most economically important tick species parasitizing cattle in Mexico are Rhipicephalus microplus , R. annulatus , and Amblyomma mixtum . Parasitism by ticks affects cattle health and production directly. Morbidity and mortality caused by tick-borne diseases augment the detrimental effect of tick infestation in cattle. Bovine babesiosis and anaplasmosis are the most important tick-borne diseases of cattle, which are caused by infectious agents transmitted by R. microplus and R. annulatus . However, there are no prophylactic therapies to control bovine babesiosis and anaplasmosis. Chemical control is the most common way to treat animals against ticks, and the use of acaricides can also help manage tick-borne diseases. However, the evolution of resistance to acaricides among cattle tick populations renders chemical control ineffective; which represents a challenge for sustainable ticks and tick-borne diseases control. The only anti-tick vaccine commercially available globally is based on the recombinant antigen Bm86. Because of its mode of immunity against R. microplus and R. annulatus , the Bm86-based vaccine also decreases the exposition of bovines to babesiosis and anaplasmosis. Research with Bm86-based vaccines documented high efficacy against R. annulatus , the efficacy levels against R. microplus varies according to the geographic origin of tick populations, and there is not effect against other ticks species such as Amblyomma spp. The impact of ticks and tick-borne diseases, the problem of chemical control due to acaricide resistance, and progress with anti-tick vaccine research efforts in Mexico are reviewed herein.

  9. Molecular identification of tick-borne pathogens in Nigerian ticks.

    PubMed

    Ogo, Ndudim Isaac; de Mera, Isabel G Fernández; Galindo, Ruth C; Okubanjo, Oluyinka O; Inuwa, Hauwa Mairo; Agbede, Rowland I S; Torina, Alessandra; Alongi, Angelina; Vicente, Joaquín; Gortázar, Christian; de la Fuente, José

    2012-07-06

    A molecular epidemiology investigation was undertaken in two Nigerian states (Plateau and Nassarawa) to determine the prevalence of pathogens of veterinary and public health importance associated with ticks collected from cattle and dogs using PCR, cloning and sequencing or reverse line blot techniques. A total of 218 tick samples, Amblyomma variegatum (N=153), Rhipicephalus (Boophilus) decoloratus (N=45), and Rhipicephalus sanguineus (N=20) were sampled. Pathogens identified in ticks included piroplasmids (Babesia spp., Babesia bigemina and Babesia divergens), Anaplasma marginale and Rickettsia africae. Piroplasmids were identified in A. variegatum, A. marginale was found in R. decoloratus, while R. africae was detected in all tick species examined. Ehrlichia spp. and Theileria spp. were not identified in any of the ticks examined. Of the 218 ticks examined, 33 (15.1%) contained pathogen DNA, with the presence of B. divergens and R. africae that are zoonotic pathogens of public health and veterinary importance. The variety of tick-borne pathogens identified in this study suggests a risk for the emergence of tick-borne diseases in domestic animals and humans, especially amongst the Fulani pastoralists in Plateau and Nassarawa states of Nigeria. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Scale-dependent effects of nonnative plant invasion on host-seeking tick abundance

    PubMed Central

    Adalsteinsson, Solny A.; D’Amico, Vincent; Shriver, W. Gregory; Brisson, Dustin; Buler, Jeffrey J.

    2016-01-01

    Nonnative, invasive shrubs can affect human disease risk through direct and indirect effects on vector populations. Multiflora rose (Rosa multiflora) is a common invader within eastern deciduous forests where tick-borne disease (e.g. Lyme disease) rates are high. We tested whether R. multiflora invasion affects blacklegged tick (Ixodes scapularis) abundance, and at what scale. We sampled host-seeking ticks at two spatial scales: fine-scale, within R. multiflora-invaded forest fragments; and patch scale, among R. multiflora-invaded and R. multiflora-free forest fragments. At a fine scale, we trapped 2.3 times more ticks under R. multiflora compared to paired traps 25 m away from R. multiflora. At the patch scale, we trapped 3.2 times as many ticks in R. multiflora-free forests compared to R. multiflora-invaded forests. Thus, ticks are concentrated beneath R. multiflora within invaded forests, but uninvaded forests support significantly more ticks. Among all covariates tested, leaf litter volume was the best predictor of tick abundance; at the patch scale, R. multiflora-invaded forests had less leaf litter than uninvaded forests. We suggest that leaf litter availability at the patch-scale plays a greater role in constraining tick abundance than the fine-scale, positive effect of invasive shrubs. PMID:27088044

  11. A Stochastic Tick-Borne Disease Model: Exploring the Probability of Pathogen Persistence.

    PubMed

    Maliyoni, Milliward; Chirove, Faraimunashe; Gaff, Holly D; Govinder, Keshlan S

    2017-09-01

    We formulate and analyse a stochastic epidemic model for the transmission dynamics of a tick-borne disease in a single population using a continuous-time Markov chain approach. The stochastic model is based on an existing deterministic metapopulation tick-borne disease model. We compare the disease dynamics of the deterministic and stochastic models in order to determine the effect of randomness in tick-borne disease dynamics. The probability of disease extinction and that of a major outbreak are computed and approximated using the multitype Galton-Watson branching process and numerical simulations, respectively. Analytical and numerical results show some significant differences in model predictions between the stochastic and deterministic models. In particular, we find that a disease outbreak is more likely if the disease is introduced by infected deer as opposed to infected ticks. These insights demonstrate the importance of host movement in the expansion of tick-borne diseases into new geographic areas.

  12. Ticks and tick-borne pathogens in wild birds in Greece.

    PubMed

    Diakou, Anastasia; Norte, Ana Cláudia; Lopes de Carvalho, Isabel; Núncio, Sofia; Nováková, Markéta; Kautman, Matej; Alivizatos, Haralambos; Kazantzidis, Savas; Sychra, Oldřich; Literák, Ivan

    2016-05-01

    Wild birds are common hosts of ticks and can transport them for long distances, contributing to the spreading of tick-borne pathogens. The information about ticks on birds and tick-borne pathogens in Greece is limited. The present study aimed to evaluate the prevalence and species of ticks infesting wild resident birds (mostly small passerines) in Greece, and to assess Borrelia and Rickettsia infection in the collected ticks. Detection of Borrelia burgdorferi s.l. was performed by nested PCR targeting the flaB gene. Rickettsia spp. were detected by PCR targeting the gltA and ompA genes. Seven (2 %) out of 403 birds examined in northern Greece in 2013 were infested with 15 ticks, identified as Ixodes frontalis, Ixodes acuminatus, Hyalomma marginatum, Hyalomma aegyptium and Hyalomma sp. All ticks were negative for Borrelia spp. while four of them were positive for rickettsiae (Rickettsia aeschlimannii in H. aegyptium and Rickettsia sp. in I. frontalis, H. aegyptium and H. marginatum). Ixodes acuminatus is reported for the first time in Greece and Sylvia borin is reported as a new host record for I. acuminatus.

  13. Molecular detection of zoonotic tick-borne pathogens from ticks collected from ruminants in four South African provinces.

    PubMed

    Mtshali, Khethiwe; Khumalo, Zth; Nakao, Ryo; Grab, Dennis J; Sugimoto, Chihiro; Thekisoe, Omm

    2016-01-01

    Ticks carry and transmit a remarkable array of pathogens including bacteria, protozoa and viruses, which may be of veterinary and/or of medical significance. With little to no information regarding the presence of tick-borne zoonotic pathogens or their known vectors in southern Africa, the aim of our study was to screen for Anaplasma phagocytophilum, Borrelia burgdorferi, Coxiella burnetii, Rickettsia species and Ehrlichia ruminantium in ticks collected and identified from ruminants in the Eastern Cape, Free State, KwaZulu-Natal and Mpumalanga Provinces of South Africa. The most abundant tick species identified in this study were Rhipicephalus evertsi evertsi (40%), Rhipicephalus species (35%), Amblyomma hebraeum (10%) and Rhipicephalus decoloratus (14%). A total of 1634 ticks were collected. DNA was extracted, and samples were subjected to PCR amplification and sequencing. The overall infection rates of ticks with the target pathogens in the four Provinces were as follows: A. phagocytophilum, 7%; C. burnetii, 7%; E. ruminantium, 28%; and Rickettsia spp., 27%. The presence of B. burgdorferi could not be confirmed. The findings of this study show that zoonotic pathogens are present in ticks in the studied South African provinces. This information will aid in the epidemiology of tick-borne zoonotic diseases in the country as well as in raising awareness about such diseases in the veterinary, medical and tourism sectors, as they may be the most affected.

  14. Tick-Borne Viruses.

    PubMed

    Shi, Junming; Hu, Zhihong; Deng, Fei; Shen, Shu

    2018-02-01

    Ticks are important vectors for the transmission of pathogens including viruses. The viruses carried by ticks also known as tick-borne viruses (TBVs), contain a large group of viruses with diverse genetic properties and are concluded in two orders, nine families, and at least 12 genera. Some members of the TBVs are notorious agents causing severe diseases with high mortality rates in humans and livestock, while some others may pose risks to public health that are still unclear to us. Herein, we review the current knowledge of TBVs with emphases on the history of virus isolation and identification, tick vectors, and potential pathogenicity to humans and animals, including assigned species as well as the recently discovered and unassigned species. All these will promote our understanding of the diversity of TBVs, and will facilitate the further investigation of TBVs in association with both ticks and vertebrate hosts.

  15. Novel Rickettsia and emergent tick-borne pathogens: A molecular survey of ticks and tick-borne pathogens in Shimba Hills National Reserve, Kenya.

    PubMed

    Mwamuye, Micky M; Kariuki, Edward; Omondi, David; Kabii, James; Odongo, David; Masiga, Daniel; Villinger, Jandouwe

    2017-02-01

    Ticks are important vectors of emerging and re-emerging zoonoses, the majority of which originate from wildlife. In recent times, this has become a global public health concern that necessitates surveillance of both known and unknown tick-borne pathogens likely to be future disease threats, as well as their tick vectors. We carried out a survey of the diversity of ticks and tick-borne pathogens in Kenya's Shimba Hills National Reserve (SHNR), an area with intensified human-livestock-wildlife interactions, where we collected 4297 questing ticks (209 adult ticks, 586 nymphs and 3502 larvae). We identified four tick species of two genera (Amblyomma eburneum, Amblyomma tholloni, Rhipicephalus maculatus and a novel Rhipicephalus sp.) based on both morphological characteristics and molecular analysis of 16S rRNA, internal transcribed spacer 2 (ITS 2) and cytochrome oxidase subunit 1 (CO1) genes. We pooled the ticks (3-8 adults, 8-15 nymphs or 30 larvae) depending on species and life-cycle stages, and screened for bacterial, arboviral and protozoal pathogens using PCR with high-resolution melting analysis and sequencing of unique melt profiles. We report the first molecular detection of Anaplasma phagocytophilum, a novel Rickettsia-like and Ehrlichia-like species, in Rh. maculatus ticks. We also detected Ehrlichia chaffeensis, Coxiella sp., Rickettsia africae and Theileria velifera in Am. eburneum ticks for the first time. Our findings demonstrate previously unidentified tick-pathogen relationships and a unique tick diversity in the SHNR that may contribute to livestock, and possibly human, morbidity in the region. This study highlights the importance of routine surveillance in similar areas to elucidate disease transmission dynamics, as a critical component to inform the development of better tick-borne disease diagnosis, prevention and control measures. Copyright © 2016 Elsevier GmbH. All rights reserved.

  16. Climate change and Ixodes tick-borne diseases of humans

    PubMed Central

    Ostfeld, Richard S.; Brunner, Jesse L.

    2015-01-01

    The evidence that climate warming is changing the distribution of Ixodes ticks and the pathogens they transmit is reviewed and evaluated. The primary approaches are either phenomenological, which typically assume that climate alone limits current and future distributions, or mechanistic, asking which tick-demographic parameters are affected by specific abiotic conditions. Both approaches have promise but are severely limited when applied separately. For instance, phenomenological approaches (e.g. climate envelope models) often select abiotic variables arbitrarily and produce results that can be hard to interpret biologically. On the other hand, although laboratory studies demonstrate strict temperature and humidity thresholds for tick survival, these limits rarely apply to field situations. Similarly, no studies address the influence of abiotic conditions on more than a few life stages, transitions or demographic processes, preventing comprehensive assessments. Nevertheless, despite their divergent approaches, both mechanistic and phenomenological models suggest dramatic range expansions of Ixodes ticks and tick-borne disease as the climate warms. The predicted distributions, however, vary strongly with the models' assumptions, which are rarely tested against reasonable alternatives. These inconsistencies, limited data about key tick-demographic and climatic processes and only limited incorporation of non-climatic processes have weakened the application of this rich area of research to public health policy or actions. We urge further investigation of the influence of climate on vertebrate hosts and tick-borne pathogen dynamics. In addition, testing model assumptions and mechanisms in a range of natural contexts and comparing their relative importance as competing models in a rigorous statistical framework will significantly advance our understanding of how climate change will alter the distribution, dynamics and risk of tick-borne disease. PMID:25688022

  17. Host specialization in ticks and transmission of tick-borne diseases: a review

    PubMed Central

    McCoy, Karen D.; Léger, Elsa; Dietrich, Muriel

    2013-01-01

    Determining patterns of host use, and the frequency at which these patterns change, are of key importance if we are to understand tick population dynamics, the evolution of tick biodiversity, and the circulation and evolution of associated pathogens. The question of whether ticks are typically host specialists or host generalists has been subject to much debate over the last half-century. Indeed, early research proposed that morphological diversity in ticks was linked to host specific adaptations and that most ticks were specialists. Later work disputed this idea and suggested that ticks are largely limited by biogeographic conditions and tend to use all locally available host species. The work presented in this review suggests that the actual answer likely lies somewhere between these two extremes. Although recent observational studies support the view that phylogenetically diverse host species share ticks when found on similar ecological ranges, theory on host range evolution predicts that host specialization should evolve in ticks given their life history characteristics. Contemporary work employing population genetic tools to examine host-associated population structure in several tick systems support this prediction and show that simple species records are not enough to determine whether a parasite is a true host generalist; host specialization does evolve in ticks at local scales, but may not always lead to speciation. Ticks therefore seem to follow a pattern of being global generalists, local specialists. Given this, the notion of host range needs to be modified from an evolutionary perspective, where one simply counts the number of hosts used across the geographic distribution, to a more ecological view, where one considers host use at a local scale, if we are to better understand the circulation of tick-borne pathogens and exposure risks for humans and livestock. PMID:24109592

  18. Host specialization in ticks and transmission of tick-borne diseases: a review.

    PubMed

    McCoy, Karen D; Léger, Elsa; Dietrich, Muriel

    2013-01-01

    Determining patterns of host use, and the frequency at which these patterns change, are of key importance if we are to understand tick population dynamics, the evolution of tick biodiversity, and the circulation and evolution of associated pathogens. The question of whether ticks are typically host specialists or host generalists has been subject to much debate over the last half-century. Indeed, early research proposed that morphological diversity in ticks was linked to host specific adaptations and that most ticks were specialists. Later work disputed this idea and suggested that ticks are largely limited by biogeographic conditions and tend to use all locally available host species. The work presented in this review suggests that the actual answer likely lies somewhere between these two extremes. Although recent observational studies support the view that phylogenetically diverse host species share ticks when found on similar ecological ranges, theory on host range evolution predicts that host specialization should evolve in ticks given their life history characteristics. Contemporary work employing population genetic tools to examine host-associated population structure in several tick systems support this prediction and show that simple species records are not enough to determine whether a parasite is a true host generalist; host specialization does evolve in ticks at local scales, but may not always lead to speciation. Ticks therefore seem to follow a pattern of being global generalists, local specialists. Given this, the notion of host range needs to be modified from an evolutionary perspective, where one simply counts the number of hosts used across the geographic distribution, to a more ecological view, where one considers host use at a local scale, if we are to better understand the circulation of tick-borne pathogens and exposure risks for humans and livestock.

  19. Epidemiological survey of ticks and tick-borne pathogens in pet dogs in south-eastern China.

    PubMed

    Zhang, Jianwei; Liu, Qingbiao; Wang, Demou; Li, Wanmeng; Beugnet, Frédéric; Zhou, Jinlin

    2017-01-01

    To understand the epidemiology of tick infestation and tick-borne diseases in pet dogs in south-eastern China and to develop a reference for their prevention and treatment, we collected 1550 ticks parasitizing 562 dogs in 122 veterinary clinics from 20 cities of south-eastern China. Dogs were tested for common tick-borne pathogens; collected ticks were identified and processed for the detection of tick-borne pathogens. The use of an in vitro ELISA diagnostic kit for antibody detection (SNAP®4Dx® Plus) on dog sera found the infection rates with Borrelia burgdorferi sensu lato, Ehrlichia canis, and Anaplasma spp. to be 0.4%, 1.3% and 2.7%, respectively. By using a specific ELISA method, the infection rate with Babesia gibsoni was 3.9%. Rhipicephalus sanguineus sensu lato, Haemaphysalis longicornis and Rhipicephalus haemaphysaloides were the major tick species identified on pet dogs. PCR tests were conducted to detect five tick-borne pathogens in 617 ticks. The infection rate was 10.2% for E. canis, 3.4% for Anaplasma platys, 2.3% for B. gibsoni, 0.3% for B. burgdorferi s.l. and 0% for Babesia canis. Some ticks were co-infected with two (1.46%) or three pathogens (0.16%). These results indicate the infestation of pet dogs by ticks infected with tick-borne pathogens in south-eastern China, and the need for effective treatment and routine prevention of tick infestations in dogs. © J. Zhang et al., published by EDP Sciences, 2017.

  20. Habitat and Vegetation Variables Are Not Enough When Predicting Tick Populations in the Southeastern United States

    PubMed Central

    Trout Fryxell, R. T.; Moore, J. E.; Collins, M. D.; Kwon, Y.; Jean-Philippe, S. R.; Schaeffer, S. M.; Odoi, A.; Kennedy, M.; Houston, A. E.

    2015-01-01

    Two tick-borne diseases with expanding case and vector distributions are ehrlichiosis (transmitted by Amblyomma americanum) and rickettiosis (transmitted by A. maculatum and Dermacentor variabilis). There is a critical need to identify the specific habitats where each of these species is likely to be encountered to classify and pinpoint risk areas. Consequently, an in-depth tick prevalence study was conducted on the dominant ticks in the southeast. Vegetation, soil, and remote sensing data were used to test the hypothesis that habitat and vegetation variables can predict tick abundances. No variables were significant predictors of A. americanum adult and nymph tick abundance, and no clustering was evident because this species was found throughout the study area. For A. maculatum adult tick abundance was predicted by NDVI and by the interaction between habitat type and plant diversity; two significant population clusters were identified in a heterogeneous area suitable for quail habitat. For D. variabilis no environmental variables were significant predictors of adult abundance; however, D. variabilis collections clustered in three significant areas best described as agriculture areas with defined edges. This study identified few landscape and vegetation variables associated with tick presence. While some variables were significantly associated with tick populations, the amount of explained variation was not useful for predicting reliably where ticks occur; consequently, additional research that includes multiple sampling seasons and locations throughout the southeast are warranted. This low amount of explained variation may also be due to the use of hosts for dispersal, and potentially to other abiotic and biotic variables. Host species play a large role in the establishment, maintenance, and dispersal of a tick species, as well as the maintenance of disease cycles, dispersal to new areas, and identification of risk areas. PMID:26656122

  1. Tick-borne Diseases in Animals and USDA Research on Tick Control

    USDA-ARS?s Scientific Manuscript database

    Tick-borne diseases represent a major threat to animal health in the United States. The cattle industry in the United States has benefited greatly from the continued USDA efforts through the Cattle Fever Tick Eradication Program in preventing the re-introduction of cattle ticks and associated pathog...

  2. Genetic recombination of tick-borne flaviviruses among wild-type strains.

    PubMed

    Norberg, Peter; Roth, Anette; Bergström, Tomas

    2013-06-05

    Genetic recombination has been suggested to occur in mosquito-borne flaviviruses. In contrast, tick-borne flaviviruses have been thought to evolve in a clonal manner, although recent studies suggest that recombination occurs also for these viruses. We re-analyzed the data and found that previous conclusions on wild type recombination were probably falsely drawn due to misalignments of nucleotide sequences, ambiguities in GenBank sequences, or different laboratory culture histories suggestive of recombination events in laboratory. To evaluate if reliable predictions of wild type recombination of tick-borne flaviviruses can be made, we analyzed viral strains sequenced exclusively for this study, and other flavivirus sequences retrieved from GenBank. We detected genetic signals supporting recombination between viruses within the three clades of TBEV-Eu, TBEV-Sib and TBEV-Fe, respectively. Our results suggest that the tick-borne encephalitis viruses may undergo recombination under natural conditions, but that geographic barriers restrict most recombination events to involve only closely genetically related viruses. Copyright © 2013 Elsevier Inc. All rights reserved.

  3. Molecular Detection of Tick-Borne Pathogens in Humans with Tick Bites and Erythema Migrans, in the Netherlands

    PubMed Central

    Jahfari, Setareh; Hofhuis, Agnetha; Fonville, Manoj; van der Giessen, Joke; van Pelt, Wilfrid; Sprong, Hein

    2016-01-01

    Background Tick-borne diseases are the most prevalent vector-borne diseases in Europe. Knowledge on the incidence and clinical presentation of other tick-borne diseases than Lyme borreliosis and tick-borne encephalitis is minimal, despite the high human exposure to these pathogens through tick bites. Using molecular detection techniques, the frequency of tick-borne infections after exposure through tick bites was estimated. Methods Ticks, blood samples and questionnaires on health status were collected from patients that visited their general practitioner with a tick bite or erythema migrans in 2007 and 2008. The presence of several tick-borne pathogens in 314 ticks and 626 blood samples of this cohort were analyzed using PCR-based methods. Using multivariate logistic regression, associations were explored between pathogens detected in blood and self-reported symptoms at enrolment and during a three-month follow-up period. Results Half of the ticks removed from humans tested positive for Borrelia burgdorferi sensu lato, Anaplasma phagocytophilum, Candidatus Neoehrlichia mikurensis, Rickettsia helvetica, Rickettsia monacensis, Borrelia miyamotoi and several Babesia species. Among 92 Borrelia burgdorferi s. l. positive ticks, 33% carried another pathogen from a different genus. In blood of sixteen out of 626 persons with tick bites or erythema migrans, DNA was detected from Candidatus Neoehrlichia mikurensis (n = 7), Anaplasma phagocytophilum (n = 5), Babesia divergens (n = 3), Borrelia miyamotoi (n = 1) and Borrelia burgdorferi s. l. (n = 1). None of these sixteen individuals reported any overt symptoms that would indicate a corresponding illness during the three-month follow-up period. No associations were found between the presence of pathogen DNA in blood and; self-reported symptoms, with pathogen DNA in the corresponding ticks (n = 8), reported tick attachment duration, tick engorgement, or antibiotic treatment at enrolment. Conclusions Based on molecular

  4. Molecular survey of hard ticks in endemic areas of tick-borne diseases in China.

    PubMed

    Lu, Xin; Lin, Xian-Dan; Wang, Jian-Bo; Qin, Xin-Cheng; Tian, Jun-Hua; Guo, Wen-Ping; Fan, Fei-Neng; Shao, Renfu; Xu, Jianguo; Zhang, Yong-Zhen

    2013-06-01

    Over the past several years, there was a substantial increase in the number of cases of known and novel tick-borne infections in humans in China. To better understand the ticks associated with these infections, we collected hard ticks from animals or around livestock shelters in 29 localities in 5 provinces (Beijing, Henan, Hubei, Inner Mongolia, and Zhejiang) where cases of tick-borne illness were reported. We collected 2950 hard ticks representing 7 species of 4 genera (Dermacentor sinicus, Haemaphysalis flava, Haemaphysalis longicornis, Ixodes granulatus, Ixodes persulcatus, Rhipicephalus microplus, and Rhipicephalus sanguineus). These ticks were identified to species using morphological characters initially. We then sequenced the mitochondrial small subunit rRNA (12S rRNA) gene, cytochrome oxidase subunit 1 (COI) gene, and the second internal transcribed spacer (ITS2) gene of these ticks, and conducted phylogenetic analyses. Our analyses showed that the molecular and morphological data are consistent in the identification of the 7 tick species. Furthermore, all these 7 tick species from China were genetically closely related to the same species or related species found outside China. Rapid and accurate identification and long-term monitoring of these ticks will be of significance to the prevention and control of tick-borne diseases in China. Copyright © 2013 Elsevier GmbH. All rights reserved.

  5. Complete genomic sequence of Powassan virus: evaluation of genetic elements in tick-borne versus mosquito-borne flaviviruses.

    PubMed

    Mandl, C W; Holzmann, H; Kunz, C; Heinz, F X

    1993-05-01

    The complete nucleotide sequence of the positive-stranded RNA genome of the tick-borne flavivirus Powassan (10,839 nucleotides) was elucidated and the amino acid sequence of all viral proteins was derived. Based on this sequence as well as serological data, Powassan virus represents the most divergent member of the tick-borne serocomplex within the genus flaviviruses, family Flaviviridae. The primary nucleotide sequence and potential RNA secondary structures of the Powassan virus genome as well as the protein sequences and the reactivities of the virion with a panel of monoclonal antibodies were compared to other tick-borne and mosquito-borne flaviviruses. These analyses corroborated significant differences between tick-borne and mosquito-borne flaviviruses, but also emphasized structural elements that are conserved among both vector groups. The comparisons among tick-borne flaviviruses revealed conserved sequence elements that might represent important determinants of the tick-borne flavivirus phenotype.

  6. Tick-borne encephalitis.

    PubMed

    Gritsun, T S; Lashkevich, V A; Gould, E A

    2003-01-01

    Tick-borne encephalitis (TBE) is one of the most dangerous human infections occurring in Europe and many parts of Asia. The etiological agent Tick-borne encephalitis virus (TBEV), is a member of the virus genus Flavivirus, of the family Flaviviridae. TBEV is believed to cause at least 11,000 human cases of encephalitis in Russia and about 3000 cases in the rest of Europe annually. Related viruses within the same group, Louping ill virus (LIV), Langat virus (LGTV) and Powassan virus (POWV), also cause human encephalitis but rarely on an epidemic scale. Three other viruses within the same group, Omsk hemorrhagic fever virus (OHFV), Kyasanur Forest disease virus (KFDV) and Alkhurma virus (ALKV), are closely related to the TBEV complex viruses and tend to cause fatal hemorrhagic fevers rather than encephalitis. This review describes the clinical manifestations associated with TBEV infections, the main molecular-biological properties of these viruses, and the different factors that define the incidence and severity of disease. The role of ticks and their local hosts in the emergence of new virus variants with different pathogenic characteristics is also discussed. This review also contains a brief history of vaccination against TBE including trials with live attenuated vaccine and modern tendencies in developing of vaccine virus strains.

  7. Tick-Pathogen Interactions and Vector Competence: Identification of Molecular Drivers for Tick-Borne Diseases

    PubMed Central

    de la Fuente, José; Antunes, Sandra; Bonnet, Sarah; Cabezas-Cruz, Alejandro; Domingos, Ana G.; Estrada-Peña, Agustín; Johnson, Nicholas; Kocan, Katherine M.; Mansfield, Karen L.; Nijhof, Ard M.; Papa, Anna; Rudenko, Nataliia; Villar, Margarita; Alberdi, Pilar; Torina, Alessandra; Ayllón, Nieves; Vancova, Marie; Golovchenko, Maryna; Grubhoffer, Libor; Caracappa, Santo; Fooks, Anthony R.; Gortazar, Christian; Rego, Ryan O. M.

    2017-01-01

    Ticks and the pathogens they transmit constitute a growing burden for human and animal health worldwide. Vector competence is a component of vectorial capacity and depends on genetic determinants affecting the ability of a vector to transmit a pathogen. These determinants affect traits such as tick-host-pathogen and susceptibility to pathogen infection. Therefore, the elucidation of the mechanisms involved in tick-pathogen interactions that affect vector competence is essential for the identification of molecular drivers for tick-borne diseases. In this review, we provide a comprehensive overview of tick-pathogen molecular interactions for bacteria, viruses, and protozoa affecting human and animal health. Additionally, the impact of tick microbiome on these interactions was considered. Results show that different pathogens evolved similar strategies such as manipulation of the immune response to infect vectors and facilitate multiplication and transmission. Furthermore, some of these strategies may be used by pathogens to infect both tick and mammalian hosts. Identification of interactions that promote tick survival, spread, and pathogen transmission provides the opportunity to disrupt these interactions and lead to a reduction in tick burden and the prevalence of tick-borne diseases. Targeting some of the similar mechanisms used by the pathogens for infection and transmission by ticks may assist in development of preventative strategies against multiple tick-borne diseases. PMID:28439499

  8. Urban Breeding Corvids as Disseminators of Ticks and Emerging Tick-Borne Pathogens.

    PubMed

    Sándor, Attila D; Kalmár, Zsuzsa; Matei, Ioana; Ionică, Angela Monica; Mărcuţan, Ioan-Daniel

    2017-02-01

    Crows (Corvidae) are common city dwellers worldwide and are increasingly important subjects of epidemiology studies. Although their importance as hosts and transmitters of a number of zoonotic parasites and pathogens is well known, there are no studies on their importance as tick hosts. After mosquitoes, ticks are the most important vectors of zoonotic pathogens, especially for those causing emerging zoonotic diseases. Pathogenic bacteria, especially Borrelia spp., Rickettsia spp., and Anaplasma spp., vectored by ticks, are the cause for most vector-borne diseases in Europe. Here we report on ticks and tick-borne pathogens harbored by urban breeding crows. A total of 36 birds (33.33%, n = 108) hosted ticks, with 91 individual ticks belonging to 6 species (Haemaphysalis concinna, Haemaphysalis parva, Haemaphysalis punctata, Hyalomma marginatum, Ixodes arboricola, and Ixodes ricinus). Rickettsia spp. DNA was found in 6.6% of ticks and 1.9% of bird tissues, whereas Anaplasma phagocytophilum was found in 5.9% of ticks and 0.9% of birds. Two rickettsial genospecies were located, Rickettsia helvetica and Rickettsia monacensis. This is the first study to determine such a diverse tick spectrum feeding on urban corvids, while highlighting their importance as tick hosts and raising concerns about their potential risk to human health.

  9. Properties of the tick-borne encephalitis virus population during persistent infection of ixodid ticks and tick cell lines.

    PubMed

    Belova, Oxana A; Litov, Alexander G; Kholodilov, Ivan S; Kozlovskaya, Liubov I; Bell-Sakyi, Lesley; Romanova, Lidiya Iu; Karganova, Galina G

    2017-10-01

    Tick-borne encephalitis virus (TBEV) is the causative agent of tick-borne encephalitis (TBE), a vector-borne zoonotic neuroinfection. For successful circulation in natural foci the virus has to survive in the vector for a long period of time. Information about the effect of long-term infection of ticks on properties of the viral population is of great importance. In recent years, changes in the eco-epidemiology of TBEV due to changes in distribution of ixodid ticks have been observed. These changes in TBEV-endemic areas could result in a shift of the main tick vector species, which in turn may lead to changes in properties of the virus. In the present study we evaluated the selective pressure on the TBEV population during persistent infection of various species of ticks and tick cell lines. TBEV effectively replicated and formed persistent infection in ticks and tick cell lines of the vector species (Ixodes spp.), potential vectors (Dermacentor spp.) and non-vector ticks (Hyalomma spp.). During TBEV persistence in Ixodes and Dermacentor ticks, properties of the viral population remained virtually unchanged. In contrast, persistent TBEV infection of tick cell lines from both vector and non-vector ticks favoured selection of viral variants with low neuroinvasiveness for laboratory mice and substitutions in the E protein that increased local positive charge of the virion. Thus, selective pressure on viral population may differ in ticks and tick cell lines during persistent infection. Nevertheless, virus variants with properties of the original strain adapted to mouse CNS were not eliminated from the viral population during long-term persistence of TBEV in ticks and tick cell lines. Copyright © 2017 Elsevier GmbH. All rights reserved.

  10. Emerging Tick-Borne Viruses in the Twenty-First Century

    PubMed Central

    Mansfield, Karen L.; Jizhou, Lv; Phipps, L. Paul; Johnson, Nicholas

    2017-01-01

    Ticks, as a group, are second only to mosquitoes as vectors of pathogens to humans and are the primary vector for pathogens of livestock, companion animals, and wildlife. The role of ticks in the transmission of viruses has been known for over 100 years and yet new pathogenic viruses are still being detected and known viruses are continually spreading to new geographic locations. Partly as a result of their novelty, tick-virus interactions are at an early stage in understanding. For some viruses, even the principal tick-vector is not known. It is likely that tick-borne viruses will continue to emerge and challenge public and veterinary health long into the twenty-first century. However, studies focusing on tick saliva, a critical component of tick feeding, virus transmission, and a target for control of ticks and tick-borne diseases, point toward solutions to emerging viruses. The aim of this review is to describe some currently emerging tick-borne diseases, their causative viruses, and to discuss research on virus-tick interactions. Through focus on this area, future protein targets for intervention and vaccine development may be identified. PMID:28744449

  11. Capybaras and ticks in the urban areas of Uberlândia, Minas Gerais, Brazil: ecological aspects for the epidemiology of tick-borne diseases.

    PubMed

    Queirogas, V L; Del Claro, K; Nascimento, A R T; Szabó, M P J

    2012-05-01

    In Brazil capybara, the biggest existing rodent species, and associated tick species, Amblyomma cajennense and Amblyomma dubitatum, are undergoing an unplanned host and parasite population expansion in both urban and rural areas. However, scientific information about such issue, particularly in urban areas, is scanty. Such rodent and ticks are associated in some municipalities, particularly in southeastern Brazil, with the transmission of the highly lethal Rickettsia rickettsia caused spotted-fever. In this study ecological aspects related to the establishment and expansion of capybaras and ticks in urban areas of Uberlândia, Minas Gerais State, Brazil were evaluated. For this purpose, capybara and tick abundance in four urban areas and an ecological reserve was determined. Abundance of capybaras varied between areas and over the sampling period and these differences were related to human activities. A positive correlation was found between capybara and tick abundance, however, the tick species had an uneven distribution within the municipality and environmental factors rather than host availability were blamed for such. On the whole these observations show that capybara populations in urban areas are associated to high environmental infestation of ticks and the increased risk of bites and of pathogen transmission to humans. At the same time the uneven distribution of tick species might implicate in an unequal risk of tick-borne diseases within the same urban area.

  12. Tick-borne pathogens in ticks collected from breeding and migratory birds in Switzerland.

    PubMed

    Lommano, Elena; Dvořák, Charles; Vallotton, Laurent; Jenni, Lukas; Gern, Lise

    2014-10-01

    From 2007 to 2010, 4558 migrating and breeding birds of 71 species were caught and examined for ticks in Switzerland. A total of 1205 specimens were collected; all were Ixodes ricinus ticks except one Ixodes frontalis female, which was found on a common chaffinch (Fringilla coelebs) for the first time in Switzerland. Each tick was analysed individually for the presence of Borrelia spp., Rickettsia spp., Anaplasma phagocytophilum and tick-borne encephalitis virus (TBEV). Altogether, 11.4% of birds (22 species) were infested by ticks and 39.8% of them (15 species) were carrying infected ticks. Bird species belonging to the genus Turdus were the most frequently infested with ticks and they were also carrying the most frequently infected ticks. Each tick-borne pathogen for which we tested was identified within the sample of bird-feeding ticks: Borrelia spp. (19.5%) and Rickettsia helvetica (10.5%) were predominantly detected whereas A. phagocytophilum (2%), Rickettsia monacensis (0.4%) and TBEV (0.2%) were only sporadically detected. Among Borrelia infections, B. garinii and B. valaisiana were largely predominant followed by B. afzelii, B. bavariensis, B. miyamotoi and B. burgdorferi ss. Interestingly, Candidatus Neoehrlichia mikurensis was identified in a few ticks (3.3%), mainly from chaffinches. Our study emphasizes the role of birds in the natural cycle of tick-borne pathogens that are of human medical and veterinary relevance in Europe. According to infection detected in larvae feeding on birds we implicate the common blackbird (Turdus merula) and the tree pipit (Anthus trivialis) as reservoir hosts for Borrelia spp., Rickettsia spp. and A. phagocytophilum. Copyright © 2014 Elsevier GmbH. All rights reserved.

  13. Update on Tick-Borne Bacterial Diseases in Travelers.

    PubMed

    Eldin, Carole; Parola, Philippe

    2018-05-22

    Ticks are the second most important vectors of infectious diseases after mosquitoes worldwide. The growth of international tourism including in rural and remote places increasingly exposes travelers to tick bite. Our aim was to review the main tick-borne infectious diseases reported in travelers in the past 5 years. In recent years, tick-borne bacterial diseases have emerged in travelers including spotted fever group (SFG) rickettsioses, borrelioses, and diseases caused by bacteria of the Anaplasmataceae family. African tick-bite fever, due to Rickettsia africae, is the most frequent agent reported in travelers returned from Sub-Saharan areas. Other SFG agents are increasingly reported in travelers, and clinicians should be aware of them. Lyme disease can be misdiagnosed in Southern countries. Organisms causing tick-borne relapsing fever are neglected pathogens worldwide, and reports in travelers have allowed the description of new species. Infections due to Anaplasmataceae bacteria are more rarely described in travelers, but a new species of Neoehrlichia has recently been detected in a traveler. The treatment of these infections relies on doxycycline, and travelers should be informed before the trip about prevention measures against tick bites.

  14. Tick-Borne Transmission of Murine Gammaherpesvirus 68

    PubMed Central

    Hajnická, Valeria; Kúdelová, Marcela; Štibrániová, Iveta; Slovák, Mirko; Bartíková, Pavlína; Halásová, Zuzana; Pančík, Peter; Belvončíková, Petra; Vrbová, Michaela; Holíková, Viera; Hails, Rosemary S.; Nuttall, Patricia A.

    2017-01-01

    Herpesviruses are a large group of DNA viruses infecting mainly vertebrates. Murine gammaherpesvirus 68 (MHV68) is often used as a model in studies of the pathogenesis of clinically important human gammaherpesviruses such as Epstein-Barr virus and Kaposi's sarcoma-associated herpesvirus. This rodent virus appears to be geographically widespread; however, its natural transmission cycle is unknown. Following detection of MHV68 in field-collected ticks, including isolation of the virus from tick salivary glands and ovaries, we investigated whether MHV68 is a tick-borne virus. Uninfected Ixodes ricinus ticks were shown to acquire the virus by feeding on experimentally infected laboratory mice. The virus survived tick molting, and the molted ticks transmitted the virus to uninfected laboratory mice on which they subsequently fed. MHV68 was isolated from the tick salivary glands, consistent with transmission via tick saliva. The virus survived in ticks without loss of infectivity for at least 120 days, and subsequently was transmitted vertically from one tick generation to the next, surviving more than 500 days. Furthermore, the F1 generation (derived from F0 infected females) transmitted MHV68 to uninfected mice on which they fed, with MHV68 M3 gene transcripts detected in blood, lung, and spleen tissue of mice on which F1 nymphs and F1 adults engorged. These experimental data fulfill the transmission criteria that define an arthropod-borne virus (arbovirus), the largest biological group of viruses. Currently, African swine fever virus (ASFV) is the only DNA virus recognized as an arbovirus. Like ASFV, MHV68 showed evidence of pathogenesis in ticks. Previous studies have reported MHV68 in free-living ticks and in mammals commonly infested with I. ricinus, and neutralizing antibodies to MHV68 have been detected in large mammals (e.g., deer) including humans. Further studies are needed to determine if these reports are the result of tick-borne transmission of MHV68 in

  15. Tick infestations and tick-borne diseases in Zimbabwe Rhodesia.

    PubMed

    Norval, R A

    1979-12-01

    The distribution of tick species in Zimbabwe Rhodesia is significantly influenced by land utilization practices. The most commonly occurring species in the over-grazed tribal areas is Boophilus decoloratus. By contrast, well-managed commercial farms and ranches support a wide range of tick species, the most important of which is Rhipicephalus appendiculatus. Until recently tick-borne diseases of cattle were efficiently controlled through dipping. The low incidence of disease was an important factor contributing to over-grazing in tribal areas. Between 1973 and 1978 political unrest resulted in a collapse of the dipping service in tribal areas. Populations of B. decoloratus built up and outbreaks of babesiosis and anaplasmosis occurred, normally between one and three years after the cessation of dipping. Reduced grazing pressure after the initial disease waves resulted in increased grass cover, allowing species such as R. appendiculatus and Amblyomma hebraeum to become re-established. Outbreaks of theileriosis and heartwater usually followed, decimating the already depleted herds. The heavy cattle mortality resulted from lack of immunity to tick-borne diseases, as a result of efficient disease control through dipping in previous years.

  16. Tick-Borne Viruses and Biological Processes at the Tick-Host-Virus Interface

    PubMed Central

    Kazimírová, Mária; Thangamani, Saravanan; Bartíková, Pavlína; Hermance, Meghan; Holíková, Viera; Štibrániová, Iveta; Nuttall, Patricia A.

    2017-01-01

    Ticks are efficient vectors of arboviruses, although less than 10% of tick species are known to be virus vectors. Most tick-borne viruses (TBV) are RNA viruses some of which cause serious diseases in humans and animals world-wide. Several TBV impacting human or domesticated animal health have been found to emerge or re-emerge recently. In order to survive in nature, TBV must infect and replicate in both vertebrate and tick cells, representing very different physiological environments. Information on molecular mechanisms that allow TBV to switch between infecting and replicating in tick and vertebrate cells is scarce. In general, ticks succeed in completing their blood meal thanks to a plethora of biologically active molecules in their saliva that counteract and modulate different arms of the host defense responses (haemostasis, inflammation, innate and acquired immunity, and wound healing). The transmission of TBV occurs primarily during tick feeding and is a complex process, known to be promoted by tick saliva constituents. However, the underlying molecular mechanisms of TBV transmission are poorly understood. Immunomodulatory properties of tick saliva helping overcome the first line of defense to injury and early interactions at the tick-host skin interface appear to be essential in successful TBV transmission and infection of susceptible vertebrate hosts. The local host skin site of tick attachment, modulated by tick saliva, is an important focus of virus replication. Immunomodulation of the tick attachment site also promotes co-feeding transmission of viruses from infected to non-infected ticks in the absence of host viraemia (non-viraemic transmission). Future research should be aimed at identification of the key tick salivary molecules promoting virus transmission, and a molecular description of tick-host-virus interactions and of tick-mediated skin immunomodulation. Such insights will enable the rationale design of anti-tick vaccines that protect against

  17. Tick-Borne Viruses and Biological Processes at the Tick-Host-Virus Interface.

    PubMed

    Kazimírová, Mária; Thangamani, Saravanan; Bartíková, Pavlína; Hermance, Meghan; Holíková, Viera; Štibrániová, Iveta; Nuttall, Patricia A

    2017-01-01

    Ticks are efficient vectors of arboviruses, although less than 10% of tick species are known to be virus vectors. Most tick-borne viruses (TBV) are RNA viruses some of which cause serious diseases in humans and animals world-wide. Several TBV impacting human or domesticated animal health have been found to emerge or re-emerge recently. In order to survive in nature, TBV must infect and replicate in both vertebrate and tick cells, representing very different physiological environments. Information on molecular mechanisms that allow TBV to switch between infecting and replicating in tick and vertebrate cells is scarce. In general, ticks succeed in completing their blood meal thanks to a plethora of biologically active molecules in their saliva that counteract and modulate different arms of the host defense responses (haemostasis, inflammation, innate and acquired immunity, and wound healing). The transmission of TBV occurs primarily during tick feeding and is a complex process, known to be promoted by tick saliva constituents. However, the underlying molecular mechanisms of TBV transmission are poorly understood. Immunomodulatory properties of tick saliva helping overcome the first line of defense to injury and early interactions at the tick-host skin interface appear to be essential in successful TBV transmission and infection of susceptible vertebrate hosts. The local host skin site of tick attachment, modulated by tick saliva, is an important focus of virus replication. Immunomodulation of the tick attachment site also promotes co-feeding transmission of viruses from infected to non-infected ticks in the absence of host viraemia (non-viraemic transmission). Future research should be aimed at identification of the key tick salivary molecules promoting virus transmission, and a molecular description of tick-host-virus interactions and of tick-mediated skin immunomodulation. Such insights will enable the rationale design of anti-tick vaccines that protect against

  18. Cluster of tick-borne infections at Fort Chaffee, Arkansas: Rickettsiae and Borrelia burgdorferi in ixodid ticks.

    PubMed

    Kardatzke, J T; Neidhardt, K; Dzuban, D P; Sanchez, J L; Azad, A F

    1992-07-01

    Human intrusion into pristine habitats increases the likelihood of acquiring infectious agents from potentially infective ticks. As part of a larger human serological investigation into tick-borne illnesses, 3,000 ixodid ticks were collected during May, August, and November 1990 at Fort Chaffee, Arkansas. Ticks were examined to determine whether they harbor rickettsiae, ehrlichiae, and Borrelia burgdorferi, and to assess relationship to human exposure to tick-borne infections at Fort Chaffee, Ark. The overall tick infection rates with SFG rickettsiae, B. burgdorferi, and ehrlichiae were 4.8, 0.1, and 0.3%, respectively.

  19. Emerging tick-borne infections in mainland China: an increasing public health threat

    PubMed Central

    Li, Xin-Lou; Liang, Song; Yang, Yang; Yao, Hong-Wu; Sun, Ruo-Xi; Sun, Ye; Chen, Wan-Jun; Zuo, Shu-Qing; Ma, Mai-Juan; Li, Hao; Jiang, Jia-Fu; Liu, Wei; Yang, X Frank; Gray, Gregory C; Krause, Peter J; Cao, Wu-Chun

    2016-01-01

    Since the beginning of the 1980s, 33 emerging tick-borne agents have been identified in mainland China, including eight species of spotted fever group rickettsiae, seven species in the family Anaplasmataceae, six genospecies in the complex Borrelia burgdorferi sensu lato, 11 species of Babesia, and the virus causing severe fever with thrombocytopenia syndrome. In this Review we have mapped the geographical distributions of human cases of infection. 15 of the 33 emerging tick-borne agents have been reported to cause human disease, and their clinical characteristics have been described. The non-specific clinical manifestations caused by tick-borne pathogens present a major diagnostic challenge and most physicians are unfamiliar with the many tick-borne diseases that present with non-specific symptoms in the early stages of the illness. Advances in and application of modern molecular techniques should help with identification of emerging tick-borne pathogens and improve laboratory diagnosis of human infections. We expect that more novel tick-borne infections in ticks and animals will be identified and additional emerging tick-borne diseases in human beings will be discovered. PMID:26453241

  20. Tick-Borne Zoonoses in the United States: Persistent and Emerging Threats to Human Health

    PubMed Central

    Eisen, Rebecca J.; Kugeler, Kiersten J.; Eisen, Lars; Beard, Charles B.; Paddock, Christopher D.

    2017-01-01

    In the United States, ticks transmit the greatest diversity of arthropod-borne pathogens and are responsible for the most cases of all vector-borne diseases. In recent decades, the number of reported cases of notifiable tick-borne diseases has steadily increased, geographic distributions of many ticks and tick-borne diseases have expanded, and new tick-borne disease agents have been recognized. In this review, we (1) describe the known disease agents associated with the most commonly human-biting ixodid ticks, (2) review the natural histories of these ticks and their associated pathogens, (3) highlight spatial and temporal changes in vector tick distributions and tick-borne disease occurrence in recent decades, and (4) identify knowledge gaps and barriers to more effective prevention of tick-borne diseases. We describe 12 major tick-borne diseases caused by 15 distinct disease agents that are transmitted by the 8 most commonly human-biting ixodid ticks in the United States. Notably, 40% of these pathogens were described within the last two decades. Our assessment highlights the importance of animal studies to elucidate how tick-borne pathogens are maintained in nature, as well as advances in molecular detection of pathogens which has led to the discovery of several new tick-borne disease agents. PMID:28369515

  1. Spatial disaggregation of tick occurrence and ecology at a local scale as a preliminary step for spatial surveillance of tick-borne diseases: general framework and health implications in Belgium.

    PubMed

    Obsomer, Valerie; Wirtgen, Marc; Linden, Annick; Claerebout, Edwin; Heyman, Paul; Heylen, Dieter; Madder, Maxime; Maris, Jo; Lebrun, Maude; Tack, Wesley; Lempereur, Laetitia; Hance, Thierry; Van Impe, Georges

    2013-06-22

    The incidence of tick-borne diseases is increasing in Europe. Sub national information on tick distribution, ecology and vector status is often lacking. However, precise location of infection risk can lead to better targeted prevention measures, surveillance and control. In this context, the current paper compiled geolocated tick occurrences in Belgium, a country where tick-borne disease has received little attention, in order to highlight the potential value of spatial approaches and draw some recommendations for future research priorities. Mapping of 89,289 ticks over 654 sites revealed that ticks such as Ixodes ricinus and Ixodes hexagonus are largely present while Dermacentor reticulatus has a patchy distribution. Suspected hot spots of tick diversity might favor pathogen exchanges and suspected hot spots of I. ricinus abundance might increase human-vector contact locally. This underlines the necessity to map pathogens and ticks in detail. While I. ricinus is the main vector, I. hexagonus is a vector and reservoir of Borrelia burgdorferi s.l., which is active the whole year and is also found in urban settings. This and other nidiculous species bite humans less frequently, but seem to harbour pathogens. Their role in maintaining a pathogenic cycle within the wildlife merits investigation as they might facilitate transmission to humans if co-occurring with I. ricinus. Many micro-organisms are found abroad in tick species present in Belgium. Most have not been recorded locally but have not been searched for. Some are transmitted directly at the time of the bite, suggesting promotion of tick avoidance additionally to tick removal. This countrywide approach to tick-borne diseases has helped delineate recommendations for future research priorities necessary to design public health policies aimed at spatially integrating the major components of the ecological cycle of tick-borne diseases. A systematic survey of tick species and associated pathogens is called for in

  2. Tick-borne encephalitis: A review of epidemiology, clinical characteristics, and management

    PubMed Central

    Bogovic, Petra; Strle, Franc

    2015-01-01

    Tick-borne encephalitis is an infection of central nervous system caused by tick-borne encephalitis virus transmitted to humans predominantly by tick bites. During the last few decades the incidence of the disease has been increasing and poses a growing health problem in almost all endemic European and Asian countries. Most cases occur during the highest period of tick activity, in Central Europe mainly from April to November. Tick-borne encephalitis is more common in adults than in children. Clinical spectrum of the disease ranges from mild meningitis to severe meningoencephalitis with or without paralysis. Rare clinical manifestations are an abortive form of the disease and a chronic progressive form. A post-encephalitic syndrome, causing long-lasting morbidity that often affects the quality of life develops in up to 50% of patients after acute tick-borne encephalitis. Clinical course and outcome vary by subtype of tick-borne encephalitis virus (the disease caused by the European subtype has milder course and better outcome than the disease caused by Siberian and Far-Easter subtypes), age of patients (increasing age is associated with less favorable outcome), and host genetic factors. Since clinical features and laboratory results of blood and cerebrospinal fluid are nonspecific, the diagnosis must be confirmed by microbiologic findings. The routine laboratory confirmation of the tick-borne encephalitis virus infection is based mainly on the detection of specific IgM and IgG antibodies in serum (and cerebrospinal fluid), usually by enzyme-linked immunosorbent assay. There is no specific antiviral treatment for tick-borne encephalitis. Vaccination can effectively prevent the disease and is indicated for persons living in or visiting tick-borne encephalitis endemic areas. PMID:25984517

  3. Tick-Borne Pathogen – Reversed and Conventional Discovery of Disease

    PubMed Central

    Tijsse-Klasen, Ellen; Koopmans, Marion P. G.; Sprong, Hein

    2014-01-01

    Molecular methods have increased the number of known microorganisms associated with ticks significantly. Some of these newly identified microorganisms are readily linked to human disease while others are yet unknown to cause human disease. The face of tick-borne disease discovery has changed with more diseases now being discovered in a “reversed way,” detecting disease cases only years after the tick-borne microorganism was first discovered. Compared to the conventional discovery of infectious diseases, reverse order discovery presents researchers with new challenges. Estimating public health risks of such agents is especially challenging, as case definitions and diagnostic procedures may initially be missing. We discuss the advantages and shortcomings of molecular methods, serology, and epidemiological studies that might be used to study some fundamental questions regarding newly identified tick-borne diseases. With increased tick-exposure and improved detection methods, more tick-borne microorganisms will be added to the list of pathogens causing disease in humans in the future. PMID:25072045

  4. Tick-borne pathogens in tick species infesting humans in Sibiu County, central Romania.

    PubMed

    Andersson, Martin O; Marga, Georgeta; Banu, Teofilia; Dobler, Gerhard; Chitimia-Dobler, Lidia

    2018-05-01

    Romania has a highly diverse tick fauna. Consequently, a high diversity of tick-transmitted pathogens might be a potential threat to humans. However, only a limited number of tick species regularly infest humans, and pathogens present in such species are therefore of particular interest from a medical perspective. In this study, 297 ticks were collected from humans during 2013 and 2014. Ixodes ricinus was the predominant tick species, accounting for 272 specimens or 91.6% of the ticks in the study. Nevertheless, other tick species were also found to infest humans: Dermacentor marginatus constituted 7% of the ticks found on humans (21/297), Haemaphysalis punctata 1% (3/297), and Haemaphysalis concinna 0.3% (1/297). Ticks were tested by PCR for a wide range of tick-borne pathogens. In total, 11.8% of the ticks carried human pathogenic bacteria, while no viral or protozoan pathogens were detected. The most frequently detected pathogen was Rickettsia spp., occurring in 5.4% of the ticks (16/297) and comprising three species: Rickettsia (R.) raoultii, R. monacensis, and R. helvetica. Borrelia s.l. occurred in 3% (9/297) of the ticks. "Candidatus Neoehrlichia mikurensis" occurred in 1.7% (5/297) and Anaplasma phagocytophilum in 1.3% (4/297). Anaplasma bovis was detected in an H. punctata and Borrelia miyamotoi in an I. ricinus. These results point to the need for further studies on the medical importance of tick-borne pathogens in Romania.

  5. Molecular detection of emerging tick-borne pathogens in Vojvodina, Serbia.

    PubMed

    Potkonjak, Aleksandar; Gutiérrez, Ricardo; Savić, Sara; Vračar, Vuk; Nachum-Biala, Yaarit; Jurišić, Aleksandar; Kleinerman, Gabriela; Rojas, Alicia; Petrović, Aleksandra; Baneth, Gad; Harrus, Shimon

    2016-02-01

    Ticks play an important role in disease transmission globally due to their capability to serve as vectors for human and animal pathogens. The Republic of Serbia is an endemic area for a large number of tick-borne diseases. However, current knowledge on these diseases in Serbia is limited. The aim of this study was to investigate the presence of new emerging tick-borne pathogens in ticks collected from dogs and the vegetation from different parts of Vojvodina, Serbia. A total of 187 ticks, including 124 Rhipicephalus sanguineus, 45 Ixodes ricinus and 18 Dermacentor reticulatus were collected from dogs. In addition, 26 questing I. ricinus ticks were collected from the vegetation, using the flagging method, from 4 different localities in Vojvodina, Serbia. DNA was extracted from each tick individually and samples were tested by either conventional or real-time PCR assays for the presence of Rickettsia spp.-DNA (gltA and ompA gene fragments), Ehrlichia/Anaplasma spp.-DNA (16S rRNA gene fragment) and Hepatozoon spp./Babesia spp.-DNA (18S rRNA gene fragment). In addition, all I. ricinus DNA samples were tested for Bartonella spp.-DNA (ITS locus) by real-time PCR. In this study, the presence of novel emerging tick-borne pathogens including Rickettsia raoultii, Rickettsia massiliae, Babesia venatorum, Babesia microti, Hepatozoon canis and Candidatus Neoehrlichia mikurensis was identified for the first time in Serbia. Our findings also confirmed the presence of Rickettsia monacensis, Babesia canis and Anaplasma phagocytophilum in ticks from Serbia. The findings of the current study highlight the great diversity of tick-borne pathogens of human and animal importance in Serbia. Physicians, public health workers and veterinarians should increase alertness to the presence of these tick-borne pathogens in this country. Copyright © 2015 Elsevier GmbH. All rights reserved.

  6. Worldwide distribution and diversity of seabird ticks: implications for the ecology and epidemiology of tick-borne pathogens.

    PubMed

    Dietrich, Muriel; Gómez-Díaz, Elena; McCoy, Karen D

    2011-05-01

    The ubiquity of ticks and their importance in the transmission of pathogens involved in human and livestock diseases are reflected by the growing number of studies focusing on tick ecology and the epidemiology of tick-borne pathogens. Likewise, the involvement of wild birds in dispersing pathogens and their role as reservoir hosts are now well established. However, studies on tick-bird systems have mainly focused on land birds, and the role of seabirds in the ecology and epidemiology of tick-borne pathogens is rarely considered. Seabirds typically have large population sizes, wide geographic distributions, and high mobility, which make them significant potential players in the maintenance and dispersal of disease agents at large spatial scales. They are parasitized by at least 29 tick species found across all biogeographical regions of the world. We know that these seabird-tick systems can harbor a large diversity of pathogens, although detailed studies of this diversity remain scarce. In this article, we review current knowledge on the diversity and global distribution of ticks and tick-borne pathogens associated with seabirds. We discuss the relationship between seabirds, ticks, and their pathogens and examine the interesting characteristics of these relationships from ecological and epidemiological points of view. We also highlight some future research directions required to better understand the evolution of these systems and to assess the potential role of seabirds in the epidemiology of tick-borne pathogens.

  7. Identification of tick-borne encephalitis virus in ticks collected in southeastern Hungary.

    PubMed

    Pintér, Réka; Madai, Mónika; Vadkerti, Edit; Németh, Viktória; Oldal, Miklós; Kemenesi, Gábor; Dallos, Bianka; Gyuranecz, Miklós; Kiss, Gábor; Bányai, Krisztián; Jakab, Ferenc

    2013-09-01

    Tick-borne encephalitis virus (TBEV) is an arthropod-borne viral pathogen causing infections in Europe and is responsible for most arbovirus central nervous system infections in Hungary. Assessing the TBEV prevalence in ticks through detection of genomic RNA is a broadly accepted approach to estimate the transmission risk from a tick bite. For this purpose, 2731 ticks were collected from the neighboring area of the town of Dévaványa, located in southeastern Hungary, which is considered a low-risk-transmission area for TBEV. Altogether, 2300 ticks were collected from the vegetation, while 431 were collected from rodents. Samples were pooled and then screened for TBEV with a newly designed semi-nested RT-PCR (RT-snPCR) targeting the NS1 genomic region. PCR results were confirmed by direct sequencing of the second round amplicons. Among the 3 different collected tick species (Ixodes ricinus, Haemaphysalis concinna, Dermacentor marginatus), I. ricinus was the only species that tested positive for TBEV. TBEV-positive ticks were collected from small mammals or from the vegetation. One nymphal pool and 4 larval pools tested positive for TBEV. The only positive nymphal pool was unfed and came from vegetation, while ticks of the 4 positive larval pools were collected from rodents. Minimal TBEV prevalence in ticks was 0.08% for unfed nymphs and 0.78% for feeding larvae. Our results indicate that further long-term investigations on the occurrence of TBEV are needed to better describe the geographic distribution and the prevalence of infected ticks in Hungary. Copyright © 2013 Elsevier GmbH. All rights reserved.

  8. Update on Tick-Borne Rickettsioses around the World: a Geographic Approach

    PubMed Central

    Paddock, Christopher D.; Socolovschi, Cristina; Labruna, Marcelo B.; Mediannikov, Oleg; Kernif, Tahar; Abdad, Mohammad Yazid; Stenos, John; Bitam, Idir; Fournier, Pierre-Edouard; Raoult, Didier

    2013-01-01

    SUMMARY Tick-borne rickettsioses are caused by obligate intracellular bacteria belonging to the spotted fever group of the genus Rickettsia. These zoonoses are among the oldest known vector-borne diseases. However, in the past 25 years, the scope and importance of the recognized tick-associated rickettsial pathogens have increased dramatically, making this complex of diseases an ideal paradigm for the understanding of emerging and reemerging infections. Several species of tick-borne rickettsiae that were considered nonpathogenic for decades are now associated with human infections, and novel Rickettsia species of undetermined pathogenicity continue to be detected in or isolated from ticks around the world. This remarkable expansion of information has been driven largely by the use of molecular techniques that have facilitated the identification of novel and previously recognized rickettsiae in ticks. New approaches, such as swabbing of eschars to obtain material to be tested by PCR, have emerged in recent years and have played a role in describing emerging tick-borne rickettsioses. Here, we present the current knowledge on tick-borne rickettsiae and rickettsioses using a geographic approach toward the epidemiology of these diseases. PMID:24092850

  9. Spatial disaggregation of tick occurrence and ecology at a local scale as a preliminary step for spatial surveillance of tick-borne diseases: general framework and health implications in Belgium

    PubMed Central

    2013-01-01

    Background The incidence of tick-borne diseases is increasing in Europe. Sub national information on tick distribution, ecology and vector status is often lacking. However, precise location of infection risk can lead to better targeted prevention measures, surveillance and control. Methods In this context, the current paper compiled geolocated tick occurrences in Belgium, a country where tick-borne disease has received little attention, in order to highlight the potential value of spatial approaches and draw some recommendations for future research priorities. Results Mapping of 89,289 ticks over 654 sites revealed that ticks such as Ixodes ricinus and Ixodes hexagonus are largely present while Dermacentor reticulatus has a patchy distribution. Suspected hot spots of tick diversity might favor pathogen exchanges and suspected hot spots of I. ricinus abundance might increase human-vector contact locally. This underlines the necessity to map pathogens and ticks in detail. While I. ricinus is the main vector, I. hexagonus is a vector and reservoir of Borrelia burgdorferi s.l., which is active the whole year and is also found in urban settings. This and other nidiculous species bite humans less frequently, but seem to harbour pathogens. Their role in maintaining a pathogenic cycle within the wildlife merits investigation as they might facilitate transmission to humans if co-occurring with I. ricinus. Many micro-organisms are found abroad in tick species present in Belgium. Most have not been recorded locally but have not been searched for. Some are transmitted directly at the time of the bite, suggesting promotion of tick avoidance additionally to tick removal. Conclusion This countrywide approach to tick-borne diseases has helped delineate recommendations for future research priorities necessary to design public health policies aimed at spatially integrating the major components of the ecological cycle of tick-borne diseases. A systematic survey of tick species and

  10. Tick-Borne Encephalitis Virus in Ticks and Roe Deer, the Netherlands.

    PubMed

    Jahfari, Setareh; de Vries, Ankje; Rijks, Jolianne M; Van Gucht, Steven; Vennema, Harry; Sprong, Hein; Rockx, Barry

    2017-06-01

    We report the presence of tick-borne encephalitis virus (TBEV) in the Netherlands. Serologic screening of roe deer found TBEV-neutralizing antibodies with a seroprevalence of 2%, and TBEV RNA was detected in 2 ticks from the same location. Enhanced surveillance and awareness among medical professionals has led to the identification of autochthonous cases.

  11. Prevalence of tick-borne encephalitis virus in Ixodes ricinus ticks from three islands in north-western Norway.

    PubMed

    Paulsen, Katrine M; Pedersen, Benedikte N; Soleng, Arnulf; Okbaldet, Yohannes B; Pettersson, John H-O; Dudman, Susanne G; Ottesen, Preben; Vik, Inger Sofie Samdal; Vainio, Kirsti; Andreassen, Åshild

    2015-09-01

    Tick-borne encephalitis (TBE) is the most important viral tick-borne disease in Europe and can cause severe disease in humans. In Norway, human cases have been reported only from the southern coast. The aim of this study was to investigate the prevalence of tick-borne encephalitis virus (TBEV) in questing Ixodes ricinus ticks from the north-western part of Norway. A total of 4509 ticks were collected by flagging in May and June 2014. A subpopulation of 2220 nymphs and 162 adult ticks were analysed by real-time PCR and positive samples were confirmed by pyrosequencing. The estimated prevalence of TBEV was 3.08% among adult ticks from Sekken in Møre og Romsdal County and 0.41% among nymphs from both Hitra and Frøya in Sør-Trøndelag County. This study indicates that TBEV might be more widespread than the distribution of reported human cases suggests. © 2015 APMIS. Published by John Wiley & Sons Ltd.

  12. Serine Protease Inhibitors in Ticks: An Overview of Their Role in Tick Biology and Tick-Borne Pathogen Transmission.

    PubMed

    Blisnick, Adrien A; Foulon, Thierry; Bonnet, Sarah I

    2017-01-01

    New tick and tick-borne pathogen control approaches that are both environmentally sustainable and which provide broad protection are urgently needed. Their development, however, will rely on a greater understanding of tick biology, tick-pathogen, and tick-host interactions. The recent advances in new generation technologies to study genomes, transcriptomes, and proteomes has resulted in a plethora of tick biomacromolecular studies. Among these, many enzyme inhibitors have been described, notably serine protease inhibitors (SPIs), whose importance in various tick biological processes is only just beginning to be fully appreciated. Among the multiple active substances secreted during tick feeding, SPIs have been shown to be directly involved in regulation of inflammation, blood clotting, wound healing, vasoconstriction and the modulation of host defense mechanisms. In light of these activities, several SPIs were examined and were experimentally confirmed to facilitate tick pathogen transmission. In addition, to prevent coagulation of the ingested blood meal within the tick alimentary canal, SPIs are also involved in blood digestion and nutrient extraction from the meal. The presence of SPIs in tick hemocytes and their involvement in tick innate immune defenses have also been demonstrated, as well as their implication in hemolymph coagulation and egg development. Considering the involvement of SPIs in multiple crucial aspects of tick-host-pathogen interactions, as well as in various aspects of the tick parasitic lifestyle, these molecules represent highly suitable and attractive targets for the development of effective tick control strategies. Here we review the current knowledge regarding this class of inhibitors in tick biology and tick-borne pathogen transmission, and their potential as targets for future tick control trials.

  13. Serine Protease Inhibitors in Ticks: An Overview of Their Role in Tick Biology and Tick-Borne Pathogen Transmission

    PubMed Central

    Blisnick, Adrien A.; Foulon, Thierry; Bonnet, Sarah I.

    2017-01-01

    New tick and tick-borne pathogen control approaches that are both environmentally sustainable and which provide broad protection are urgently needed. Their development, however, will rely on a greater understanding of tick biology, tick-pathogen, and tick-host interactions. The recent advances in new generation technologies to study genomes, transcriptomes, and proteomes has resulted in a plethora of tick biomacromolecular studies. Among these, many enzyme inhibitors have been described, notably serine protease inhibitors (SPIs), whose importance in various tick biological processes is only just beginning to be fully appreciated. Among the multiple active substances secreted during tick feeding, SPIs have been shown to be directly involved in regulation of inflammation, blood clotting, wound healing, vasoconstriction and the modulation of host defense mechanisms. In light of these activities, several SPIs were examined and were experimentally confirmed to facilitate tick pathogen transmission. In addition, to prevent coagulation of the ingested blood meal within the tick alimentary canal, SPIs are also involved in blood digestion and nutrient extraction from the meal. The presence of SPIs in tick hemocytes and their involvement in tick innate immune defenses have also been demonstrated, as well as their implication in hemolymph coagulation and egg development. Considering the involvement of SPIs in multiple crucial aspects of tick-host-pathogen interactions, as well as in various aspects of the tick parasitic lifestyle, these molecules represent highly suitable and attractive targets for the development of effective tick control strategies. Here we review the current knowledge regarding this class of inhibitors in tick biology and tick-borne pathogen transmission, and their potential as targets for future tick control trials. PMID:28589099

  14. Tick-borne rickettsial pathogens in questing ticks, removed from humans and animals in Mexico.

    PubMed

    Sosa-Gutierrez, Carolina G; Vargas-Sandoval, Margarita; Torres, Javier; Gordillo-Pérez, Guadalupe

    2016-09-30

    Tick-borne rickettsial diseases (TBRD) are commonly encountered in medical and veterinary clinical settings. The control of these diseases is difficult, requiring disruption of a complex transmission chain involving a vertebrate host and ticks. The geographical distribution of the diseases is related to distribution of the vector, which is an indicator of risk for the population. A total of 1107 were collected by tick drag from forests, ecotourism parks and hosts at 101 sites in 22 of the 32 states of Mexico. Collected ticks were placed in 1.5 mL cryovials containing 70% ethanol and were identified to species. Ticks were pooled according to location/host of collection, date of collection, sex, and stage of development. A total of 51 ticks were assayed by polymerase chain reaction (PCR) to confirm species identification using morphological methods. A total of 477 pools of ticks were assayed using PCR techniques for selected tick-borne pathogens. Anaplasma phagocytophilum was the most commonly detected pathogen (45 pools), followed by, Ehrlichia (E.) canis (42), Rickettsia (R.) rickettsii (11), E. chaffeensis (8), and R. amblyommii (1). Rhipicephalus sanguineus was the tick most frequently positive for selected pathogens. Overall, our results indicate that potential tick vectors positive for rickettsial pathogens are distributed throughout the area surveyed in Mexico.

  15. Deer presence rather than abundance determines the population density of the sheep tick, Ixodes ricinus, in Dutch forests.

    PubMed

    Hofmeester, Tim R; Sprong, Hein; Jansen, Patrick A; Prins, Herbert H T; van Wieren, Sipke E

    2017-09-19

    Understanding which factors drive population densities of disease vectors is an important step in assessing disease risk. We tested the hypothesis that the density of ticks from the Ixodes ricinus complex, which are important vectors for tick-borne diseases, is determined by the density of deer, as adults of these ticks mainly feed on deer. We performed a cross-sectional study to investigate I. ricinus density across 20 forest plots in the Netherlands that ranged widely in deer availability to ticks, and performed a deer-exclosure experiment in four pairs of 1 ha forest plots in a separate site. Ixodes ricinus from all stages were more abundant in plots with deer (n = 17) than in plots without deer (n = 3). Where deer were present, the density of ticks did not increase with the abundance of deer. Experimental exclosure of deer reduced nymph density by 66% and adult density by 32% within a timeframe of two years. In this study, deer presence rather than abundance explained the density of I. ricinus. This is in contrast to previous studies and might be related to the relatively high host-species richness in Dutch forests. This means that reduction of the risk of acquiring a tick bite would require the complete elimination of deer in species rich forests. The fact that small exclosures (< 1 ha) substantially reduced I. ricinus densities suggests that fencing can be used to reduce tick-borne disease risk in areas with high recreational pressure.

  16. Awareness of tick-borne disease and compliance with using tick preventive products of dog owners in Hong Kong.

    PubMed

    Boost, Maureen V; Tung, Choi-Yin; Ip, Claudia Hoi-Ki; Man, July Fung-Oi; Hui, Toni Wing-Tung; Leung, Candy Fung-Yee; Mak, Maggie Yuen-Wa; Yuen, Queeny; O'Donoghue, Margaret M

    2017-02-01

    Tick-borne disease in dogs is common in South-east Asia and includes babesiosis and ehrlichiosis. These diseases can be largely prevented by compliant use of tick preventive products. This study investigated knowledge of ticks and tick-borne disease and use of tick preventive agents by a large sample of dog owners in Hong Kong. A total of 492 valid questionnaires were completed by owners attending veterinary practices, approached by researchers at common dog-walking areas, or targeted via local social media sites for pet owners. A high proportion of respondents were aware of tick-borne disease (79%) and this correlated well with use of preventive products. However, 18% of owners did not use any protection, mainly due to lack of knowledge of the risk of disease. Targeted advice stressing the importance of tick protection use and frequent follow-up at veterinary clinics could help reduce the risk of tick-borne disease. It would be beneficial if veterinarians provided training of frontline staff at the clinics to ensure they provide essential information to clients in an easily understandable format. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Evaluation of Imaging Methods in Tick-Borne Encephalitis.

    PubMed

    Zawadzki, Radosław; Garkowski, Adam; Kubas, Bożena; Zajkowska, Joanna; Hładuński, Marcin; Jurgilewicz, Dorota; Łebkowska, Urszula

    2017-01-01

    Tick-borne encephalitis (TBE) is caused by a virus that belongs to the Flaviviridae family and is transmitted by tick bites. The disease has a biphasic course. Diagnosis is based on laboratory examinations because of non-specific clinical features, which usually entails the detection of specific IgM antibodies in either blood or cerebrospinal fluid that appear in the second phase of the disease. Neurological symptoms, time course of the disease, and imaging findings are multifaceted. During the second phase of the disease, after the onset of neurological symptoms, magnetic resonance imaging (MRI) abnormalities are observed in a limited number of cases. However, imaging features may aid in predicting the prognosis of the disease.

  18. Concurrent micro-RNA mediated silencing of tick-borne flavivirus replication in tick vector and in the brain of vertebrate host.

    PubMed

    Tsetsarkin, Konstantin A; Liu, Guangping; Kenney, Heather; Hermance, Meghan; Thangamani, Saravanan; Pletnev, Alexander G

    2016-09-13

    Tick-borne viruses include medically important zoonotic pathogens that can cause life-threatening diseases. Unlike mosquito-borne viruses, whose impact can be restrained via mosquito population control programs, for tick-borne viruses only vaccination remains the reliable means of disease prevention. For live vaccine viruses a concern exists, that spillovers from viremic vaccinees could result in introduction of genetically modified viruses into sustainable tick-vertebrate host transmission cycle in nature. To restrict tick-borne flavivirus (Langat virus, LGTV) vector tropism, we inserted target sequences for tick-specific microRNAs (mir-1, mir-275 and mir-279) individually or in combination into several distant regions of LGTV genome. This caused selective attenuation of viral replication in tick-derived cells. LGTV expressing combinations of target sequences for tick- and vertebrate CNS-specific miRNAs were developed. The resulting viruses replicated efficiently and remained stable in simian Vero cells, which do not express these miRNAs, however were severely restricted to replicate in tick-derived cells. In addition, simultaneous dual miRNA targeting led to silencing of virus replication in live Ixodes ricinus ticks and abolished virus neurotropism in highly permissive newborn mice. The concurrent restriction of adverse replication events in vertebrate and invertebrate hosts will, therefore, ensure the environmental safety of live tick-borne virus vaccine candidates.

  19. A survey of tick-borne pathogens in dogs and their ticks in the Pantanal biome, Brazil.

    PubMed

    Melo, A L T; Witter, R; Martins, T F; Pacheco, T A; Alves, A S; Chitarra, C S; Dutra, V; Nakazato, L; Pacheco, R C; Labruna, M B; Aguiar, D M

    2016-03-01

    Tick and blood samples collected from domestic dogs in the Brazilian Pantanal were tested by molecular methods for the presence of tick-borne protozoa and bacteria. Among 320 sampled dogs, 3.13% were infected by Babesia vogeli (Piroplasmida: Babesiidae), 8.75% by Hepatozoon canis (Eucoccidiorida: Hepatozoidae), 7.19% by Anaplasma platys (Rickettsiales: Anaplasmataceae), and 0.94% by an unclassified Anaplasma sp. In three tick species collected from dogs, the following tick-borne agents were detected: (a) B. vogeli, An. platys and Ehrlichia canis (Rickettsiales: Anaplasmataceae), infecting Rhipicephalus sanguineus sensu lato (Ixodida: Ixodidae) ticks; (b) H. canis, an unclassified Anaplasma sp. and Rickettsia amblyommii (Rickettsiales: Rickettsiaceae), infecting Amblyomma cajennense sensu lato (Ixodida: Ixodidae) ticks, and (c) Rickettsia sp. strain Atlantic rainforest, an emerging human pathogen, infecting Amblyomma ovale ticks. Molecular analysis, based on a mitochondrial gene, revealed that the Am. cajennense s.l. ticks of the present study corresponded to Amblyomma sculptum, a member of the Am. cajennense species complex, and that Rh. sanguineus s.l. belonged to the tropical lineage. Whereas dogs are exposed to a number of tick-borne bacterial and protozoan agents in the Pantanal biome, humans are potentially exposed to infection by spotted fever group rickettsiae (e.g. R. amblyommii and Rickettsia sp. strain Atlantic rainforest) because both Am. sculptum and Am. ovale are among the most important human-biting ticks in Brazil. © 2015 The Royal Entomological Society.

  20. Risk of encountering ticks and tick-borne pathogens in a rapidly growing metropolitan area in the U.S. Great Plains.

    PubMed

    Noden, Bruce H; Loss, Scott R; Maichak, Courtney; Williams, Faithful

    2017-01-01

    The prevalence of tick-borne diseases has increased dramatically in many urban areas of the U.S., yet little is known about the ecology of ticks and tick-borne pathogens in relation to characteristics of North American urban and suburban landscapes. This study aimed to begin identification of the risk of encountering ticks and tick-borne pathogens within a rapidly expanding metropolitan area in the U.S. Great Plains region. Ten sites across Oklahoma City, Oklahoma were selected for tick sampling based on presence of tick habitat and level of urbanization intensity. Sampling was conducted using CO 2 traps and flagging in June, July and October 2015. A total of 552 ticks were collected from eight of the ten sampled greenspaces. The majority of ticks collected in summer were Amblyomma americanum (N=534 (97.8%)), followed by Dermacentor variabilis (N=10 (1.8%)) and Amblyomma maculatum (N=2 (0.3%)). Ixodes scapularis adult females (N=4) and nymphal A. americanum (N=2) were also collected in October 2015. Tick species diversity was highest in sites with >15% of the surrounding landscape composed of undeveloped land. Rickettsia sp. (including R. amblyommii and 'Candidatus R. andeanae'), Ehrlichia chaffeensis and/or E. ewingii were detected in tick pools from all eight sites where ticks were found. Our data suggest that the risk of encountering ticks and tick-borne pathogens exists throughout the Oklahoma City metropolitan area and that tick populations are likely influenced by urbanization intensity. Continued research is needed to clarify the full range of abiotic and biotic features of urban landscapes that influence the risk of encountering ticks and transmitting tick-borne diseases. Copyright © 2016 Elsevier GmbH. All rights reserved.

  1. Relapsing Fevers: Neglected Tick-Borne Diseases

    PubMed Central

    Talagrand-Reboul, Emilie; Boyer, Pierre H.; Bergström, Sven; Vial, Laurence; Boulanger, Nathalie

    2018-01-01

    Relapsing fever still remains a neglected disease and little is known on its reservoir, tick vector and physiopathology in the vertebrate host. The disease occurs in temperate as well as tropical countries. Relapsing fever borreliae are spirochaetes, members of the Borreliaceae family which also contain Lyme disease spirochaetes. They are mainly transmitted by Ornithodoros soft ticks, but some species are vectored by ixodid ticks. Traditionally a Borrelia species is associated with a specific vector in a particular geographical area. However, new species are regularly described, and taxonomical uncertainties deserve further investigations to better understand Borrelia vector/host adaptation. The medical importance of Borrelia miyamotoi, transmitted by Ixodes spp., has recently spawned new interest in this bacterial group. In this review, recent data on tick-host-pathogen interactions for tick-borne relapsing fevers is presented, with special focus on B. miyamotoi. PMID:29670860

  2. Tick-borne viruses: a review from the perspective of therapeutic approaches.

    PubMed

    Lani, Rafidah; Moghaddam, Ehsan; Haghani, Amin; Chang, Li-Yen; AbuBakar, Sazaly; Zandi, Keivan

    2014-09-01

    Several important human diseases worldwide are caused by tick-borne viruses. These diseases have become important public health concerns in recent years. The tick-borne viruses that cause diseases in humans mainly belong to 3 families: Bunyaviridae, Flaviviridae, and Reoviridae. In this review, we focus on therapeutic approaches for several of the more important tick-borne viruses from these 3 families. These viruses are Crimean-Congo hemorrhagic fever virus (CCHF) and the newly discovered tick-borne phleboviruses, known as thrombocytopenia syndromevirus (SFTSV), Heartland virus and Bhanja virus from the family Bunyaviridae, tick-borne encephalitis virus (TBEV), Powassan virus (POWV), Louping-ill virus (LIV), Omsk hemorrhagic fever virus (OHFV), Kyasanur Forest disease virus (KFDV), and Alkhurma hemorrhagic fever virus (AHFV) from the Flaviviridae family. To date, there is no effective antiviral drug available against most of these tick-borne viruses. Although there is common usage of antiviral drugs such as ribavirin for CCHF treatment in some countries, there are concerns that ribavirin may not be as effective as once thought against CCHF. Herein, we discuss also the availability of vaccines for the control of these viral infections. The lack of treatment and prevention approaches for these viruses is highlighted, and we hope that this review may increase public health awareness with regard to the threat posed by this group of viruses. Copyright © 2014 Elsevier GmbH. All rights reserved.

  3. Epidemiological analysis of tick-borne diseases in Zambia.

    PubMed

    Simuunza, Martin; Weir, William; Courcier, Emily; Tait, Andy; Shiels, Brian

    2011-02-10

    Tick-borne diseases are a constraint to livestock production in many developing countries as they cause high morbidity and mortality, which results in decreased production of meat, milk and other livestock by-products. The most important tick-borne diseases of livestock in sub-Saharan Africa are East Coast fever (caused by Theileria parva), babesiosis (caused by Babesia bigemina and B. bovis), anaplasmosis (caused by Anaplasma marginale) and heartwater (caused by Ehrlichia ruminantium). Despite their economic importance, information on the epidemiology of these diseases in many countries, including Zambia, is often inadequate, making rational disease control strategies difficult to implement. In this study 18S and 16S rRNA gene PCR assays were used for a comprehensive epidemiological analysis of tick-borne disease of cattle in three provinces of Zambia (Lusaka, Central and Eastern). All the disease pathogens under study (T. parva, T. mutans, T. taurotragi, B. bovis, B. bigemina, Anaplasma spp and E. ruminantium) were prevalent in each of the provinces surveyed. However, variation was observed in prevalence between regions and seasons. There was no association between live vaccination against East Coast fever and being PCR positive for T. parva. A number of risk factors were shown to be associated with (a) the occurrence of tick-borne pathogens in cattle and (b) cattle tick burdens in the wet season. A negative association was observed between the number of co-infecting pathogens and the erythrocyte packed cell volume (PCV) of carrier cattle. Crown Copyright © 2010. Published by Elsevier B.V. All rights reserved.

  4. Research on the ecology of ticks and tick-borne pathogens—methodological principles and caveats

    PubMed Central

    Estrada-Peña, Agustín; Gray, Jeremy S.; Kahl, Olaf; Lane, Robert S.; Nijhof, Ard M.

    2013-01-01

    Interest in tick-transmitted pathogens has experienced an upsurge in the past few decades. Routine application of tools for the detection of fragments of foreign DNA in ticks, together with a high degree of interest in the quantification of disease risk for humans, has led to a marked increase in the number of reports on the eco-epidemiology of tick-borne diseases. However, procedural errors continue to accumulate in the scientific literature, resulting in misleading information. For example, unreliable identification of ticks and pathogens, erroneous interpretations of short-term field studies, and the hasty acceptance of some tick species as vectors have led to ambiguities regarding the vector role of these arthropods. In this review, we focus on the ecological features driving the life cycle of ticks and the resulting effects on the eco-epidemiology of tick-transmitted pathogens. We review the factors affecting field collections of ticks, and we describe the biologically and ecologically appropriate procedures for describing tick host-seeking activity and its correlation with environmental traits. We detail the climatic variables that have biological importance on ticks and explain how they should be properly measured and analyzed. We also provide evidence to critically reject the use of some environmental traits that are being increasingly reported as the drivers of the behavior of ticks. With the aim of standardization, we propose unambiguous definitions of the status of hosts and ticks regarding their ability to maintain and spread a given pathogen. We also describe laboratory procedures and standards for evaluating the vectorial capacity of a tick or the reservoir role of a host. This approach should provide a coherent framework for the reporting of research findings concerning ticks and tick-borne diseases. PMID:23964348

  5. Research on the ecology of ticks and tick-borne pathogens--methodological principles and caveats.

    PubMed

    Estrada-Peña, Agustín; Gray, Jeremy S; Kahl, Olaf; Lane, Robert S; Nijhof, Ard M

    2013-01-01

    Interest in tick-transmitted pathogens has experienced an upsurge in the past few decades. Routine application of tools for the detection of fragments of foreign DNA in ticks, together with a high degree of interest in the quantification of disease risk for humans, has led to a marked increase in the number of reports on the eco-epidemiology of tick-borne diseases. However, procedural errors continue to accumulate in the scientific literature, resulting in misleading information. For example, unreliable identification of ticks and pathogens, erroneous interpretations of short-term field studies, and the hasty acceptance of some tick species as vectors have led to ambiguities regarding the vector role of these arthropods. In this review, we focus on the ecological features driving the life cycle of ticks and the resulting effects on the eco-epidemiology of tick-transmitted pathogens. We review the factors affecting field collections of ticks, and we describe the biologically and ecologically appropriate procedures for describing tick host-seeking activity and its correlation with environmental traits. We detail the climatic variables that have biological importance on ticks and explain how they should be properly measured and analyzed. We also provide evidence to critically reject the use of some environmental traits that are being increasingly reported as the drivers of the behavior of ticks. With the aim of standardization, we propose unambiguous definitions of the status of hosts and ticks regarding their ability to maintain and spread a given pathogen. We also describe laboratory procedures and standards for evaluating the vectorial capacity of a tick or the reservoir role of a host. This approach should provide a coherent framework for the reporting of research findings concerning ticks and tick-borne diseases.

  6. Strategies for new and improved vaccines against ticks and tick-borne diseases.

    PubMed

    de la Fuente, J; Kopáček, P; Lew-Tabor, A; Maritz-Olivier, C

    2016-12-01

    Ticks infest a variety of animal species and transmit pathogens causing disease in both humans and animals worldwide. Tick-host-pathogen interactions have evolved through dynamic processes that accommodated the genetic traits of the hosts, pathogens transmitted and the vector tick species that mediate their development and survival. New approaches for tick control are dependent on defining molecular interactions between hosts, ticks and pathogens to allow for discovery of key molecules that could be tested in vaccines or new generation therapeutics for intervention of tick-pathogen cycles. Currently, tick vaccines constitute an effective and environmentally sound approach for the control of ticks and the transmission of the associated tick-borne diseases. New candidate protective antigens will most likely be identified by focusing on proteins with relevant biological function in the feeding, reproduction, development, immune response, subversion of host immunity of the tick vector and/or molecules vital for pathogen infection and transmission. This review addresses different approaches and strategies used for the discovery of protective antigens, including focusing on relevant tick biological functions and proteins, reverse genetics, vaccinomics and tick protein evolution and interactomics. New and improved tick vaccines will most likely contain multiple antigens to control tick infestations and pathogen infection and transmission. © 2016 John Wiley & Sons Ltd.

  7. A study of ticks and tick-borne livestock pathogens in Pakistan.

    PubMed

    Karim, Shahid; Budachetri, Khemraj; Mukherjee, Nabanita; Williams, Jaclyn; Kausar, Asma; Hassan, Muhammad Jawadul; Adamson, Steven; Dowd, Scot E; Apanskevich, Dmitry; Arijo, Abdullah; Sindhu, Zia Uddin; Kakar, Muhammad Azam; Khan, Raja Muhammad Dilpazir; Ullah, Shafiq; Sajid, Muhammad Sohail; Ali, Abid; Iqbal, Zafar

    2017-06-01

    As obligate blood-feeding arthropods, ticks transmit pathogens to humans and domestic animals more often than other arthropod vectors. Livestock farming plays a vital role in the rural economy of Pakistan, and tick infestation causes serious problems with it. However, research on tick species diversity and tick-borne pathogens has rarely been conducted in Pakistan. In this study, a systematic investigation of the tick species infesting livestock in different ecological regions of Pakistan was conducted to determine the microbiome and pathobiome diversity in the indigenous ticks. A total of 3,866 tick specimens were morphologically identified as 19 different tick species representing three important hard ticks, Rhipicephalus, Haemaphysalis and Hyalomma, and two soft ticks, Ornithodorus and Argas. The bacterial diversity across these tick species was assessed by bacterial 16S rRNA gene sequencing using a 454-sequencing platform on 10 of the different tick species infesting livestock. The notable genera detected include Ralstonia, Clostridium, Staphylococcus, Rickettsia, Lactococcus, Lactobacillus, Corynebacterium, Enterobacter, and Enterococcus. A survey of Spotted fever group rickettsia from 514 samples from the 13 different tick species generated rickettsial-specific amplicons in 10% (54) of total ticks tested. Only three tick species Rhipicephalus microplus, Hyalomma anatolicum, and H. dromedarii had evidence of infection with "Candidatus Rickettsia amblyommii" a result further verified using a rompB gene-specific quantitative PCR (qPCR) assay. The Hyalomma ticks also tested positive for the piroplasm, Theileria annulata, using a qPCR assay. This study provides information about tick diversity in Pakistan, and pathogenic bacteria in different tick species. Our results showed evidence for Candidatus R. amblyommii infection in Rhipicephalus microplus, H. anatolicum, and H. dromedarii ticks, which also carried T. annulata.

  8. Rickettsial and other tick-borne infections.

    PubMed

    Flicek, Barbara Fouts

    2007-03-01

    prophylaxsis is beneficial to the tick-bitten patient to prevent disease. It must be kept in mind that the risk of transmission of disease increases with the duration of attachment and generally requires greater than 24 to 48 hours. The degree of tick engorgement or the time since tick exposure and discovery of the tick may be used to establish the likely duration of attachment and the risk of disease transmission. Reducing and controlling tick populations is difficult. Habitat modifications, including vegetation management by cutting, burning, and herbicide treatment, and drainage of wet areas are one strategy for tick control, but their effects are often short-lived, and they can cause severe ecologic damage. Chemicals used to control ticks may cause environmental contamination, and therefore, toxicity for humans and animals. Biologic control methods for ticks include the promotion of natural predators. Natural predators of ticks are beetles, spiders, and ants, and parasites such as insects, mites and nematodes. Tick control is best based on the concept of integrated pest management, in which different control methods are adapted to one area or against one tick species with due consideration to their environmental effects. Tick-borne diseases are increasing in prevalence. Perhaps it is because people are undertaking more outdoor activities, which result in contact with ticks and their pathogens. Clinicians should be aware of the clinical sign of tick-transmitted diseases, because morbidity and mortality as a result of these diseases increases substantially if there are delays in diagnosis and treatment. Tick-borne illness occur in distinctive geographic areas. The reporting of these illnesses and diseases to the health department enables the gathering of information and statistics. The public should be informed about the risks of disease in tick-infested areas and the means of preventing infections. The most common diseases are caused by Rickettsia, Borrelia, and Ehrichia

  9. Ecological Factors Characterizing the Prevalence of Bacterial Tick-Borne Pathogens in Ixodes ricinus Ticks in Pastures and Woodlands ▿ §

    PubMed Central

    Halos, Lénaïg; Bord, Séverine; Cotté, Violaine; Gasqui, Patrick; Abrial, David; Barnouin, Jacques; Boulouis, Henri-Jean; Vayssier-Taussat, Muriel; Vourc'h, Gwenaël

    2010-01-01

    Ecological changes are recognized as an important driver behind the emergence of infectious diseases. The prevalence of infection in ticks depends upon ecological factors that are rarely taken into account simultaneously. Our objective was to investigate the influences of forest fragmentation, vegetation, adult tick hosts, and habitat on the infection prevalence of three tick-borne bacteria, Borrelia burgdorferi sensu lato, Anaplasma phagocytophilum, and Rickettsia sp. of the spotted fever group, in questing Ixodes ricinus ticks, taking into account tick characteristics. Samples of questing nymphs and adults were taken from 61 pastures and neighboring woodlands in central France. The ticks were tested by PCR of pools of nymphs and individual adults. The individual infection prevalence was modeled using multivariate regression. The highest infection prevalences were found in adult females collected in woodland sites for B. burgdorferi sensu lato and A. phagocytophilum (16.1% and 10.7%, respectively) and in pasture sites for Rickettsia sp. (8.7%). The infection prevalence in nymphs was lower than 6%. B. burgdorferi sensu lato was more prevalent in woodlands than in pastures. Forest fragmentation favored B. burgdorferi sensu lato and A. phagocytophilum prevalence in woodlands, and in pastures, the B. burgdorferi sensu lato prevalence was favored by shrubby vegetation. Both results are probably because large amounts of edges or shrubs increase the abundance of small vertebrates as reservoir hosts. The Rickettsia sp. prevalence was maximal on pasture with medium forest fragmentation. Female ticks were more infected by B. burgdorferi sensu lato than males and nymphs in woodland sites, which suggests an interaction between the ticks and the bacteria. This study confirms the complexity of the tick-borne pathogen ecology. The findings support the importance of small vertebrates as reservoir hosts and make a case for further studies in Europe on the link between the

  10. Partial Characterization of Tick-Borne Encephalitis Virus Isolates from Ticks of Southern Ukraine.

    PubMed

    Yurchenko, Oksana O; Dubina, Dmytro O; Vynograd, Nataliya O; Gonzalez, Jean-Paul

    2017-08-01

    Tick-borne encephalitis (TBE) is the most common tick-borne viral infection in Eurasia; thousands of human cases are annually reported from several European countries. Several tick species are vectors of the tick-borne encephalitis virus (TBEV), while TBE appears to be spreading from the Eurasian continent westward to Europe. Fifteen study sites were chosen from five territories of southern Ukraine, including Odessa, Mykolaiv, Kherson Oblast, the Autonomous Republic of Crimea, and Sevastopol. Tick collection was performed in spring season of three consecutive years (1988-1990) using either flagging technique or direct collection of specimens feeding on cattle. A total of 15,243 tick imagoes and nymphs were collected from nine species, including Dermacentor marginatus, D. reticulatus, Haemaphysalis parva, H. punctata, Hyalomma marginatum, Ixodes ricinus, Rhipicephalus bursa, R. rossicus, and R. sanguineus, pooled in 282 monospecific samples. Supernatant of grinded pool was used for inoculation to suckling mice for virus isolation. Eight TBEV isolates were identified from ticks among six study sites. Ticks showed a minimum infection rate from 0.11% to 0.81%. Phylogenetic analysis of the envelope (E) protein gene of seven isolates, assigned all to the European subtype (TBEV-Eu) showing a maximum identity of 97.17% to the "Pan" TBEV-Eu reference strain. Compared to 104 TBEV-Eu isolates they clustered within the same clade as the Pan reference strain and distinguished from other TBEV-Eu isolates. Amino acid sequence analysis of the South Ukrainian TBEV-Eu isolates revealed the presence of four amino acid substitutions 67 (N), 266 (R), 306 (V), and 407 (R), in the ectodomains II and III and in the stem-anchor region of the E protein gene. This study confirmed TBEV-Eu subtype distribution in the southern region of Ukraine, which eventually overlaps with TBEV-FE (Far Eastern subtype) and TBEV-Sib (Siberian subtype) domains, showing the heterogeneity of TBEV circulating in

  11. Partial Characterization of Tick-Borne Encephalitis Virus Isolates from Ticks of Southern Ukraine

    PubMed Central

    Dubina, Dmytro O.; Vynograd, Nataliya O.; Gonzalez, Jean-Paul

    2017-01-01

    Abstract Tick-borne encephalitis (TBE) is the most common tick-borne viral infection in Eurasia; thousands of human cases are annually reported from several European countries. Several tick species are vectors of the tick-borne encephalitis virus (TBEV), while TBE appears to be spreading from the Eurasian continent westward to Europe. Fifteen study sites were chosen from five territories of southern Ukraine, including Odessa, Mykolaiv, Kherson Oblast, the Autonomous Republic of Crimea, and Sevastopol. Tick collection was performed in spring season of three consecutive years (1988–1990) using either flagging technique or direct collection of specimens feeding on cattle. A total of 15,243 tick imagoes and nymphs were collected from nine species, including Dermacentor marginatus, D. reticulatus, Haemaphysalis parva, H. punctata, Hyalomma marginatum, Ixodes ricinus, Rhipicephalus bursa, R. rossicus, and R. sanguineus, pooled in 282 monospecific samples. Supernatant of grinded pool was used for inoculation to suckling mice for virus isolation. Eight TBEV isolates were identified from ticks among six study sites. Ticks showed a minimum infection rate from 0.11% to 0.81%. Phylogenetic analysis of the envelope (E) protein gene of seven isolates, assigned all to the European subtype (TBEV-Eu) showing a maximum identity of 97.17% to the “Pan” TBEV-Eu reference strain. Compared to 104 TBEV-Eu isolates they clustered within the same clade as the Pan reference strain and distinguished from other TBEV-Eu isolates. Amino acid sequence analysis of the South Ukrainian TBEV-Eu isolates revealed the presence of four amino acid substitutions 67 (N), 266 (R), 306 (V), and 407 (R), in the ectodomains II and III and in the stem-anchor region of the E protein gene. This study confirmed TBEV-Eu subtype distribution in the southern region of Ukraine, which eventually overlaps with TBEV-FE (Far Eastern subtype) and TBEV-Sib (Siberian subtype) domains, showing the heterogeneity of TBEV

  12. Ticks are more suitable than red foxes for monitoring zoonotic tick-borne pathogens in northeastern Italy.

    PubMed

    Da Rold, Graziana; Ravagnan, Silvia; Soppelsa, Fabio; Porcellato, Elena; Soppelsa, Mauro; Obber, Federica; Citterio, Carlo Vittorio; Carlin, Sara; Danesi, Patrizia; Montarsi, Fabrizio; Capelli, Gioia

    2018-03-20

    Northeastern Italy is a hotspot for several tick-borne pathogens, transmitted to animals and humans mainly by Ixodes ricinus. Here we compare the results of molecular monitoring of ticks and zoonotic TBPs over a six-year period, with the monitoring of red foxes (Vulpes vulpes) in an endemic area. In the period 2011-2016, 2,578 ticks were collected in 38 sites of 20 municipalities of Belluno Province. Individual adults (264), pooled larvae (n = 330) and nymphs (n = 1984) were screened for tick-borne encephalitis virus, Borrelia burgdorferi (s.l.), Rickettsia spp., Babesia spp., Anaplasma phagocytophilum and "Candidatus Neoehrlichia mikurensis" by specific SYBR green real-time PCR assays and sequencing. The spleens of 97 foxes, culled in the period 2015-2017 during sport hunting or population control programs, were also screened. Overall, nine different pathogens were found in I. ricinus nymph and adult ticks: Rickettsia helvetica (3.69%); R. monacensis (0.49%); four species of the B. burgdorferi (s.l.) complex [B. afzelii (1.51%); B. burgdorferi (s.s.) (1.25%); B. garinii (0.18%); and B. valaisiana (0.18%)]; A. phagocytophilum (3.29%); "Candidatus N. mikurensis" (1.73%); and Babesia venatorum (0.04%). Larvae were collected and screened in the first year only and two pools (0.6%) were positive for R. helvetica. Tick-borne encephalitis virus was not found in ticks although human cases do occur in the area. The rate of infection in ticks varied widely according to tick developmental stage, site and year of collection. As expected, adults were the most infected, with 27.6% harboring at least one pathogen compared to 7.3% of nymphs. Pathogens with a minimum infection rate above 1% were recorded every year. None of the pathogens found in ticks were detectable in the foxes, 52 (54%) of which were instead positive for Babesia cf. microti (also referred to as Babesia microti-like, "Theileria annae", "Babesia annae" and "Babesia vulpes"). The results show that foxes

  13. U.S. healthcare providers’ experience with Lyme and other tick-borne diseases

    PubMed Central

    Brett, Meghan E.; Hinckley, Alison F.; Zielinski-Gutierrez, Emily C.; Mead, Paul S.

    2015-01-01

    Surveillance indicates that tick-borne diseases are a common problem in the United States. Nevertheless, little is known regarding the experience or management practices of healthcare providers who treat these conditions. The purpose of the present study was to characterize the frequency of tick-borne diseases in clinical practice and the knowledge of healthcare providers regarding their management. Four questions about tick-borne diseases were added to the 2009 Docstyles survey, a nationally representative survey of >2000 U.S. healthcare providers. Topics included diseases encountered, management of patients with early Lyme disease (LD), provision of tick-bite prophylaxis, and sources of information on tick-borne diseases. Overall, 51.3% of practitioners had treated at least one patient for a tick-borne illness in the previous year. Among these, 75.1% had treated one type of disease, 19.0% two types of disease, and 5.9% three or more diseases. LD was encountered by 936 (46.8%) providers; Rocky Mountain spotted fever was encountered by 184 (9.2%) providers. Given a scenario involving early LD, 89% of providers would prescribe antibiotics at the first visit, with or without ordering a blood test. Tick-bite prophylaxis was prescribed by 31.0% of all practitioners, including 41.1% in high-LD-incidence states and 26.0% in low-incidence states. Tick-borne diseases are encountered frequently in clinical practice. Most providers would treat early LD promptly, suggesting they are knowledgeable regarding the limitations of laboratory testing in this setting. Conversely, providers in low-LD-incidence states frequently prescribe tick-bite prophylaxis, suggesting a need for education to reduce potential misdiagnosis and overtreatment. PMID:24713280

  14. Survey of selected tick-borne diseases in dogs in Finland.

    PubMed

    Pérez Vera, Cristina; Kapiainen, Suvi; Junnikkala, Sami; Aaltonen, Kirsi; Spillmann, Thomas; Vapalahti, Olli

    2014-06-23

    Due to climate changes during the last decades, ticks have progressively spread into higher latitudes in northern Europe. Although some tick borne diseases are known to be endemic in Finland, to date there is limited information with regard to the prevalence of these infections in companion animals. We determined the antibody and DNA prevalence of the following organisms in randomly selected client-owned and clinically healthy hunting dogs living in Finland: Ehrlichia canis (Ec), Anaplasma phagocytophilum (Ap), Borrelia burgdorferi (Bb) and Bartonella. Anti-Ap, -Bb and -Ec antibodies were determined in 340 Finnish pet dogs and 50 healthy hunting dogs using the 4DX Snap®Test (IDEXX Laboratories). In addition, PCRs for the detection of Ap and Bartonella DNA were performed. Univariate and multivariate logistic regression analyses were used to identify risk factors associated with seropositivity to a vector borne agent. The overall seroprevalence was highest for Ap (5.3%), followed by Bb (2.9%), and Ec (0.3%). Seropositivities to Ap and Bb were significantly higher in the Åland Islands (p <0.001), with prevalence of Ap and Bb antibodies of 45 and 20%, respectively. In healthy hunting dogs, seropositivity rates of 4% (2/50) and 2% (1/50) were recorded for Ap and Bb, respectively. One client-owned dog and one hunting dog, both healthy, were infected with Ap as determined by PCR, while being seronegative. For Bartonella spp., none of the dogs tested was positive by PCR. This study represents the first data of seroprevalence to tick borne diseases in the Finnish dog population. Our results indicate that dogs in Finland are exposed to vector borne diseases, with Ap being the most seroprevalent of the diseases tested, followed by Bb. Almost 50% of dogs living in Åland Islands were Ap seropositive. This finding suggests the possibility of a high incidence of Ap infection in humans in this region. Knowing the distribution of seroprevalence in dogs may help predict the

  15. Tick-borne encephalitis.

    PubMed

    Dumpis, U; Crook, D; Oksi, J

    1999-04-01

    Tick-borne encephalitis (TBE) is a zoonotic arbovirus infection endemic to Russia and Eastern and Central Europe. Despite being a common and serious life-threatening disease for which a mass vaccination program was implemented in Austria, there is only limited reference to this disease in the English-language literature. TBE is transmitted to humans usually by the bite of a tick (either Ixodes persulcatus or Ixodes ricinus); occasionally, cases occur following consumption of infected unpasteurized milk. Transmission is seasonal and occurs in spring and summer, particularly in rural areas favored by the vector. TBE is a serious cause of acute central nervous system disease, which may result in death or long-term neurological sequelae. Effective vaccines are available in a few countries. The risk for travelers of acquiring TBE is increasing with the recent rise in tourism to areas of endemicity during spring and summer.

  16. A study of ticks and tick-borne livestock pathogens in Pakistan

    PubMed Central

    Budachetri, Khemraj; Mukherjee, Nabanita; Williams, Jaclyn; Kausar, Asma; Hassan, Muhammad Jawadul; Adamson, Steven; Dowd, Scot E.; Apanskevich, Dmitry; Arijo, Abdullah; Sindhu, Zia Uddin; Kakar, Muhammad Azam; Khan, Raja Muhammad Dilpazir; Ullah, Shafiq; Sajid, Muhammad Sohail; Ali, Abid; Iqbal, Zafar

    2017-01-01

    Background As obligate blood-feeding arthropods, ticks transmit pathogens to humans and domestic animals more often than other arthropod vectors. Livestock farming plays a vital role in the rural economy of Pakistan, and tick infestation causes serious problems with it. However, research on tick species diversity and tick-borne pathogens has rarely been conducted in Pakistan. In this study, a systematic investigation of the tick species infesting livestock in different ecological regions of Pakistan was conducted to determine the microbiome and pathobiome diversity in the indigenous ticks. Methodology/Principal findings A total of 3,866 tick specimens were morphologically identified as 19 different tick species representing three important hard ticks, Rhipicephalus, Haemaphysalis and Hyalomma, and two soft ticks, Ornithodorus and Argas. The bacterial diversity across these tick species was assessed by bacterial 16S rRNA gene sequencing using a 454-sequencing platform on 10 of the different tick species infesting livestock. The notable genera detected include Ralstonia, Clostridium, Staphylococcus, Rickettsia, Lactococcus, Lactobacillus, Corynebacterium, Enterobacter, and Enterococcus. A survey of Spotted fever group rickettsia from 514 samples from the 13 different tick species generated rickettsial-specific amplicons in 10% (54) of total ticks tested. Only three tick species Rhipicephalus microplus, Hyalomma anatolicum, and H. dromedarii had evidence of infection with “Candidatus Rickettsia amblyommii” a result further verified using a rompB gene-specific quantitative PCR (qPCR) assay. The Hyalomma ticks also tested positive for the piroplasm, Theileria annulata, using a qPCR assay. Conclusions/Significance This study provides information about tick diversity in Pakistan, and pathogenic bacteria in different tick species. Our results showed evidence for Candidatus R. amblyommii infection in Rhipicephalus microplus, H. anatolicum, and H. dromedarii ticks, which

  17. Borrelia miyamotoi, Other Vector-Borne Agents in Cat Blood and Ticks in Eastern Maryland.

    PubMed

    Shannon, Avery B; Rucinsky, Renee; Gaff, Holly D; Brinkerhoff, R Jory

    2017-12-01

    We collected blood and tick samples in eastern Maryland to quantify vector-borne pathogen exposure and infection in healthy cats and to assess occupational disease risk to veterinary professionals and others who regularly interact with household pets. Thirty-six percent of healthy cats parasitized by ticks at time of examination (9/25) were exposed to, and 14% of bloods (7/49) tested PCR-positive for, at least one vector-borne pathogen including several bloods and ticks with Borrelia miyamotoi, a recently recognized tick-borne zoonotic bacterium. There was no indication that high tick burdens were associated with exposure to vector-borne pathogens. Our results underscore the potential importance of cats to human vector-borne disease risk.

  18. A Molecular Survey of Tick-Borne Pathogens from Ticks Collected in Central Queensland, Australia.

    PubMed

    Chalada, Melissa Judith; Stenos, John; Vincent, Gemma; Barker, Dayana; Bradbury, Richard Stewart

    2018-03-01

    Central Queensland (CQ) is a large and isolated, low population density, remote tropical region of Australia with a varied environment. The region has a diverse fauna and several species of ticks that feed upon that fauna. This study examined 518 individual ticks: 177 Rhipicephalus sanguineus (brown dog tick), 123 Haemaphysalis bancrofti (wallaby tick), 102 Rhipicephalus australis (Australian cattle tick), 47 Amblyomma triguttatum (ornate kangaroo tick), 57 Ixodes holocyclus (paralysis tick), 9 Bothriocroton tachyglossi (CQ short-beaked echidna tick), and 3 Ornithodoros capensis (seabird soft tick). Tick midguts were pooled by common host or environment and screened for four genera of tick-borne zoonoses by PCR and sequencing. The study examined a total of 157 midgut pools of which 3 contained DNA of Coxiella burnetii, 13 Rickettsia gravesii, 1 Rickettsia felis, and 4 other Rickettsia spp. No Borrelia spp. or Babesia spp. DNA were recovered.

  19. Comparative analysis of the roles of Ixodes persulcatus and I. trianguliceps ticks in natural foci of ixodid tick-borne borrelioses in the Middle Urals, Russia.

    PubMed

    Korenberg, Edward I; Kovalevskii, Yurii V; Gorelova, Natalya B; Nefedova, Valentina V

    2015-04-01

    Long-term studies on natural foci of ixodid tick-borne borrelioses (ITBB) have been performed in Chusovskoi district of Perm region, the Middle Urals, where the vectors of these infections are represented by two ixodid tick species: the taiga tick Ixodes persulcatus and many times less abundant vole tick I. trianguliceps. Over 10 years, more than 6000 half-engorged ticks were collected from small forest mammals using the standard procedure, and 1027 I. persulcatus and 1142 I. trianguliceps ticks, individually or in pools, were used to inoculate BSK-2 medium. As a result, 199 Borrelia isolates were obtained. Among them, 177 isolates were identified, and the rrf(5S)-rrl(23S) intergenic spacer sequence was determined in 57 isolates. The prevalence of Borrelia infection in I. persulcatus larvae and nymphs averaged 31.0 and 53.3%, while that in I. trianguliceps larvae, nymphs, and adult ticks was five to ten times lower: 2.6, 10.2, and 8.1%, respectively. Each of the two tick species was found to carry both ITBB agents circulating in the Middle Ural foci (Borrelia garinii and B. afzelii), but the set of genogroups and genovariants of these spirochetes in I. trianguliceps proved to be far less diverse. According to the available data, this tick, compared to I. persulcatus, is generally less susceptible to Borrelia infection (especially by B. afzelii). Taking into account of its relatively low abundance, it appears that I. trianguliceps cannot seriously influence the course of epizootic process in ITBB foci of the study region, whereas highly abundant I. persulcatus with the high level of Borrelia infection is obviously a key component of these parasitic systems. A similar situation may well be typical for the entire geographic range shared by the two tick species. Copyright © 2015. Published by Elsevier GmbH.

  20. Effects of wildlife and cattle on tick abundance in central Kenya.

    PubMed

    Keesing, Felicia; Allan, Brian F; Young, Truman P; Ostfeld, Richard S

    2013-09-01

    In African savannas, large mammals, both wild and domestic, support an abundant and diverse population of tick ectoparasites. Because of the density of ticks and the many pathogens that they vector, cattle in East Africa are often treated with acaricides. While acaricides are known to be effective at reducing tick burdens on cattle, their effects on the overall abundance and community composition of ticks in savanna ecosystems are less well understood. It is also not known how well tick populations can be maintained in the absence of large mammals. We evaluated the effects of wildlife and of acaricide-treated cattle on host-seeking tick populations in a long-term, exclusion experiment in central Kenya. Over seven years, we sampled larval, nymphal, and adult ticks monthly on replicated treatment plots that controlled for the presence of cattle and for the presence of two guilds of large wild mammals: megaherbivores (giraffes and elephants) and all other large wild herbivores (> 15 kg). Two species of ticks were found in this habitat; across all surveys, 93% were Rhipicephalus pulchellus and 7% were R. praetextatus. The presence of acaricide-treated cattle dramatically reduced the abundance of host-seeking nymphal and adult ticks but did not affect the abundance of host-seeking larval ticks. The abundance of larval ticks was determined by the presence of large wild mammals, which appear to import gravid female ticks into the experimental plots. On plots with no large mammals, either wild or domestic, larval and nymphal ticks were rare. Adult R. pulchellus were most abundant in plots that allowed wildlife but excluded cattle. Adult R. praetextatus were relatively abundant in plots without any large mammals. These differences suggest that these ticks utilize different members of the host community. The reduction in ticks that results from the presence of acaricide-treated cattle has potential health benefits for humans and wildlife, but these benefits must be weighed

  1. Tick-borne illness after transplantation: Case and review.

    PubMed

    Mascarenhas, Tresa Reena; Silibovsky, Randi S; Singh, Pooja; Belden, Katherine A

    2018-04-01

    Tick-borne infections in solid organ transplant recipients are an infrequent and difficult diagnostic challenge owing to multiple routes of acquisition and unusual presentations. A 67-year-old male recipient of a combined liver and kidney transplant presented with recurrent fevers following surgery. Standard microbiologic workup was non-diagnostic. Shortness of breath, confusion, lethargy, and hypotension developed along with progressive anemia, requiring multiple blood transfusions. Workup suggested hemolysis and review of the peripheral smear was diagnostic for Babesia microti infection. Tick transmission, transmission via blood products, and/or the transplanted organ were all considered. More extensive questioning revealed a history of intermittent fevers for several months before transplantation. Testing of pre-transplant blood was positive for B. microti antibodies, suggesting infection prior to transplantation. The delayed diagnosis of babesiosis in this patient highlights the need for a detailed exposure history prior to transplantation, as well as considering the potential for atypical presentations of tick-borne infections in immune suppressed solid organ recipients. Furthermore, this case illustrates the importance of early Infectious Disease consultation to meet the challenges exhibited by febrile transplant patients. Infectious Diseases physicians are trained to consider, diagnose, and treat tick-borne infections, contributing to improved clinical outcome. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  2. TRANSLATING ECOLOGY, PHYSIOLOGY, BIOCHEMISTRY, AND POPULATION GENETICS RESEARCH TO MEET THE CHALLENGE OF TICK AND TICK-BORNE DISEASES IN NORTH AMERICA.

    PubMed

    Esteve-Gassent, Maria D; Castro-Arellano, Ivan; Feria-Arroyo, Teresa P; Patino, Ramiro; Li, Andrew Y; Medina, Raul F; de León, Adalberto A Pérez; Rodríguez-Vivas, Roger Iván

    2016-05-01

    Emerging and re-emerging tick-borne diseases threaten public health and the wellbeing of domestic animals and wildlife globally. The adoption of an evolutionary ecology framework aimed to diminish the impact of tick-borne diseases needs to be part of strategies to protect human and animal populations. We present a review of current knowledge on the adaptation of ticks to their environment, and the impact that global change could have on their geographic distribution in North America. Environmental pressures will affect tick population genetics by selecting genotypes able to withstand new and changing environments and by altering the connectivity and isolation of several tick populations. Research in these areas is particularly lacking in the southern United States and most of Mexico with knowledge gaps on the ecology of these diseases, including a void in the identity of reservoir hosts for several tick-borne pathogens. Additionally, the way in which anthropogenic changes to landscapes may influence tick-borne disease ecology remains to be fully understood. Enhanced knowledge in these areas is needed in order to implement effective and sustainable integrated tick management strategies. We propose to refocus ecology studies with emphasis on metacommunity-based approaches to enable a holistic perspective addressing whole pathogen and host assemblages. Network analyses could be used to develop mechanistic models involving multihost-pathogen communities. An increase in our understanding of the ecology of tick-borne diseases across their geographic distribution will aid in the design of effective area-wide tick control strategies aimed to diminish the burden of pathogens transmitted by ticks. © 2016 Wiley Periodicals, Inc.

  3. Translating ecology, physiology, biochemistry and population genetics research to meet the challenge of tick and tick-borne diseases in North America

    PubMed Central

    Esteve-Gassent, Maria D.; Castro-Arellano, Ivan; Feria-Arroyo, Teresa P.; Patino, Ramiro; Li, Andrew Y.; Medina, Raul F.; Pérez de León, Adalberto A.; Rodríguez-Vivas, Roger Iván

    2016-01-01

    Emerging and re-emerging tick-borne diseases threaten public health and the wellbeing of domestic animals and wildlife globally. The adoption of an evolutionary ecology framework aimed to diminish the impact of tick-borne diseases needs to be part of strategies to protect human and animal populations. We present a review of current knowledge on the adaptation of ticks to their environment, and the impact that global change could have on their geographic distribution in North America. Environmental pressures will affect tick population genetics by selecting genotypes able to withstand new and changing environments and by altering the connectivity and isolation of several tick populations. Research in these areas is particularly lacking in the southern US and most of Mexico with knowledge gaps on the ecology of these diseases, including a void in the identity of reservoir hosts for several tick-borne pathogens. Additionally, the way in which anthropogenic changes to landscapes may influence tick-borne disease ecology remains to be fully understood. Enhanced knowledge in these areas is needed in order to implement effective and sustainable integrated tick management strategies. We propose to refocus ecology studies with emphasis on metacommunity-based approaches to enable a holistic perspective addressing whole pathogen and host assemblages. Network analyses could be used to develop mechanistic models involving multi host-pathogen communities. An increase in our understanding of the ecology of tick-borne diseases across their geographic distribution will aid in the design of effective area-wide tick control strategies aimed to diminish the burden of pathogens transmitted by ticks. PMID:27062414

  4. [Latinamerican guidelines of RIICER for diagnosis of tick-borne rickettsioses].

    PubMed

    Oteo, José A; Nava, Santiago; Sousa, Rita de; Mattar, Salim; Venzal, José M; Abarca, Katia; Labruna, Marcelo B; Zavala-Castro, Jorge

    2014-02-01

    Tick-borne rickettsioses are worldwide infectious diseases that are considered emerging and re-emerging. Until recently the only tick-borne rickettsiosis present in Latin America was Rickettsia rickettsii infection, but to date, with the incorporation of new tools as PCR and sequencing and the quick cellular close tube cultures (Shell-vial), new species has been involved as human pathogens. In these guidelines, we offer an update of the microbiological assays for diagnosing rickettsioses. Besides we have included a section in which the most important hard ticks involved in human rickettsioses in Latinoamerica are detailed.

  5. Increased Relative Risk of Tick-Borne Encephalitis in Warmer Weather.

    PubMed

    Daniel, Milan; Danielová, Vlasta; Fialová, Alena; Malý, Marek; Kříž, Bohumír; Nuttall, Patricia A

    2018-01-01

    Tick-borne encephalitis (TBE) is a serious acute neuroinfection of humans caused by a tick-borne flavivirus. The disease is typically seasonal, linked to the host-seeking activity of Ixodes ricinus (predominantly nymphs), the principal European tick vector species. To address the need for accurate risk predictions of contracting TBE, data on 4,044 TBE cases reported in the Czech Republic during 2001-2006 were compared with questing activity of I. ricinus nymphs monitored weekly at a defined location for the same 6-year period. A time shift of 21 days between infected tick bite and recorded disease onset provided the optimal model for comparing the number of cases of TBE with numbers of questing nymphs. Mean annual distribution of TBE cases and tick counts showed a similar bimodal distribution. Significantly, the ratio of TBE cases to questing nymphs was highest in the summer-autumn period even though the number of questing nymphs peaked in the spring-summer period. However, this pattern changed during a period of extreme meteorological events of flooding and abnormally high temperatures, indicating that changes in climate affect the incidence of TBE. Previous studies failed to link human behavior with changes in incidence of TBE but showed extrinsic temperature impacts arbovirus replication. Hence, we hypothesize the apparent discrepancy between peak nymphal tick activity and greatest risk of contracting TBE is due to the effect of temperature on virus replication in the tick vector. Relative proportions of questing nymphs and the numbers of weeks in which they were found were greater in summer-autumn compared with spring-summer at near-ground temperatures >5°C and at standard day and weekly average temperatures of >15°C. Thus, during the summer-autumn period, the virus dose in infected tick bites is likely greater owing to increased virus replication at higher microclimatic temperatures, consequently increasing the relative risk of contracting TBE per summer

  6. Host surveys, ixodid tick biology and transmission scenarios as related to the tick-borne pathogen, Ehrlichia canis

    PubMed Central

    Stich, R. W.; Schaefer, John J.; Bremer, William G.; Needham, Glen R.; Jittapalapong, Sathaporn

    2008-01-01

    The ehrlichioses have been subject to increasing interest from veterinary and public health perspectives, but experimental studies of these diseases and their etiologic agents can be challenging. Ehrlichia canis, the primary etiologic agent of canine monocytic ehrlichiosis, is relatively well characterized and offers unique advantages and opportunities to study interactions between a monocytotropic pathogen and both its vertebrate and invertebrate hosts. Historically, advances in tick-borne disease control strategies have typically followed explication of tick-pathogen-vertebrate interactions, thus it is reasonable to expect novel, more sustainable approaches to control of these diseases as the transmission of their associated infections are investigated at the molecular through ecological levels. Better understanding of the interactions between E. canis and its canine and tick hosts would also elucidate similar interactions for other Ehrlichia species as well as the potential roles of canine sentinels, reservoirs and models of tick-borne zoonoses. This article summarizes natural exposure studies and experimental investigations of E. canis in the context of what is understood about biological vectors of tick-borne Anaplasmataceae. PMID:18963493

  7. Molecular identification of tick-borne pathogens in asymptomatic individuals with human immunodeficiency virus type 1 (HIV-1) infection: a retrospective study.

    PubMed

    Welc-Falęciak, Renata; Kowalska, Justyna D; Bednarska, Małgorzata; Szatan, Magdalena; Pawełczyk, Agnieszka

    2018-05-18

    The studies on the occurrence and diversity of tick-borne infections in HIV-infected individuals have been few, and the subject has been relatively neglected when compared with other common infections associated with HIV. In HIV-positive patients in whom a serological diagnostics is complicated due to reduced positive predictive value, a method where the microorganism is detected directly is of great value. Therefore, we performed a molecular study to ascertain the prevalence and incidence of tick-borne infections in HIV-infected persons in Poland, an endemic area for Ixodes ricinus ticks. Genomic DNA was isolated from whole blood of tested patients. Detection of tick-borne pathogens was performed by amplification and sequencing of different loci. Molecular and phylogenetic analyses of obtained nucleotide sequences were performed. Serum samples were analyzed for antibodies against tick-borne pathogens by using commercial tests in all patients. Among 148 studied blood samples from HIV-infected patients, two cases (1.4%) of infection with tick-borne pathogen were reported. No symptoms of tick-borne infection were observed in these cases. In one case a patient was infected with Anaplasma phagocytophilum - the agent of human granulocytic anaplasmosis (HGA) and in the other with Borrelia garinii. Our study revealed the first case of HIV positive patient infected with A. phagocytophilum. Asymptomatic tick-borne infection can occur in HIV-positive patients. The detailed history of tick bites, especially in endemic tick areas, should be considered as part of anamnesis in routine clinical care of HIV-positive patients.

  8. Non-systemic transmission of tick-borne diseases: A network approach

    NASA Astrophysics Data System (ADS)

    Ferreri, Luca; Bajardi, Paolo; Giacobini, Mario

    2016-10-01

    Tick-borne diseases can be transmitted via non-systemic (NS) transmission. This occurs when tick gets the infection by co-feeding with infected ticks on the same host resulting in a direct pathogen transmission between the vectors, without infecting the host. This transmission is peculiar, as it does not require any systemic infection of the host. The NS transmission is the main efficient transmission for the persistence of the tick-borne encephalitis virus in nature. By describing the heterogeneous ticks aggregation on hosts through a bipartite graphs representation, we are able to mathematically define the NS transmission and to depict the epidemiological conditions for the pathogen persistence. Despite the fact that the underlying network is largely fragmented, analytical and computational results show that the larger is the variability of the aggregation, and the easier is for the pathogen to persist in the population.

  9. Fatal Tick-Borne Encephalitis Virus Infections Caused by Siberian and European Subtypes, Finland, 2015.

    PubMed

    Kuivanen, Suvi; Smura, Teemu; Rantanen, Kirsi; Kämppi, Leena; Kantonen, Jonas; Kero, Mia; Jääskeläinen, Anu; Jääskeläinen, Anne J; Sane, Jussi; Myllykangas, Liisa; Paetau, Anders; Vapalahti, Olli

    2018-05-01

    In most locations except for Russia, tick-borne encephalitis is mainly caused by the European virus subtype. In 2015, fatal infections caused by European and Siberian tick-borne encephalitis virus subtypes in the same Ixodes ricinus tick focus in Finland raised concern over further spread of the Siberian subtype among widespread tick species.

  10. Genetic Characterization of the Tick-Borne Orbiviruses

    PubMed Central

    Belaganahalli, Manjunatha N.; Maan, Sushila; Maan, Narender S.; Brownlie, Joe; Tesh, Robert; Attoui, Houssam; Mertens, Peter P. C.

    2015-01-01

    The International Committee for Taxonomy of Viruses (ICTV) recognizes four species of tick-borne orbiviruses (TBOs): Chenuda virus, Chobar Gorge virus, Wad Medani virus and Great Island virus (genus Orbivirus, family Reoviridae). Nucleotide (nt) and amino acid (aa) sequence comparisons provide a basis for orbivirus detection and classification, however full genome sequence data were only available for the Great Island virus species. We report representative genome-sequences for the three other TBO species (virus isolates: Chenuda virus (CNUV); Chobar Gorge virus (CGV) and Wad Medani virus (WMV)). Phylogenetic comparisons show that TBOs cluster separately from insect-borne orbiviruses (IBOs). CNUV, CGV, WMV and GIV share low level aa/nt identities with other orbiviruses, in ‘conserved’ Pol, T2 and T13 proteins/genes, identifying them as four distinct virus-species. The TBO genome segment encoding cell attachment, outer capsid protein 1 (OC1), is approximately half the size of the equivalent segment from insect-borne orbiviruses, helping to explain why tick-borne orbiviruses have a ~1 kb smaller genome. PMID:25928203

  11. Genetic characterization of the tick-borne orbiviruses.

    PubMed

    Belaganahalli, Manjunatha N; Maan, Sushila; Maan, Narender S; Brownlie, Joe; Tesh, Robert; Attoui, Houssam; Mertens, Peter P C

    2015-04-28

    The International Committee for Taxonomy of Viruses (ICTV) recognizes four species of tick-borne orbiviruses (TBOs): Chenuda virus, Chobar Gorge virus, Wad Medani virus and Great Island virus (genus Orbivirus, family Reoviridae). Nucleotide (nt) and amino acid (aa) sequence comparisons provide a basis for orbivirus detection and classification, however full genome sequence data were only available for the Great Island virus species. We report representative genome-sequences for the three other TBO species (virus isolates: Chenuda virus (CNUV); Chobar Gorge virus (CGV) and Wad Medani virus (WMV)). Phylogenetic comparisons show that TBOs cluster separately from insect-borne orbiviruses (IBOs). CNUV, CGV, WMV and GIV share low level aa/nt identities with other orbiviruses, in 'conserved' Pol, T2 and T13 proteins/genes, identifying them as four distinct virus-species. The TBO genome segment encoding cell attachment, outer capsid protein 1 (OC1), is approximately half the size of the equivalent segment from insect-borne orbiviruses, helping to explain why tick-borne orbiviruses have a ~1 kb smaller genome.

  12. Tick-Borne Encephalitis with Hemorrhagic Syndrome, Novosibirsk Region, Russia, 1999

    PubMed Central

    Ternovoi, Vladimir A.; Kurzhukov, Gennady P.; Sokolov, Yuri V.; Ivanov, Gennady Y.; Ivanisenko, Vladimir A.; Loktev, Alexander V.; Ryder, Robert W.; Netesov, Sergey V.

    2003-01-01

    Eight fatal cases of tick-borne encephalitis with unusual hemorrhagic syndrome were identified in 1999 in the Novosibirsk Region, Russia. To study these strains, we sequenced cDNA fragments of protein E gene from six archival formalin-fixed brain samples. Phylogenetic analysis showed tick-borne encephalitis variants clustered with a Far Eastern subtype (homology 94.7%) but not with the Siberian subtype (82%). PMID:12781020

  13. Tick-Borne Diseases in Turkey: A Review Based on One Health Perspective.

    PubMed

    Inci, Abdullah; Yildirim, Alparslan; Duzlu, Onder; Doganay, Mehmet; Aksoy, Serap

    2016-12-01

    The importance of tick-borne diseases is increasing all over the world, including Turkey. Global warming, environmental and ecological changes and the existence of suitable habitats increase the impact of ticks and result in frequent emergence or re-emergence of tick-borne diseases (TBDs) with zoonotic characteristics. In Turkey, almost 19 TBDs have been reported in animals and men, involving four protozoa (babesiosis, theileriosis, cytauxzoonosis, hepatozoonosis), one filarial nematode (acanthocheilonemasis), ten bacterial agents (anaplasmosis, ehrlichiosis, aegyptianellosis, tick-borne typhus, Candidatus Rickettsia vini, Lyme borreliosis, tick-borne relapsing fever [TBRF], tularaemia, bartonellosis, and hemoplasmosis), and four viral infections (tick-borne encephalitis [TBE], Crimean-Congo Haemorrhagic Fever [CCHF], louping-ill [LI], and lumpy skin disease [LSD]). The growing number of TBD cases, in particular the fatal viral epidemics in humans, have led to increased public awareness and concern against TBDs in recent years. The World Health Organization (WHO) has developed a new political concept, called the "One Health" initiative, which is especially relevant for developing strategies against tick infestations and TBD control in humans and animals. It would be beneficial for Turkey to adopt this new strategy and establish specific research and control programs in coordination with international organizations like WHO, the World Organization for Animal Health (OIE), the Food and Agriculture Organization (FAO), the Centers for Disease Control and Prevention (CDC), and the European Center for Disease Prevention and Control (ECDC) to combat TBDs based on the "One Health Initiative" concept. In this article, we review the occurrence of primary TBDs in man and animals in Turkey in light of the "One Health" perspective.

  14. Invasion of two tick-borne diseases across New England: harnessing human surveillance data to capture underlying ecological invasion processes

    PubMed Central

    Walter, Katharine S.; Pepin, Kim M.; Webb, Colleen T.; Gaff, Holly D.; Krause, Peter J.; Pitzer, Virginia E.; Diuk-Wasser, Maria A.

    2016-01-01

    Modelling the spatial spread of vector-borne zoonotic pathogens maintained in enzootic transmission cycles remains a major challenge. The best available spatio-temporal data on pathogen spread often take the form of human disease surveillance data. By applying a classic ecological approach—occupancy modelling—to an epidemiological question of disease spread, we used surveillance data to examine the latent ecological invasion of tick-borne pathogens. Over the last half-century, previously undescribed tick-borne pathogens including the agents of Lyme disease and human babesiosis have rapidly spread across the northeast United States. Despite their epidemiological importance, the mechanisms of tick-borne pathogen invasion and drivers underlying the distinct invasion trajectories of the co-vectored pathogens remain unresolved. Our approach allowed us to estimate the unobserved ecological processes underlying pathogen spread while accounting for imperfect detection of human cases. Our model predicts that tick-borne diseases spread in a diffusion-like manner with occasional long-distance dispersal and that babesiosis spread exhibits strong dependence on Lyme disease. PMID:27252022

  15. Ticks and Tick-Borne Pathogens Associated with Feral Swine in Edwards Plateau and Gulf Prairies and Marshes Ecoregions of Texas

    DTIC Science & Technology

    2011-05-01

    for previous exposure to tick-borne pathogens in the genera Rickettsia and Ehrlichia (N=888) and Borrelia (N=849). Prevalence percentages by...immunoassay were 27.59%, 13.18%, and 2.12% for Rickettsia , Ehrlichia, and Borrelia, respectively. Samples positive by ELISA for exposure to Borrelia were...pathogen transmissions cycles in Texas. 15. SUBJECT TERMS Ticks, feral swine, bacteria, tick-borne pathogens, pigs, ecology, Rickettsia , Borrelia

  16. Widespread distribution of ticks and selected tick-borne pathogens in Kentucky (USA).

    PubMed

    Lockwood, Bessie H; Stasiak, Iga; Pfaff, Madeleine A; Cleveland, Christopher A; Yabsley, Michael J

    2018-03-01

    The geographical distribution of Ixodes scapularis and Amblyomma maculatum ticks is poorly understood in Kentucky. We conducted a convenience survey of wildlife species (white-tailed deer (Odocoileus virginianus), elk (Cervus canadensis) and black bears (Ursus americanus)) for ticks from October 2015 to January 2017. We detected four tick species including Amblyomma americanum, Dermacentor albipictus, I. scapularis and A. maculatum. Although the former two tick species were previously known to be widely distributed in Kentucky, we also found that I. scapularis and A. maculatum were also widespread. Because of the limited data available for pathogens from I. scapularis and A. maculatum, we tested them for Borrelia and Rickettsia spp. by polymerase chain reaction assays. Prevalence of Borrelia burgdorferi sensu stricto and Rickettsia parkeri were 11% and 3%, respectively. These data indicate that public health measures are important to prevent tick-borne diseases in Kentucky. Copyright © 2018 Elsevier GmbH. All rights reserved.

  17. Predictive Factors for Fatal Tick-Borne Spotted Fever in Brazil.

    PubMed

    de Oliveira, S V; Willemann, M C A; Gazeta, G S; Angerami, R N; Gurgel-Gonçalves, R

    2017-11-01

    In Brazil, two pathogenic Rickettsia species have been identified causing tick-borne spotted fever (SF). The aetiological agent Rickettsia rickettsii causes serious illness, particularly in the south-eastern region of the country. Moreover, the Rickettsia sp. strain Atlantic Rainforest cause milder clinical manifestations in south-eastern, south and north-east regions. This study has sought to analyse predictive factors for fatal SF. A case-control study was performed using disease notification records in Brazil. The cases included were individuals with laboratory confirmation and fatal progression of SF, while the controls included individuals with SF who were cured. A total of 386 cases and 415 controls were identified (1 : 1.1), and the cases and controls were similar in age. The factors identified as being protective against death were reported presence of ticks (odds ratio [OR], 0.60; 95% confidence interval [CI], 0.41-0.88), residing in urban areas (OR, 0.47, 95% CI, 0.31-0.74) and presenting lymphadenopathy (OR, 0.43; 95% CI, 0.23-0.82). Males exhibited a greater chance of death (OR, 1.57; 95% CI, 1.13-2.18), as did patients who were hospitalized (OR, 10.82; 95% CI, 6.38-18.35) and who presented hypotension or shock (OR, 10.80; 95% CI, 7.33-15.93), seizures (OR, 11.24; 95% CI, 6.49-19.45) and coma (OR of 15.16; 95% CI, 8.51-27.02). The study demonstrates the severity profile of the SF cases, defined either as the frequency of hospitalization (even in cases that were cured) or as the increased frequency of the clinical complications typically found in critical patients. Opportune clinical diagnosis, a careful evaluation of the epidemiological aspects of the disease and adequate care for patients are determining factors for reducing SF fatality rates. © 2017 Blackwell Verlag GmbH.

  18. Using Landscape Analysis to Test Hypotheses about Drivers of Tick Abundance and Infection Prevalence with Borrelia burgdorferi.

    PubMed

    Ferrell, A Michelle; Brinkerhoff, R Jory

    2018-04-12

    Patterns of vector-borne disease risk are changing globally in space and time and elevated disease risk of vector-borne infection can be driven by anthropogenic modification of the environment. Incidence of Lyme disease, caused by the bacterium Borrelia burgdorferi sensu stricto, has risen in a number of locations in North America and this increase may be driven by spatially or numerically expanding populations of the primary tick vector, Ixodes scapularis . We used a model selection approach to identify habitat fragmentation and land-use/land cover variables to test the hypothesis that the amount and configuration of forest cover at spatial scales relevant to deer, the primary hosts of adult ticks, would be the predominant determinants of tick abundance. We expected that land cover heterogeneity and amount of forest edge, a habitat thought to facilitate deer foraging and survival, would be the strongest driver of tick density and that larger spatial scales (5-10 km) would be more important than smaller scales (1 km). We generated metrics of deciduous and mixed forest fragmentation using Fragstats 4.4 implemented in ArcMap 10.3 and found, after adjusting for multicollinearity, that total forest edge within a 5 km buffer had a significant negative effect on tick density and that the proportion of forested land cover within a 10 km buffer was positively associated with density of I. scapularis nymphs. None of the 1 km fragmentation metrics were found to significantly improve the fit of the model. Elevation, previously associated with increased density of I. scapularis nymphs in Virginia, while significantly predictive in univariate analysis, was not an important driver of nymph density relative to fragmentation metrics. Our results suggest that amount of forest cover (i.e., lack of fragmentation) is the most important driver of I. scapularis density in our study system.

  19. Multistrain Infections with Lyme Borreliosis Pathogens in the Tick Vector.

    PubMed

    Durand, Jonas; Herrmann, Coralie; Genné, Dolores; Sarr, Anouk; Gern, Lise; Voordouw, Maarten J

    2017-02-01

    Mixed or multiple-strain infections are common in vector-borne diseases and have important implications for the epidemiology of these pathogens. Previous studies have mainly focused on interactions between pathogen strains in the vertebrate host, but little is known about what happens in the arthropod vector. Borrelia afzelii and Borrelia garinii are two species of spirochete bacteria that cause Lyme borreliosis in Europe and that share a tick vector, Ixodes ricinus Each of these two tick-borne pathogens consists of multiple strains that are often differentiated using the highly polymorphic ospC gene. For each Borrelia species, we studied the frequencies and abundances of the ospC strains in a wild population of I. ricinus ticks that had been sampled from the same field site over a period of 3 years. We used quantitative PCR (qPCR) and 454 sequencing to estimate the spirochete load and the strain diversity within each tick. For B. afzelii, there was a negative relationship between the two most common ospC strains, suggesting the presence of competitive interactions in the vertebrate host and possibly the tick vector. The flat relationship between total spirochete abundance and strain richness in the nymphal tick indicates that the mean abundance per strain decreases as the number of strains in the tick increases. Strains with the highest spirochete load in the nymphal tick were the most common strains in the tick population. The spirochete abundance in the nymphal tick appears to be an important life history trait that explains why some strains are more common than others in nature. Lyme borreliosis is the most common vector-borne disease in the Northern Hemisphere and is caused by spirochete bacteria that belong to the Borrelia burgdorferi sensu lato species complex. These tick-borne pathogens are transmitted among vertebrate hosts by hard ticks of the genus Ixodes Each Borrelia species can be further subdivided into genetically distinct strains. Multiple

  20. Tick-Borne Diseases in Turkey: A Review Based on One Health Perspective

    PubMed Central

    Yildirim, Alparslan; Duzlu, Onder; Doganay, Mehmet; Aksoy, Serap

    2016-01-01

    The importance of tick-borne diseases is increasing all over the world, including Turkey. Global warming, environmental and ecological changes and the existence of suitable habitats increase the impact of ticks and result in frequent emergence or re-emergence of tick-borne diseases (TBDs) with zoonotic characteristics. In Turkey, almost 19 TBDs have been reported in animals and men, involving four protozoa (babesiosis, theileriosis, cytauxzoonosis, hepatozoonosis), one filarial nematode (acanthocheilonemasis), ten bacterial agents (anaplasmosis, ehrlichiosis, aegyptianellosis, tick-borne typhus, Candidatus Rickettsia vini, Lyme borreliosis, tick-borne relapsing fever [TBRF], tularaemia, bartonellosis, and hemoplasmosis), and four viral infections (tick-borne encephalitis [TBE], Crimean-Congo Haemorrhagic Fever [CCHF], louping-ill [LI], and lumpy skin disease [LSD]). The growing number of TBD cases, in particular the fatal viral epidemics in humans, have led to increased public awareness and concern against TBDs in recent years. The World Health Organization (WHO) has developed a new political concept, called the “One Health” initiative, which is especially relevant for developing strategies against tick infestations and TBD control in humans and animals. It would be beneficial for Turkey to adopt this new strategy and establish specific research and control programs in coordination with international organizations like WHO, the World Organization for Animal Health (OIE), the Food and Agriculture Organization (FAO), the Centers for Disease Control and Prevention (CDC), and the European Center for Disease Prevention and Control (ECDC) to combat TBDs based on the “One Health Initiative” concept. In this article, we review the occurrence of primary TBDs in man and animals in Turkey in light of the “One Health” perspective. PMID:27977689

  1. Abundance of adult ticks (Acari: Ixodidae) in the Chernobyl nuclear power plant exclusion zone.

    PubMed

    Movila, A; Deriabina, T; Morozov, A; Sitnicova, N; Toderas, I; Uspenskaia, I; Alekhnovici, A

    2012-08-01

    The Chernobyl nuclear disaster resulted in contamination of vast areas in Europe. To date, there is little knowledge about the effects of radioactive contamination on tick species. We sampled ticks from vegetation and large-sized wild mammals belonging to orders Carnivora and Artiodactyla at sites with 0.76, 1.91, and 4.50 mSv/hr ionizing radiation background values in the Polesky State Radio-Ecological Reserve of the Chernobyl nuclear disaster zone in spring 2010. Altogether, 122 questing ticks were collected from vegetation. Among collected ticks, Dermacentor reticulatus (Fabricius) was, by far, the most abundant species (99.2%), followed by Ixodes ricnus (L.) (0.8%), which was collected only at the 0.76 mSv/hr site. The average sex ratio female∶male was 2.9∶1.0. In parallel with the present study, we examined 3 Sus scrofa (L.), 2 Nyctereutes procyonoides (Gray), and 1 Alces alces (L.) at the 4.50 mSv/hr site; 96 D. reticulatus ticks were found on 2 N. procyonoides specimens. The mean density and the intensity of infestation were 16 ticks per animal and 48 ticks per infested animal, respectively. Future investigations are warranted to further characterize the role of various tick vectors, vertebrate reservoirs, and diversity of tick-borne pathogens in the Chernobyl exclusion zone.

  2. [Role of Powassan virus in the etiological structure of tick-borne encephalitis in the Primorsky Kray].

    PubMed

    Leonova, G N; Isachkova, L M; Baranov, N I; Krugliak, S P

    1980-01-01

    Composite studies conducted annually in the Primorsky kray showed the tick-borne encephalitis virus to play the main etiological role in the group of encephalites with the spring-summer incidence. In 1976--1978, virological studies of 69 cases of the disease yielded 11 strains of tick-borne encephalitis virus. In 1978, from the blood of clinically normal woman after a tick bite strain 555 was first isolated which was identified as Powassan virus, and antigenemia was observed for 53 days using the fluorescent antibody technique. In the same period, serological examinations of the blood sera from 117 patients demonstrated antibody to tick-borne encephalitis virus in 69.2%, to Powassan virus in 4,3% and to both viruses simultaneously in 4.3%. Besides, antibody to tick-borne encephalitis virus, Powassan virus and both viruses simultaneously was found in patients with progredient forms of tick-borne encephalitis and in subjects with the history of tick attachment.

  3. Prevalence of tick-borne pathogens in ticks collected from migratory birds in Latvia.

    PubMed

    Capligina, Valentina; Salmane, Ineta; Keišs, Oskars; Vilks, Karlis; Japina, Kristine; Baumanis, Viesturs; Ranka, Renate

    2014-02-01

    Migratory birds act as hosts and long-distance vectors for several tick-borne infectious agents. Here, feeding Ixodes ticks were collected from migratory birds during the autumn migration period in Latvia and screened for the presence of epidemiologically important non-viral pathogens. A total of 93 DNA samples of ticks (37 larvae and 56 nymphs) removed from 41 birds (order Passeriformes, 9 species) was tested for Lyme borreliosis spirochaetes, Anaplasma phagocytophilum, Rickettsia spp., and Babesia spp. Borrelia burgdorferi DNA was detected in 18% of the tick samples, and a majority of infected ticks were from thrush (Turdus spp.) birds. Among the infected ticks, Borrelia valaisiana was detected in 41% of cases, Borrelia garinii in 35%, and mixed Bo. valaisiana and Bo. garinii infection in 24%. Anaplasma phagocytophilum DNA was detected in 2% of ticks, R. helvetica in 12%, and Babesia spp. pathogens in 4% of ticks. Among these samples, 3 Babesia species were identified: Ba. divergens, Ba. microti, and Ba. venatorum. Coinfection with different pathogens that included mixed infections with different Borrelia genospecies was found in 20% of nymphal and 3% of larval Ixodes ticks. These results suggest that migratory birds may support the circulation and spread of medically significant zoonoses in Europe. Copyright © 2013 Elsevier GmbH. All rights reserved.

  4. Molecular survey of neglected bacterial pathogens reveals an abundant diversity of species and genotypes in ticks collected from animal hosts across Romania.

    PubMed

    Andersson, Martin O; Tolf, Conny; Tamba, Paula; Stefanache, Mircea; Radbea, Gabriel; Frangoulidis, Dimitrios; Tomaso, Herbert; Waldenström, Jonas; Dobler, Gerhard; Chitimia-Dobler, Lidia

    2018-03-20

    Ticks are transmitting a wide range of bacterial pathogens that cause substantial morbidity and mortality in domestic animals. The full pathogen burden transmitted by tick vectors is incompletely studied in many geographical areas, and extensive studies are required to fully understand the diversity and distribution of pathogens transmitted by ticks. We sampled 824 ticks of 11 species collected in 19 counties in Romania. Ticks were collected mainly from dogs, but also from other domestic and wild animals, and were subjected to molecular screening for pathogens. Rickettsia spp. was the most commonly detected pathogen, occurring in 10.6% (87/824) of ticks. Several species were detected: Rickettsia helvetica, R. raoultii, R. massiliae, R. monacensis, R. slovaca and R. aeschlimannii. A single occurrence of the zoonotic bacterium Bartonella vinsonii berkhoffii was detected in a tick collected from a dog. Anaplasma phagocytophilum occurred in four samples, and sequences similar to Anaplasma marginale/ovis were abundant in ticks from ruminants. In addition, molecular screening showed that ticks from dogs were carrying an Ehrlichia species identical to the HF strain as well as the enigmatic zoonotic pathogen "Candidatus Neoehrlichia mikurensis". An organism similar to E. chaffeensis or E. muris was detected in an Ixodes ricinus collected from a fox. We describe an abundant diversity of bacterial tick-borne pathogens in ticks collected from animal hosts in Romania, both on the level of species and genotypes/strains within these species. Several findings were novel for Romania, including Bartonella vinsonii subsp. berkhoffii that causes bacteremia and endocarditis in dogs. "Candidatus Neoehrlichia mikurensis" was detected in a tick collected from a dog. Previously, a single case of infection in a dog was diagnosed in Germany. The results warrant further studies on the consequences of tick-borne pathogens in domestic animals in Romania.

  5. Molecular detection of severe fever with thrombocytopenia syndrome and tick-borne encephalitis viruses in ixodid ticks collected from vegetation, Republic of Korea, 2014.

    PubMed

    Yun, Seok-Min; Lee, Ye-Ji; Choi, WooYoung; Kim, Heung-Chul; Chong, Sung-Tae; Chang, Kyu-Sik; Coburn, Jordan M; Klein, Terry A; Lee, Won-Ja

    2016-07-01

    Ticks play an important role in transmission of arboviruses responsible for emerging infectious diseases, and have a significant impact on human, veterinary, and wildlife health. In the Republic of Korea (ROK), little is known about information regarding the presence of tick-borne viruses and their vectors. A total of 21,158 ticks belonging to 3 genera and 6 species collected at 6 provinces and 4 metropolitan areas in the ROK from March to October 2014 were assayed for selected tick-borne pathogens. Haemaphysalis longicornis (n=17,570) was the most numerously collected, followed by Haemaphysalis flava (n=3317), Ixodes nipponensis (n=249), Amblyomma testudinarium (n=11), Haemaphysalis phasiana (n=8), and Ixodes turdus (n=3). Ticks were pooled (adults 1-5, nymphs 1-30, and larvae 1-50) and tested by one-step reverse transcription polymerase chain reaction (RT-PCR) or nested RT-PCR for the detection of severe fever with thrombocytopenia virus (SFTSV), tick-borne encephalitis virus (TBEV), Powassan virus (POWV), Omsk hemorrhagic fever virus (OHFV), and Langat virus (LGTV). The overall maximum likelihood estimation (MLE) [estimated numbers of viral RNA positive ticks/1000 ticks] for SFTSV and TBEV was 0.95 and 0.43, respectively, while, all pools were negative for POWV, OHFV, and LGTV. The purpose of this study was to determine the prevalence of SFTSV, TBEV, POWV, OHFV, and LGTV in ixodid ticks collected from vegetation in the ROK to aid our understanding of the epidemiology of tick-borne viral diseases. Results from this study emphasize the need for continuous tick-based arbovirus surveillance to monitor the emergence of tick-borne diseases in the ROK. Copyright © 2016 The Authors. Published by Elsevier GmbH.. All rights reserved.

  6. Problem of ticks and tick-borne diseases in India with special emphasis on progress in tick control research: a review.

    PubMed

    Ghosh, Srikant; Nagar, Gaurav

    2014-12-01

    Ticks, as vectors of several zoonotic diseases, are ranked second only to mosquitoes as vectors. The diseases spread by ticks are a major constraint to animal productivity while causing morbidity and mortality in both animals and humans. A number of tick species have been recognised since long as vectors of lethal pathogens, viz. Crimean-Congo haemorrhagic fever virus (CCHFV), Kyasanur forest disease virus (KFDV), Babesia spp, Theileria, Rickettsia conorii, Anaplasma marginale, etc. and the damages caused by them are well-recognised. There is a need to reassess the renewed threat posed by the tick vectors and to prioritize the tick control research programme. This review is focused on the major tick-borne human and animal diseases in India and the progress in vector control research with emphasis on acaricide resistance, tick vaccine and the development of potential phytoacaricides as an integral part of integrated tick control programme.

  7. Detection of tick-borne encephalitis virus in I. ricinus ticks collected from autumn migratory birds in Latvia.

    PubMed

    Kazarina, Alisa; Japiņa, Kristīne; Keišs, Oskars; Salmane, Ineta; Bandere, Dace; Capligina, Valentina; Ranka, Renāte

    2015-03-01

    Birds have a potential of spreading ticks via bird migration routes. In this study, we screened 170 ticks removed during autumn 2010 from 55 birds belonging to 10 species for the presence of tick-borne encephalitis virus (TBEV). In total, TBEV RNA was detected in 14% of I. ricinus tick samples obtained from different birds species. The results of this study indicate the possible role of migrating birds in the dispersal of TBEV-infected ticks along the southward migration route. Copyright © 2014 Elsevier GmbH. All rights reserved.

  8. Experimental Transmission of Karshi (Mammalian Tick-Borne Flavivirus Group) Virus by Ornithodoros Ticks >2,900 Days after Initial Virus Exposure Supports the Role of Soft Ticks as a Long-Term Maintenance Mechanism for Certain Flaviviruses.

    PubMed

    Turell, Michael J

    2015-01-01

    Members of the mammalian tick-borne flavivirus group, including tick-borne encephalitis virus, are responsible for at least 10,000 clinical cases of tick-borne encephalitis each year. To attempt to explain the long-term maintenance of members of this group, we followed Ornithodoros parkeri, O. sonrai, and O. tartakovskyi for >2,900 days after they had been exposed to Karshi virus, a member of the mammalian tick-borne flavivirus group. Ticks were exposed to Karshi virus either by allowing them to feed on viremic suckling mice or by intracoelomic inoculation. The ticks were then allowed to feed individually on suckling mice after various periods of extrinsic incubation to determine their ability to transmit virus by bite and to determine how long the ticks would remain infectious. The ticks remained efficient vectors of Karshi virus, even when tested >2,900 d after their initial exposure to virus, including those ticks exposed to Karshi virus either orally or by inoculation. Ornithodoros spp. ticks were able to transmit Karshi virus for >2,900 days (nearly 8 years) after a single exposure to a viremic mouse. Therefore, these ticks may serve as a long-term maintenance mechanism for Karshi virus and potentially other members of the mammalian tick-borne flavivirus group.

  9. The first detection of the tick-borne encephalitis virus (TBEV) RNA in Dermacentor reticulatus ticks collected from the lowland European bison (Bison bonasus bonasus L.).

    PubMed

    Biernat, Beata; Karbowiak, Grzegorz; Stańczak, Joanna; Masny, Aleksander; Werszko, Joanna

    2016-01-01

    Tick borne encephalitis virus (TBEV) (Flaviviridae, Flavivirus) is the causative agent of tick-borne encephalitis (TBE), a potentially fatal neurological infection. The disease is endemic in a large region in Eurasia, where is transmitted mainly by hard ticks: Ixodes ricinus and I. persulcatus. It is known that also Dermacentor reticulatus is involved in a circulation of TBEV, but the knowledge of its importance in the TBE epidemiology is still insufficient. The Białowieża Primeval Forest is located in eastern Poland and it is a well-known endemic focus of tick-borne encephalitis. The aim of this study was to identify the prevalence of tick-borne encephalitis virus (TBEV) in Dermacentor reticulatus ticks collected from European bison (Bison bonasus bonasus), an important host of hard ticks in the Białowieża Primeval Forest. In the years 2008-2009, a total of 114 adult D. reticulatus ticks were collected from 7 European bison and examined individually for the presence of TBEV RNA using nested RT-PCR assay. Positive results were noted in 18.42% of ticks. This is the first record of TBEV infection in ticks collected from European bison.

  10. Immunological control of ticks and tick-borne diseases that impact cattle health and production in Mexico

    USDA-ARS?s Scientific Manuscript database

    The cattle industry is one of the most important agroeconomic activities in Mexico. The national herd is estimated to include approximately 33.5 million head of cattle. Ticks and tick-borne diseases are principal factors with a negative impact on cattle health and production in Mexico. The most econ...

  11. Infection of Macaca Radiata with Viruses of the Tick-Borne Encephalitis Group

    DTIC Science & Technology

    1992-01-01

    3411 IC Microbial Patho genesis 1 992, 13: 399 409 ET AD-A265 505 N9 3U 9312898 I Infection of Macaca radiata with viruses of the tick - borne...Diseases, Frederick, MD 21702-5011, U.SA.), M. K. Rippy, K. T. McKee Jr., P. M. Zack and C. J. Peters. Infection of Macaca radiata with viruses of the tick ...for human disease caused by other, related strains of this group of viruses. Key words: Macaca radiata; tick -borne encephalitis; pathogenesis; Kyasanur

  12. Tick-Borne Encephalitis in Sheep, Romania.

    PubMed

    Salat, Jiri; Mihalca, Andrei D; Mihaiu, Marian; Modrý, David; Ruzek, Daniel

    2017-12-01

    Little is known about the occurrence of tick-borne encephalitis in Romania. Sheep are an infection source for humans and are useful sentinels for risk analysis. We demonstrate high antibody prevalence (15.02%) among sheep used as sentinels for this disease in 80% of the tested localities in 5 counties of northwestern Romania.

  13. Spatial distribution of a population at risk: an important factor for understanding the recent rise in tick-borne diseases (Lyme borreliosis and tick-borne encephalitis in the Czech Republic).

    PubMed

    Zeman, Petr; Benes, Cestmir

    2013-12-01

    Recent rise in tick-borne diseases in many parts of Europe is a phenomenon in need of an explanation. We analyzed temporal trends in spatial distribution of a population at risk of Lyme borreliosis, tick-borne encephalitis, and as a control, also of a 'non-tick-borne disease' in the Czech Republic in 1997-2010. Analysis revealed that the population's exposure had been increasingly confined to the nearest surroundings of residences or in totally residential locations and that the incidence of the diseases depended in some causal way on how close to residences people exposed themselves to the risk. The rise in Lyme borreliosis and tick-borne encephalitis was solely due to infections acquired at or near patients' homes (<5 km), while the number of cases acquired further away was decreasing. The detected patterns in the data question some of the hypotheses which may be applicable in explaining the rise in disease incidences in the Czech Republic including the effect of climate change. Potentially causal factors are discussed. Copyright © 2013 Elsevier GmbH. All rights reserved.

  14. Smear Campaign: Misattribution of Pancytopenia to a Tick-Borne Illness.

    PubMed

    Lee, Jessica; Azzawi, Soraya; Peluso, Michael J; Richterman, Aaron; Batlle, Haiyan Ramirez; Yialamas, Maria A

    2018-04-01

    We report the case of a 51-year-old woman presenting with a targetoid rash and pancytopenia after a tick bite. Initial evaluation was notable for severe neutropenia on the complete blood cell count differential, a positive Lyme IgM antibody, and a peripheral blood smear demonstrating atypical lymphocytes. While her pancytopenia was initially attributed to tick-borne illness, peripheral flow cytometry showed 7% myeloblasts, and a bone marrow biopsy confirmed 60% blasts. The patient was ultimately diagnosed with acute myelogenous leukemia, in addition to early, localized Lyme disease. This case highlights the differential diagnosis for pancytopenia, cytopenia patterns for different tick-borne illnesses, the risk of premature closure in internal medicine, and management of Lyme disease in hosts with altered immunity.

  15. Correlation of TBE Incidence with Red Deer and Roe Deer Abundance in Slovenia

    PubMed Central

    Knap, Nataša; Avšič-Županc, Tatjana

    2013-01-01

    Tick-borne encephalitis (TBE) is a virus infection which sometimes causes human disease. The TBE virus is found in ticks and certain vertebrate tick hosts in restricted endemic localities termed TBE foci. The formation of natural foci is a combination of several factors: the vectors, a suitable and numerous enough number of hosts and in a habitat with suitable vegetation and climate. The present study investigated the influence of deer on the incidence of tick-borne encephalitis. We were able to obtain data from deer culls. Using this data, the abundance of deer was estimated and temporal and spatial analysis was performed. The abundance of deer has increased in the past decades, as well as the incidence of tick-borne encephalitis. Temporal analysis confirmed a correlation between red deer abundance and tick-borne encephalitis occurrence. Additionally, spatial analysis established, that in areas with high incidence of tick-borne encephalitis red deer density is higher, compared to areas with no or few human cases of tick-borne encephalitis. However, such correlation could not be confirmed between roe deer density and the incidence of tick-borne encephalitis. This is presumably due to roe deer density being above a certain threshold so that availability of tick reproduction hosts has no apparent effect on ticks' host finding and consequently may not be possible to correlate with incidence of human TBE. PMID:23776668

  16. Ticks and tick-borne novel bunyavirus collected from the natural environment and domestic animals in Jinan city, East China.

    PubMed

    Wang, Dong; Wang, Yongming; Yang, Guoliang; Liu, Huiyuan; Xin, Zheng

    2016-02-01

    Since 2011, 73 cases of the severe fever with thrombocytopenia syndrome, a novel tick-borne disease, have been reported in Jinan city through information system for disease control and prevention. Therefore, this study aimed to investigate the species, distribution, host animals of ticks and tick-borne pathogens. A total of 722 ticks were collected from two types of natural environment and six kinds of domestic animal in Jinan city. All the sampled ticks belonged to the same species, namely Haemaphysalis longicornis, and 94.7% of them were adult. The density of free-living ticks in grassland was nearly six times that in shrub. The prevalence of the goat (53.3%) was highest among the domestic animals. The host body region most frequently parasitized by H. longicornis was the head (77.8%), especially ears and periocular region. Novel bunyavirus was detected on the free-ranging goats in Jinan city. Acaricide treatment with a higher concentration on the ears, periocular region and the groin of domestic animals should be recommended to control the ticks effectively.

  17. Ticks and Tick-Borne Pathogens of the Caribbean: Current Understanding and Future Directions for More Comprehensive Surveillance.

    PubMed

    Gondard, Mathilde; Cabezas-Cruz, Alejandro; Charles, Roxanne A; Vayssier-Taussat, Muriel; Albina, Emmanuel; Moutailler, Sara

    2017-01-01

    Ticks are obligate hematophagous arthropods of significant importance to human and veterinary medicine. They transmit a vast array of pathogens, including bacteria, viruses, protozoa, and helminths. Most epidemiological data on ticks and tick-borne pathogens (TBPs) in the West Indies are limited to common livestock pathogens such as Ehrlichia ruminantium, Babesia spp. (i.e., B. bovis and B. bigemina ), and Anaplasma marginale , and less information is available on companion animal pathogens. Of note, human tick-borne diseases (TBDs) remain almost completely uncharacterized in the West Indies. Information on TBP presence in wildlife is also missing. Herein, we provide a comprehensive review of the ticks and TBPs affecting human and animal health in the Caribbean, and introduce the challenges associated with understanding TBD epidemiology and implementing successful TBD management in this region. In particular, we stress the need for innovative and versatile surveillance tools using high-throughput pathogen detection (e.g., high-throughput real-time microfluidic PCR). The use of such tools in large epidemiological surveys will likely improve TBD prevention and control programs in the Caribbean.

  18. Translating ecology, physiology, biochemistry and population genetics research to meet the challenge of tick and tick-borne diseases in North America

    USDA-ARS?s Scientific Manuscript database

    Emerging and re-emerging tick-borne diseases threaten public health and the wellbeing of domestic animals and wildlife globally. The adoption of an evolutionary ecology framework aimed to diminish the impact of tick-borne diseases needs to be part of strategies to protect human and animal population...

  19. Translating ecology, physiology, biochemistry and molecular biology research to meet grand challenge of tick and tick-borne diseases in North America

    USDA-ARS?s Scientific Manuscript database

    Emerging and re-emerging tick-borne diseases threaten public health and the wellbeing of domestic animals and wildlife globally. The use of science-based technology to diminish the impact of tick-borne diseases should be an active research effort aimed to protect human and animal populations. Here, ...

  20. Epidemiology of Tick-Borne Borreliosis in Morocco

    PubMed Central

    Diatta, Georges; Souidi, Yassine; Granjon, Laurent; Arnathau, Céline; Durand, Patrick; Chauvancy, Gilles; Mané, Youssouph; Sarih, M'hammed; Belghyti, Driss; Renaud, François; Trape, Jean-François

    2012-01-01

    Background The presence in Morocco of Argasid ticks of the Ornithodoros erraticus complex, the vector of tick-borne relapsing fever (TBRF) in North Africa, has been known since 1919, but the disease is rarely diagnosed and few epidemiological data are available. Methodology/Principal Findings Between 2006 and 2011, we investigated the presence of Ornithodoros ticks in rodent burrows in 34 sites distributed across Morocco. We also collected small mammals in 10 sites and we investigated TBRF in febrile patients in Kenitra district. The prevalence of Borrelia infections was assessed by nested PCR amplification in ticks and the brain tissue of small mammals, and by evaluation of thick blood films in patients. A high proportion of burrows were infested with ticks of the O. erraticus complex in all regions of Morocco, with a mean of 39.5% for the whole country. Borrelia infections were found in 39/382 (10.2%) of the ticks and 12/140 (8.6%) of the rodents and insectivores studied by PCR amplification, and 102 patients tested positive by thick blood film. Five small mammalian species were found infected: Dipodillus campestris, Meriones shawi, Gerbillus hoogstrali, Gerbillus occiduus and Atelerix algirus. Three Borrelia species were identified in ticks and/or rodents: B. hispanica, B. crocidurae and B. merionesi. Conclusions/Significance Tick populations belonging to O. erraticus complex are widely distributed in Morocco and a high proportion of ticks and small mammals are infected by Borrelia species. Although rarely diagnosed, TBRF may be a common cause of morbidity in all regions of Morocco. PMID:23029574

  1. Past and future perspectives on mathematical models of tick-borne pathogens.

    PubMed

    Norman, R A; Worton, A J; Gilbert, L

    2016-06-01

    Ticks are vectors of pathogens which are important both with respect to human health and economically. They have a complex life cycle requiring several blood meals throughout their life. These blood meals take place on different individual hosts and potentially on different host species. Their life cycle is also dependent on environmental conditions such as the temperature and habitat type. Mathematical models have been used for the more than 30 years to help us understand how tick dynamics are dependent on these environmental factors and host availability. In this paper, we review models of tick dynamics and summarize the main results. This summary is split into two parts, one which looks at tick dynamics and one which looks at tick-borne pathogens. In general, the models of tick dynamics are used to determine when the peak in tick densities is likely to occur in the year and how that changes with environmental conditions. The models of tick-borne pathogens focus more on the conditions under which the pathogen can persist and how host population densities might be manipulated to control these pathogens. In the final section of the paper, we identify gaps in the current knowledge and future modelling approaches. These include spatial models linked to environmental information and Geographic Information System maps, and development of new modelling techniques which model tick densities per host more explicitly.

  2. Experimental Transmission of Karshi and Langat (Tick-Borne Encephalitis Virus Complex) Viruses by Ornithodoros Ticks (Acari: Argasidae)

    DTIC Science & Technology

    2004-01-01

    mosquitoes and Ornithodoros ticks were evaluated for their potential to transmit Karshi and Langat (tick-borne encephalitis virus complex) viruses in the...orally exposed to Langat virus, were able to transmit this virus after more than 3 years, the longest interval tested. Therefore, Ornithodoros spp

  3. A Roadmap for Tick-Borne Flavivirus Research in the "Omics" Era.

    PubMed

    Grabowski, Jeffrey M; Hill, Catherine A

    2017-01-01

    Tick-borne flaviviruses (TBFs) affect human health globally. Human vaccines provide protection against some TBFs, and antivirals are available, yet TBF-specific control strategies are limited. Advances in genomics offer hope to understand the viral complement transmitted by ticks, and to develop disruptive, data-driven technologies for virus detection, treatment, and control. The genome assemblies of Ixodes scapularis , the North American tick vector of the TBF, Powassan virus, and other tick vectors, are providing insights into tick biology and pathogen transmission and serve as nucleation points for expanded genomic research. Systems biology has yielded insights to the response of tick cells to viral infection at the transcript and protein level, and new protein targets for vaccines to limit virus transmission. Reverse vaccinology approaches have moved candidate tick antigenic epitopes into vaccine development pipelines. Traditional drug and in silico screening have identified candidate antivirals, and target-based approaches have been developed to identify novel acaricides. Yet, additional genomic resources are required to expand TBF research. Priorities include genome assemblies for tick vectors, "omic" studies involving high consequence pathogens and vectors, and emphasizing viral metagenomics, tick-virus metabolomics, and structural genomics of TBF and tick proteins. Also required are resources for forward genetics, including the development of tick strains with quantifiable traits, genetic markers and linkage maps. Here we review the current state of genomic research on ticks and tick-borne viruses with an emphasis on TBFs. We outline an ambitious 10-year roadmap for research in the "omics era," and explore key milestones needed to accomplish the goal of delivering three new vaccines, antivirals and acaricides for TBF control by 2030.

  4. Tick-borne Diseases: The Big Two | NIH MedlinePlus the Magazine

    MedlinePlus

    ... been a tick bite. Photo: CDC/James Gathany Lyme disease Lyme disease is the most common tick-borne disease in ... nervous system can develop in patients with late Lyme disease. Lyme disease has different stages. The rash is ...

  5. The burden of tick-borne diseases in the Altai region of Russia.

    PubMed

    Dedkov, V G; Simonova, E G; Beshlebova, O V; Safonova, M V; Stukolova, O A; Verigina, E V; Savinov, G V; Karaseva, I P; Blinova, E A; Granitov, V M; Arsenjeva, I V; Shipulin, G A

    2017-08-01

    This article presents the results of a comprehensive survey of the burden of tick-borne infectious diseases (TBIDs) in the Altai region of Russia. Official data for TBID incidence were analyzed and 201 samples from patients with suspected TBID were studied. Furthermore, questing ticks and ticks recovered from humans were examined to estimate prevalence of TBID-causative agents. The Altai region was determined to have a heightened risk for TBIDs in Russia. The most epidemiologically significant tick-borne illness in this area is spotted fever group rickettsiosis, while nationally in Russia, the leading TBID is Lyme borreliosis. The prevalence of mixed infection was 12.4% among the studied cases. Additionally, the prevalence of poorly studied pathogens - Kemerovo virus (KEMV) and Rickettsia tarasevichiae - in ticks from the Altai region was determined. Copyright © 2017 Elsevier GmbH. All rights reserved.

  6. Tick-borne encephalitis: a disease neglected by travel medicine.

    PubMed

    Haditsch, Martin; Kunze, Ursula

    2013-01-01

    Tick-borne encephalitis (TBE) is a vector-borne disease that is primarily transmitted to humans by infected ticks and causes infection of the central nervous system. Clinical presentations range from meningitis to encephalitis with or without myelitis, and infection may result in death or long-term neurological sequelae. TBE is endemic in regions of at least 27 European as well as in some Asian countries. Infection and disease, however, can be averted successfully by tick-bite prevention and active vaccination. The risk of infection has shifted from daily life and occupational exposure to leisure-time activities, including travelling. Outdoor activities during the tick season with contact with nature increase the risk of tick bites. Although the number of travel-associated cases is unknown, it is certainly under-estimated because there is hardly any awareness of TBE in non-endemic countries. Therefore, the majority of cases remain undiagnosed, also because of the lack of diagnostic serology, as there is no routine screening for TBE in non-endemic regions. Because of the increasing number of travellers from TBE non-endemic to endemic regions, and in view of the fact that TBE was included in the list of notifiable diseases in the European Union in September 2012, this disease needs to become an important issue in travel medicine. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Prevalence of tick-borne pathogens in Ixodes ricinus and Dermacentor reticulatus ticks from different geographical locations in Belarus.

    PubMed

    Reye, Anna L; Stegniy, Valentina; Mishaeva, Nina P; Velhin, Sviataslau; Hübschen, Judith M; Ignatyev, George; Muller, Claude P

    2013-01-01

    Worldwide, ticks are important vectors of human and animal pathogens. Besides Lyme Borreliosis, a variety of other bacterial and protozoal tick-borne infections are of medical interest in Europe. In this study, 553 questing and feeding Ixodes ricinus (n = 327) and Dermacentor reticulatus ticks (n = 226) were analysed by PCR for Borrelia, Rickettsia, Anaplasma, Coxiella, Francisella and Babesia species. Overall, the pathogen prevalence in ticks was 30.6% for I. ricinus and 45.6% for D. reticulatus. The majority of infections were caused by members of the spotted-fever group rickettsiae (24.4%), 9.4% of ticks were positive for Borrelia burgdorferi sensu lato, with Borrelia afzelii being the most frequently detected species (40.4%). Pathogens with low prevalence rates in ticks were Anaplasma phagocytophilum (2.2%), Coxiella burnetii (0.9%), Francisella tularensis subspecies (0.7%), Bartonella henselae (0.7%), Babesia microti (0.5%) and Babesia venatorum (0.4%). On a regional level, hotspots of pathogens were identified for A. phagocytophilum (12.5-17.2%), F. tularensis ssp. (5.5%) and C. burnetii (9.1%), suggesting established zoonotic cycles of these pathogens at least at these sites. Our survey revealed a high burden of tick-borne pathogens in questing and feeding I. ricinus and D. reticulatus ticks collected in different regions in Belarus, indicating a potential risk for humans and animals. Identified hotspots of infected ticks should be included in future surveillance studies, especially when F. tularensis ssp. and C. burnetii are involved.

  8. Tick repellents and acaricides of botanical origin: a green roadmap to control tick-borne diseases?

    PubMed

    Benelli, Giovanni; Pavela, Roman; Canale, Angelo; Mehlhorn, Heinz

    2016-07-01

    Arthropods are dangerous vectors of agents of deadly diseases, which may hit as epidemics or pandemics in the increasing world population of humans and animals. Among them, ticks transmit more pathogen species than any other group of blood-feeding arthropods worldwide. Thus, the effective and eco-friendly control of tick vectors in a constantly changing environment is a crucial challenge. A number of novel routes have been attempted to prevent and control tick-borne diseases, including the development of (i) vaccines against viruses vectored by ticks; (ii) pheromone-based control tools, with special reference to the "lure and kill" techniques; (iii) biological control programmes relying on ticks' natural enemies and pathogens; and (iv) the integrated pest management practices aimed at reducing tick interactions with livestock. However, the extensive employment of acaricides and tick repellents still remains the two most effective and ready-to-use strategies. Unfortunately, the first one is limited by the rapid development of resistance in ticks, as well as by serious environmental concerns. On the other hand, the exploitation of plants as sources of effective tick repellents is often promising. Here, we reviewed current knowledge concerning the effectiveness of plant extracts as acaricides or repellents against tick vectors of public health importance, with special reference to Ixodes ricinus, Ixodes persulcatus, Amblyomma cajennense, Haemaphysalis bispinosa, Haemaphysalis longicornis, Hyalomma anatolicum, Hyalomma marginatum rufipes, Rhipicephalus appendiculatus, Rhipicephalus (Boophilus) microplus, Rhipicephalus pulchellus, Rhipicephalus sanguineus and Rhipicephalus turanicus. Eighty-three plant species from 35 botanical families were selected. The most frequent botanical families exploited as sources of acaricides and repellents against ticks were Asteraceae (15 % of the selected studies), Fabaceae (9 %), Lamiaceae (10 %), Meliaceae (5 %), Solanaceae (6

  9. Ticks and the city - are there any differences between city parks and natural forests in terms of tick abundance and prevalence of spirochaetes?

    PubMed

    Kowalec, Maciej; Szewczyk, Tomasz; Welc-Falęciak, Renata; Siński, Edward; Karbowiak, Grzegorz; Bajer, Anna

    2017-11-21

    Ixodes ricinus ticks are commonly encountered in either natural or urban areas, contributing to Lyme disease agents Borreliella [(Borrelia burgdorferi (sensu lato)] spp. and Borrelia miyamotoi enzootic cycles in cities. It is an actual problem whether urbanization affects pathogen circulation and therefore risk of infection. The aim of the study was to evaluate main tick-borne disease risk factors in natural, endemic areas of north-east (NE) Poland (Białowieża) and urban areas of central Poland (Warsaw), measuring tick abundance/density, prevalence of infection with spirochaetes and diversity of these pathogens in spring-early summer and late summer-autumn periods between 2012 and 2015. Questing I. ricinus ticks were collected from three urban sites in Warsaw, central Poland and three natural sites in Białowieża, NE Poland. A total of 2993 ticks were analyzed for the presence of Borreliella spp. and/or Borrelia miyamotoi DNA by PCR. Tick abundance was analyzed by General Linear Models (GLM). Prevalence and distribution of spirochaetes was analyzed by Maximum Likelihood techniques based on log-linear analysis of contingency tables (HILOGLINEAR). Species typing and molecular phylogenetic analysis based on the sequenced flaB marker were carried out. Overall 4617 I. ricinus ticks were collected (2258 nymphs and 2359 adults). We report well established population of ticks in urban areas (10.1 ± 0.9 ticks/100 m 2 ), as in endemic natural areas with higher mean tick abundance (16.5 ± 1.5 ticks/100 m 2 ). Tick densities were the highest in spring-early summer in both types of areas. We observed no effect of the type of area on Borreliella spp. and B. miyamotoi presence in ticks, resulting in similar prevalence of spirochaetes in urban and natural areas [10.9% (95% CI: 9.7-12.2%) vs 12.4% (95% CI: 10.1-15.1%), respectively]. Prevalence of spirochaetes was significantly higher in the summer-autumn period than in the spring-early summer [15.0% (95% CI: 12

  10. A multiplex serologic platform for diagnosis of tick-borne diseases.

    PubMed

    Tokarz, Rafal; Mishra, Nischay; Tagliafierro, Teresa; Sameroff, Stephen; Caciula, Adrian; Chauhan, Lokendrasingh; Patel, Jigar; Sullivan, Eric; Gucwa, Azad; Fallon, Brian; Golightly, Marc; Molins, Claudia; Schriefer, Martin; Marques, Adriana; Briese, Thomas; Lipkin, W Ian

    2018-02-16

    Tick-borne diseases are the most common vector-borne diseases in the United States, with serology being the primary method of diagnosis. We developed the first multiplex, array-based assay for serodiagnosis of tick-borne diseases called the TBD-Serochip. The TBD-Serochip was designed to discriminate antibody responses to 8 major tick-borne pathogens present in the United States, including Anaplasma phagocytophilum, Babesia microti, Borrelia burgdorferi, Borrelia miyamotoi, Ehrlichia chaffeensis, Rickettsia rickettsii, Heartland virus and Powassan virus. Each assay contains approximately 170,000 12-mer linear peptides that tile along the protein sequence of the major antigens from each agent with 11 amino acid overlap. This permits accurate identification of a wide range of specific immunodominant IgG and IgM epitopes that can then be used to enhance diagnostic accuracy and integrate differential diagnosis into a single assay. To test the performance of the TBD-Serochip, we examined sera from patients with confirmed Lyme disease, babesiosis, anaplasmosis, and Powassan virus disease. We identified a wide range of specific discriminatory epitopes that facilitated accurate diagnosis of each disease. We also identified previously undiagnosed infections. Our results indicate that the TBD-Serochip is a promising tool for a differential diagnosis not available with currently employed serologic assays for TBDs.

  11. Climate change and the epidemiology of selected tick-borne and mosquito-borne diseases: update from the International Society of Dermatology Climate Change Task Force.

    PubMed

    Andersen, Louise K; Davis, Mark D P

    2017-03-01

    Climate change refers to variation in the climate of a specific region or globally over time. A change has been reported in the epidemiology of tick- and mosquito-borne diseases in recent decades. Investigators have postulated that this effect may be associated with climate change. We reviewed the English-language literature describing changes in the epidemiology of specific tick- and mosquito-borne diseases, including the tick-borne diseases of Lyme disease, tularemia, Crimean-Congo hemorrhagic fever, Mediterranean spotted fever, and Rocky Mountain spotted fever and the mosquito-borne diseases of dengue, malaria, West Nile virus infection, Ross River virus disease, and Barmah Forest virus disease. We postulate that the changing epidemiology of tick- and mosquito-borne diseases is related to climate change. © 2016 The International Society of Dermatology.

  12. Distribution of tick-borne diseases in Japan: Past patterns and implications for the future.

    PubMed

    Yamaji, Kayoko; Aonuma, Hiroka; Kanuka, Hirotaka

    2018-04-20

    The rapid geographical spread of tick-borne diseases (TBDs) worldwide has recently provoked significant concerns amongst public health authorities. Tick-borne pathogens are maintained in enzootic cycles involving ticks and wild animal hosts, with epizootic spread to other mammals, including livestock and humans. Despite the increasing public health concern, current TBD diagnostic tests and treatments are inadequate, and predictive models of future risks posed by TBDs are limited by the heterogeneity of environmental, vector, and host factors, even in neighboring regions. In recent years, infections resulting in severe fever with thrombocytopenia syndrome (SFTS), Japanese spotted fever, and the scrub typhus pathogens have been reported frequently in addition to traditional TBDs in Japan. The Japanese archipelago is extremely elongated from north to south and its climate varies considerably, creating remarkable regional differences in tick species. The importance of continuous surveillance of TBDs has been growing in terms of geopathology - studies dealing with the relationships between geographic factors and the causes of specific diseases - in Japan and neighboring areas among eastern Asian countries, including China and Korea. In this review, we summarize detailed information regarding the history and epidemic status of human TBDs in Japan. Copyright © 2018 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  13. Effects of Climate and Climate Change on Vectors and Vector-Borne Diseases: Ticks Are Different.

    PubMed

    Ogden, Nick H; Lindsay, L Robbin

    2016-08-01

    There has been considerable debate as to whether global risk from vector-borne diseases will be impacted by climate change. This has focussed on important mosquito-borne diseases that are transmitted by the vectors from infected to uninfected humans. However, this debate has mostly ignored the biological diversity of vectors and vector-borne diseases. Here, we review how climate and climate change may impact those most divergent of arthropod disease vector groups: multivoltine insects and hard-bodied (ixodid) ticks. We contrast features of the life cycles and behaviour of these arthropods, and how weather, climate, and climate change may have very different impacts on the spatiotemporal occurrence and abundance of vectors, and the pathogens they transmit. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

  14. West African Cattle Farmers' Perception of Tick-Borne Diseases.

    PubMed

    Adehan, Safiou B; Adakal, Hassane; Gbinwoua, Donald; Yokossi, Daté; Zoungrana, Sébastien; Toé, Patrice; Ouedraogo, Mathieu; Gbaguidi, A Michel; Adoligbé, Camus; Fandohan, A Belarmin; Hounmanou, Gildas; Glèlè Kakaï, Romain; Farougou, Souaïbou; De Clercq, Eva M

    2018-03-13

    Worldwide, cattle production is struggling to face the negative impacts caused by ticks and Rhipicephalus (Boophilus) microplus is one of the most harmful ticks for livestock. Most of the people in West Africa depend on cattle farming and subsistence agriculture. The presence of ticks on cattle is a major problem faced by smallholder farmers who fight for their livelihood. National and regional tick control programs could assist these rural communities in protecting their livelihoods against ticks and tick-borne diseases, but only if they take into account the targeted herders and their perception on cattle management and tick control. This paper aims to provide a better insight in the socio-economic characteristics of Beninese cattle farmers, and their perception on tick burden, as well as to document common tick control strategies. Different tick species and their seasonality are well understood by cattle herders. For tick control, many still use manual tick removal, especially in the north of the country. The high cost of acaricides, the lack of financial means of African farmers, and of the local stockbreeders in particular, limits the use of acaricides in livestock breeding in Benin. While aiming to increase the meat or milk production of their animals, stockbreeders who can afford it sometimes turn to an abusive use of acaricides, which might in time lead to an increase in tick resistance. This study remains one of the rare studies to report extensively on the perceptions of West African cattle herders.

  15. A Roadmap for Tick-Borne Flavivirus Research in the “Omics” Era

    PubMed Central

    Grabowski, Jeffrey M.; Hill, Catherine A.

    2017-01-01

    Tick-borne flaviviruses (TBFs) affect human health globally. Human vaccines provide protection against some TBFs, and antivirals are available, yet TBF-specific control strategies are limited. Advances in genomics offer hope to understand the viral complement transmitted by ticks, and to develop disruptive, data-driven technologies for virus detection, treatment, and control. The genome assemblies of Ixodes scapularis, the North American tick vector of the TBF, Powassan virus, and other tick vectors, are providing insights into tick biology and pathogen transmission and serve as nucleation points for expanded genomic research. Systems biology has yielded insights to the response of tick cells to viral infection at the transcript and protein level, and new protein targets for vaccines to limit virus transmission. Reverse vaccinology approaches have moved candidate tick antigenic epitopes into vaccine development pipelines. Traditional drug and in silico screening have identified candidate antivirals, and target-based approaches have been developed to identify novel acaricides. Yet, additional genomic resources are required to expand TBF research. Priorities include genome assemblies for tick vectors, “omic” studies involving high consequence pathogens and vectors, and emphasizing viral metagenomics, tick-virus metabolomics, and structural genomics of TBF and tick proteins. Also required are resources for forward genetics, including the development of tick strains with quantifiable traits, genetic markers and linkage maps. Here we review the current state of genomic research on ticks and tick-borne viruses with an emphasis on TBFs. We outline an ambitious 10-year roadmap for research in the “omics era,” and explore key milestones needed to accomplish the goal of delivering three new vaccines, antivirals and acaricides for TBF control by 2030. PMID:29312896

  16. Tick-Borne Relapsing Fever Spirochetes in the Americas

    PubMed Central

    Lopez, Job E.; Krishnavahjala, Aparna; Garcia, Melissa N.; Bermudez, Sergio

    2016-01-01

    Relapsing fever spirochetes are tick- and louse-borne pathogens that primarily afflict those in impoverished countries. Historically the pathogens have had a significant impact on public health, yet currently they are often overlooked because of the nonspecific display of disease. In this review, we discuss aspects of relapsing fever (RF) spirochete pathogenesis including the: (1) clinical manifestation of disease; (2) ability to diagnose pathogen exposure; (3) the pathogen’s life cycle in the tick and mammal; and (4) ecological factors contributing to the maintenance of RF spirochetes in nature. PMID:28959690

  17. Transmission bottlenecks and RNAi collectively influence tick-borne flavivirus evolution.

    PubMed

    Grubaugh, Nathan D; Rückert, Claudia; Armstrong, Philip M; Bransfield, Angela; Anderson, John F; Ebel, Gregory D; Brackney, Doug E

    2016-07-01

    Arthropod-borne RNA viruses exist within hosts as heterogeneous populations of viral variants and, as a result, possess great genetic plasticity. Understanding the micro-evolutionary forces shaping these viruses can provide insights into how they emerge, adapt, and persist in new and changing ecological niches. While considerable attention has been directed toward studying the population dynamics of mosquito-borne viruses, little is known about tick-borne virus populations. Therefore, using a mouse and Ixodes scapularis tick transmission model, we examined Powassan virus (POWV; Flaviviridae, Flavivirus ) populations in and between both the vertebrate host and arthropod vector. We found that genetic bottlenecks, RNAi-mediated diversification, and selective constraints collectively influence POWV evolution. Together, our data provide a mechanistic explanation for the slow, long-term evolutionary trends of POWV, and suggest that all arthropod-borne viruses encounter similar selective pressures at the molecular level (i.e. RNAi), yet evolve much differently due to their unique rates and modes of transmission.

  18. Observations on changes in abundance of questing Ixodes ricinus, castor bean tick, over a 35-year period in the eastern part of its range (Russia, Tula region).

    PubMed

    Korotkov, Yu; Kozlova, T; Kozlovskaya, L

    2015-06-01

    Ixodes ricinus (Acari: Ixodidae) L. transmit a wide variety of pathogens to vertebrates including viruses, bacteria and protozoa. Understanding of the epidemiology of tick-borne infections requires basic knowledge of the regional and local factors influencing tick population dynamics. The present study describes the results of monitoring of a questing I. ricinus population, conducted over 35 years (1977-2011) in the eastern, poorly studied part of its range (Russia, Tula region). We have found that the multiannual average abundance of ticks is small and varies depending on the biotope and degree of urban transformation. Tick abundance for the first 14 years of observations (1977-1990) was at the lower limit of the sensitivity of our methods throughout the study area (0.1-0.9 specimens per 1-km transect). In the following 21 years (1991-2011), a manifold increase in abundance was observed, which reached 18.1 ± 1.8 individuals per 1-km transect in moist floodplain terraces, and 4.8 ± 0.9 in xerophylic hill woods. Long-term growth of tick abundance occurred in spite of a relatively constant abundance of small mammals and only minor fluctuations in the abundance of large wild animals. Climate and anthropogenic changes appear to be the main contributors to increased abundance of the tick. © 2015 The Royal Entomological Society.

  19. Tick-borne diseases and autoimmunity: A comprehensive review.

    PubMed

    Rodríguez, Yhojan; Rojas, Manuel; Gershwin, M Eric; Anaya, Juan-Manuel

    2018-03-01

    Tick-borne diseases (TBDs) are emerging and reemerging diseases transmitted by ticks, which portray wide heterogeneity and global distribution. TBDs may present acute clinical pictures that resemble those of autoimmune diseases (i.e., musculoskeletal symptoms, cutaneous involvement, neurologic impairment, renal failure, etc.), and in some cases infection is considered a triggering factor for autoimmunity (e.g., rheumatoid arthritis, autoimmune thyroid disease, vasculitides). The clinician should consider TBDs among the differential diagnoses when approaching autoimmune-like signs in areas of tick infestation. Epidemiological setting (e.g., endemic areas, seasons) and an accurate diagnostic approach (i.e., clinical history, physical examination and laboratory tests) are necessary to confirm TBDs. Further, control and prevention of TBDs is warranted. Research in the fields of ticks microbiome and vaccination (i.e., wildlife and humans) are ahead to control vector transmission and bacterial infection. This review offers a comprehensive update on TBDs and their relationship with autoimmunity. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Surveillance of tick-borne encephalitis virus in wild birds and ticks in Tomsk city and its suburbs (Western Siberia).

    PubMed

    Mikryukova, Tamara P; Moskvitina, Nina S; Kononova, Yulia V; Korobitsyn, Igor G; Kartashov, Mikhail Y; Tyuten Kov, Oleg Y; Protopopova, Elena V; Romanenko, Vladimir N; Chausov, Evgeny V; Gashkov, Sergey I; Konovalova, Svetlana N; Moskvitin, Sergey S; Tupota, Natalya L; Sementsova, Alexandra O; Ternovoi, Vladimir A; Loktev, Valery B

    2014-03-01

    To study the role of wild birds in the transmission of tick borne encephalitis virus (TBEV), we investigated randomly captured wild birds bearing ixodid ticks in a very highly endemic TBE region located in Tomsk city and its suburbs in the south of Western Siberia, Russia. The 779 wild birds representing 60 species were captured carrying a total of 841 ticks, Ixodes pavlovskyi Pom., 1946 (n=531), Ixodes persulcatus P. Sch., 1930 (n=244), and Ixodes plumbeus Leach. 1815 (n=66). The highest average number of ticks per bird in a particular species was found for the fieldfare (Turdus pilaris Linnaeus, 1758) (5.60 ticks/bird) and the tree pipit (Anthus trivialis Linnaeus, 1758) (13.25 ticks/bird). Samples from wild birds and ticks collected in highly endemic periods from 2006 to 2011 were tested for the TBEV markers using monoclonal modified enzyme immunoassay (EIA) and RT-PCR. TBEV RNA and antigen were found in 9.7% and 22.8% samples collected from wild birds, respectively. TBEV markers were also detected in 14.1% I. persulcatus ticks, 5.2% I. pavlovskyi, and 4.2% I. plumbeus ticks collected from wild birds. Two TBEV strains were also isolated on PKE (pig kidney embryo) cells from fieldfare and Blyth's reed warbler (Acrocephalus dumetorum Blyth, 1849). Sequencing of 5'-NCR of TBEV revealed that all TBEV isolates belong to Far Eastern (dominate) and Siberian genotypes. Several phylogenetic subgroups included TBEV sequences novel for the Tomsk region. Our data suggest that wild birds are potential disseminators of TBEV, TBEV-infected ixodid ticks, and possibly other tick-borne infections. Copyright © 2013 Elsevier GmbH. All rights reserved.

  1. COMPARISON BETWEEN PROTON MAGNETIC RESONANCE SPECTROSCOPY FINDINGS IN DOGS WITH TICK-BORNE ENCEPHALITIS AND CLINICALLY NORMAL DOGS.

    PubMed

    Sievert, Christine; Richter, Henning; Beckmann, Katrin; Kircher, Patrick R; Carrera, Ines

    2017-01-01

    In vivo diagnosis of tick-borne encephalitis is difficult due to high seroprevalence and rapid viral clearance, limiting detection of antibodies in blood and cerebrospinal fluid. Magnetic resonance imaging (MRI) characteristics of tick-borne encephalitis have been reported, however MRI studies can also be negative despite the presence of neurologic signs. Magnetic resonance spectroscopy ( 1 H MRS) is an imaging method that provides additional information about the metabolic characteristics of brain tissues. The purpose of this retrospective cross-sectional study was to describe brain metabolites using short echo time single-voxel 1 H MRS in dogs with confirmed tick-borne encephalitis and compare them with healthy dogs. Inclusion criteria for the affected dogs were neurological symptoms suggestive of tick-borne encephalitis, previous endemic stay and tick-bite, diagnostic quality brain MRI and 1 H MRS studies, and positive antibody titers or confirmation of tick-borne encephalitis with necropsy. Control dogs were 10, clinically normal beagles that had been used in a previous study. A total of six affected dogs met inclusion criteria. All dogs affected with tick-borne encephalitis had 1 H MRS metabolite concentration alterations versus control dogs. These changes included mild to moderate decreases in N-acetyl aspartate and creatine peaks, and mild increases in glutamate/glutamine peaks. No lactate or lipid signal was detected in any dog. Myoinositol and choline signals did not differ between affected and control dogs. In conclusion, findings supported the use of 1 H MRS as an adjunctive imaging method for dogs with suspected tick-borne encephalitis and inconclusive conventional MRI findings. © 2016 American College of Veterinary Radiology.

  2. Stability of a Tick-Borne Flavivirus in Milk

    PubMed Central

    Offerdahl, Danielle K.; Clancy, Niall G.; Bloom, Marshall E.

    2016-01-01

    The tick-borne flaviviruses (TBFV) occur worldwide and the tick-borne encephalitis virus (TBEV) members of the group often cause severe, debilitating neurological disease in humans. Although the primary route of infection is through the bite of an infected tick, alimentary infection through the consumption of TBEV-contaminated dairy products is also well-documented and is responsible for some disease in endemic areas. Experimental infection of goats, cattle, and sheep with TBEV shows that the virus can be excreted in the milk of infected animals. Additionally, the virus remains infectious after exposure to low pH levels, similar to those found in the stomach. To evaluate the survival of virus in milk, we studied the stability of the BSL-2 TBFV, Langat virus, in unpasteurized goat milk over time and after different thermal treatments. Virus was stable in milk maintained under refrigeration conditions; however, there was a marked reduction in virus titer after incubation at room temperature. High temperature, short time pasteurization protocols completely inactivated the virus. Interestingly, simulation of a typical thermal regime utilized for cheese did not completely inactivate the virus in milk. These findings stress the importance of proper milk handling and pasteurization processes in areas endemic for TBEV. PMID:27243000

  3. Stability of a Tick-Borne Flavivirus in Milk.

    PubMed

    Offerdahl, Danielle K; Clancy, Niall G; Bloom, Marshall E

    2016-01-01

    The tick-borne flaviviruses (TBFV) occur worldwide and the tick-borne encephalitis virus (TBEV) members of the group often cause severe, debilitating neurological disease in humans. Although the primary route of infection is through the bite of an infected tick, alimentary infection through the consumption of TBEV-contaminated dairy products is also well-documented and is responsible for some disease in endemic areas. Experimental infection of goats, cattle, and sheep with TBEV shows that the virus can be excreted in the milk of infected animals. Additionally, the virus remains infectious after exposure to low pH levels, similar to those found in the stomach. To evaluate the survival of virus in milk, we studied the stability of the BSL-2 TBFV, Langat virus, in unpasteurized goat milk over time and after different thermal treatments. Virus was stable in milk maintained under refrigeration conditions; however, there was a marked reduction in virus titer after incubation at room temperature. High temperature, short time pasteurization protocols completely inactivated the virus. Interestingly, simulation of a typical thermal regime utilized for cheese did not completely inactivate the virus in milk. These findings stress the importance of proper milk handling and pasteurization processes in areas endemic for TBEV.

  4. Ticks

    USGS Publications Warehouse

    Ginsberg, H.S.; Faulde, M.K.

    2008-01-01

    The most common vector-borne diseases in both Europe and North America are transmitted by ticks. Lyme borreliosis (LB), a tick-borne bacterial zoonosis, is the most highly prevalent. Other important tick-borne diseases include TBE (tick-borne encephalitis) and Crimean-Congo haemorrhagic fever in Europe, Rocky Mountain spotted fever (RMSF) in North America, and numerous less common tick-borne bacterial, viral, and protozoan diseases on both continents. The major etiological agent of LB is Borrelia burgdorferi in North America, while in Europe several related species of Borrelia can also cause human illness. These Borrelia genospecies differ in clinical manifestations, ecology (for example, some have primarily avian and others primarily mammalian reservoirs), and transmission cycles, so the epizootiology of LB is more complex in Europe than in North America. Ticks dwell predominantly in woodlands and meadows, and in association with animal hosts, with only limited colonization of human dwellings by a few species. Therefore, suburbanization has contributed substantially to the increase in tick-borne disease transmission in North America by fostering increased exposure of humans to tick habitat. The current trend toward suburbanization in Europe could potentially result in similar increases in transmission of tick-borne diseases. Incidence of tick-borne diseases can be lowered by active public education campaigns, targeted at the times and places of greatest potential for encounter between humans and infected ticks. Similarly, vaccines (e.g., against TBE) are most effective when made available to people at greatest risk, and for high-prevalence diseases such as LB. Consultation with vector-borne disease experts during the planning stages of new human developments can minimize the potential for residents to encounter infected ticks (e.g., by appropriate dwelling and landscape design). Furthermore, research on tick vectors, pathogens, transmission ecology, and on

  5. Ticks and Tick Bites Presenting as "Funny Moles": A Review of Different Presentations and a Focus on Tick-borne Diseases.

    PubMed

    Kallini, Joseph R; Khachemoune, Amor

    2017-03-01

    Purpose: To describe a man with an adherent tick mimicking a melanoma, summarize the salient features of this condition, and review other cases of ticks mistaken for dermatoses. Background: Ticks are obligatory ectoparasites. Disease-causing ticks belong to two families: Ixodidae (hard ticks) and Argasidae (soft ticks). Ticks thrive by consuming blood from animal hosts, and the transfer of infected blood from one host to the next is the method by which ticks spread disease. Materials and methods: The authors describe a man who presented to their dermatology clinic in New York with an unusual black pigmented lesion on the right zygomatic region of his face. He was worried about how rapidly the lesion had developed and the tingling of the skin surrounding it. Since the patient had a history of nonmelanoma skin cancer, he was concerned that the lesion was a melanoma. An excisional biopsy of the lesion revealed a non- Ixodes tick with a surrounding tick-bite reaction. Results: Ticks cause cutaneous manifestations through physical trauma and their salivary contents. A number of reports describe a similar phenomenon of a persistent tick being mistaken for a nodule or tumor. Management includes complete removal of a tick, either mechanically or surgically, along with the appropriate work-up for tick-borne diseases in the relevant geographic location. The decision to test for systemic disease depends on the clinical presentation of the patient and geographic location of the tick bite. Conclusion: A patient presented to the authors' dermatology clinic with a pigmented lesion suspicious for a melanoma, but the lesion was actually an adherent non- Ixodes tick. This case illustrates the importance of keeping insects and arthropods in the differential diagnosis of a sudden- and recent-onset pigmented skin lesion.

  6. Tick-Borne Encephalitis Virus Habitats in North East Germany: Reemergence of TBEV in Ticks after 15 Years of Inactivity

    PubMed Central

    Krienke, Anja; Riebold, Diana; Loebermann, Micha; Littmann, Martina; Fiedler, Karin; Klaus, Christine; Süss, Jochen; Reisinger, Emil Christian

    2014-01-01

    The incidence of tick-borne encephalitis has risen in Europe since 1990 and the tick-borne encephalitis virus (TBEV) has been documented to be spreading into regions where it was not previously endemic. In Mecklenburg-West Pomerania, a federal state in Northern Germany, TBEV was not detectable in over 16,000 collected ticks between 1992 and 2004. Until 2004, the last human case of TBE in the region was reported in 1985. Following the occurrence of three autochthonous human cases of TBE after 2004, however, we collected ticks from the areas in which the infections were contracted. To increase the chance of detecting TBEV-RNA, some of the ticks were fed on mice. Using nested RT-PCR, we were able to confirm the presence of TBEV in ticks for the first time after 15 years. A phylogenetic analysis revealed a close relationship between the sequences we obtained and a TBEV sequence from Mecklenburg-East Pomerania published in 1992 and pointed to the reemergence of a natural focus of TBEV after years of low activity. Our results imply that natural foci of TBEV may either persist at low levels of activity for years or reemerge through the agency of migrating birds. PMID:25110671

  7. Impact of a freeway on the dispersal of ticks and Ixodes ricinus-borne pathogens: forested resting areas may become Lyme disease hotspots.

    PubMed

    Hornok, Sándor; Mulvihill, Maria; Szőke, Krisztina; Gönczi, Enikő; Sulyok, Kinga M; Gyuranecz, Miklós; Hofmann-Lehmann, Regina

    2017-06-01

    Man-made barriers are well known for their effects on ecosystems. Habitat fragmentation, for instance, is a recognised consequence of modern-day infrastructure. The aim of the present study was to investigate the diversity and abundance of tick species, as well as the risks of acquiring tick-borne infections in habitats adjacent to a freeway. Therefore, ixodid ticks were collected from the vegetation at two-week intervals (in the main tick season, from March to June) in eight habitats of different types (forest, grove, grassland) along both sides of a freeway. Ixodes ricinus females were molecularly screened for three species of tick-borne bacteria. In the study period, 887 ixodid ticks were collected. These included 704 I. ricinus (79.4%), 51 Dermacentor reticulatus (5.7%), 78 D. marginatus (8.8%), 35 Haemaphysalis inermis (3.9%) and 19 H. concinna (2.1%). There was no significant difference in the abundance of tick species between similar habitats separated by the freeway, except for the absence of Dermacentor spp. on one side. In I. ricinus females, the overall prevalence of Anaplasma phagocytophilum was low, and (in part due to this low rate) did not show significant difference between the two sides of the freeway. Rickettsia helvetica had significantly different overall prevalence between two distant habitats along the same side of the freeway (12.3% vs. 31.4%), but not between habitats on the opposite sides. Borrelia burgdorferi s.l. showed significantly different overall prevalence between habitats both on the same and on the opposite sides of the freeway (8.6-35.9%), and the difference was higher if relevant habitats were also separated by the freeway. Importantly, the prevalence rate of the Lyme disease agent was highest in a forested resting area of the freeway, and was significantly inversely proportional to the prevalence of A. phagocytophilum (taking into account all evaluated habitats), apparently related to deer population density. Prevalence rates

  8. Detection of Tick-Borne Pathogens in Lambs Undergoing Prophylactic Treatment Against Ticks on Two Swedish Farms.

    PubMed

    Grandi, Giulio; Aspán, Anna; Pihl, Jenny; Gustafsson, Katarina; Engström, Fredrik; Jinnerot, Tomas; Söderlund, Robert; Chirico, Jan

    2018-01-01

    Tick-borne pathogens (TBPs), especially Anaplasma phagocytophilum , cause disease in grazing livestock. Tick prophylaxis is, therefore, a routine practice in sheep flocks in Sweden, especially in central, southern, and coastal areas of the country where ixodid ticks ( Ixodes ricinus and Haemaphysalis punctata ) are present. In the present study, the status of infection by A. phagocytophilum and other TBPs in lambs treated with tick prophylaxis has been assessed serologically and with polymerase chain reaction (PCR). Blood samples ( n  = 78) from lambs ( n  = 20) subjected to regular tick prophylactic treatment (flumethrin, Bayticol ® ) at two sites in different regions in Sweden (Östergötland, Gotland) were collected on four occasions from May until July 2013. The severity of clinical signs in Anaplasma- infected animals is known to differ between these two regions. In total, 20% of blood samples were PCR-positive for A. phagocytophilum . Serological analyses showed that 33% of all collected samples were positive for A. phagocytophilum , while 2.5% were positive for Borrelia burgdorferi s.l. and 13% for tick-borne encephalitis virus (TBEV). Percentages of lambs positive were 75 and 45% for A. phagocytophilum antibodies and DNA, respectively, while 10 and 45% were serologically positive for B. burgdorferi s.l. and TBEV, respectively. Sequencing of partial 16S rRNA genes from Anaplasma PCR positive samples revealed presence of A. phagocytophilum in all animals in Östergötland, while sequences consistent with A. phagocytophilum as well as A. capra and A. bovis were found on the island of Gotland. This is the first report of the occurrence of the latter two species in Sweden.

  9. Tick-borne encephalitis (TBE): an underestimated risk…still: report of the 14th annual meeting of the International Scientific Working Group on Tick-Borne Encephalitis (ISW-TBE).

    PubMed

    Kunze, Ursula

    2012-06-01

    Today, the risk of getting tick-borne encephalitis (TBE) is still underestimated in many parts of Europe and worldwide. Therefore, the 14th meeting of the International Scientific Working Group on Tick-Borne Encephalitis (ISW-TBE) - a group of neurologists, general practitioners, clinicians, travel physicians, virologists, pediatricians, and epidemiologists - was held under the title "Tick-borne encephalitis: an underestimated risk…still". Among the discussed issues were: TBE, an underestimated risk in children, a case report in two Dutch travelers, the very emotional report of a tick victim, an overview of the epidemiological situation, investigations to detect new TBE cases in Italy, TBE virus (TBEV) strains circulation in Northern Europe, TBE Program of the European Centre for Disease Prevention and Control (ECDC), efforts to increase the TBE vaccination rate in the Czech Republic, positioning statement of the World Health Organization (WHO), and TBE in dogs. To answer the question raised above: Yes, the risk of getting TBE is underestimated in children and adults, because awareness is still too low. It is still underestimated in several areas of Europe, where, for a lack of human cases, TBEV is thought to be absent. It is underestimated in travelers, because they still do not know enough about the risk, and diagnostic awareness in non-endemic countries is still low. Copyright © 2012. Published by Elsevier GmbH. All rights reserved.

  10. First report of Rickettsia raoultii in field collected Dermacentor reticulatus ticks from Austria.

    PubMed

    Duscher, Georg G; Hodžić, Adnan; Weiler, Martin; Vaux, Alexander G C; Rudolf, Ivo; Sixl, Wolfdieter; Medlock, Jolyon M; Versteirt, Veerle; Hubálek, Zdenek

    2016-07-01

    In a set of pooled field collected Dermacentor reticulatus ticks, Rickettsia raoultii, the causative agent of Tick-borne lymphadenopathy/Dermacentor-borne necrosis erythema and lymphadenopathy, was found for the first time in Austria. The coordinates of the positive locations for tick and pathogen abundance are given and shown in a map. Copyright © 2016 Elsevier GmbH. All rights reserved.

  11. Complete sequence of two tick-borne flaviviruses isolated from Siberia and the UK: analysis and significance of the 5' and 3'-UTRs.

    PubMed

    Gritsun, T S; Venugopal, K; Zanotto, P M; Mikhailov, M V; Sall, A A; Holmes, E C; Polkinghorne, I; Frolova, T V; Pogodina, V V; Lashkevich, V A; Gould, E A

    1997-05-01

    The complete nucleotide sequence of two tick-transmitted flaviviruses, Vasilchenko (Vs) from Siberia and louping ill (LI) from the UK, have been determined. The genomes were respectively, 10928 and 10871 nucleotides (nt) in length. The coding strategy and functional protein sequence motifs of tick-borne flaviviruses are presented in both Vs and LI viruses. The phylogenies based on maximum likelihood, maximum parsimony and distance analysis of the polyproteins, identified Vs virus as a member of the tick-borne encephalitis virus subgroup within the tick-borne serocomplex, genus Flavivirus, family Flaviviridae. Comparative alignment of the 3'-untranslated regions revealed deletions of different lengths essentially at the same position downstream of the stop codon for all tick-borne viruses. Two direct 27 nucleotide repeats at the 3'-end were found only for Vs and LI virus. Immediately following the deletions a region of 332-334 nt with relatively conserved primary structure (67-94% identity) was observed at the 3'-non-coding end of the virus genome. Pairwise comparisons of the nucleotide sequence data revealed similar levels of variation between the coding region, and the 5' and 3'-termini of the genome, implying an equivalent strong selective control for translated and untranslated regions. Indeed the predicted folding of the 5' and 3'-untranslated regions revealed patterns of stem and loop structures conserved for all tick-borne flaviviruses suggesting a purifying selection for preservation of essential RNA secondary structures which could be involved in translational control and replication. The possible implications of these findings are discussed.

  12. Prevalence of ticks and tick-borne pathogens: Babesia and Borrelia species in ticks infesting cats of Great Britain.

    PubMed

    Davies, Saran; Abdullah, Swaid; Helps, Chris; Tasker, Séverine; Newbury, Hannah; Wall, Richard

    2017-09-15

    In a study of tick and tick-borne pathogen prevalence, between May and October 2016, 278 veterinary practices in Great Britain examined 1855 cats. Six-hundred and one cats were found to have attached ticks. The most frequently recorded tick species was Ixodes ricinus (57.1%), followed by Ixodes hexagonus (41.4%) and Ixodes trianguliceps (1.5%). Male cats, 4-6 years of age living in rural areas were most likely to be carrying a tick; hair length and tick treatment history had no significant association with attachment. For cats that were parasitized by ticks in large urban areas, I. hexagonus was the most frequent species recorded. Molecular analysis was possible for 541 individual tick samples, others were too damaged for analysis; Babesia spp., and Borrelia burgdorferi sensu lato were identified in 1.1% (n=6) and 1.8% (n=10) of these, respectively. Babesia spp. included Babesia vulpes sp. nov./Babesia microti-like (n=4) in I. hexagonus and Babesia venatorum (n=2) in I. ricinus. Borrelia burgdorferi s.l. species included Borrelia garinii (n=6) and Borrelia afzelii (n=4). The majority of B. burgorferi s.l. cases were found in I. ricinus, with B. afzelii in one I. hexagonus nymph. No Borrelia or Babesia spp. were present in I. trianguliceps. To determine a true prevalence for ticks on cats, practices that only submitted questionnaires from cats with ticks and practices that submitted fewer than 5 returns per week were removed; amongst those considered to have adhered strictly to the collection protocol, feline tick prevalence amongst cats that had access to the outdoors was 6.6%. These results show that ticks can be found on cats throughout Great Britain, which harbour a range of species of Babesia and B. burgdorferi s.l. and that cats, particularly in green spaces within urban areas, may form an important host for I. hexagonus, a known vector of pathogens. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Risk of exposure to ticks (Ixodidae) and the prevalence of tick-borne encephalitis virus (TBEV) in ticks in Southern Poland.

    PubMed

    Cuber, Piotr; Andreassen, Åshild; Vainio, Kirsti; Asman, Marek; Dudman, Susanne; Szilman, Piotr; Szilman, Ewa; Ottesen, Preben; Ånestad, Gabriel; Cieśla-Nobis, Sabina; Solarz, Krzysztof

    2015-04-01

    The article presents the results of the first study on seasonal activity of ticks and prevalence of tick-borne encephalitis virus (TBEV) in nymphs from the Silesian Province (Southern Poland). Previous studies on the prevalence of TBEV in ticks in Poland have been conducted mostly in northern and eastern regions, but none in the Silesian Province itself. The aims of this study were to analyse the seasonal variation in tick populations and compare TBEV prevalence in nymphs from different geographical locations in the Silesia. A total of 5160 questing Ixodes ricinus ticks were collected by the flagging method from 23 localities in southern Poland in 2010. Micro-climatic parameters (air temperature and humidity) were measured in order to estimate their influence on tick population. The highest tick activity was recorded in spring and was positively correlated with relative air humidity (RH). TBEV in the Silesian Province was analysed in 1750 nymphs and an overall prevalence was 0.11% (2 pools out of 175 analysed). The results of this study show that TBEV pool prevalence in nymphs is low in accordance with the low number of TBE cases reported within the region. Copyright © 2015 Elsevier GmbH. All rights reserved.

  14. Abundance of the tick Dermacentor reticulatus in an ecosystem of abandoned meadows: Experimental intervention and the critical importance of mowing.

    PubMed

    Bajer, Anna; Rodo, Anna; Alsarraf, Mohammed; Dwużnik, Dorota; Behnke, Jerzy M; Mierzejewska, Ewa J

    2017-11-15

    The effect of agricultural activities on the environment has been falling in many areas of Europe in recent years and the associated abandonment of crop fields, meadows and pastures may enable an increase in tick densities. In the present study we assessed whether regular mowing would have a negative effect on Dermacentor reticulatus populations and whether the cessation of regular mowing would cause an increase in abundance of D. reticulatus ticks. Two field experiments were conducted during a five-year period (2012-2016) in the Mazowieckie (Mazovia) region of Central Poland. Experiment 1: The long-term effect of mowing on tick population was tested in the meadow ecosystem of Stoski, an old fallow land plot that was mowed three times a year. Experiment 2: Neglecting the cultivation by abandonment of arable land was evaluated in Kury village. Four areas (2 experimental 'fallow lands', 2 control meadows) were selected. The first fallow land plot was a fenced off area comprising mostly of a horse pasture and the second fallow land plot was designated in an old abandoned orchard. At each site, ticks were collected in consecutive springs and autumns by dragging at least twice during each season from experimental and control areas. Altogether 1452 D. reticulatus ticks were collected and their densities were compared by multifactorial ANOVA. In the end of the first experiment, a significant decrease (6 times) in tick abundance was observed in the mowed area in comparison to old fallow land. In the end of the second experiment, tick abundance was three times higher in the experimental fallow lands in comparison to the control meadows. In conclusion it was found that regular mowing significantly reduced the density of questing D. reticulatus ticks in open areas. Cessation of mowing may enhance the number of ticks and the associated risk of acquiring tick-borne diseases. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. The enzootic life-cycle of Borrelia burgdorferi (sensu lato) and tick-borne rickettsiae: an epidemiological study on wild-living small mammals and their ticks from Saxony, Germany.

    PubMed

    Obiegala, Anna; Król, Nina; Oltersdorf, Carolin; Nader, Julian; Pfeffer, Martin

    2017-03-13

    Borrelia burgdorferi (sensu lato) and rickettsiae of the spotted fever group are zoonotic tick-borne pathogens. While small mammals are confirmed reservoirs for certain Borrelia spp., little is known about the reservoirs for tick-borne rickettsiae. Between 2012 and 2014, ticks were collected from the vegetation and small mammals which were trapped in Saxony, Germany. DNA extracted from ticks and the small mammals' skin was analyzed for the presence of Rickettsia spp. and B. burgdorferi (s.l.) by qPCR targeting the gltA and p41 genes, respectively. Partial sequencing of the rickettsial ompB gene and an MLST of B. burgdorferi (s.l.) were conducted for species determination. In total, 673 small mammals belonging to eight species (Apodemus agrarius, n = 7; A. flavicollis, n = 214; Microtus arvalis, n = 8; Microtus agrestis, n = 1; Mustela nivalis, n = 2; Myodes glareolus, n = 435; Sorex araneus, n = 5; and Talpa europaea, n = 1) were collected and examined. In total, 916 questing ticks belonging to three species (Ixodes ricinus, n = 741; Dermacentor reticulatus, n = 174; and I. trianguliceps, n = 1) were collected. Of these, 474 ticks were further investigated. The prevalence for Rickettsia spp. and B. burgdorferi (s.l.) in the investigated small mammals was 25.3 and 31.2%, respectively. The chance of encountering Rickettsia spp. in M. glareolus was seven times higher for specimens infested with D. reticulatus than for those which were free of D. reticulatus (OR: 7.0; 95% CI: 3.3-14.7; P < 0.001). In total, 11.4% of questing I. ricinus and 70.5% of D. reticulatus were positive for Rickettsia spp. DNA of B. burgdorferi (s.l.) was detected only in I. ricinus (5.5%). Sequence analysis revealed 9 R. helvetica, 5 R. raoultii, and 1 R. felis obtained from 15 small mammal samples. Small mammals may serve as reservoirs for Rickettsia spp. and B. burgdorferi (s.l.). While the prevalence for Rickettsia spp. in M. glareolus is most

  16. Factors associated with tick bites and pathogen prevalence in ticks parasitizing humans in Georgia, USA.

    PubMed

    Gleim, Elizabeth R; Garrison, Laurel E; Vello, Marianne S; Savage, Mason Y; Lopez, Gaylord; Berghaus, Roy D; Yabsley, Michael J

    2016-03-02

    The incidence and emergence of tick-borne diseases has increased dramatically in the United States during the past 30 years, yet few large-scale epidemiological studies have been performed on individuals bitten by ticks. Epidemiological information, including disease development, may provide valuable information regarding effectiveness of tick bite prevention education, pathogen transmission, human-disease dynamics, and potential implications for under reporting of tick-borne diseases. Ticks found attached to Georgia residents were submitted for identification and polymerase chain reaction (PCR) testing for Francisella tularensis, Ehrlichia, Anaplasma, Borrelia, and Rickettsia spp. Tick bite victims were interviewed three weeks after the tick bite to identify various epidemiologic factors associated with infestation and if signs suggestive of a tick-borne disease had developed. Fisher's exact test of independence was used to evaluate associations between various factors evaluated in the study. A multivariable logistic regression model was used for the prediction of non-specific illness post-tick bite. From April 2005-December 2006, 444 participants submitted 597 ticks (426 Amblyomma americanum, 142 Dermacentor variabilis, 19 A. maculatum, 7 Ixodes scapularis, 3 Amblyomma sp.) which originated from 95 counties. Only 25 (34 %) of 74 interviewed individuals purposely took tick bite prevention measures. Ticks that were PCR positive for bacterial organisms were attached to 136 participants. Of the 77 participants who developed non-specific illness, 50 did not have PCR positive ticks, whereas 27 did have PCR positive tick (s). Of those 27 individuals, 12 fit the criteria for a possible tick-borne illness (i.e., tick attached >6 h [if known], ≥4 day incubation period, and the individual exhibited clinical symptoms typical of a tick-borne illness without exhibiting cough, sore throat, or sinus congestion). Ticks from these individuals were positive for R. amblyommii (n

  17. The phenology of ticks and the effects of long-term prescribed burning on tick population dynamics in southwestern Georgia and northwestern Florida.

    PubMed

    Gleim, Elizabeth R; Conner, L Mike; Berghaus, Roy D; Levin, Michael L; Zemtsova, Galina E; Yabsley, Michael J

    2014-01-01

    Some tick populations have increased dramatically in the past several decades leading to an increase in the incidence and emergence of tick-borne diseases. Management strategies that can effectively reduce tick populations while better understanding regional tick phenology is needed. One promising management strategy is prescribed burning. However, the efficacy of prescribed burning as a mechanism for tick control is unclear because past studies have provided conflicting data, likely due to a failure of some studies to simulate operational management scenarios and/or account for other predictors of tick abundance. Therefore, our study was conducted to increase knowledge of tick population dynamics relative to long-term prescribed fire management. Furthermore, we targeted a region, southwestern Georgia and northwestern Florida (USA), in which little is known regarding tick dynamics so that basic phenology could be determined. Twenty-one plots with varying burn regimes (burned surrounded by burned [BB], burned surrounded by unburned [BUB], unburned surrounded by burned [UBB], and unburned surrounded by unburned [UBUB]) were sampled monthly for two years while simultaneously collecting data on variables that can affect tick abundance (e.g., host abundance, vegetation structure, and micro- and macro-climatic conditions). In total, 47,185 ticks were collected, of which, 99% were Amblyomma americanum, 0.7% were Ixodes scapularis, and fewer numbers of Amblyomma maculatum, Ixodes brunneus, and Dermacentor variabilis. Monthly seasonality trends were similar between 2010 and 2011. Long-term prescribed burning consistently and significantly reduced tick counts (overall and specifically for A. americanum and I. scapularis) regardless of the burn regimes and variables evaluated. Tick species composition varied according to burn regime with A. americanum dominating at UBUB, A. maculatum at BB, I. scapularis at UBB, and a more even composition at BUB. These data indicate that

  18. Canine tick-borne diseases in pet dogs from Romania.

    PubMed

    Andersson, Martin O; Tolf, Conny; Tamba, Paula; Stefanache, Mircea; Waldenström, Jonas; Dobler, Gerhard; Chițimia-Dobler, Lidia

    2017-03-23

    Tick-borne diseases are of substantial concern worldwide for animals as well as humans. Dogs have been a human companion for millennia, and their significant impact on human life renders disease in dogs to be of great concern. Tick-borne diseases in dogs represent a substantial diagnostic challenge for veterinarians in that clinical signs are often diffuse and overlapping. In addition, co-infections with two or more pathogens enhance this problem further. Molecular methods are useful to disentangle co-infections and to accurately describe prevalence and geographical distribution of tick-borne diseases. At this point, this information is lacking in many areas worldwide. Romania is one such area, where prevalence and distribution of several important pathogens need to be further investigated. To address this, we screened blood samples from 96 sick dogs with molecular methods for eight different pathogens including Babesia spp., Theileria spp., Hepatozoon spp., Anaplasma spp., Ehrlichia spp., "Candidatus Neoehrlichia mikurensis", Mycoplasma spp., and Borrelia spp. As many as 45% (43/96) of the dogs in the study were infected with protozoan parasites. Babesia canis was the most frequent of these (28 infected dogs), whereas Hepatozoon canis was detected in 15% (14/96) and Babesia gibsoni was found in a single sample. Bacterial infection with Mycoplasma spp. occurred in 18% (17/96) of the sampled dogs. Obtained bacterial sequences revealed the occurrence of two species: Mycoplasma canis and "Candidatus Mycoplasma haematoparvum". In several cases co-infection with protozoan parasites and Mycoplasma sp. were detected. All dogs were negative for Anaplasma spp., Ehrlichia spp., "Ca. Neoehrlichia mikurensis", and for Borrelia spp. The results from the present study reinforce the notion that Babesia canis is an important pathogen in the Romanian dog population. However, more surprisingly, another protozoan species, H. canis, seems to be infecting dogs to a larger extent than

  19. Avian migrants facilitate invasions of neotropical ticks and tick-borne pathogens into the United States.

    PubMed

    Cohen, Emily B; Auckland, Lisa D; Marra, Peter P; Hamer, Sarah A

    2015-12-01

    Migratory birds have the potential to transport exotic vectors and pathogens of human and animal health importance across vast distances. We systematically examined birds that recently migrated to the United States from the Neotropics for ticks. We screened both ticks and birds for tick-borne pathogens, including Rickettsia species and Borrelia burgdorferi. Over two spring seasons (2013 and 2014), 3.56% of birds (n = 3,844) representing 42.35% of the species examined (n = 85) were infested by ticks. Ground-foraging birds with reduced fuel stores were most commonly infested. Eight tick species were identified, including seven in the genus Amblyomma, of which only Amblyomma maculatum/Amblyomma triste is known to be established in the United States. Most ticks on birds (67%) were neotropical species with ranges in Central and South America. Additionally, a single Ixodes genus tick was detected. A total of 29% of the ticks (n = 137) and no avian blood samples (n = 100) were positive for infection with Rickettsia species, including Rickettsia parkeri, an emerging cause of spotted fever in humans in the southern United States, a species in the group of Rickettsia monacensis, and uncharacterized species and endosymbionts of unknown pathogenicity. No avian tick or blood samples tested positive for B. burgdorferi, the etiologic agent of Lyme disease. An extrapolation of our findings suggests that anywhere from 4 to 39 million exotic neotropical ticks are transported to the United States annually on migratory songbirds, with uncertain consequences for human and animal health if the current barriers to their establishment and spread are overcome. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  20. Tick-borne encephalitis virus, Borrelia burgdorferi sensu lato, Borrelia miyamotoi, Anaplasma phagocytophilum and Candidatus Neoehrlichia mikurensis in Ixodes ricinus ticks collected from recreational islands in southern Norway.

    PubMed

    Kjelland, Vivian; Paulsen, Katrine M; Rollum, Rikke; Jenkins, Andrew; Stuen, Snorre; Soleng, Arnulf; Edgar, Kristin S; Lindstedt, Heidi H; Vaino, Kirsti; Gibory, Moustafa; Andreassen, Åshild K

    2018-04-12

    The aim of this study was to determine the occurrence of tick-borne pathogens of medical importance in questing ticks collected from five recreationally used islands along the Norwegian coastline. Furthermore, since coinfection may affect the disease severity, this study aimed to determine the extent of coinfection in individual ticks or co-localization of tick-borne pathogens. In all, 4158 questing Ixodes ricinus ticks were analyzed. For detection of tick-borne encephalitis virus (TBEV), nymphs (3690) were analyzed in pools of ten. To detect Borrelia burgdorferi sensu lato, B. miyamotoi, Anaplasma phagocytophilum and Candidatus Neoehrlichia mikurensis, 468 nymphs were analyzed individually. A total of five nymph pools was infected with TBEV, giving an overall prevalence of 0.14%. In the individually analyzed ticks, B. burgdorferi s. l. (15.6%), Candidatus N. mikurensis (11%), A. phagocytophilum (1.4%) and B. miyamotoi (0.9%) were detected. Coinfection was found in 3.3% of the ticks, and the only dual infection observed was with B. afzelii and Candidatus N. mikurensis. This association was significantly higher than what would occur by random chance. Copyright © 2018 Elsevier GmbH. All rights reserved.

  1. Impact of air temperature variation on the ixodid ticks habitat and tick-borne encephalitis incidence in the Russian Arctic: the case of the Komi Republic.

    PubMed

    Tokarevich, N; Tronin, A; Gnativ, B; Revich, B; Blinova, O; Evengard, B

    2017-01-01

    The causes of the recent rise of tick-borne encephalitis (TBE) incidence in Europe are discussed. Our objective was to estimate the impact of air temperature change on TBE incidence in the European part of the Russian Arctic. We analysed the TBE incidence in the Komi Republic (RK) over a 42-year period in relation to changes in local annual average air temperature, air temperature during the season of tick activity, tick abundance, TBE-prevalence in ticks, tick-bite incidence rate, and normalised difference vegetation index within the area under study. In 1998-2011 in RK a substantial growth of TBE virus (TBEV) prevalence both in questing and feeding ticks was observed. In 1992-2011 there was 23-fold growth of the tick-bite incidence rate in humans, a northward shift of the reported tick bites, and the season of tick bites increased from 4 to 6 months. In 1998-2011 there was more than 6-fold growth of average annual TBE incidence compared with 1970-1983 and 1984-1997 periods. This resulted both from the northward shift of TBE, and its growth in the south. In our view it was related to local climate change as both the average annual air temperature, and the air temperature during the tick activity season grew substantially. We revealed in RK a strong correlation between the change in the air temperature and that in TBE incidence. The satellite data showed NDVI growth within RK, i.e. alteration of the local ecosystem under the influence of climate change. The rise in TBE incidence in RK is related considerably to the expansion of the range of Ixodes persulcatus. The territory with reported TBE cases also expanded northward. Climate change is an important driver of TBE incidence rate growth.

  2. Tick-borne haemoparasites and Anaplasmataceae in domestic dogs in Zambia.

    PubMed

    Qiu, Yongjin; Kaneko, Chiho; Kajihara, Masahiro; Ngonda, Saasa; Simulundu, Edgar; Muleya, Walter; Thu, May June; Hang'ombe, Mudenda Bernard; Katakura, Ken; Takada, Ayato; Sawa, Hirofumi; Simuunza, Martin; Nakao, Ryo

    2018-05-01

    Tick-borne diseases (TBDs), including emerging and re-emerging infectious diseases, are important threats to human and animal health worldwide. Indeed, the number of reported human and animal infectious cases of novel TBD agents has increased in recent decades. However, TBDs tend to be neglected, especially in resource-limited countries that often have limited diagnostic capacity. The aim of this molecular survey was to detect and characterise tick-borne pathogens (Babesia, Theileria, and Hepatozoon parasites and Anaplasmataceae bacteria) in domestic dogs in Zambia. In total, 247 canine peripheral blood samples were collected in Lusaka, Mazabuka, Monze, and Shangombo. Conventional PCR to detect the selected pathogens was performed using DNA extracted from canine blood. One hundred eleven samples were positive for protozoa and 5 were positive for Anaplasmataceae. Sequencing of thirty-five randomly selected protozoa-positive samples revealed the presence of Babesia rossi, Babesia vogeli, and Hepatozoon canis 18S rDNA. Based on these sequences, a multiplex PCR system was developed to yield PCR products with different amplicons, the size of which depended on the parasite species; thus, each species could be identified without the need for sequence analysis. Approximately 40% of dogs were positive for H. canis. In particular, the positive rate (75.2%) of H. canis infection was significantly higher in Shangombo than in other sampling sites. Multiplex PCR assay detected B. rossi and B. vogeli infections in five and seven dogs, respectively, indicating that this approach is useful for detecting parasites with low prevalence. Sequencing analysis of gltA and groEL genes of Anaplasmataceae revealed that two and one dogs in Lusaka were infected with Anaplasma platys and Ehrlichia canis, respectively. The data indicated that Zambian dogs were infected with multiple tick-borne pathogens such as H. canis, B. rossi, B. vogeli, A. platys, E. canis and uncharacterized Ehrlichia sp

  3. Reducing the Risk of Tick-Borne Diseases through Smart, Safe and Sustainable Pest Control

    EPA Pesticide Factsheets

    Each year PestWise programs form new partnerships to address ongoing and emerging issues. Reducing the risk from ticks and tick-borne disease is an issue of importance and EPA is contributing to a larger federal effort.

  4. [Tick borne encephalitis and enviromental changes].

    PubMed

    Zajkowska, Joanna; Malzahn, Elzbieta; Kondrusik, Maciej; Grygorczuk, Sambor; Pancewicz, Sławomir S; Kuśmierczyk, Justyna; Czupryna, Piotr; Hermanowska-Szpakowicz, Teresa

    2006-01-01

    Currently observed markedly increased incidence of various tick borne diseases in many parts of Europe is due to documented climatic changes as well anthropogenic influence on habitat structure. One of the analyzed factors is tendency to increase of the spring temperatures, especially in the third decade of the April. Such conditions (spring temperatures above 7-10 degrees C) let the nymphs and larvae of Ixodes ricinus to feed simultaneously on rodents. This increases the risk of infection of Ixodes ricinus with TBE virus, so dangerous for humans.

  5. Tick-borne flavivirus infection in Ixodes scapularis larvae: development of a novel method for synchronous viral infection of ticks

    PubMed Central

    Mitzel, Dana N.; Wolfinbarger, James B.; Daniel Long, R.; Masnick, Max; Best, Sonja M.; Bloom, Marshall E.

    2007-01-01

    Following a bite from an infected tick, tick-borne flaviviruses cause encephalitis, meningitis and hemorrhagic fever in humans. Although these viruses spend most of their time in the tick, little is known regarding the virus-vector interactions. We developed a simple method for synchronously infecting Ixodes scapularis larvae with Langat virus (LGTV) by immersion in media containing the virus. This technique resulted in approximately 96% of ticks becoming infected. LGTV infection and replication were demonstrated by both viral antigen expression and the accumulation of viral RNA. Furthermore, ticks transmitted LGTV to 100% of the mice and maintained the virus through molting into the next life stage. This technique circumvents limitations present in the current methods by mimicking the natural route of infection and by using attenuated virus strains to infect ticks; thereby, making this technique a powerful tool to study both virus and tick determinants of replication, pathogenesis and transmission. PMID:17490700

  6. Tick-borne encephalitis virus in ticks detached from humans and follow-up of serological and clinical response.

    PubMed

    Lindblom, Pontus; Wilhelmsson, Peter; Fryland, Linda; Sjöwall, Johanna; Haglund, Mats; Matussek, Andreas; Ernerudh, Jan; Vene, Sirkka; Nyman, Dag; Andreassen, Ashild; Forsberg, Pia; Lindgren, Per-Eric

    2014-02-01

    The risk of tick-borne encephalitis virus (TBEV) infection after a tick bite remains largely unknown. To address this, we investigated the presence of TBEV in ticks detached from humans in an attempt to relate viral copy number, TBEV subtype, and tick feeding time with the serological and clinical response of the tick-bitten participants. Ticks, blood samples, and questionnaires were collected from tick-bitten humans at 34 primary health care centers in Sweden and in the Åland Islands (Finland). A total of 2167 ticks was received from 1886 persons in 2008-2009. Using a multiplex quantitative real-time PCR, 5 TBEV-infected ticks were found (overall prevalence 0.23%, copy range <4×10(2)-7.7×10(6)per tick). One unvaccinated person bitten by a tick containing 7.7×10(6) TBEV copies experienced symptoms. Another unvaccinated person bitten by a tick containing 1.8×10(3) TBEV copies developed neither symptoms nor TBEV antibodies. The remaining 3 persons were protected by vaccination. In contrast, despite lack of TBEV in the detached ticks, 2 persons developed antibodies against TBEV, one of whom reported symptoms. Overall, a low risk of TBEV infection was observed, and too few persons got bitten by TBEV-infected ticks to draw certain conclusions regarding the clinical outcome in relation to the duration of the blood meal and virus copy number. However, this study indicates that an antibody response may develop without clinical symptoms, that a bite by an infected tick not always leads to an antibody response or clinical symptoms, and a possible correlation between virus load and tick feeding time. Copyright © 2013 Elsevier GmbH. All rights reserved.

  7. Emerging arthropod-borne diseases of companion animals in Europe.

    PubMed

    Beugnet, Frederic; Marié, Jean-Lou

    2009-08-26

    Vector-borne diseases are caused by parasites, bacteria or viruses transmitted by the bite of hematophagous arthropods (mainly ticks and mosquitoes). The past few years have seen the emergence of new diseases, or re-emergence of existing ones, usually with changes in their epidemiology (i.e. geographical distribution, prevalence, and pathogenicity). The frequency of some vector-borne diseases of pets is increasing in Europe, i.e. canine babesiosis, granulocytic anaplasmosis, canine monocytic ehrlichiosis, thrombocytic anaplasmosis, and leishmaniosis. Except for the last, these diseases are transmitted by ticks. Both the distribution and abundance of the three main tick species, Rhipicephalus sanguineus, Dermacentor reticulatus and Ixodes ricinus are changing. The conditions for such changes involve primarily human factors, such as travel with pets, changes in human habitats, social and leisure activities, but climate changes also have a direct impact on arthropod vectors (abundance, geographical distribution, and vectorial capacity). Besides the most known diseases, attention should be kept on tick-borne encephalitis, which seems to be increasing in western Europe, as well as flea-borne diseases like the flea-transmitted rickettsiosis. Here, after consideration of the main reasons for changes in tick vector ecology, an overview of each "emerging" vector-borne diseases of pets is presented.

  8. Use of a tick-borne disease manual increases accuracy of tick identification among primary care providers in Lyme disease endemic areas.

    PubMed

    Butler, Amber D; Carlson, Meredith L; Nelson, Christina A

    2017-02-01

    Given the high incidence of tick bites and tick-borne diseases in the United States, it is important for primary care providers to recognize common ticks and the pathogens they may transmit. If a patient has removed and saved an attached tick, identifying the tick helps guide clinical management and determine whether antibiotic prophylaxis for Lyme disease is appropriate. To investigate providers' ability to recognize common ticks and the pathogens they may transmit, we asked 76 primary care providers from Lyme disease endemic areas to identify the common name or genus of preserved ticks found in their area. At baseline, 10.5%, 46.1%, and 57.9% of participants correctly identified an adult female blacklegged tick (engorged), dog tick, and lone star tick, respectively. Less than half of participants identified the three pathogens most frequently transmitted by blacklegged ticks. Use of a reference manual with tick photographs and drawings substantially improved identification of ticks and associated pathogens and therefore should be encouraged in clinical practice. Copyright © 2016 Elsevier GmbH. All rights reserved.

  9. Golden jackals (Canis aureus) as hosts for ticks and tick-borne pathogens in Serbia.

    PubMed

    Sukara, Ratko; Chochlakis, Dimosthenis; Ćirović, Duško; Penezić, Aleksandra; Mihaljica, Darko; Ćakić, Sanja; Valčić, Miroslav; Tselentis, Yannis; Psaroulaki, Anna; Tomanović, Snežana

    2018-04-10

    The golden jackal (Canis aureus) is a medium-sized canid species native to Europe. This species is characterized by rapid large-scale expansion. A similar trend is also observed in Serbia, where the species is now distributed in more than a half of the territory. Although jackals prefer habitats in human-dominated landscapes, these animals have not been studied well enough from an eco-epidemiological point of view, and little is known about their potential for carrying zoonotic pathogens. In a study conducted during a three-year period (01/2010-02/2013), a total of 216 hunted or road-killed golden jackals were collected from 10 localities in Serbia. Ticks, when present, were removed, and after necropsy, spleen samples were collected from each animal. All tick and spleen samples were tested for the DNA of bacterial and protozoan tick-borne pathogens (Borrelia species, Bartonella species, Rickettsia species, Anaplasma species, Coxiella burnetii, Francisella species and Babesia species) by multiplex real-time PCR, conventional PCR and sequencing analyses. The DNA of Babesia canis was detected in nine out of 216 (4.2%) spleen samples, and two samples (0.9%) tested positive for Anaplasma phagocytophilum. In 118 ticks collected from jackals, the DNA of two Babesia species (Ba. canis and Ba. microti), three Borrelia species (Bo. garinii, Bo. valaisiana, and Bo. lusitaniae) and A. marginale was detected. From the aspect of public health surveillance, the potential role of the golden jackal in the maintenance of vector-borne zoonotic pathogens in Serbia must be considered, and further eco-epidemiological studies should be performed to determine the precise role of this animal species in zoonotic disease transmission cycles. Copyright © 2018 Elsevier GmbH. All rights reserved.

  10. Federal Initiative: Tick-Borne Disease Integrated Pest Management White Paper

    EPA Pesticide Factsheets

    The numbers of human cases of Lyme disease and other tick-borne diseases (TBDs) reported each year to CDC have been increasing steadily in the United States (US), currently totaling tens of thousands of diagnosed human cases annually.

  11. Co-infections and transmission dynamics in a tick-borne bacterium community exposed to songbirds.

    PubMed

    Heylen, Dieter; Fonville, Manoj; van Leeuwen, Arieke Docters; Sprong, Hein

    2016-03-01

    We investigated the transmission dynamics of a community of tick-borne pathogenic bacteria in a common European songbird (Parus major). Tick-naïve birds were infested with three successive batches (spaced 5 days apart) of field-collected Ixodes ricinus nymphs, carrying the following tick-borne bacteria: Rickettsia helvetica (16.9%), Borrelia garinii (1.9%), Borrelia miyamotoi (1.6%), Anaplasma phagocytophilum (1.2%) and Candidatus Neoehrlichia mikurensis (0.4%). Fed ticks were screened for the pathogens after moulting to the next developmental phase. We found evidence for early transmission (within 2.75 days after exposure) of R. helvetica and B. garinii, and to a lesser extent of A. phagocytophilum based on the increased infection rates of ticks during the first infestation. The proportion of ticks infected with R. helvetica remained constant over the three infestations. In contrast, the infection rate of B. garinii in the ticks increased over the three infestations, indicating a more gradual development of host tissue infection. No interactions were found among the different bacterium species during transmission. Birds did not transmit or amplify the other bacterial species. We show that individual birds can transmit several pathogenic bacterium species at the same time using different mechanisms, and that the transmission facilitation by birds increases the frequency of co-infections in ticks. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

  12. Report on Tick-Borne Disease and Integrated Pest Management Conference

    EPA Pesticide Factsheets

    The US Environmental Protection Agency (EPA) and the Centers for Disease Control and Prevention (CDC) co-hosted a conference on Tick-Borne Disease Integrated Pest Management on March 5-6, 2013, in Arlington, VA. This document summarizes this meeting.

  13. Molecular identification of tick-borne pathogens in ticks collected from dogs and small ruminants from Greece.

    PubMed

    Chaligiannis, Ιlias; Fernández de Mera, Isabel G; Papa, Anna; Sotiraki, Smaragda; de la Fuente, José

    2018-04-01

    Ticks are vectors for a variety of human and animal pathogens (bacteria, protozoa and viruses). In order to investigate the pathogens carried by ticks in Greece, a total of 179 adult ticks (114 female and 65 male) were collected from domestic animals (sheep, goats and dogs) from 14 prefectures of six regions of Greece. Among them, 40 were Dermacentor marginatus, 25 Haemaphysalis parva, 22 H. sulcata, one H. punctata, 13 Ixodes gibbosus, 77 Rhipicephalus sanguineus s.l. and one R. bursa. All ticks were tested for the presence of DNA of Anaplasma spp., Babesia spp., Coxiella burnetii, Rickettsia spp. and Theileria spp. The collected ticks were examined by PCR and reverse line blot (RLB) assay. A prevalence of 20.1% for Anaplasma spp., 15.6% for Babesia spp. (identifying B. bigemina, B. divergens, B. ovis and B. crassa), 17.9% for C. burnetii, 15.1% for Rickettsia spp., and 21.2% for Theileria spp. (identifying T. annulata, T. buffeli/orientalis, T. ovis and T. lestoquardi) was found. The results of this study demonstrate the variety of tick-borne pathogens of animal and human importance circulating in Greece, and that awareness is needed to minimize the risk of infection, especially among farmers and pet owners.

  14. Isolation and characterization of Kabuto Mountain virus, a new tick-borne phlebovirus from Haemaphysalis flava ticks in Japan.

    PubMed

    Ejiri, Hiroko; Lim, Chang-Kweng; Isawa, Haruhiko; Yamaguchi, Yukie; Fujita, Ryosuke; Takayama-Ito, Mutsuyo; Kuwata, Ryusei; Kobayashi, Daisuke; Horiya, Madoka; Posadas-Herrera, Guillermo; Iizuka-Shiota, Itoe; Kakiuchi, Satsuki; Katayama, Yukie; Hayashi, Toshihiko; Sasaki, Toshinori; Kobayashi, Mutsuo; Morikawa, Shigeru; Maeda, Ken; Mizutani, Tetsuya; Kaku, Koki; Saijo, Masayuki; Sawabe, Kyoko

    2018-01-15

    In Japan, indigenous tick-borne phleboviruses (TBPVs) and their associated diseases first became evident in 2013 by reported human cases of severe fever with thrombocytopenia syndrome (SFTS). In this study, we report a novel member of the genus Phlebovirus designated as Kabuto Mountain virus (KAMV), which was isolated from the ixodid tick Haemaphysalis flava in Hyogo, Japan. A complete viral genome sequencing and phylogenetic analyses showed that KAMV is a novel member of TBPVs, which is closely related to the Uukuniemi and Kaisodi group viruses. However, unlike the Uukuniemi group viruses, the 165-nt intergenic region (IGR) in the KAMV S segment was highly C-rich in the genomic sense and not predicted to form a secondary structure, which are rather similar to those of the Kaisodi group viruses and most mosquito/sandfly-borne phleboviruses. Furthermore, the NSs protein of KAMV was highly divergent from those of other TBPVs. These results provided further insights into the genetic diversity and evolutionary relationships of TBPVs. KAMV could infect and replicate in some rodent and primate cell lines. We evaluated the infectivity and pathogenicity of KAMV in suckling mice, where we obtained a virulent strain after two passages via intracerebral inoculation. This is the first report showing the existence of a previously unrecognized TBPV in Japan, other than the SFTS virus. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Characterization of a siberian virus isolated from a patient with progressive chronic tick-borne encephalitis.

    PubMed

    Gritsun, T S; Frolova, T V; Zhankov, A I; Armesto, M; Turner, S L; Frolova, M P; Pogodina, V V; Lashkevich, V A; Gould, E A

    2003-01-01

    A strain of Tick-borne encephalitis virus designated Zausaev (Za) was isolated in Siberia from a patient who died of a progressive (2-year) form of tick-borne encephalitis 10 years after being bitten by a tick. The complete genomic sequence of this virus was determined, and an attempt was made to correlate the sequence with the biological characteristics of the virus. Phylogenetic analysis demonstrated that this virus belongs to the Siberian subtype of Tick-borne encephalitis virus. Comparison of Za virus with two related viruses, a Far Eastern isolate, Sofjin, and a Siberian isolate, Vasilchenko, revealed differences among the three viruses in pathogenicity for Syrian hamsters, cytopathogenicity for PS cells, plaque morphology, and the electrophoretic profiles of virus-specific nonstructural proteins. Comparative amino acid alignments revealed 10 individual amino acid substitutions in the Za virus polyprotein sequence that were different from those of other tick-borne flaviviruses. Notably, the dimeric form of the Za virus NS1 protein migrated in polyacrylamide gels as a heterogeneous group of molecules with a significantly higher electrophoretic mobility than those of the Sofjin and Vasilchenko viruses. Two amino acid substitutions, T(277)-->V and E(279)-->G, within the NS1 dimerization domain are probably responsible for the altered oligomerization of Za virus NS1. These studies suggest that the patient from whom Za virus was isolated died due to increased pathogenicity of the latent virus following spontaneous mutagenesis.

  16. Characterization of a Siberian Virus Isolated from a Patient with Progressive Chronic Tick-Borne Encephalitis

    PubMed Central

    Gritsun, T. S.; Frolova, T. V.; Zhankov, A. I.; Armesto, M.; Turner, S. L.; Frolova, M. P.; Pogodina, V. V.; Lashkevich, V. A.; Gould, E. A.

    2003-01-01

    A strain of Tick-borne encephalitis virus designated Zausaev (Za) was isolated in Siberia from a patient who died of a progressive (2-year) form of tick-borne encephalitis 10 years after being bitten by a tick. The complete genomic sequence of this virus was determined, and an attempt was made to correlate the sequence with the biological characteristics of the virus. Phylogenetic analysis demonstrated that this virus belongs to the Siberian subtype of Tick-borne encephalitis virus. Comparison of Za virus with two related viruses, a Far Eastern isolate, Sofjin, and a Siberian isolate, Vasilchenko, revealed differences among the three viruses in pathogenicity for Syrian hamsters, cytopathogenicity for PS cells, plaque morphology, and the electrophoretic profiles of virus-specific nonstructural proteins. Comparative amino acid alignments revealed 10 individual amino acid substitutions in the Za virus polyprotein sequence that were different from those of other tick-borne flaviviruses. Notably, the dimeric form of the Za virus NS1 protein migrated in polyacrylamide gels as a heterogeneous group of molecules with a significantly higher electrophoretic mobility than those of the Sofjin and Vasilchenko viruses. Two amino acid substitutions, T277→V and E279→G, within the NS1 dimerization domain are probably responsible for the altered oligomerization of Za virus NS1. These studies suggest that the patient from whom Za virus was isolated died due to increased pathogenicity of the latent virus following spontaneous mutagenesis. PMID:12477807

  17. Factors affecting the ecology of tick-borne encephalitis in Slovenia.

    PubMed

    Knap, N; Avšič-Županc, T

    2015-07-01

    Recognition of factors that influence the formation of tick-borne encephalitis (TBE) foci is important for assessing the risk of humans acquiring the viral infection and for establishing what can be done (within reasonable boundaries) to minimize that risk. In Slovenia, the dynamics of the TBE vector, i.e. Ixodes ricinus, was studied over a 4-year period and the prevalence of infection in ticks was established. Two groups of tick hosts were investigated: deer and small mammals. Red deer have been confirmed as having a direct influence on the incidence of TBE and rodents have been recognized as important sentinels for TBE infections, although their role in the enzootic cycle of the virus still remains to be elucidated. Last, forest and agricultural areas, which are influenced by human activity, are suitable habitats for ticks, and important for TBEV transmission and establishment. Human behaviour is also therefore an important factor and should always be considered in studies of TBE ecology.

  18. Tick-borne encephalitis among U.S. travelers to Europe and Asia - 2000-2009.

    PubMed

    2010-03-26

    Tick-borne encephalitis virus (TBEV) is the most common arbovirus transmitted by ticks in Europe. Approximately 10,000 cases of tick-borne encephalitis (TBE) are reported annually in Europe and Russia. Although TBE is endemic in parts of China, information regarding its incidence is limited. TBEV is closely related to Powassan virus (POWV), another tick-borne flavivirus that is a rare cause of encephalitis in North America and Russia; TBEV and POWV can cross-react in serologic tests. Before 2000, two cases of TBE in North American travelers to Europe were reported. State health officials or clinicians send specimens from patients with unexplained encephalitis to CDC as part of routine surveillance and diagnostic testing. CDC recently reviewed all 2000-2009 laboratory records to identify cases of TBE among U.S. travelers; the five cases identified are summarized in this report. All five cases had TBEV or POWV immunoglobulin M (IgM) antibodies in serum and were confirmed as acute TBE cases by plaque-reduction neutralization tests against both viruses. All four patients who had traveled to Europe or Russia had biphasic illnesses (a common feature of TBE) and made nearly complete recoveries. The fifth patient, the first reported case of TBE in a U.S. traveler to China, had a monophasic illness with severe encephalitis and neurologic sequelae. Health-care providers should be aware of TBE, should counsel travelers about measures to reduce exposure to tick bites, and should consider the diagnosis of TBE in travelers returning from TBE-endemic countries with meningitis or encephalitis.

  19. Tick-borne encephalitis virus and the immune response of the mammalian host.

    PubMed

    Dörrbecker, Bastian; Dobler, Gerhard; Spiegel, Martin; Hufert, Frank T

    2010-07-01

    Tick-borne encephalitis (TBE) is caused by Tick-borne encephalitis virus (TBEV), one of the most prevalent arboviruses in Europe and in many parts of Asia. Transmission of TBEV to humans usually occurs by bite of an infected tick or rarely by ingestion of unpasteurized milk products of infected livestock. TBEV infection induces an innate and adaptive immune response, nevertheless it is able to replicate in several cell types of the immune system at the same time which probably contributes to the spread of the virus in the human host. Furthermore, TBEV can enter the central nervous system (CNS) by yet not well understood mechanisms via the blood brain barrier (BBB) or the olfactory neurons which leads to serious neurological disorders like meningitis, encephalitis or even meningoencephalitis. In this article we review the known facts and possible hypotheses of interaction of TBEV with components of the mammalian immune system and their implications for TBEV-mediated pathogenesis. Copyright © 2010 Elsevier Ltd. All rights reserved.

  20. Identification and characterization of novel mosquito-borne (Kammavanpettai virus) and tick-borne (Wad Medani) reoviruses isolated in India.

    PubMed

    Yadav, Pragya D; Shete, Anita M; Nyayanit, Dimpal A; Albarino, Cesar G; Jain, Shilpi; Guerrero, Lisa W; Kumar, Sandeep; Patil, Deepak Y; Nichol, Stuart T; Mourya, Devendra T

    2018-06-25

    In 1954, a virus named Wad Medani virus (WMV) was isolated from Hyalomma marginatum ticks from Maharashtra State, India. In 1963, another virus was isolated from Sturnia pagodarum birds in Tamil Nadu, India, and named Kammavanpettai virus (KVPTV) based on the site of its isolation. Originally these virus isolates could not be identified with conventional methods. Here we describe next-generation sequencing studies leading to the determination of their complete genome sequences, and identification of both virus isolates as orbiviruses (family Reoviridae). Sequencing data showed that KVPTV has an AT-rich genome, whereas the genome of WMV is GC-rich. The size of the KVPTV genome is 18 234 nucleotides encoding proteins ranging 238-1290 amino acids (aa) in length. Similarly, the size of the WMV genome is 16 941 nucleotides encoding proteins ranging 214-1305 amino acids in length. Phylogenetic analysis of the VP1 gene, along with the capsid genes VP5 and VP7, revealed that KVPTV is likely a novel mosquito-borne virus and WMV is a tick-borne orbivirus. This study focuses on the phylogenetic comparison of these newly identified orbiviruses with mosquito-, tick- and Culicoides-borne orbiviruses isolated in India and other countries.

  1. The Phenology of Ticks and the Effects of Long-Term Prescribed Burning on Tick Population Dynamics in Southwestern Georgia and Northwestern Florida

    PubMed Central

    Gleim, Elizabeth R.; Conner, L. Mike; Berghaus, Roy D.; Levin, Michael L.; Zemtsova, Galina E.; Yabsley, Michael J.

    2014-01-01

    Some tick populations have increased dramatically in the past several decades leading to an increase in the incidence and emergence of tick-borne diseases. Management strategies that can effectively reduce tick populations while better understanding regional tick phenology is needed. One promising management strategy is prescribed burning. However, the efficacy of prescribed burning as a mechanism for tick control is unclear because past studies have provided conflicting data, likely due to a failure of some studies to simulate operational management scenarios and/or account for other predictors of tick abundance. Therefore, our study was conducted to increase knowledge of tick population dynamics relative to long-term prescribed fire management. Furthermore, we targeted a region, southwestern Georgia and northwestern Florida (USA), in which little is known regarding tick dynamics so that basic phenology could be determined. Twenty-one plots with varying burn regimes (burned surrounded by burned [BB], burned surrounded by unburned [BUB], unburned surrounded by burned [UBB], and unburned surrounded by unburned [UBUB]) were sampled monthly for two years while simultaneously collecting data on variables that can affect tick abundance (e.g., host abundance, vegetation structure, and micro- and macro-climatic conditions). In total, 47,185 ticks were collected, of which, 99% were Amblyomma americanum, 0.7% were Ixodes scapularis, and fewer numbers of Amblyomma maculatum, Ixodes brunneus, and Dermacentor variabilis. Monthly seasonality trends were similar between 2010 and 2011. Long-term prescribed burning consistently and significantly reduced tick counts (overall and specifically for A. americanum and I. scapularis) regardless of the burn regimes and variables evaluated. Tick species composition varied according to burn regime with A. americanum dominating at UBUB, A. maculatum at BB, I. scapularis at UBB, and a more even composition at BUB. These data indicate that

  2. Acute Tick-borne Rickettsiosis Caused by Rickettsia sibirica in the Russian Far East

    PubMed Central

    Sidelnikov, Yuri; Ivanov, Leonid; Mokretsova, Eugenia; Fournier, Pierre-Edouard; Tarasevich, Irina; Raoult, Didier

    2004-01-01

    An acute tick-borne rickettsiosis caused by Rickettsia heilongjiangensis was diagnosed in 13 patients from the Russian Far East in 2002. We amplified and sequenced four portions of three rickettsial genes from the patients’ skin biopsy results and blood samples and showed that the amplified rickettsial genes belong to R. heilongjiangensis, which was recently isolated from Dermacentor sylvarum ticks in nearby regions of China. This rickettsia, belonging to subgroup of R. japonica, was previously suggested to be pathogenic for humans on the basis of serologic findings. We tested serum samples with different rickettsial antigens from 11 patients and confirmed increasing titers of immunoglobulin (Ig) G and IgM to spotted fever group rickettsiae, including R. heilongjiangensis. Clinical and epidemiologic data on these patients shows that this disease is similar to other tick-borne rickettsioses. PMID:15200813

  3. Tick-borne encephalitis in a naturally infected sheep.

    PubMed

    Böhm, Brigitte; Schade, Benjamin; Bauer, Benjamin; Hoffmann, Bernd; Hoffmann, Donata; Ziegler, Ute; Beer, Martin; Klaus, Christine; Weissenböck, Herbert; Böttcher, Jens

    2017-08-22

    Tick-borne encephalitis (TBE) is the most important viral tick borne zoonosis in Europe. In Germany, about 250 human cases are registered annually, with the highest incidence reported in the last years coming from the federal states Bavaria and Baden-Wuerttemberg. In veterinary medicine, only sporadic cases in wild and domestic animals have been reported; however, a high number of wild and domestic animals have tested positive for the tick-borne encephalitis virus (TBEV) antibody. In May 2015, a five-month-old lamb from a farm with 15 Merino Land sheep and offspring in Nersingen/Bavaria, a TBEV risk area, showed impaired general health with pyrexia and acute neurological signs. The sheep suffered from ataxia, torticollis, tremor, nystagmus, salivation and finally somnolence with inappetence and recumbency. After euthanasia, pathological, histopathological, immunohistochemical, bacteriological, parasitological and virological analyses were performed. Additionally, blood samples from the remaining, healthy sheep in the herd were taken for detection of TBEV antibody titres. At necropsy and accompanying parasitology, the sheep showed a moderate to severe infection with Trichostrongylids, Moniezia and Eimeria species. Histopathology revealed mild to moderate necrotising, lymphohistiocytic and granulocytic meningoencephalitis with gliosis and neuronophagia. Immunohistochemistry for TBEV was negative. RNA of a TBEV strain, closely related to the Kumlinge A52 strain, was detected in the brain by quantitative reverse transcriptase polymerase chain reaction (RT-qPCR) and subsequent PCR product sequencing. A phylogenetic analysis revealed a close relationship to the TBEV of central Europe. TBEV was cultured from brain tissue. Serologically, one of blood samples from the other sheep in the herd was positive for TBEV in an enzyme-linked immunosorbent assay (ELISA) and in a serum neutralisation test (SNT), and one was borderline in an ELISA. To the authors' knowledge this is the

  4. Tick-borne Encephalitis from Eating Goat Cheese in a Mountain Region of Austria

    PubMed Central

    Aberle, Stephan W.; Stiasny, Karin; Werner, Philipp; Mischak, Andreas; Zainer, Bernhard; Netzer, Markus; Koppi, Stefan; Bechter, Elmar; Heinz, Franz X.

    2009-01-01

    We report transmission of tick-borne encephalitis virus (TBEV) in July 2008 through nonpasteurized goat milk to 6 humans and 4 domestic pigs in an alpine pasture 1,500 m above sea level. This outbreak indicates the emergence of ticks and TBEV at increasing altitudes in central Europe and the efficiency of oral transmission of TBEV. PMID:19861072

  5. Investigation of tick-borne bacteria (Rickettsia spp., Anaplasma spp., Ehrlichia spp. and Borrelia spp.) in ticks collected from Andean tapirs, cattle and vegetation from a protected area in Ecuador.

    PubMed

    Pesquera, Cristina; Portillo, Aránzazu; Palomar, Ana M; Oteo, José A

    2015-01-24

    Ixodid ticks play an important role in the transmission and ecology of infectious diseases. Information about the circulation of tick-borne bacteria in ticks is lacking in Ecuador. Our aims were to investigate the tick species that parasitize Andean tapirs and cattle, and those present in the vegetation from the buffer zone of the Antisana Ecological Reserve and Cayambe-Coca National Park (Ecuador), and to investigate the presence of tick-borne bacteria. Tick species were identified based on morphologic and genetic criteria. Detection of tick-borne bacteria belonging to Rickettsia, Anaplasma, Ehrlichia and Borrelia genera was performed by PCRs. Our ticks included 91 Amblyomma multipunctum, 4 Amblyomma spp., 60 Rhipicephalus microplus, 5 Ixodes spp. and 1 Ixodes boliviensis. A potential Candidatus Rickettsia species closest to Rickettsia monacensis and Rickettsia tamurae (designated Rickettsia sp. 12G1) was detected in 3 R. microplus (3/57, 5.3%). In addition, Anaplasma spp., assigned at least to Anaplasma phagocytophilum (or closely related genotypes) and Anaplasma marginale, were found in 2 A. multipunctum (2/87, 2.3%) and 13 R. microplus (13/57, 22.8%). This is the first description of Rickettsia sp. in ticks from Ecuador, and the analyses of sequences suggest the presence of a potential novel Rickettsia species. Ecuadorian ticks from Andear tapirs, cattle and vegetation belonging to Amblyomma and Rhipicephalus genera were infected with Anaplasmataceae. Ehrlichia spp. and Borrelia burgdorferi sensu lato were not found in any ticks.

  6. Prevalence of tick-borne pathogens in questing Ixodes ricinus ticks in urban and suburban areas of Switzerland.

    PubMed

    Oechslin, Corinne P; Heutschi, Daniel; Lenz, Nicole; Tischhauser, Werner; Péter, Olivier; Rais, Olivier; Beuret, Christian M; Leib, Stephen L; Bankoul, Sergei; Ackermann-Gäumann, Rahel

    2017-11-09

    Throughout Europe, Ixodes ricinus transmits numerous pathogens. Its widespread distribution is not limited to rural but also includes urbanized areas. To date, comprehensive data on pathogen carrier rates of I. ricinus ticks in urban areas of Switzerland is lacking. Ixodes ricinus ticks sampled at 18 (sub-) urban collection sites throughout Switzerland showed carrier rates of 0% for tick-borne encephalitis virus, 18.0% for Borrelia burgdorferi (sensu lato), 2.5% for Borrelia miyamotoi, 13.5% for Rickettsia spp., 1.4% for Anaplasma phagocytophilum, 6.2% for "Candidatus Neoehrlichia mikurensis", and 0.8% for Babesia venatorum (Babesia sp., EU1). Site-specific prevalence at collection sites with n > 45 ticks (n = 9) significantly differed for B. burgdorferi (s.l.), Rickettsia spp., and "Ca. N. mikurensis", but were not related to the habitat type. Three hundred fifty eight out of 1078 I. ricinus ticks (33.2%) tested positive for at least one pathogen. Thereof, about 20% (71/358) were carrying two or three different potentially disease-causing agents. Using next generation sequencing, we could detect true pathogens, tick symbionts and organisms of environmental or human origin in ten selected samples. Our data document the presence of pathogens in the (sub-) urban I. ricinus tick population in Switzerland, with carrier rates as high as those in rural regions. Carriage of multiple pathogens was repeatedly observed, demonstrating the risk of acquiring multiple infections as a consequence of a tick bite.

  7. Babesia canis and tick-borne encephalitis virus (TBEV) co-infection in a sled dog.

    PubMed

    Bajer, Anna; Rodo, Anna; Bednarska, Malgorzata; Mierzejewska, Ewa; Welc-Falęciak, Renata

    2013-01-01

    Sporting dogs, including sled dogs, are particularly prone to tick-borne infection either due to training/racing in forest areas or through visits to endemic areas. The aim was to present tick-borne infections in a 6-dog racing team after a race in Estonia. On the 4th day after return to Poland, the first dog presented with babesiosis symptoms and was diagnosed and treated accordingly. Next morning, the dog showed neurological symptoms and was diagnosed with tick-borne encephalitis (TBE). Diagnosis was confirmed by a high level of IgG antibodies (922 IU/ml), detected in serum 3 months later. The second dog presented with babesiosis symptoms on the 7th day after return. Babesia DNA was extracted from blood, amplified and sequenced to answer the question of whether the dogs became infected during the race in Estonia or in Poland. Sequencing of a fragment of Babesia 18S rDNA revealed that these two isolates were identical to one another and closely related to the B. canis sequence originally isolated from the dog and Dermacentor reticulatus ticks in Poland. Thus, this is the first confirmed case of B.canis and TBEV co-infection and first confirmed case of TBE in a dog in Poland.

  8. Mutational analysis of three predicted 5'-proximal stem-loop structures in the genome of tick-borne encephalitis virus indicates different roles in RNA replication and translation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rouha, Harald; Hoenninger, Verena M.; Thurner, Caroline

    2011-08-15

    Flavivirus gene expression is modulated by RNA secondary structure elements at the terminal ends of the viral RNA molecule. For tick-borne encephalitis virus (TBEV), four stem-loop (SL) elements have been predicted in the first 180 nucleotides of the viral genome: 5'-SL1, 5'-SL2, 5'-SL3 and 5'-SL4. The last three of these appear to be unique to tick-borne flaviviruses. Here, we report their characterization by mutagenesis in a TBEV luciferase reporter system. By manipulating their thermodynamic properties, we found that an optimal stability of the 5'-SL2 is required for efficient RNA replication. 5'-SL3 formation is also important for viral RNA replication, butmore » although it contains the viral start codon, its formation is dispensable for RNA translation. 5'-SL4 appears to facilitate both RNA translation and replication. Our data suggest that maintenance of the balanced thermodynamic stability of these SL elements is important for temporal regulation of its different functions.« less

  9. Ticks threatening lineage of Anatolian wild sheep (Ovis gmelinii anatolica) and determination of their tick-borne pathogens.

    PubMed

    Orkun, Ömer; Emir, Hasan; Karaer, Zafer

    2016-09-15

    We aimed to determine the ticks of the Anatolian wild sheep and to define their tick-borne pathogens while molecularly studying their relationships with those of the domestic sheep. Furthermore, another aim of this study is to investigate tick paralysis resulting in the death of the Anatolian wild sheep. Ticks and blood samples were collected from the wild sheep whilst tick samples were also collected from hares, guinea fowls, chickens, and a turkey living in the Anatolian wild sheep breeding area. While PCR amplification was carried out for the detection of Babesia spp., Theileria spp. and Anaplasma spp. in blood samples, CCHF virus was screened in the tick samples in addition to the above-mentioned pathogens. Theileria spp. was detected in blood samples of 45 wild sheep. A total of 3494 ticks were collected from 52 Anatolian wild sheep, 5 hares, 5 guinea fowls, 2 chickens, and 1 turkey whereas 98 ticks were collected from the ground. B. ovis and T. ovis were detected in tick pools (Rh. bursa and H. excavatum) that were collected from the wild sheep. The paralysis was diagnosed in both of the hind legs of the newborn lambs infested with a great number of ticks. We also report that the tick species (H. excavatum and Rh. bursa) are determined to cause tick paralysis and tick toxicosis, which are associated with mortality especially in lambs. T. ovis and B. ovis were detected and studied for the first time in Anatolian wild sheep and in their ticks. The results of phylogenetic analyses showed that T. ovis and B. ovis isolates are genetically very close to the isolates that were previously obtained from the domestic small ruminants. We show that the Anatolian wild sheep can play the role of a reservoir for T. ovis. The presence of the CCHF virus has also been clearly shown and it has been observed that this virus, which is very pathogenic for humans, is anywise circulating in the region. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. [The role of wild murine rodents in the selection of different strains of tick-borne encephalitis and Powassan viruses].

    PubMed

    Leonova, G N; Krugliak, S P; Lozovskaia, S A; Rybachuk, V N

    1987-01-01

    The study demonstrated the role of wild murine rodents in selection of different strains of tick-borne encephalitis and Powassan viruses, determined their ecological characteristics reflected in the epidemiological features of tick-borne encephalitis and Powassan encephalitis in southern Far East.

  11. Lone star tick abundance, fire, and bison grazing in tall-grass prairie

    USGS Publications Warehouse

    Cully, J.F.

    1999-01-01

    Lone star ticks (Amblyomma americanum L.) were collected by drag samples of 1 km transects on 12 watersheds at Konza Prairie Research Natural Area near Manhattan, Kans., during summer 1995-1996. Watersheds were treated to 2 experimental treatments: 3 burn intervals (1-year, 4-year, and 20-year) and 2 grazing treatments (grazed by bison (Bos bison L.) or ungrazed). The objectives were to determine whether fire interval, time since most recent burn, and the presence of large ungulate grazers would cause changes in lone star tick abundance in tallgrass prairie in central Kansas. Watersheds burned at 1-year intervals had fewer larvae and adults than watersheds burned at 4-year or 20-year intervals. Watersheds burned during the year of sampling had fewer ticks than watersheds burned one or more years in the past. For watersheds burned 1 or more years in the past there was no effect from time since burn. The presence of bison did not affect tick abundance. Spring burning is an effective method to reduce tick populations in tallgrass prairie during the year of the burn.

  12. Effects of tick control by acaricide self-treatement of white-tailed deer on host-seeking tick infection prevalence and entomologic risk for Ixodes scapularis-borne pathogens

    USDA-ARS?s Scientific Manuscript database

    We evaluated the effects of tick control by acaricide self-treatment of white-tailed deer on the infection prevalence and entomologic risk for three I. scapularis-borne bacteria in host-seeking ticks. Ticks were collected from vegetation in areas treated with the ‘4-Poster’ device and from control a...

  13. Tick-borne encephalitis virus in dogs - is this an issue?

    PubMed Central

    2011-01-01

    The last review on Tick-borne encephalitis (TBE) in dogs was published almost ten years ago. Since then, this zoonotic tick-borne arbovirus has been geographically spreading and emerging in many regions in Eurasia and continues to do so. Dogs become readily infected with TBE virus but they are accidental hosts not capable to further spread the virus. They seroconvert upon infection but they seem to be much more resistant to the clinical disease than humans. Apart from their use as sentinels in endemic areas, however, an increasing number of case reports appeared during the last decade thus mirroring the rising public health concerns. Owing to the increased mobility of people travelling to endemic areas with their companion dogs, this consequently leads to problems in recognizing and diagnosing this severe infection in a yet non-endemic area, simply because the veterinarians are not considering TBE. This situation warrants an update on the epidemiology, clinical presentation and possible preventions of TBE in the dog. PMID:21489255

  14. Synanthropic Mammals as Potential Hosts of Tick-Borne Pathogens in Panama.

    PubMed

    Bermúdez, Sergio E; Gottdenker, Nicole; Krishnvajhala, Aparna; Fox, Amy; Wilder, Hannah K; González, Kadir; Smith, Diorene; López, Marielena; Perea, Milixa; Rigg, Chystrie; Montilla, Santiago; Calzada, José E; Saldaña, Azael; Caballero, Carlos M; Lopez, Job E

    2017-01-01

    Synanthropic wild mammals can be important hosts for many vector-borne zoonotic pathogens. The aim of this study was determine the exposure of synanthropic mammals to two types of tick-borne pathogens in Panama, spotted fever group Rickettsia (SFGR) and Borrelia relapsing fever (RF) spirochetes. One hundred and thirty-one wild mammals were evaluated, including two gray foxes, two crab-eating foxes (from zoos), four coyotes, 62 opossum and 63 spiny rats captured close to rural towns. To evaluate exposure to SFGR, serum samples from the animals were tested by indirect immunofluorescence assay (IFA) using Rickettsia rickettsii and Candidatus Rickettsia amblyommii antigen. Immunoblotting was performed using Borrelia turicatae protein lysates and rGlpQ, to assess infection caused by RF spirochetes. One coyote (25%) and 27 (43%) opossums showed seroreactivity to SFGR. Of these opossums, 11 were seroreactive to C. R. amblyommii. Serological reactivity was not detected to B. turicatae in mammal samples. These findings may reflect a potential role of both mammals in the ecology of tick-borne pathogens in Panama.

  15. Synanthropic Mammals as Potential Hosts of Tick-Borne Pathogens in Panama

    PubMed Central

    Bermúdez, Sergio E.; Gottdenker, Nicole; Krishnvajhala, Aparna; Fox, Amy; Wilder, Hannah K.; González, Kadir; Smith, Diorene; López, Marielena; Perea, Milixa; Rigg, Chystrie; Montilla, Santiago; Calzada, José E.; Saldaña, Azael; Caballero, Carlos M.

    2017-01-01

    Synanthropic wild mammals can be important hosts for many vector-borne zoonotic pathogens. The aim of this study was determine the exposure of synanthropic mammals to two types of tick-borne pathogens in Panama, spotted fever group Rickettsia (SFGR) and Borrelia relapsing fever (RF) spirochetes. One hundred and thirty-one wild mammals were evaluated, including two gray foxes, two crab-eating foxes (from zoos), four coyotes, 62 opossum and 63 spiny rats captured close to rural towns. To evaluate exposure to SFGR, serum samples from the animals were tested by indirect immunofluorescence assay (IFA) using Rickettsia rickettsii and Candidatus Rickettsia amblyommii antigen. Immunoblotting was performed using Borrelia turicatae protein lysates and rGlpQ, to assess infection caused by RF spirochetes. One coyote (25%) and 27 (43%) opossums showed seroreactivity to SFGR. Of these opossums, 11 were seroreactive to C. R. amblyommii. Serological reactivity was not detected to B. turicatae in mammal samples. These findings may reflect a potential role of both mammals in the ecology of tick-borne pathogens in Panama. PMID:28060928

  16. Survey of tick-borne zoonotic viruses in wild deer in Hokkaido, Japan.

    PubMed

    Uchida, Leo; Hayasaka, Daisuke; Ngwe Tun, Mya Myat; Morita, Kouichi; Muramatsu, Yasukazu; Hagiwara, Katsuro

    2018-04-19

    Tick-borne encephalitis (TBE) and severe fever with thrombocytopenia syndrome (SFTS) are both tick-borne zoonotic diseases caused by TBE virus (TBEV) and SFTS phlebovirus (SFTSV). In 2016, a second domestic TBE case was reported in Hokkaido, Japan, after an absence of 23 years. We conducted IgG ELISA for TBEV and SFTSV on 314 deer (Cervus nippon yesoensis) serum samples collected from 3 places in Hokkaido. There were 7 seropositive samples for TBEV but none for SFTSV by ELISA. The specificity of the 7 positive samples was confirmed by neutralization tests against TBEV, and 5 sera showed 320 to 640 of 50% focus reduction endpoint titers. Our results provide information about the infectious status of TBEV in wild deer in Hokkaido, Japan.

  17. Emerging horizons for tick-borne pathogens: from the ‘one pathogen–one disease’ vision to the pathobiome paradigm

    PubMed Central

    Vayssier-Taussat, Muriel; Kazimirova, Maria; Hubalek, Zdenek; Hornok, Sándor; Farkas, Robert; Cosson, Jean-François; Bonnet, Sarah; Vourch, Gwenaël; Gasqui, Patrick; Mihalca, Andrei Daniel; Plantard, Olivier; Silaghi, Cornelia; Cutler, Sally; Rizzoli, Annapaola

    2015-01-01

    Ticks, as vectors of several notorious zoonotic pathogens, represent an important and increasing threat for human and animal health in Europe. Recent applications of new technology revealed the complexity of the tick microbiome, which may affect its vectorial capacity. Appreciation of these complex systems is expanding our understanding of tick-borne pathogens, leading us to evolve a more integrated view that embraces the ‘pathobiome’; the pathogenic agent integrated within its abiotic and biotic environments. In this review, we will explore how this new vision will revolutionize our understanding of tick-borne diseases. We will discuss the implications in terms of future research approaches that will enable us to efficiently prevent and control the threat posed by ticks. PMID:26610021

  18. Risk of tick-borne diseases in various categories of employment among forestry workers in eastern Poland.

    PubMed

    Cisak, Ewa; Zając, Violetta; Wójcik-Fatla, Angelina; Dutkiewicz, Jacek

    2012-01-01

    Among the zoonotic agents causing occupational diseases, those transmitted by ticks are very important, in particular the spirochetes Borrelia burgdorferi which are the common cause of occupational Lyme borreliosis in forestry and agricultural workers. The objective of this study was an evaluation of the exposure of forestry workers employed at individual workplaces to infection with tick-borne pathogens (especially Borrelia burgdorferi spirochetes), based on epidemiological investigation and serologic tests. Epidemiological studies covered 111 forestry employees from eastern Poland employed in 4 randomly-selected forest inspectorates which replied to questions in the area of epidemiology and prophylaxis of diseases transmitted by ticks. Eighty-two forestry workers employed in one forest inspectorate were examined for the presence of specific anti-Borrelia burgdorferi antibodies. The correlation between individual items of the questionnaire was assessed by Spearman's test. Results of serological tests were assessed by Mann-Whitney test. Statistical analysis of the results indicated that the workers performing manual jobs in the forest are at the greatest risk of tick bite and contraction of tick-borne disease. They are aware of the risk, but use the improper method of removal of ticks with the fingers. Comparisons of the relationship between job category and the results of serologic study, expressed in BBU/ml, revealed that the serologic response was significantly greater in manual workers than in administrative workers (p=0.019). All other comparisons did not produce significant results. Therefore, providing a simple tweezer-like device to forest inspectorates seems to be an effective mean of protection against Lyme borreliosis and other tick-borne diseases.

  19. Behavioral asymmetries in ticks - Lateralized questing of Ixodes ricinus to a mechatronic apparatus delivering host-borne cues.

    PubMed

    Benelli, Giovanni; Romano, Donato; Rocchigiani, Guido; Caselli, Alice; Mancianti, Francesca; Canale, Angelo; Stefanini, Cesare

    2018-02-01

    Ticks are considered among the most dangerous arthropod vectors of disease agents to both humans and animals worldwide. Lateralization contributes to biological fitness in many animals, conferring important functional advantages, therefore studying its role in tick perception would critically improve our knowledge about their host-seeking behavior. In this research, we evaluated if Ixodes ricinus (L.) (Ixodiidae) ticks have a preference in using the right or the left foreleg to climb on a host. We developed a mechatronic device moving a tuft of fox skin with fur as host-mimicking combination of cues. This engineered approach allows to display a realistic combination of both visual and olfactory host-borne stimuli, which is prolonged over the time and standardized for each replicate. In the first experiment, the mechatronic apparatus delivered host-borne cues frontally, to evaluate the leg preference during questing as response to a symmetrical stimulus. In the second experiment, host-borne cues were provided laterally, in an equal proportion to the left and to the right of the tick, to investigate if the host direction affected the questing behavior. In both experiments, the large majority of the tested ticks showed individual-level left-biased questing acts, if compared to the ticks showing right-biased ones. Furthermore, population-level left-biased questing responses were observed post-exposure to host-mimicking cues provided frontally or laterally to the tick. Overall, this is the first report on behavioral asymmetries in ticks of medical and veterinary importance. Moreover, the mechatronic apparatus developed in this research can be exploited to evaluate the impact of repellents on tick questing in highly reproducible standardized conditions. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Tick-Borne Encephalitis Virus Diversity in Ixodid Ticks and Small Mammals in South-Western Siberia, Russia.

    PubMed

    Bakhvalova, Valentina N; Chicherina, Galina S; Potapova, Olga F; Panov, Victor V; Glupov, Victor V; Potapov, Mikhail A; Seligman, Stephen J; Morozova, Olga V

    2016-08-01

    The persistence of tick-borne encephalitis virus (TBEV) in nature is maintained by numerous species of reservoir hosts, multiple transmissions between vertebrates and invertebrates, and the virus adaptation to its hosts. Our Aim: was to compare TBEV isolates from ticks and small wild mammals to estimate their roles in the circulation of the viral subtypes. TBEV isolates from two species of ixodid ticks, four species of rodents, and one species of shrews in the Novosibirsk region, South-Western Siberia, Russia, were analyzed using bioassay, hemagglutination, hemagglutination inhibition, neutralization tests, ELISA, reverse transcription with real-time PCR, and phylogenetic analysis. TBEV RNA and/or protein E were found in 70.9% ± 3.0% of mammals and in 3.8% ± 0.4% of ticks. The TBEV infection rate, main subtypes, and neurovirulence were similar between ixodid tick species. However, the proportions of the virus that were pathogenic for laboratory mice and of the Far-Eastern (FE) subtype, as well as the viral loads with the Siberian and the European subtypes for the TBEV in Ixodes pavlovskyi Pomerantsev, 1946 were higher than in Ixodes persulcatus (P. Schulze, 1930). Percentages of infected Myodes rutilus, Sicista betulina, and Sorex araneus exceeded those of Apodemus agrarius and Myodes rufocanus. Larvae and nymphs of ticks were found mainly on rodents, especially on Myodes rufocanus and S. betulina. The proportion of TBEV-mixed infections with different subtypes in the infected ticks (55.9% ± 6.5%) was higher than in small mammals (36.1% ± 4.0%) (p < 0.01). Molecular typing revealed mono- or mixed infection with three main subtypes of TBEV in ticks and small mammals. The Siberian subtype was more common in ixodid ticks, and the FE subtype was more common in small mammals (p < 0.001). TBEV isolates of the European subtype were rare. TBEV infection among different species of small mammals did not correlate with their infestation rate with

  1. Chapter 4. Recent epidemiology of tick-borne encephalitis an effect of climate change?

    PubMed

    Korenberg, E I

    2009-01-01

    Consideration is given to the opinion of some specialists that the rise in tick-borne encephalitis (TBE) morbidity at the turn of the century has been accounted for by new features of TBE epidemiology as well as by global climate change. It is shown that neither the reputed current expansion of the ranges of main TBE vectors, the taiga (Ixodes persulcatus) and sheep (Ixodes ricinus) ticks, nor the significant rise of their abundance and TBE virus prevalence in them are confirmed by any objective data. The concept of recent tick expansion to large cities and human TBE infection in newly formed urban foci disagrees with the facts repeatedly described during the past four decades. There is no reliable information on the expansion of TBE nosological range. The influence of newly formed anthropurgic foci and of changes in the contribution of city dwellers to the general morbidity structure on the current epidemiological situation is estimated. As in the case of any other zoonosis with natural focality, the level of epidemiological manifestation of TBE foci is determined by two main parameters: the intensity of virus circulation in the foci (i.e., their loimopotential) and the frequency of human contact with them. Attention is paid to the character of interaction between these two factors, which accounted for a major outbreak of TBE morbidity at the end of the twentieth century, followed by a long-term decrease in its level.

  2. Occurrence of tick-borne haemoparasites in cattle in the Mungwi District, Northern Province, Zambia.

    PubMed

    Tembo, Stephen; Collins, Nicola E; Sibeko-Matjila, Kgomotso P; Troskie, Milana; Vorster, Ilse; Byaruhanga, Charles; Oosthuizen, Marinda C

    2018-03-01

    Little is known about the occurrence of haemoparasites in cattle in communal grazing areas of Mungwi District of Northern Province, Zambia. Clinical signs and post mortem lesions are pathognomonic of mixed tick-borne infections especially babesiosis, anaplasmosis and East Coast fever. The main objective of this study was to screen selected communal herds of cattle for tick-borne haemoparasites, and identify the tick vectors associated with the high cattle mortalities due to suspected tick-borne diseases in the local breeds of cattle grazing along the banks of the Chambeshi River in Mungwi District, Northern Province, Zambia. A total of 299 cattle blood samples were collected from July to September 2010 from Kapamba (n = 50), Chifulo (n = 102), Chisanga (n = 38), Kowa (n = 95) and Mungwi central (n = 14) in the Mungwi District. A total of 5288 ticks were also collected from the sampled cattle from April to July 2011. DNA was extracted from the cattle blood and the hypervariable region of the parasite small subunit rRNA gene was amplified and subjected to the reverse line blot (RLB) hybridization assay. The results of the RLB assay revealed the presence of tick-borne haemoparasites in 259 (86.6%) cattle blood samples occurring either as single (11.0%) or mixed (75.6%) infections. The most prevalent species present were the benign Theileria mutans (54.5%) and T. velifera (51.5%). Anaplasma marginale (25.7%), Babesia bovis (7.7%) and B. bigemina (3.3%) DNA were also detected in the samples. Only one sample (from Kapamba) tested positive for the presence of T. parva. This was an unexpected finding; also because the tick vector, Rhipicephalus appendiculatus, was identified on animals from Kowa (14.0%), Chisanga (8.5%), Chifulo (6.0%) and Kapamba (1.4%). One sample (from Kapamba) tested positive for the presence of Ehrlichia ruminantium even though Amblyomma variegatum ticks were identified from 52.9% of the sampled animals from all study areas. There

  3. Incident Tick-Borne Infections in a Cohort of North Carolina Outdoor Workers.

    PubMed

    Wallace, John W; Nicholson, William L; Perniciaro, Jamie L; Vaughn, Meagan F; Funkhouser, Sheana; Juliano, Jonathan J; Lee, Sangmi; Kakumanu, Madhavi L; Ponnusamy, Loganathan; Apperson, Charles S; Meshnick, Steven R

    2016-05-01

    Tick-borne diseases cause substantial morbidity throughout the United States, and North Carolina has a high incidence of spotted fever rickettsioses and ehrlichiosis, with sporadic cases of Lyme disease. The occupational risk of tick-borne infections among outdoor workers is high, particularly those working on publicly managed lands. This study identified incident tick-borne infections and examined seroconversion risk factors among a cohort of North Carolina outdoor workers. Workers from the North Carolina State Divisions of Forestry, Parks and Recreation, and Wildlife (n = 159) were followed for 2 years in a randomized controlled trial evaluating the effectiveness of long-lasting permethrin-impregnated clothing. Antibody titers against Rickettsia parkeri, Rickettsia rickettsii, "Rickettsia amblyommii," and Ehrlichia chaffeensis were measured at baseline (n = 130), after 1 year (n = 82), and after 2 years (n = 73). Titers against Borrelia burgdorferi were measured at baseline and after 2 years (n = 90). Baseline seroprevalence, defined as indirect immunofluorescence antibody titers of 1/128 or greater, was R. parkeri (24%), R. rickettsii (19%), "R. amblyommii" (12%), and E. chaffeensis (4%). Incident infection was defined as a fourfold increase in titer over a 1-year period. There were 40 total seroconversions to at least one pathogen, including R. parkeri (n = 19), "R. amblyommii" (n = 14), R. rickettsii (n = 9), and E. chaffeensis (n = 8). There were no subjects whose sera were reactive to B. burgdorferi C6 antigen. Thirty-eight of the 40 incident infections were subclinical. The overall risk of infection by any pathogen during the study period was 0.26, and the risk among the NC Division of Forest Resources workers was 1.73 times that of workers in other divisions (95% confidence interval [CI]: 1.02, 2.92). The risk of infection was lower in subjects wearing permethrin-impregnated clothing, but not significantly (risk ratio

  4. Powassan Virus—A New Reemerging Tick-Borne Disease

    PubMed Central

    Fatmi, Syed Soheb; Zehra, Rija; Carpenter, David O.

    2017-01-01

    Powassan virus is a neurovirulent flavivirus consisting of two lineages causing meningoencephalitis. It is the only member of the tick-borne encephalitis serogroup which is present in mainland North America. With a total number of 27 cases from 1958 to 1998 and 98 cases from 1999 to 2016, reported cases have increased by 671% over the last 18 years. Powassan infection is transmitted by different tick species in different geographical regions. Ixodes scapularis is the primary vector that transmits the virus on the East Coast of US and Ixodes cookei in the Midwest and Canada, while Hemaphysalis longicornis is the vector in Russia. Powassan has no singular pathognomonic finding and presents with a wide spectrum of symptoms including severe neurological symptoms. The clinical challenge lies within the management of the disease as there is no standard diagnostic protocol and most cases are only diagnosed after a patient goes through an extensive workup for other infectious disease. The diagnosis is established by a combination of imaging and serologic tests. In case of Powassan meningoencephalitis, computed tomography scan and magnetic resonance imaging show vascular insults, which are also seen in cases of tick-borne encephalitis virus, another flavivirus of medical importance. Serologic tests are the gold standard for diagnosis, although testing is not widely available and only state health departments and Center for Disease Control and Prevention can perform Powassan-specific IgM antibody testing utilizing enzyme-linked immunosorbent assay and immunofluorescence antibody. Powassan is also of veterinary medical importance. Wildlife animals act as a reservoir to the pathogens, hence possessing threat to humans and domestic animals. This review highlights Powassan’s neurotropic presentation, epidemiology, diagnostic challenges, and prevalence. Strong emphasis is placed on establishing diagnostic protocols, widespread Powassan-specific IgM testing, role of the vector

  5. Powassan Virus-A New Reemerging Tick-Borne Disease.

    PubMed

    Fatmi, Syed Soheb; Zehra, Rija; Carpenter, David O

    2017-01-01

    Powassan virus is a neurovirulent flavivirus consisting of two lineages causing meningoencephalitis. It is the only member of the tick-borne encephalitis serogroup which is present in mainland North America. With a total number of 27 cases from 1958 to 1998 and 98 cases from 1999 to 2016, reported cases have increased by 671% over the last 18 years. Powassan infection is transmitted by different tick species in different geographical regions. Ixodes scapularis is the primary vector that transmits the virus on the East Coast of US and Ixodes cookei in the Midwest and Canada, while Hemaphysalis longicornis is the vector in Russia. Powassan has no singular pathognomonic finding and presents with a wide spectrum of symptoms including severe neurological symptoms. The clinical challenge lies within the management of the disease as there is no standard diagnostic protocol and most cases are only diagnosed after a patient goes through an extensive workup for other infectious disease. The diagnosis is established by a combination of imaging and serologic tests. In case of Powassan meningoencephalitis, computed tomography scan and magnetic resonance imaging show vascular insults, which are also seen in cases of tick-borne encephalitis virus, another flavivirus of medical importance. Serologic tests are the gold standard for diagnosis, although testing is not widely available and only state health departments and Center for Disease Control and Prevention can perform Powassan-specific IgM antibody testing utilizing enzyme-linked immunosorbent assay and immunofluorescence antibody. Powassan is also of veterinary medical importance. Wildlife animals act as a reservoir to the pathogens, hence possessing threat to humans and domestic animals. This review highlights Powassan's neurotropic presentation, epidemiology, diagnostic challenges, and prevalence. Strong emphasis is placed on establishing diagnostic protocols, widespread Powassan-specific IgM testing, role of the vector

  6. Microclimate and the zoonotic cycle of tick-borne encephalitis virus in Switzerland.

    PubMed

    Burri, C; Bastic, V; Maeder, G; Patalas, E; Gern, L

    2011-05-01

    The focal distribution of tick-borne encephalitis virus (TBEV; Flaviviridae, Flavivirus) appears to depend mainly on cofeeding transmission between infected Ixodes ricinus L. nymphs and uninfected larvae. To better understand the role of cofeeding ticks in the transmission of TBEV, we investigated tick infestation of rodents and the influence of microclimate on the seasonality of questing I. ricinus ticks. A 3-yr study was carried out at four sites, including two confirmed TBEV foci. Free-living ticks and rodents were collected monthly, and microclimatic data were recorded. A decrease in questing nymph density was observed in 2007, associated with low relative humidity and high temperatures in spring. One site, Thun, did not show this decrease, probably because of microclimatic conditions in spring that favored the questing nymph population. During the same year, the proportion of rodents carrying cofeeding ticks was lower at sites where the questing nymph density decreased, although the proportion of infested hosts was similar among years. TBEV was detected in 0.1% of questing ticks, and in 8.6 and 50.0% of larval ticks feeding on two rodents. TBEV was detected at all but one site, where the proportion of hosts with cofeeding ticks was the lowest. The proportion of hosts with cofeeding ticks seemed to be one of the factors that distinguished a TBEV focus from a non-TBEV focus. The enzootic cycle of TBEV might be disrupted when dry and hot springs occur during consecutive years.

  7. Prevalence and Diversity of Tick-Borne Pathogens in Nymphal Ixodes scapularis (Acari: Ixodidae) in Eastern National Parks.

    PubMed

    Johnson, Tammi L; Graham, Christine B; Boegler, Karen A; Cherry, Cara C; Maes, Sarah E; Pilgard, Mark A; Hojgaard, Andrias; Buttke, Danielle E; Eisen, Rebecca J

    2017-05-01

    Tick-borne pathogens transmitted by Ixodes scapularis Say (Acari: Ixodidae), also known as the deer tick or blacklegged tick, are increasing in incidence and geographic distribution in the United States. We examined the risk of tick-borne disease exposure in 9 national parks across six Northeastern and Mid-Atlantic States and the District of Columbia in 2014 and 2015. To assess the recreational risk to park visitors, we sampled for ticks along frequently used trails and calculated the density of I. scapularis nymphs (DON) and the density of infected nymphs (DIN). We determined the nymphal infection prevalence of I. scapularis with a suite of tick-borne pathogens including Borrelia burgdorferi, Borrelia miyamotoi, Anaplasma phagocytophilum, and Babesia microti. Ixodes scapularis nymphs were found in all national park units; DON ranged from 0.40 to 13.73 nymphs per 100 m2. Borrelia burgdorferi, the causative agent of Lyme disease, was found at all sites where I. scapularis was documented; DIN with B. burgdorferi ranged from 0.06 to 5.71 nymphs per 100 m2. Borrelia miyamotoi and A. phagocytophilum were documented at 60% and 70% of the parks, respectively, while Ba. microti occurred at just 20% of the parks. Ixodes scapularis is well established across much of the Northeastern and Mid-Atlantic States, and our results are generally consistent with previous studies conducted near the areas we sampled. Newly established I. scapularis populations were documented in two locations: Washington, D.C. (Rock Creek Park) and Greene County, Virginia (Shenandoah National Park). This research demonstrates the potential risk of tick-borne pathogen exposure in national parks and can be used to educate park visitors about the importance of preventative actions to minimize tick exposure. Published by Oxford University Press on behalf of Entomological Society of America 2016. This work is written by US Government employees and is in the public domain in the US.

  8. Prevention of infectious tick-borne diseases in humans: Comparative studies of the repellency of different dodecanoic acid-formulations against Ixodes ricinus ticks (Acari: Ixodidae)

    PubMed Central

    Schwantes, Ulrich; Dautel, Hans; Jung, Gerd

    2008-01-01

    Background Ticks of the species Ixodes ricinus are the main vectors of Lyme Borreliosis and Tick-borne Encephalitis – two rapidly emerging diseases in Europe. Repellents provide a practical means of protection against tick bites and can therefore minimize the transmission of tick-borne diseases. We developed and tested seven different dodecanoic acid (DDA)-formulations for their efficacy in repelling host-seeking nymphs of I. ricinus by laboratory screening. The ultimately selected formulation was then used for comparative investigations of commercially available tick repellents in humans. Methods Laboratory screening tests were performed using the Moving-object (MO) bioassay. All test formulations contained 10% of the naturally occurring active substance DDA and differed only in terms of the quantitative and qualitative composition of inactive ingredients and fragrances. The test procedure used in the human bioassays is a modification of an assay described by the U.S. Environmental Protection Agency and recommended for regulatory affairs. Repellency was computed using the equation: R = 100 - NR/N × 100, where NR is the number of non-repelled ticks, and N is the respective number of control ticks. All investigations were conducted in a controlled laboratory environment offering standardized test conditions. Results All test formulations strongly repelled nymphs of I. ricinus (100-81% protection) as shown by the MO-bioassay. The majority of ticks dropped off the treated surface of the heated rotating drum that served as the attractant (1 mg/cm2 repellent applied). The 10% DDA-based formulation, that produced the best results in laboratory screening, was as effective as the coconut oil-based reference product. The mean protection time of both preparations was generally similar and averaged 8 hours. Repellency investigations in humans showed that the most effective 10% DDA-based formulation (~1.67 mg/cm2 applied) strongly avoided the attachment of I. ricinus nymphs

  9. Coexistence of antibodies to tick-borne pathogens of babesiosis, ehrlichiosis, and Lyme borreliosis in human sera.

    PubMed

    Magnarelli, L A; Dumler, J S; Anderson, J F; Johnson, R C; Fikrig, E

    1995-11-01

    Serum specimens from persons with or without Lyme borreliosis were analyzed by indirect fluorescent antibody staining methods for total immunoglobulins to Babesia microti, Ehrlichia chaffeensis (Arkansas strain), and Ehrlichia equi (MRK strain). There was serologic evidence of human exposure to multiple tick-borne agents in 15 (6.6%) of 227 serum samples obtained in Connecticut and Minnesota. Of these, 10 serum samples were from Connecticut patients who had erythema migrans and antibodies to Borrelia burgdorferi (range, 1:160 to 1:40, 960). A maximal antibody titer of 1:640 was noted for a B. microti infection, whereas titration end points of 1:640 and 1:1,280 were recorded for E. chaffeensis and E. equi seropositives, respectively. In specificity tests, there was no cross-reactivity among the antisera and antigens tested for the four tick-borne pathogens. On the basis of serologic testing, a small group of persons who had Lyme borreliosis had been exposed to one or more other tick-borne agents, but there was no clinical diagnosis of babesiosis or ehrlichiosis. Therefore, if the clinical picture is unclear or multiple tick-associated illnesses are suspected, more extensive laboratory testing is suggested.

  10. Exosomes serve as novel modes of tick-borne flavivirus transmission from arthropod to human cells and facilitates dissemination of viral RNA and proteins to the vertebrate neuronal cells

    PubMed Central

    Neupane, Biswas; Bai, Fengwei; Sherman, Michael B.; Choi, Kyung H.; Neelakanta, Girish

    2018-01-01

    Molecular determinants and mechanisms of arthropod-borne flavivirus transmission to the vertebrate host are poorly understood. In this study, we show for the first time that a cell line from medically important arthropods, such as ticks, secretes extracellular vesicles (EVs) including exosomes that mediate transmission of flavivirus RNA and proteins to the human cells. Our study shows that tick-borne Langat virus (LGTV), a model pathogen closely related to tick-borne encephalitis virus (TBEV), profusely uses arthropod exosomes for transmission of viral RNA and proteins to the human- skin keratinocytes and blood endothelial cells. Cryo-electron microscopy showed the presence of purified arthropod/neuronal exosomes with the size range of 30 to 200 nm in diameter. Both positive and negative strands of LGTV RNA and viral envelope-protein were detected inside exosomes derived from arthropod, murine and human cells. Detection of Nonstructural 1 (NS1) protein in arthropod and neuronal exosomes further suggested that exosomes contain viral proteins. Viral RNA and proteins in exosomes derived from tick and mammalian cells were secured, highly infectious and replicative in all tested evaluations. Treatment with GW4869, a selective inhibitor that blocks exosome release affected LGTV loads in both arthropod and mammalian cell-derived exosomes. Transwell-migration assays showed that exosomes derived from infected-brain-microvascular endothelial cells (that constitute the blood-brain barrier) facilitated LGTV RNA and protein transmission, crossing of the barriers and infection of neuronal cells. Neuronal infection showed abundant loads of both tick-borne LGTV and mosquito-borne West Nile virus RNA in exosomes. Our data also suggest that exosome-mediated LGTV viral transmission is clathrin-dependent. Collectively, our results suggest that flaviviruses uses arthropod-derived exosomes as a novel means for viral RNA and protein transmission from the vector, and the vertebrate

  11. General framework for comparative quantitative studies on transmission of tick-borne diseases using Lyme borreliosis in Europe as an example.

    PubMed

    Randolph, S E; Craine, N G

    1995-11-01

    Models of tick-borne diseases must take account of the particular biological features of ticks that contrast with those of insect vectors. A general framework is proposed that identifies the parameters of the transmission dynamics of tick-borne diseases to allow a quantitative assessment of the relative contributions of different host species and alternative transmission routes to the basic reproductive number, Ro, of such diseases. Taking the particular case of the transmission of the Lyme borreliosis spirochaete, Borrelia burgdorferi, by Ixodes ticks in Europe, and using the best, albeit still inadequate, estimates of the parameter values and a set of empirical data from Thetford Forest, England, we show that squirrels and the transovarial transmission route make quantitatively very significant contributions to Ro. This approach highlights the urgent need for more robust estimates of certain crucial parameter values, particularly the coefficients of transmission between ticks and vertebrates, before we can progress to full models that incorporate seasonality and heterogeneity among host populations for the natural dynamics of transmission of borreliosis and other tick-borne diseases.

  12. Prevalence of tick-borne encephalitis virus in ixodid ticks collected from the republic of Korea during 2011-2012.

    PubMed

    Yun, Seok-Min; Song, Bong Gu; Choi, Wooyoung; Park, Won Il; Kim, Sung Yun; Roh, Jong Yul; Ryou, Jungsang; Ju, Young Ran; Park, Chan; Shin, E-Hyun

    2012-12-01

    In this study, we demonstrated that TBEV-infected ticks have been distributed in the ROK, combined with our previous results. These results suggest that TBEV may exist in the ROK, and H. longicornis, H. flava, and I. nipponensis may be potential vectors of TBEV. In addition, these results emphasize the need for further epidemiological research of TBEV. We examined for the presence of RNA of TBEV by reverse transcriptase-nested polymerase chain reaction (RT-nested PCR) using ixodid ticks captured in 25 localities of 10 provinces. Ticks were collected by the flagging and dragging method or using sentinel BG traps at forests, grass thickets, and grassland. A total of 13,053 ticks belonging to two genera and four species were collected and pooled (1292 pools), according to collection site, species of tick, and developmental stage. Among 1292 pools, the envelope (E) protein gene of TBEV was detected using RT-nested PCR in 10 pools (3 pools of the 1,331 adult ticks and 7 pools of the 11,169 nymph ticks) collected from Gangwon-do province, Jeonrabuk-do province, and Jeju Island. The minimum infection rates for TBEV of Haemaphysalis longicornis, Haemaphysalis flava, and Ixodes nipponensis were 0.06%, 0.17%, and 2.38%, respectively. Phylogenetic analysis based on the partial E protein gene was performed to identify relationships between the TBEV strains. This showed that 10 Korean strains clustered with the Western subtype. In this study, we investigated the prevalence of tick-borne encephalitis virus (TBEV) in ixodid ticks from various regions of the Republic of Korea (ROK) during 2011-2012 to identify whether TBEV is circulating and to determine the endemic regions of TBEV.

  13. Tick-borne infectious diseases in Australia.

    PubMed

    Graves, Stephen R; Stenos, John

    2017-04-17

    Tick bites in Australia can lead to a variety of illnesses in patients. These include infection, allergies, paralysis, autoimmune disease, post-infection fatigue and Australian multisystem disorder. Rickettsial (Rickettsia spp.) infections (Queensland tick typhus, Flinders Island spotted fever and Australian spotted fever) and Q fever (Coxiella burnetii) are the only systemic bacterial infections that are known to be transmitted by tick bites in Australia. Three species of local ticks transmit bacterial infection following a tick bite: the paralysis tick (Ixodes holocyclus) is endemic on the east coast of Australia and causes Queensland tick typhus due to R. australis and Q fever due to C. burnetii; the ornate kangaroo tick (Amblyomma triguttatum) occurs throughout much of northern, central and western Australia and causes Q fever; and the southern reptile tick (Bothriocroton hydrosauri) is found mainly in south-eastern Australia and causes Flinders Island spotted fever due to R. honei. Much about Australian ticks and the medical outcomes following tick bites remains unknown. Further research is required to increase understanding of these areas.

  14. Changes in the geographical distribution and abundance of the tick Ixodes ricinus during the past 30 years in Sweden

    PubMed Central

    2012-01-01

    Background Ixodes ricinus is the main vector in Europe of human-pathogenic Lyme borreliosis (LB) spirochaetes, the tick-borne encephalitis virus (TBEV) and other pathogens of humans and domesticated mammals. The results of a previous 1994 questionnaire, directed at people living in Central and North Sweden (Svealand and Norrland) and aiming to gather information about tick exposure for humans and domestic animals, suggested that Ixodes ricinus ticks had become more widespread in Central Sweden and the southern part of North Sweden from the early 1980s to the early 1990s. To investigate whether the expansion of the tick's northern geographical range and the increasing abundance of ticks in Sweden were still occurring, in 2009 we performed a follow-up survey 16 years after the initial study. Methods A questionnaire similar to the one used in the 1994 study was published in Swedish magazines aimed at dog owners, home owners, and hunters. The questionnaire was published together with a popular science article about the tick's biology and role as a pathogen vector in Sweden. The magazines were selected to get information from people familiar with ticks and who spend time in areas where ticks might be present. Results Analyses of data from both surveys revealed that during the near 30-year period from the early 1980s to 2008, I. ricinus has expanded its distribution range northwards. In the early 1990s ticks were found in new areas along the northern coastline of the Baltic Sea, while in the 2009 study, ticks were reported for the first time from many locations in North Sweden. This included locations as far north as 66°N and places in the interior part of North Sweden. During this 16-year period the tick's range in Sweden was estimated to have increased by 9.9%. Most of the range expansion occurred in North Sweden (north of 60°N) where the tick's coverage area doubled from 12.5% in the early 1990s to 26.8% in 2008. Moreover, according to the respondents, the abundance

  15. Influence of altitude on tick-borne encephalitis infection risk in the natural foci of the Altai Republic, Southern Siberia.

    PubMed

    Shchuchinova, L D; Kozlova, I V; Zlobin, V I

    2015-04-01

    The Altai Republic is a highly endemic area as far as tick-borne encephalitis (TBE) is concerned. The aim of the research was to study the effect of altitude on the risk of tick-borne encephalitis infection in the Altai Republic. The paper analyzes the following data: the study of ixodid ticks collected from the vegetation in 116 sites at the 200-2383m elevation above sea level in 2012-2014, TBE virus prevalence of these vectors, tick-bite incidence rate, and TBE incidence rate of the population. Species identification of 4503 specimens has shown that the most common species are Dermacentor nuttalli (45.3%), Ixodes persulcatus (33.1%), Dermacentor silvarum (9.4%), Dermacentor reticulatus (8.9%), and Haemaphysalis concinna (5.0%). A total of 2997 adult ixodid ticks were studied for the presence of the TBE virus; 2163 samples were examined by ELISA, while 834 specimens were tested by PCR. The TBE virus prevalence of Dermacentor spp. ticks in both reactions was significantly higher than of Ixodes persulcatus ticks (p<0.001). The work shows that the altitude is an important factor in the development of the epidemiological situation of tick-borne encephalitis: the higher the elevation of the area above sea level, the smaller the range of vectors. There is also a change of a leading species: in middle altitude (800-1700m above sea level) the virus is transmitted by ticks of D. nuttalli along with I. persulcatus, and in high mountains (above 1700m above sea level) D. nuttalli becomes an absolute dominant species. However, these species of ticks are less effective vectors than I. persulcatus. With the increase of altitude the tick-bite incidence rate decreases (r=-0.78, p<0.05), and TBE incidence also reduces (r=-0.67, p<0.05). Copyright © 2015 Elsevier GmbH. All rights reserved.

  16. Serologic Evidence of Tick-Borne Encephalitis Virus Infection in a Patient with Suspected Lyme Disease in Japan.

    PubMed

    Yoshii, Kentaro; Sato, Kozue; Ishizuka, Mariko; Kobayashi, Shintaro; Kariwa, Hiroaki; Kawabata, Hiroki

    2018-05-29

    Tick-borne encephalitis (TBE) is widely prevalent on the Eurasian continent, including Japan, but four cases of TBE have been reported in Japan. To inspect unconfirmed TBE cases in Japan, we conducted a retrospective seroepidemiological study of a total of 158 samples from 81 meningoencephalitis patients suspected as Lyme disease. Two serum samples from one patient showed neutralizing antibodies against TBE virus. The patient with severe and progressive encephalitis had a history of tick bite in Hokkaido in 2012. These results demonstrated that tick-borne encephalitis virus (TBEV) case was actually unconfirmed in Japan. Further seroepidemiological surveys are required to identify unconfirmed TBEV infections to consider the pros and cons of introducing specific countermeasures including vaccination in Japan.

  17. Replication enhancer elements within the open reading frame of tick-borne encephalitis virus and their evolution within the Flavivirus genus

    PubMed Central

    Tuplin, A.; Evans, D. J.; Buckley, A.; Jones, I. M.; Gould, E. A.; Gritsun, T. S.

    2011-01-01

    We provide experimental evidence of a replication enhancer element (REE) within the capsid gene of tick-borne encephalitis virus (TBEV, genus Flavivirus). Thermodynamic and phylogenetic analyses predicted that the REE folds as a long stable stem–loop (designated SL6), conserved among all tick-borne flaviviruses (TBFV). Homologous sequences and potential base pairing were found in the corresponding regions of mosquito-borne flaviviruses, but not in more genetically distant flaviviruses. To investigate the role of SL6, nucleotide substitutions were introduced which changed a conserved hexanucleotide motif, the conformation of the terminal loop and the base-paired dsRNA stacking. Substitutions were made within a TBEV reverse genetic system and recovered mutants were compared for plaque morphology, single-step replication kinetics and cytopathic effect. The greatest phenotypic changes were observed in mutants with a destabilized stem. Point mutations in the conserved hexanucleotide motif of the terminal loop caused moderate virus attenuation. However, all mutants eventually reached the titre of wild-type virus late post-infection. Thus, although not essential for growth in tissue culture, the SL6 REE acts to up-regulate virus replication. We hypothesize that this modulatory role may be important for TBEV survival in nature, where the virus circulates by non-viraemic transmission between infected and non-infected ticks, during co-feeding on local rodents. PMID:21622960

  18. [Borrelia miyamotoi: a recently identified human pathogenic tick-borne relapsing fever spirochete].

    PubMed

    Szekeres, Sándor; Lakos, András; Földvári, Gábor

    2017-07-01

    Borrelia miyamotoi is a recently described relapsing fever spirochete transmitted by ticks of the Ixodes ricinus complex. This pathogen is different from Borrelia burgdorferi sensu lato (the Lyme borreliosis spirochetes) in its epidemiology, ecology and also genetics. Over 50 patients have been described worldwide with Borrelia miyamotoi disease, and three immunocompromised patients were reported with neurological symptoms. Our knowledge about Borrelia miyamotoi infection in ticks and its distribution in different habitats and also the mechanism of the infection is limited. The most common symptom is fever; thus it can be easily confused with other tick-borne diseases. Due to the intensive research in recent years, Borrelia miyamotoi infection in ticks and hosts has been reported from different regions and also the number of patients is increasing, thus this bacterium is considered as an emerging pathogen. In this literature review we would like to summarize the available knowledge about this spirochete. Orv Hetil. 2017, 158(29): 1124-1130.

  19. Identification of genetic determinants of a tick-borne flavivirus associated with host-specific adaptation and pathogenicity.

    PubMed

    Mitzel, Dana N; Best, Sonja M; Masnick, Max F; Porcella, Stephen F; Wolfinbarger, James B; Bloom, Marshall E

    2008-11-25

    Tick-borne flaviviruses are maintained in nature in an enzootic cycle involving a tick vector and a vertebrate host. Thus, the virus replicates in two disparate hosts, each providing selective pressures that can influence virus replication and pathogenicity. To identify viral determinants associated with replication in the individual hosts, plaque purified Langat virus (TP21pp) was adapted to growth in mouse or tick cell lines to generate two virus variants, MNBp20 and ISEp20, respectively. Virus adaptation to mouse cells resulted in four amino acid changes in MNBp20 relative to TP21pp, occurring in E, NS4A and NS4B. A comparison between TP21pp and ISEp20 revealed three amino acid modifications in M, NS3 and NS4A of ISEp20. ISEp20, but not MNBp20, was attenuated following intraperitoneal inoculation of mice. Following isolation from mice brains, additional mutations reproducibly emerged in E and NS3 of ISEp20 that were possibly compensatory for the initial adaptation to tick cells. Thus, our data implicate a role for E, M, NS3, NS4A and NS4B in host adaptation and pathogenicity of tick-borne flaviviruses.

  20. Molecular Detection and Serological Evidence of Tick-Borne Encephalitis Virus in Serbia.

    PubMed

    Potkonjak, Aleksandar; Petrović, Tamaš; Ristanović, Elizabeta; Lalić, Ivica; Vračar, Vuk; Savić, Sara; Turkulov, Vesna; Čanak, Grozdana; Milošević, Vesna; Vidanović, Dejan; Jurišić, Aleksandar; Petrović, Aleksandra; Petrović, Vladimir

    2017-12-01

    Tick-borne encephalitis (TBE) is a zoonotic flaviviral infection that is a growing public health concern in European countries. The aims of this research were to detect and characterize tick-borne encephalitis virus (TBEV) in Ixodes ricinus ticks at presumed natural foci in Serbia, and to determine seroprevalence of TBEV IgG antibodies in humans and animals. A total of 500 I. ricinus ticks were examined for the presence of TBEV by real-time RT-PCR, and conventional nested PCR and sequencing. To determine TBEV seroprevalence, 267 human sera samples were collected, as were 200 sera samples from different animal species. All sera samples were examined by ELISA for the presence of anti-TBEV antibodies. To exclude cross-reactivity, all sera samples were tested for anti-West Nile virus (WNV) antibodies and all human sera samples were also tested for anti-Usutu virus antibodies by ELISA. Results of this preliminary study indicated TBEV activity in Serbia at two microfoci. Several decades after the previous documentation of TBEV in Serbia, we have demonstrated the presence of TBEV in I. ricinus questing nymphs (prevalence 2% and 6.6% at the two different localities) and anti-TBEV antibodies in humans (seroprevalence 0.37%). Moreover, we show for the first time TBEV seroprevalence in several animal species in Serbia, including dogs (seroprevalence 17.5%), horses (5%), wild boars (12.5%), cattle (2.5%), and roe deer (2.5%). None of the goats tested was positive for anti-TBEV IgG antibodies. TBEV isolate from I. ricinus tick in this study belonged to the Western European subtype. To understand the true public health concern in Serbia, detailed epidemiological, clinical, virological, and acarological research are required. This is important for implementation of effective control measures to reduce the incidence of TBE in Serbia.

  1. Molecular survey on zoonotic tick-borne bacteria and chlamydiae in feral pigeons (Columba livia domestica).

    PubMed

    Ebani, Valentina Virginia; Bertelloni, Fabrizio; Mani, Paolo

    2016-04-01

    To determine the presence of zoonotic tick-borne bacteria in feral pigeons (Columba livia domestica) from urban areas. Spleen samples from 84 feral pigeons, found dead with traumatic injuries in urban areas, were examined by PCR to detect DNA of Anaplasma phagocytophilum, Bartonella spp., Borrelia burgdorferi sensu lato, Coxiella burnetii, Rickettsia spp., and Chlamydophila spp. Twenty (23.8%) pigeons were infected by tick-borne agents, in particular 2 (2.38%) animals resulted positive for Bartonella spp., 5 (5.95%) for C. burnetii, 5 (5.95%) for Rickettsia spp., 13 (15.47%) for B. burgdorferi sensu lato. All birds scored negative for A. phagocytophilum. Moreover, 17 (20.23%) pigeons were positive for Chlamydophila spp. and among them 10 (11.9%) for Chlamydophila psittaci. Mixed infections by two or three agents were detected in 8 (9.52%) animals. Feral pigeons living in urban and periurban areas are a hazard for the human health as source of several pathogens. The obtained results confirm pigeons as reservoirs of chlamydial agents and suggest that they may be involved in the epidemiology of zoonotic tick-borne infections too. Copyright © 2016 Hainan Medical College. Production and hosting by Elsevier B.V. All rights reserved.

  2. Emergence of tick-borne pathogens (Borrelia burgdorferi sensu lato, Anaplasma phagocytophilum, Ricketsia raoultii and Babesia microti) in the Kyiv urban parks, Ukraine.

    PubMed

    Didyk, Yuliya M; Blaňárová, Lucia; Pogrebnyak, Svyatoslav; Akimov, Igor; Peťko, Branislav; Víchová, Bronislava

    2017-02-01

    To date, only limited data about the presence of ticks and circulation of tick-borne pathogens in urban parks of Kyiv in northern Ukraine are available. In total, 767 ticks (696 Ixodes ricinus and 69 Dermacentor reticulatus) collected in seven urban parks and one suburban oak wood park in Kyiv were individually analyzed by the PCR assays. Tick-borne pathogens, namely spirochetes from Borrelia burgdorferi sensu lato complex, Anaplasma phagocytophilum, and Babesia microti, were detected in 11.1% of tested I. ricinus ticks. In total, 4% of I. ricinus ticks tested positive for the presence of B. burdorferi s.l. (Borrelia afzelii and Borrelia garinii), 5.2% for A. phagocytophilum, and Ba. microti was confirmed in 1.9% of examined ticks. Mixed infections were recorded in four DNA samples, representing the prevalence of 0.6%. One female and two I. ricinus nymphs were simultaneously infected with B. afzelii and A. phagocytophilum, and one female carried B. afzelii and Ba. microti. In addition, 10.1% of D. reticulatus ticks tested positive for Rickettsia raoultii. Identification of infectious agents and their diversity, assessment of the relative epidemiological importance and determination of the prevalence in questing ticks from central parts of the cities are crucial steps towards the tick-borne diseases surveillance in urban environment. Copyright © 2016 Elsevier GmbH. All rights reserved.

  3. EAN consensus review on prevention, diagnosis and management of tick-borne encephalitis.

    PubMed

    Taba, P; Schmutzhard, E; Forsberg, P; Lutsar, I; Ljøstad, U; Mygland, Å; Levchenko, I; Strle, F; Steiner, I

    2017-10-01

    Tick-borne encephalitis (TBE) is an infection of the central nervous system (CNS) caused by tick-borne encephalitis virus (TBEV) and transmitted by ticks, with a variety of clinical manifestations. The incidence of TBE in Europe is increasing due to an extended season of the infection and the enlargement of endemic areas. Our objectives are to provide recommendations on the prevention, diagnosis and management of TBE, based on evidence or consensus decisions. For systematic evaluation, the literature was searched from 1970 to 2015 (including early online publications of 2016), and recommendations were based on evidence or consensus decisions of the Task Force when evidence-based data were not available. Vaccination against TBE is recommended for all age groups above 1 year in highly endemic areas (≥5 cases/100 000/year), but also for individuals at risk in areas with a lower incidence. Travellers to endemic areas should be vaccinated if their visits will include extensive outdoor activities. Post-exposure prophylaxis after a tick bite is not recommended. A case of TBE is defined by the presence of clinical signs of meningitis, meningoencephalitis or meningoencephalomyelitis with cerebrospinal fluid (CSF) pleocytosis (>5 × 10 6 cells/l) and the presence of specific TBEV serum immunoglobulin M (IgM) and IgG antibodies, CSF IgM antibodies or TBEV IgG seroconversion. TBEV-specific polymerase chain reaction in blood is diagnostic in the first viremic phase but it is not sensitive in the second phase of TBE with clinical manifestations of CNS inflammation. Lumbar puncture should be performed in all patients with suspected CNS infection unless there are contraindications. Imaging of the brain and spinal cord has a low sensitivity and a low specificity, but it is useful for differential diagnosis. No effective antiviral or immunomodulating therapy is available for TBE; therefore the treatment is symptomatic. Patients with a potentially life threatening

  4. Mapping the distribution of tick-borne encephalitis in mainland China.

    PubMed

    Sun, Ruo-Xi; Lai, Sheng-Jie; Yang, Yang; Li, Xin-Lou; Liu, Kun; Yao, Hong-Wu; Zhou, Hang; Li, Yu; Wang, Li-Ping; Mu, Di; Yin, Wen-Wu; Fang, Li-Qun; Yu, Hong-Jie; Cao, Wu-Chun

    2017-06-01

    Tick-borne encephalitis (TBE) has become an increasing public health threat in recent years, ranging from Europe, through far-eastern Russia to Japan and northern China. However, the neglect of its expansion and scarce analyses of the dynamics have made the overall disease burden and the risk distribution of the disease being unclear in mainland China. In this study, we described epidemiological characteristics of 2117 reported human TBE cases from 2006 to 2013 in mainland China. About 99% of the cases were reported in forest areas of northeastern China, and 93% of reported infections occurred during May-July. Cases were primarily male (67%), mostly in 30-59 years among all age-gender groups. Farmers (31.6%), domestic workers (20.1%) and forest workers (17.9%) accounted for the majority of the patients, and the proportions of patients from farmers and domestic workers were increasing in recent years. The epidemiological features of TBE differed slightly across the affected regions. The distribution and features of the disease in three main endemic areas of mainland China were also summarized. Using the Boosted Regression Trees (BRT) model, we found that the presence of TBE was significantly associated with a composite meteorological index, altitude, the coverage of broad-leaved forest, the coverage of mixed broadleaf-conifer forest, and the distribution of Ixodes persulcatus (I. persulcatus) ticks. The model-predicted probability of presence of human TBE cases in mainland China was mapped at the county level. The spatial distribution of human TBE in China was largely driven by the distributions of forests and I. persulcatus ticks, altitude, and climate. Enhanced surveillance and intervention for human TBE in the high-risk regions, particularly on the forest areas in north-eastern China, is necessary to prevent human infections. Copyright © 2017 The Authors. Published by Elsevier GmbH.. All rights reserved.

  5. Ticks and tick-borne pathogens and putative symbionts of black bears (Ursus americanus floridanus) from Georgia and Florida.

    PubMed

    Yabsley, Michael J; Nims, Todd N; Savage, Mason Y; Durden, Lance A

    2009-10-01

    Ticks were collected from 38 black bears (Ursus americanus floridanus) from northwestern Florida (n = 18) from 2003 to 2005 and southern Georgia (n = 20) in 2006. Five species (Amblyomma americanum, A. maculatum, Dermacentor variabilis, Ixodes scapularis, and I. affinis) were collected from Florida bears, and 4 species (A. americanum, A. maculatum, D. variabilis, I. scapularis) were collected from bears in Georgia. Ixodes scapularis was the most frequently collected tick, followed by D. variabilis, A. americanum, A. maculatum, and I. affinis. The collection of I. affinis from a Florida bear represents a new host record. A subset of ticks was screened for pathogens and putative symbionts by polymerase chain reaction (PCR). The zoonotic tick-borne pathogens Ehrlichia chaffeensis and Rickettsia parkeri were detected in 1 of 23 (4.3%) A. americanum and 1 of 12 (8.3%) A. maculatum, respectively. The putative zoonotic pathogen "Rickettsia amblyommii" was detected in 4 (17.4%) A. americanum and 1 (8.3%) A. maculatum. Other putative symbiotic rickettsiae detected included R. bellii and R. montanensis in D. variabilis, a Rickettsia cooleyi-like sp. and Rickettsia sp. Is-1 in I. scapularis, and Rickettsia TR39-like sp. in I. scapularis and A. americanum. All ticks were PCR-negative for Anaplasma phagocytophilum, Panola Mountain Ehrlichia sp., E. ewingii, Francisella tularensis, and Borrelia spp.

  6. Co-Infection and Genetic Diversity of Tick-Borne Pathogens in Roe Deer from Poland

    PubMed Central

    Werszko, Joanna; Cydzik, Krystian; Bajer, Anna; Michalik, Jerzy; Behnke, Jerzy M.

    2013-01-01

    Abstract Wild species are essential hosts for maintaining Ixodes ticks and the tick-borne diseases. The aim of our study was to estimate the prevalence, the rate of co-infection with Babesia, Bartonella, and Anaplasma phagocytophilum, and the molecular diversity of tick-borne pathogens in roe deer in Poland. Almost half of the tested samples provided evidence of infection with at least 1 species. A. phagocytophilum (37.3%) was the most common and Bartonella (13.4%) the rarest infection. A total of 18.3% of all positive samples from roe deer were infected with at least 2 pathogens, and one-third of those were co-infected with A. phagocytophilum, Bartonella, and Babesia species. On the basis of multilocus molecular studies we conclude that: (1) Two different genetic variants of A. phagocytophilum, zoonotic and nonzoonotic, are widely distributed in Polish roe deer population; (2) the roe deer is the host for zoonotic Babesia (Bab. venatorum, Bab. divergens), closely related or identical with strains/species found in humans; (3) our Bab. capreoli and Bab. divergens isolates differed from reported genotypes at 2 conserved base positions, i.e., positions 631 and 663; and (4) this is the first description of Bart. schoenbuchensis infections in roe deer in Poland. We present 1 of the first complex epidemiological studies on the prevalence of Babesia, Bartonella, and A. phagocytophilum in naturally infected populations of roe deer. These game animals clearly have an important role as reservoir hosts of tick-borne pathogens, but the pathogenicity and zoonotic potential of the parasite genotypes hosted by roe deer requires further detailed investigation. PMID:23473225

  7. Babesia canis and other tick-borne infections in dogs in Central Poland.

    PubMed

    Welc-Faleciak, Renata; Rodo, Anna; Siński, Edward; Bajer, Anna

    2009-12-23

    Vector-borne infections constitute increasing health problem in dogs worldwide, including sled dogs, dramatically decreasing the fitness of working dogs and even leading to death. In the period 2006-2008 eighty-two blood samples were collected from eight sled dog kennels in Central Poland. The prevalence of four vector-borne infections (Babesia canis, Bartonella sp., Anaplasma/Ehrlichia and Borrelia burgdorferi) was estimated in 82 sled dogs using PCR and nested PCR for diagnosis and the same methods were used to identify the vector-borne pathogens in 26 dogs presenting at veterinary clinics with symptoms of vector-borne diseases. None of four studied vector-borne pathogens was detected in samples originating from veterinary clinics. Among the remaining 82 dogs B. canis infections were confirmed in three dogs undergoing treatment for babesiosis. The DNA of tick-borne pathogens was also found among 22 (27.8%) of the 79 apparently healthy dogs, including 20 cases of B. canis infection (25.3%), one case of B. burgdorferi s.l. infection and one case of Anaplasma phagocytophilum infection. No evidence of Bartonella spp. and Ehrlichia canis infections were found in this set of samples. Sequencing of a Babesia fragment of 18S rDNA amplified from acute (n=5) and asymptomatic (n=5) cases revealed that all isolates were identical to the Babesia canis canis sequence, originally isolated from Dermacentor reticulatus ticks in Poland. A range of factors was shown to affect the distribution of babesiosis in sled dogs. The data are also discussed in respect to the health risk factors generated by asymptomatic B. canis infections and the efficiency of chemoprophylaxis measures taken by sled dog owners.

  8. Point prevalence survey for tick-borne pathogens in military working dogs, shelter animals, and pet populations in northern Colombia.

    PubMed

    McCown, M E; Alleman, A; Sayler, K A; Chandrashekar, R; Thatcher, B; Tyrrell, P; Stillman, B; Beall, M; Barbet, A F

    2014-01-01

    Based on the high tick-borne pathogen results from a 2011 surveillance study in three Colombian cities, an in-depth point prevalence survey was conducted to determine the seroprevalence of tick-borne pathogens at a specific point in time in 70 working dogs, 101 shelter dogs, and 47 client-owned dogs in Barranquilla, Colombia. Of the 218 serum samples, 163 (74%) were positive for Ehrlichia canis and 116 (53%) for Anaplasma platys. Exposure to tick-borne pathogens was highest in shelter and working dogs where more than 90% of the samples were seropositive or positive on polymerase chain reaction for one or more organisms as compared to 51% in client-owned animals. Surveillance for exposure to tick-borne pathogens provides vital information necessary to protect and conserve the health of local humans and animals, deployed military service members, and working dogs in various parts of the world. This study and resultant data demonstrate the value of following a broad-based surveillance study with a more specific, focused analysis in an area of concern. This area?s high levels of exposure warrant emphasis by medical planners and advisors on precautionary measures for military dogs, Special Operations Forces personnel, and the local public. 2014.

  9. The abundance of the Lyme disease pathogen Borrelia afzelii declines over time in the tick vector Ixodes ricinus.

    PubMed

    Jacquet, Maxime; Genné, Dolores; Belli, Alessandro; Maluenda, Elodie; Sarr, Anouk; Voordouw, Maarten J

    2017-05-25

    The population dynamics of vector-borne pathogens inside the arthropod vector can have important consequences for vector-to-host transmission. Tick-borne spirochete bacteria of the Borrelia burgdorferi (sensu lato) species complex cause Lyme borreliosis in humans and spend long periods of time (>12 months) in their Ixodes tick vectors. To date, few studies have investigated the dynamics of Borrelia spirochete populations in unfed Ixodes nymphal ticks. Larval ticks from our laboratory colony of I. ricinus were experimentally infected with B. afzelii, and killed at 1 month and 4 months after the larva-to-nymph moult. The spirochete load was also compared between engorged larval ticks and unfed nymphs (from the same cohort) and between unfed nymphs and unfed adult ticks (from the same cohort). The spirochete load of B. afzelii in each tick was estimated using qPCR. The mean spirochete load in the 1-month-old nymphs (~14,000 spirochetes) was seven times higher than the 4-month-old nymphs (~2000 spirochetes). Thus, the nymphal spirochete load declined by 80% over a period of 3 months. An engorged larval tick acquired ~100 spirochetes, and this population was 20 times larger in a young, unfed nymph. The spirochete load also appeared to decline in adult ticks. Comparison between wild and laboratory populations found that lab ticks were more susceptible to acquiring B. afzelii. The spirochete load of B. afzelii declines dramatically over time in domesticated I. ricinus nymphs under laboratory conditions. Future studies should investigate whether temporal declines in spirochete load occur in wild Ixodes ticks under natural conditions and whether these declines influence the tick-to-host transmission of Borrelia.

  10. U.S. public's experience with ticks and tick-borne diseases: Results from national HealthStyles surveys.

    PubMed

    Hook, Sarah A; Nelson, Christina A; Mead, Paul S

    2015-06-01

    Surveillance data indicate that tick-borne diseases (TBDs) are a substantial public health problem in the United States, yet information on the frequency of tick exposure and TBD awareness and prevention practices among the general population is limited. The objective of this study was to gain a more complete understanding of the U.S. public's experience with TBDs using data from annual, nationally representative HealthStyles surveys. There were 4728 respondents in 2009, 4050 in 2011, and 3503 in 2012. Twenty-one percent of respondents reported that a household member found a tick on his or her body during the previous year; of these, 10.1% reported consultation with a health care provider as a result. Overall, 63.7% of respondents reported that Lyme disease (LD) occurs in the area where they live, including 49.4% of respondents from the West South Central and 51.1% from the Mountain regions where LD does not occur. Conversely, in the New England and Mid-Atlantic regions where LD, anaplasmosis, and babesiosis are common, 13.9% and 20.8% of respondents, respectively, reported either that no TBDs occur in their area or that they had not heard of any of these diseases. The majority of respondents (51.2%) reported that they did not routinely take any personal prevention steps against tick bites during warm weather. Results from these surveys indicate that exposure to ticks is common and awareness of LD is widespread. Nevertheless, use of TBD prevention measures is relatively infrequent among the U.S. public, highlighting the need to better understand barriers to use of prevention measures. Published by Elsevier GmbH.

  11. Predicting the risk of Lyme borreliosis after a tick bite, using a structural equation model.

    PubMed

    Hofhuis, Agnetha; van de Kassteele, Jan; Sprong, Hein; van den Wijngaard, Cees C; Harms, Margriet G; Fonville, Manoj; Docters van Leeuwen, Arieke; Simões, Mariana; van Pelt, Wilfrid

    2017-01-01

    Understanding and quantification of the risk of Lyme borreliosis after a tick bite can aid development of prevention strategies against Lyme borreliosis. We used 3,525 single tick bite reports from three large prospective studies on the transmission risk of tick-borne pathogens to humans, with 50 reports of Lyme borreliosis during the follow-up period, among 1,973 reports with known outcome. A structural equation model was applied to estimate the risk of Lyme borreliosis after a tick bite, and quantify the influence of: developmental stage of the tick, detection of Borrelia burgdorferi s.l. DNA in the tick by PCR, tick engorgement, patient-estimated duration of tick attachment, and patient age. The overall risk of developing Lyme borreliosis after a tick bite was 2.6% (95%CI 1.4-5.1). The risk increased with: - Tick engorgement: 1.4% (95%CI 0.7%-2.3%) for low engorgement to 5.5% (95%CI 2.8%-9.2%) for substantially engorged ticks;- Rising patient-estimated tick attachment duration: 2.0% (95%CI 1.3%-2.8%) after <12 hours, to 5.2% (95%CI 3.0%-8.9%) after ≥4 days;- Detection of Borrelia burgdorferi s.l. DNA in ticks: 6.7% (95%CI 3.6%-13.5%), versus 1.4% (95%CI 0.7%-2.9%) when ticks tested negative.The highest observed risk of Lyme borreliosis was 14.4% (95%CI 6.8%-24.6%) after one tick bite of a substantially engorged tick that tested positive for Borrelia burgdorferi s.l. DNA, which corresponds to one new case of Lyme borreliosis per 7 (95%CI 4-15) of such tick bites. An individual's risk of Lyme borreliosis after a tick bite can be predicted with tick engorgement, patient-estimated duration of tick attachment, and detection of Borrelia burgdorferi s.l. DNA in the tick.

  12. Infection and exposure to vector-borne pathogens in rural dogs and their ticks, Uganda.

    PubMed

    Proboste, Tatiana; Kalema-Zikusoka, Gladys; Altet, Laura; Solano-Gallego, Laia; Fernández de Mera, Isabel G; Chirife, Andrea D; Muro, Jesús; Bach, Ester; Piazza, Antonio; Cevidanes, Aitor; Blanda, Valeria; Mugisha, Lawrence; de la Fuente, José; Caracappa, Santo; Millán, Javier

    2015-06-05

    In rural parts of Africa, dogs live in close association with humans and livestock, roam freely, and usually do not receive prophylactic measures. Thus, they are a source of infectious disease for humans and for wildlife such as protected carnivores. In 2011, an epidemiological study was carried out around three conservation areas in Uganda to detect the presence and determine the prevalence of vector-borne pathogens in rural dogs and associated ticks to evaluate the risk that these pathogens pose to humans and wildlife. Serum samples (n = 105), blood smears (n = 43) and blood preserved on FTA cards (n = 38) and ticks (58 monospecific pools of Haemaphysalis leachi and Rhipicephalus praetextatus including 312 ticks from 52 dogs) were collected from dogs. Dog sera were tested by indirect immunofluorescence to detect the presence of antibodies against Rickettsia conorii and Ehrlichia canis. Antibodies against R. conorii were also examined by indirect enzyme immunoassay. Real time PCR for the detection of Rickettsia spp., Anaplasmataceae, Bartonella spp. and Babesia spp. was performed in DNA extracted from FTA cards and ticks. 99% of the dogs were seropositive to Rickettsia spp. and 29.5% to Ehrlichia spp. Molecular analyses revealed that 7.8% of the blood samples were infected with Babesia rossi, and all were negative for Rickettsia spp. and Ehrlichia spp. Ticks were infected with Rickettsia sp. (18.9%), including R. conorii and R. massiliae; Ehrlichia sp. (18.9%), including E. chaffeensis and Anaplasma platys; and B. rossi (1.7%). Bartonella spp. was not detected in any of the blood or tick samples. This study confirms the presence of previously undetected vector-borne pathogens of humans and animals in East Africa. We recommend that dog owners in rural Uganda be advised to protect their animals against ectoparasites to prevent the transmission of pathogens to humans and wildlife.

  13. A Controlled Trial of a Novel Primary Prevention Program for Lyme Disease and Other Tick-Borne Illnesses

    ERIC Educational Resources Information Center

    Daltroy, Lawren H.; Phillips, Charlotte; Lew, Robert; Wright, Elizabeth; Shadick, Nancy A.; Liang, Matthew H.

    2007-01-01

    To evaluate a theory-based educational program to prevent Lyme disease and other tick-borne illnesses (TBI), a randomized controlled trial of an educational program was delivered to ferry passengers traveling to an endemic area in southeastern Massachusetts. Rates of TBI and precautionary and tick check behaviors were measured over three summers…

  14. Vertebrate Ticks Distribution and Their Role as Vectors in Relation to Road Edges and Underpasses.

    PubMed

    Delgado, Juan D; Abreu-Yanes, Estefanía; Abreu-Acosta, Néstor; Flor, Manuel D; Foronda, Pilar

    2017-06-01

    Roads fragment vertebrate populations and affect the dynamics and dispersal patterns of vertebrate parasites. We evaluated how vertebrate ticks distribute near roads and road underpasses in human-caused road-fragmented landscapes in Seville, SW Spain. We sampled 49 stations with 93 individualized sampling points and assessed tick abundance. We explored the relationship between tick presence and abundance and distance to the nearest road and underpass (drainage culverts and other passages used by vertebrates), and landscape features through categorical regression and nonparametric statistics. The presence of the tick-borne pathogens Borrelia sp. and Bartonella sp. was also analyzed by PCR. We found preliminary evidence of high relative tick abundance next to roads and in the vicinity of road underpasses. Plant cover type was related to tick presence in this road context. Implications of road permeability and edge effect in patterns of vertebrate-tick relationships in road fragmentation contexts are discussed. Both Borrelia sp. and Bartonella sp. were detected in the ticks analyzed. This is the first report of these bacteria in ticks from Seville. The results confirm the potential risk of acquiring Lyme disease and bartonellosis in this area.

  15. Avoiding Ticks

    MedlinePlus

    ... ticks that bite humans How ticks spread disease Diseases transmitted by ticks Trends in tickborne diseases Tickborne diseases ... Emerging and Zoonotic Infectious Diseases (NCEZID) Division of Vector-Borne Diseases (DVBD) Email Recommend Tweet YouTube Instagram Listen Watch ...

  16. Severe fever with thrombocytopenia syndrome, an emerging tick-borne zoonosis.

    PubMed

    Liu, Quan; He, Biao; Huang, Si-Yang; Wei, Feng; Zhu, Xing-Quan

    2014-08-01

    Severe fever with thrombocytopenia syndrome (SFTS) is an emerging haemorrhagic fever that was first described in rural areas of China. The causative agent, SFTS virus (SFTSV), is a novel phlebovirus in the Bunyaviridae family. Since the first report in 2010, SFTS has been found in 11 provinces of China, with about 2500 reported cases, and an average case-fatality rate of 7·3%. The disease was also reported in Japan and Korea in 2012; Heartland virus, another phlebovirus genetically closely related to SFTSV, was isolated from two patients in the USA. The disease has become a substantial risk to public health, not only in China, but also in other parts of the world. The virus could undergo rapid evolution by gene mutation, reassortment, and homologous recombination in tick vectors and vertebrate reservoir hosts. No specific treatment of SFTS is available, and avoiding tick bites is an important measure to prevent the infection and transmission of SFTSV. This Review provides information on the molecular characteristics and ecology of this emerging tick-borne virus and describes the epidemiology, clinical signs, pathogenesis, diagnosis, treatment, and prevention of human infection with SFTSV. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Targeting a global health problem: Vaccine design and challenges for the control of tick-borne diseases.

    PubMed

    de la Fuente, José; Contreras, Marinela; Estrada-Peña, Agustín; Cabezas-Cruz, Alejandro

    2017-09-12

    It has been over twenty years since the first vaccines for the control of tick infestations became commercially available. These vaccines proved their efficacy and the potential of this approach for the control of tick-borne diseases (TBDs), which represent a growing burden for human and animal health worldwide. In all these years, research in this area has produced new tick-derived and pathogen-derived candidate protective antigens. However, the potential of vaccines for the control of TBDs has been underestimated due to major challenges to reduce tick infestations, pathogen infection, multiplication and transmission, tick attachment and feeding time and/or host pathogen infection. Nevertheless, vaccines constitute the most safe and effective intervention for the control of TBDs in humans, domestic and wild animals. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Isolation, preliminary characterization, and full-genome analyses of tick-borne encephalitis virus from Mongolia.

    PubMed

    Frey, Stefan; Mossbrugger, Ilona; Altantuul, Damdin; Battsetseg, Jigjav; Davaadorj, Rendoo; Tserennorov, Damdindorj; Buyanjargal, Tsoodol; Otgonbaatar, Dashdavaa; Zöller, Lothar; Speck, Stephanie; Wölfel, Roman; Dobler, Gerhard; Essbauer, Sandra

    2012-12-01

    Tick-borne encephalitis virus (TBEV) causes one of the most important inflammatory diseases of the central nervous system, namely severe encephalitis in Europe and Asia. Since the 1980s tick-borne encephalitis is known in Mongolia with increasing numbers of human cases reported during the last years. So far, however, data on TBEV strains are still sparse. We herein report the isolation of a TBEV strain from Ixodes persulcatus ticks collected in Mongolia in 2010. Phylogenetic analysis of the E-gene classified this isolate as Siberian subtype of TBEV. The Mongolian TBEV strain showed differences in virus titers, plaque sizes, and growth properties in two human neuronal cell-lines. In addition, the 10,242 nucleotide long open-reading frame and the corresponding polyprotein sequence were revealed. The isolate grouped in the genetic subclade of the Siberian subtype. The strain Zausaev (AF527415) and Vasilchenko (AF069066) had 97 and 94 % identity on the nucleotide level. In summary, we herein describe first detailed data regarding TBEV from Mongolia. Further investigations of TBEV in Mongolia and adjacent areas are needed to understand the intricate dispersal of this virus.

  19. Prevalence of tick-borne encephalitis virus in Ixodes ricinus ticks in northern Europe with particular reference to Southern Sweden.

    PubMed

    Pettersson, John H-O; Golovljova, Irina; Vene, Sirkka; Jaenson, Thomas G T

    2014-03-11

    In northern Europe, the tick-borne encephalitis virus (TBEV) of the European subtype is usually transmitted to humans by the common tick Ixodes ricinus. The aims of the present study are (i) to obtain up-to-date information on the TBEV prevalence in host-seeking I. ricinus in southern and central Sweden; (ii) to compile and review all relevant published records on the prevalence of TBEV in ticks in northern Europe; and (iii) to analyse and try to explain how the TBE virus can be maintained in natural foci despite an apparently low TBEV infection prevalence in the vector population. To estimate the mean minimum infection rate (MIR) of TBEV in I. ricinus in northern Europe (i.e. Denmark, Norway, Sweden and Finland) we reviewed all published TBEV prevalence data for host-seeking I. ricinus collected during 1958-2011. Moreover, we collected 2,074 nymphs and 906 adults of I. ricinus from 29 localities in Sweden during 2008. These ticks were screened for TBEV by RT-PCR. The MIR for TBEV in nymphal and adult I. ricinus was 0.28% for northern Europe and 0.23% for southern Sweden. The infection prevalence of TBEV was significantly lower in nymphs (0.10%) than in adult ticks (0.55%). At a well-known TBEV-endemic locality, Torö island south-east of Stockholm, the TBEV prevalence (MIR) was 0.51% in nymphs and 4.48% in adults of I. ricinus. If the ratio of nymphs to adult ticks in the TBEV-analysed sample differs from that in the I. ricinus population in the field, the MIR obtained will not necessarily reflect the TBEV prevalence in the field. The relatively low TBEV prevalence in the potential vector population recorded in most studies may partly be due to: (i) inclusion of uninfected ticks from the 'uninfected areas' surrounding the TBEV endemic foci; (ii) inclusion of an unrepresentative, too large proportion of immature ticks, compared to adult ticks, in the analysed tick pools; and (iii) shortcomings in the laboratory techniques used to detect the virus that may be

  20. Effects of tick infestation and tick-borne disease infections (heartwater, anaplasmosis and babesiosis) on the lactation and weight gain of Mashona cattle in south-eastern Zimbabwe.

    PubMed

    Meltzer, M I; Norval, R A; Donachie, P L

    1995-08-01

    The effects of ticks and tick-borne disease infections on the lactation and weight gain of Mashona cattle were studied at Mbizi Quarantine Station in the south-eastern lowveld of Zimbabwe. Twenty-nine Mashona cows were allocated to 2 balanced groups and kept in separate paddocks at a stocking rate of one animal per 8 ha. One group received regular acaricide treatment to control bont (Amblyomma hebraeum) and other ticks. The other group was left untreated. The cows were artificially inseminated. The acaricide-treated cows and calves were essentially tick free throughout the experiment, while the untreated cows and calves were continuously tick infested. There was a drought-related decline in tick infestations in the second year of the experiment. Antibodies to Cowdria ruminantium, Babesia bigemina and Anaplasma marginale were detected in cows and calves from both groups, though the untreated group had significantly higher titres to C. ruminantium (P < 0.001). The total, measured amount of milk suckled by untreated calves was significantly more than treated calves (273 kg vs. 241 kg, P < or = 0.05). By interpolating between the twice weekly measurements, it was calculated that over the entire lactation untreated calves suckled an average of 935 kg/hd vs. 837 kg/hd for the treated group. There were no statistical differences in the weights of the 2 groups of calves at birth, weaning, 180 and 210 days post partum (P < 0.05). For cows, there were no statistically significant differences in gestation periods (288 vs. 279 days), reconception rates or weight patterns over time (P < 0.05). The results show that intensive acaricide treatment in areas of Zimbabwe where heartwater is enzootically stable is uneconomical. The maintenance of enzootic stability for tick-borne diseases through minimal tick control is clearly a more economic and practical control option.

  1. Tick abundance: a one year study on the impact of flood events along the banks of the river Danube, Austria.

    PubMed

    Weiler, Martin; Duscher, Georg Gerhard; Wetscher, Monika; Walochnik, Julia

    2017-02-01

    The abundance of questing ticks depends on various factors. In this study, the impact of a major flood event on tick abundance and activity was observed. Ticks were collected on a weekly basis in two approximately 2 km 2 large floodplain areas on the inner and the outer bank of the river Danube north of Vienna, Austria. In 2013 before a 200 year flood event, an average of 55 ticks per hour was collected in the area on the outer bank and 21 ticks per hour in the area on the inner bank. After the flood event the tick activity was massively reduced, with 12 ticks per hour on the outer bank and 1.1 ticks per hour on the inner bank. The most distinctive factor between the two areas was the level of sediment after the flooding, with almost no sediment in the outer bank, whereas on the inner bank the average height of sediment was 270 mm. Our data indicate the residual sediment has a greater impact on tick abundance and activity than the flooding itself. Besides the direct effect of ticks being buried under the sediment, there may be important indirect effects of the sediment on the habitat of the ticks and/or the host animals. We assume that this is the reason for the generally significantly lower numbers of questing ticks in this area on the inner bank of the Danube in this region, with periodical flood events.

  2. The occurrence of Ixodes ricinus ticks and important tick-borne pathogens in areas with high tick-borne encephalitis prevalence in different altitudinal levels of the Czech Republic Part II. Ixodes ricinus ticks and genospecies of Borrelia burgdorferi sensu lato complex.

    PubMed

    Daniel, M; Rudenko, N; Golovchenko, M; Danielová, V; Fialová, A; Kříž, B; Malý, M

    Three years long research study (2011-2013) on population density of Ixodes ricinus and the infection rate of the pathogens that they transmit was conducted in four topographically distant areas in the Czech Republic. In the previous decade (2001-2010) thirteen loci with increased incidence of tick borne encephalitis cases were defined, suggesting the permanent interaction of human population with ticks and indicating the landmarks for study of the presence of other tick borne pathogens. The work program included the identification of existing spectrum of spirochetes from Borrelia burgdorferi sensu lato complex and the conditions of their occurrence and distribution. In the areas of the Ústí nad Labem Region, Olomouc Region, South Bohemian Region, and Highlands Region, 600 m2 plots were selected in the local optimal I. ricinus habitats where tick flagging was performed every year in the spring-summer and autumn seasons of the tick questing activity. Collected adult ticks (1369 males and 1404 females) were individually screened for B. burgdorferi s. l. spirochets. Spirochetes from B. burgdorferi s.l. complex were detected in all 13 studies sites in all altitudes from 280 to 1030 meters a. s. l. The total rate of infection was determined as 11.4% (males 10.4%, females 12.4%) with range limits from 1.4% (Ústí nad Labem in 2011) to 19.7% (South Bohemian Region, 2012).Genospecies were detected in various proportions and in different combinations: Borrelia afzelii, B. garinii, B. burgdorferi s. s., B. bavariensis, B. bissettii, B. valaisiana, B. spielmanii and B. lusitaniae. The three-year observation justifies the assumption that the regional differences in infectivity of I. ricinus are based on the character of the local biocenosis of the respective region. The dynamics of its seasonal changes, conditioned by climatic factors, determines the annual differences. Three of the medically most important Borrelia species formed a core group among all detected genospecies

  3. Economic downturn results in tick-borne disease upsurge.

    PubMed

    Godfrey, Elinor R; Randolph, Sarah E

    2011-03-15

    The emergence of zoonoses is due both to changes in human activities and to changes in their natural wildlife cycles. One of the most significant vector-borne zoonoses in Europe, tick-borne encephalitis (TBE), doubled in incidence in 1993, largely as a consequence of the socio-economic transition from communism to capitalism and associated environmental changes. To test the effect of the current economic recession, unemployment in 2009 and various socio-economic indices were compared to weather indices (derived from principal component analyses) as predictors for the change in TBE case numbers in 2009 relative to 2004-08, for 14 European countries. Greatest increases in TBE incidence occurred in Latvia, Lithuania and Poland (91, 79 and 45%, respectively). The weather was rejected as an explanatory variable. Indicators of high background levels of poverty, e.g. percent of household expenditure on food, were significant predictors. The increase in unemployment in 2009 relative to 2008 together with 'in-work risk of poverty' is the only case in which a multivariate model has a second significant term. Background socio-economic conditions determine susceptibility to risk of TBE, while increased unemployment triggered a sudden increase in risk. Mechanisms behind this result may include reduced resistance to infection through stress; reduced uptake of costly vaccination; and more exposure of people to infected ticks in their forest habitat as they make greater use of wild forest foods, especially in those countries, Lithuania and Poland, with major marketing opportunities in such products. Recognition of these risk factors could allow more effective protection through education and a vaccination programme targeted at the economically most vulnerable.

  4. Economic downturn results in tick-borne disease upsurge

    PubMed Central

    2011-01-01

    Background The emergence of zoonoses is due both to changes in human activities and to changes in their natural wildlife cycles. One of the most significant vector-borne zoonoses in Europe, tick-borne encephalitis (TBE), doubled in incidence in 1993, largely as a consequence of the socio-economic transition from communism to capitalism and associated environmental changes. Methods To test the effect of the current economic recession, unemployment in 2009 and various socio-economic indices were compared to weather indices (derived from principal component analyses) as predictors for the change in TBE case numbers in 2009 relative to 2004-08, for 14 European countries. Results Greatest increases in TBE incidence occurred in Latvia, Lithuania and Poland (91, 79 and 45%, respectively). The weather was rejected as an explanatory variable. Indicators of high background levels of poverty, e.g. percent of household expenditure on food, were significant predictors. The increase in unemployment in 2009 relative to 2008 together with 'in-work risk of poverty' is the only case in which a multivariate model has a second significant term. Conclusion Background socio-economic conditions determine susceptibility to risk of TBE, while increased unemployment triggered a sudden increase in risk. Mechanisms behind this result may include reduced resistance to infection through stress; reduced uptake of costly vaccination; and more exposure of people to infected ticks in their forest habitat as they make greater use of wild forest foods, especially in those countries, Lithuania and Poland, with major marketing opportunities in such products. Recognition of these risk factors could allow more effective protection through education and a vaccination programme targeted at the economically most vulnerable. PMID:21406086

  5. [Tick-borne recurrent fever. Description of 5 cases].

    PubMed

    Sánchez-Yebra, W; Díaz, Y; Molina, P; Sedeño; Giner, P; Vitutia, M M; Anda, P

    1997-02-01

    Tick-borne relapsing fever (FRGT) is a worldwide zoonosis. The disease is caused by spirochetes of the genus Borrelia, and is transmitted to man by ticks of the genus Ornithodoros (O. erraticus in Spain). 5 FRTG cases attended in our hospital in a 2 years period are described. Diagnosis was established in all cases by demonstration of borreliae in peripheral blood. Three Borrelia strains were isolated from blood of 3 of our patients and they are maintained by passages through mice. High fever, tachycardia and headache were noted in all cases accompanied in 2 of them by hepatosplenomegaly. Three of the patients complained of arthromyalgias or lumbar myalgia. Treatment with doxycicline was curative in all of them. FRGT incidence in our country is probably underestimated due to the low suspicion of the disease and the specificity of the clinical symptoms. The isolement of the causative Borrelia strain will allow the development of more specific serological tests necessary to establish the prevalence of this disease as well to assess its implication in chronic diseases, as is observed in other borreliosis (i.e. Lyme disease), that might be missed at this moment.

  6. Tick-borne Encephalitis Associated with Consumption of Raw Goat Milk, Slovenia, 2012

    PubMed Central

    Hudopisk, Neda; Korva, Miša; Janet, Evgen; Simetinger, Marjana; Grgič-Vitek, Marta; Gubenšek, Jakob; Natek, Vladimir; Kraigher, Alenka; Strle, Franc

    2013-01-01

    Tick-borne encephalitis (TBE) developed in 3 persons in Slovenia who drank raw milk; a fourth person, who had been vaccinated against TBE, remained healthy. TBE virus RNA was detected in serum and milk of the source goat. Persons in TBE-endemic areas should be encouraged to drink only boiled/pasteurized milk and to be vaccinated. PMID:23697658

  7. Molecular Detection of Tick-Borne Pathogen Diversities in Ticks from Livestock and Reptiles along the Shores and Adjacent Islands of Lake Victoria and Lake Baringo, Kenya.

    PubMed

    Omondi, David; Masiga, Daniel K; Fielding, Burtram C; Kariuki, Edward; Ajamma, Yvonne Ukamaka; Mwamuye, Micky M; Ouso, Daniel O; Villinger, Jandouwe

    2017-01-01

    Although diverse tick-borne pathogens (TBPs) are endemic to East Africa, with recognized impact on human and livestock health, their diversity and specific interactions with tick and vertebrate host species remain poorly understood in the region. In particular, the role of reptiles in TBP epidemiology remains unknown, despite having been implicated with TBPs of livestock among exported tortoises and lizards. Understanding TBP ecologies, and the potential role of common reptiles, is critical for the development of targeted transmission control strategies for these neglected tropical disease agents. During the wet months (April-May; October-December) of 2012-2013, we surveyed TBP diversity among 4,126 ticks parasitizing livestock and reptiles at homesteads along the shores and islands of Lake Baringo and Lake Victoria in Kenya, regions endemic to diverse neglected tick-borne diseases. After morphological identification of 13 distinct Rhipicephalus, Amblyomma , and Hyalomma tick species, ticks were pooled (≤8 individuals) by species, host, sampling site, and collection date into 585 tick pools. By supplementing previously established molecular assays for TBP detection with high-resolution melting analysis of PCR products before sequencing, we identified high frequencies of potential disease agents of ehrlichiosis (12.48% Ehrlichia ruminantium , 9.06% Ehrlichia canis ), anaplasmosis (6.32% Anaplasma ovis , 14.36% Anaplasma platys , and 3.08% Anaplasma bovis ,), and rickettsiosis (6.15% Rickettsia africae , 2.22% Rickettsia aeschlimannii , 4.27% Rickettsia rhipicephali , and 4.95% Rickettsia spp.), as well as Paracoccus sp. and apicomplexan hemoparasites (0.51% Theileria sp., 2.56% Hepatozoon fitzsimonsi , and 1.37% Babesia caballi ) among tick pools. Notably, we identified E. ruminantium in both Amblyomma and Rhipicephalus pools of ticks sampled from livestock in both study areas as well as in Amblyomma falsomarmoreum (66.7%) and Amblyomma nuttalli (100%) sampled

  8. Predicting the risk of Lyme borreliosis after a tick bite, using a structural equation model

    PubMed Central

    Sprong, Hein; van den Wijngaard, Cees C.; Harms, Margriet G.; Fonville, Manoj; Docters van Leeuwen, Arieke; Simões, Mariana; van Pelt, Wilfrid

    2017-01-01

    Background Understanding and quantification of the risk of Lyme borreliosis after a tick bite can aid development of prevention strategies against Lyme borreliosis. Methods We used 3,525 single tick bite reports from three large prospective studies on the transmission risk of tick-borne pathogens to humans, with 50 reports of Lyme borreliosis during the follow-up period, among 1,973 reports with known outcome. A structural equation model was applied to estimate the risk of Lyme borreliosis after a tick bite, and quantify the influence of: developmental stage of the tick, detection of Borrelia burgdorferi s.l. DNA in the tick by PCR, tick engorgement, patient-estimated duration of tick attachment, and patient age. Results The overall risk of developing Lyme borreliosis after a tick bite was 2.6% (95%CI 1.4–5.1). The risk increased with: - Tick engorgement: 1.4% (95%CI 0.7%-2.3%) for low engorgement to 5.5% (95%CI 2.8%-9.2%) for substantially engorged ticks; - Rising patient-estimated tick attachment duration: 2.0% (95%CI 1.3%-2.8%) after <12 hours, to 5.2% (95%CI 3.0%-8.9%) after ≥4 days; - Detection of Borrelia burgdorferi s.l. DNA in ticks: 6.7% (95%CI 3.6%-13.5%), versus 1.4% (95%CI 0.7%-2.9%) when ticks tested negative. The highest observed risk of Lyme borreliosis was 14.4% (95%CI 6.8%-24.6%) after one tick bite of a substantially engorged tick that tested positive for Borrelia burgdorferi s.l. DNA, which corresponds to one new case of Lyme borreliosis per 7 (95%CI 4–15) of such tick bites. Conclusions An individual's risk of Lyme borreliosis after a tick bite can be predicted with tick engorgement, patient-estimated duration of tick attachment, and detection of Borrelia burgdorferi s.l. DNA in the tick. PMID:28742149

  9. Neoehrlichiosis: an emerging tick-borne zoonosis caused by Candidatus Neoehrlichia mikurensis.

    PubMed

    Silaghi, Cornelia; Beck, Relja; Oteo, José A; Pfeffer, Martin; Sprong, Hein

    2016-03-01

    Candidatus Neoehrlichia mikurensis is an emerging tick-borne pathogen causing a systemic inflammatory syndrome mostly in persons with underlying hematologic or autoimmune diseases. As it is neither well-known nor well-recognized, it might be misdiagnosed as recurrence of the underlying disease or as an unrelated arteriosclerotic vascular event. The pathogen is transmitted by hard ticks of the genus Ixodes and is closely associated with rodents in which transplacental transmission occurs. Transovarial transmission in ticks has not yet been shown. Infection rates vary greatly in ticks and rodents, but the causes for its spatiotemporal variations are largely unknown. This review summarizes the current state of knowledge on the geographical distribution and clinical importance of Ca. N. mikurensis. By elucidating the life history traits of this pathogen and determining more accurately its incidence in the human population, a better assessment of its public health relevance can be made. Most urgent research needs are the in vitro-cultivation of the pathogen, the development of specific serological tests, the determination of the full genomic sequence, the routine implementation of molecular diagnosis in diseased patients with a particular panel of underlying diseases, and promoting the knowledge about neoehrlichiosis among general practitioners, hospital physicians and the risk groups such as forest workers or immune-compromised people to raise awareness about this disease that can easily be treated when correctly diagnosed.

  10. Study on the occurrence of tick-borne encephalitis virus RNA in European bison (Bison bonasus) eliminated at Białowieza Primeval Forest (north-eastern Poland) in 2005-2009.

    PubMed

    Biernat, Beata; Karbowiak, Grzegorz

    2014-01-01

    Tick-borne encephalitis virus (TBEV) (Flaviviridae, Flavivirus) is an arthropod-borne virus, an etiologic agent of tick-borne encephalitis (TBE), an infection involving the central nervous system. The disease is endemic in a large region in Eurasia where it is transmitted mainly by Ixodes ricinus in Europe and I. persulcatus ticks in Asia. This is the most important tick-transmitted arbovirus of human pathogenicity in Europe. The Białowieza Primeval Forest is a well-known endemic focus of tick-borne encephalitis. The aim of this study was to identify the prevalence of tickborne encephalitis virus (TBEV) in European bison, the important hosts of ticks in the Białowieza Primeval Forest. In the years 2005-2009, 95 blood samples were collected from European bison and examined for the presence of TBEV using nRT-PCR method. No positive results were obtained. For better understanding of TBEV vertebrate reservoir hosts in Poland, further investigations are needed.

  11. Strategies, Research Priorities, and Partnerships for Community IPM to Prevent Tick-Borne Diseases--2011 Conference

    EPA Pesticide Factsheets

    The U.S. Environmental Protection Agency (EPA) held the Promoting Community Integrated Pest Management to Prevent Tick-Borne Diseases Conference on March 30th and 31st, 2011 in Arlington, Virginia. Read the meeting summary.

  12. Vector biodiversity did not associate with tick-borne pathogen prevalence in small mammal communities in northern and central California.

    PubMed

    Foley, Janet; Piovia-Scott, Jonah

    2014-04-01

    Vector and host abundance affect infection transmission rates, prevalence, and persistence in communities. Biological diversity in hosts and vectors may provide "rescue" hosts which buffer against pathogen extinction and "dilution" hosts which reduce the force of infection in communities. Anaplasma phagocytophilum is a tick-transmitted zoonotic pathogen that circulates in small mammal and tick communities characterized by varying levels of biological diversity. We examined the prevalence of A. phagocytophilum in Ixodes spp. ticks in 11 communities in northern and central California. A total of 1020 ticks of 8 species was evaluated. Five percent of ticks (5 species) were PCR-positive, with the highest prevalence (6-7%) in I. pacificus and I. ochotonae. In most species, adults had a higher prevalence than nymphs or larvae. PCR prevalence varied between 0% and 40% across sites; the infection probability in ticks increased with infestation load and prevalence in small mammals, but not tick species richness, diversity, evenness, or small mammal species richness. No particular tick species was likely to "rescue" infection in the community; rather the risk of A. phagocytophilum infection is related to exposure to particular tick species and life stages, and overall tick abundance. Copyright © 2014 Elsevier GmbH. All rights reserved.

  13. Underreporting of Lyme and Other Tick-Borne Diseases in Residents of a High-Incidence County, Minnesota, 2009.

    PubMed

    Schiffman, E K; McLaughlin, C; Ray, J A E; Kemperman, M M; Hinckley, A F; Friedlander, H G; Neitzel, D F

    2018-03-01

    Lyme disease (LD), anaplasmosis, babesiosis and other tick-borne diseases (TBDs) attributed to Ixodes ticks are thought to be widely underreported in the United States. To identify TBD cases diagnosed in 2009, but not reported to the Minnesota Department of Health (MDH), diagnostic and procedural billing codes suggestive of tick-borne diseases were used to select medical charts for retrospective review in medical facilities serving residents of a highly endemic county in Minnesota. Of 444 illness events, 352 (79%) were not reported. Of these, 102 (29%) met confirmed or probable surveillance case criteria, including 91 (26%) confirmed LD cases with physician-diagnosed erythema migrans (EM). For each confirmed and probable LD, probable anaplasmosis and confirmed babesiosis case reported to MDH in 2009, 2.8, 1.3, 1.2 and 1.0 cases were likely diagnosed, respectively. These revised estimates provide a more accurate assessment and better understanding of the burden of these diseases in a highly endemic county. © 2016 Blackwell Verlag GmbH.

  14. The effect of deer management on the abundance of Ixodes ricinus in Scotland.

    PubMed

    Gilbert, L; Maffey, G L; Ramsay, S L; Hester, A J

    2012-03-01

    The management of wildlife hosts for controlling parasites and disease has a history of mixed success. Deer can be important hosts for ticks, such as Ixodes ricinus, which is the primary vector of disease-causing zoonotic pathogens in Europe. Deer are generally managed by culling and fencing for forestry protection, habitat conservation, and commercial hunting, and in this study we test whether these deer management methods can be useful for controlling ticks, with implications for tick-borne pathogens. At different spatial scales and habitats we tested the hypotheses that tick abundance is reduced by (1) culling deer and (2) deer exclusion using fencing. We compared abundance indices of hosts and questing I. ricinus nymphs using a combination of small-scale fencing experiments on moorland, a large-scale natural experiment of fenced and unfenced pairs of forests, and cross-sectional surveys of forest and moorland areas with varying deer densities. As predicted, areas with fewer deer had fewer ticks, and fenced exclosures had dramatically fewer ticks in both large-scale forest and small-scale moorland plots. Fencing and reducing deer density were also associated with higher ground vegetation. The implications of these results on other hosts, pathogen prevalence, and disease risk are discussed. This study provides evidence of how traditional management methods of a keystone species can reduce a generalist parasite, with implications for disease risk mitigation.

  15. Molecular Detection of Tick-Borne Pathogen Diversities in Ticks from Livestock and Reptiles along the Shores and Adjacent Islands of Lake Victoria and Lake Baringo, Kenya

    PubMed Central

    Omondi, David; Masiga, Daniel K.; Fielding, Burtram C.; Kariuki, Edward; Ajamma, Yvonne Ukamaka; Mwamuye, Micky M.; Ouso, Daniel O.; Villinger, Jandouwe

    2017-01-01

    Although diverse tick-borne pathogens (TBPs) are endemic to East Africa, with recognized impact on human and livestock health, their diversity and specific interactions with tick and vertebrate host species remain poorly understood in the region. In particular, the role of reptiles in TBP epidemiology remains unknown, despite having been implicated with TBPs of livestock among exported tortoises and lizards. Understanding TBP ecologies, and the potential role of common reptiles, is critical for the development of targeted transmission control strategies for these neglected tropical disease agents. During the wet months (April–May; October–December) of 2012–2013, we surveyed TBP diversity among 4,126 ticks parasitizing livestock and reptiles at homesteads along the shores and islands of Lake Baringo and Lake Victoria in Kenya, regions endemic to diverse neglected tick-borne diseases. After morphological identification of 13 distinct Rhipicephalus, Amblyomma, and Hyalomma tick species, ticks were pooled (≤8 individuals) by species, host, sampling site, and collection date into 585 tick pools. By supplementing previously established molecular assays for TBP detection with high-resolution melting analysis of PCR products before sequencing, we identified high frequencies of potential disease agents of ehrlichiosis (12.48% Ehrlichia ruminantium, 9.06% Ehrlichia canis), anaplasmosis (6.32% Anaplasma ovis, 14.36% Anaplasma platys, and 3.08% Anaplasma bovis,), and rickettsiosis (6.15% Rickettsia africae, 2.22% Rickettsia aeschlimannii, 4.27% Rickettsia rhipicephali, and 4.95% Rickettsia spp.), as well as Paracoccus sp. and apicomplexan hemoparasites (0.51% Theileria sp., 2.56% Hepatozoon fitzsimonsi, and 1.37% Babesia caballi) among tick pools. Notably, we identified E. ruminantium in both Amblyomma and Rhipicephalus pools of ticks sampled from livestock in both study areas as well as in Amblyomma falsomarmoreum (66.7%) and Amblyomma nuttalli (100%) sampled from

  16. A Predictive Model Has Identified Tick-Borne Encephalitis High-Risk Areas in Regions Where No Cases Were Reported Previously, Poland, 1999-2012.

    PubMed

    Stefanoff, Pawel; Rubikowska, Barbara; Bratkowski, Jakub; Ustrnul, Zbigniew; Vanwambeke, Sophie O; Rosinska, Magdalena

    2018-04-04

    During 1999–2012, 77% of the cases of tick-borne encephalitis (TBE) were recorded in two out of 16 Polish provinces. However, historical data, mostly from national serosurveys, suggest that the disease could be undetected in many areas. The aim of this study was to identify which routinely-measured meteorological, environmental, and socio-economic factors are associated to TBE human risk across Poland, with a particular focus on areas reporting few cases, but where serosurveys suggest higher incidence. We fitted a zero-inflated Poisson model using data on TBE incidence recorded in 108 NUTS-5 administrative units in high-risk areas over the period 1999–2012. Subsequently we applied the best fitting model to all Polish municipalities. Keeping the remaining variables constant, the predicted rate increased with the increase of air temperature over the previous 10–20 days, precipitation over the previous 20–30 days, in forestation, forest edge density, forest road density, and unemployment. The predicted rate decreased with increasing distance from forests. The map of predicted rates was consistent with the established risk areas. It predicted, however, high rates in provinces considered TBE-free. We recommend raising awareness among physicians working in the predicted high-risk areas and considering routine use of household animal surveys for risk mapping.

  17. Bovine anaplasmosis and tick-borne pathogens in cattle of the Galapagos Islands.

    PubMed

    Gioia, G V; Vinueza, R L; Marsot, M; Devillers, E; Cruz, M; Petit, E; Boulouis, H J; Moutailler, S; Monroy, F; Coello, M A; Gondard, M; Bournez, L; Haddad, N; Zanella, G

    2018-03-22

    A cross-sectional study was conducted to determine the species of Anaplasma spp. and estimate its prevalence in cattle of the three main cattle-producing Galapagos Islands (Santa Cruz, San Cristóbal and Isabela) using indirect PCR assays, genetic sequencing and ELISA. Ticks were also collected from cattle and scanned for 47 tick-borne pathogens in a 48 × 48 real-time PCR chip. A mixed effects logistic regression was performed to identify potential risk factors explaining Anaplasma infection in cattle. A. phagocytophilum was not detected in any of the tested animals. Genetic sequencing allowed detection of A. platys-like strains in 11 (36.7%) of the 30 Anaplasma spp.-positive samples analysed. A. marginale was widespread in the three islands with a global between-herd prevalence of 100% [89; 100] 95% CI and a median within-herd prevalence of 93%. A significant association was found between A. marginale infection and age with higher odds of being positive for adults (OR = 3.3 [1.2; 9.9] 95% Bootstrap CI ). All collected ticks were identified as Rhipicephalus microplus. A. marginale, Babesia bigemina, Borrelia theileri and Francisella-like endosymbiont were detected in tick pools. These results show that the Galapagos Islands are endemic for A. marginale. © 2018 Blackwell Verlag GmbH.

  18. TRIM79α, an interferon-stimulated gene product, restricts tick-borne encephalitis virus replication by degrading the viral RNA polymerase

    PubMed Central

    Taylor, R. Travis; Lubick, Kirk J.; Robertson, Shelly J.; Broughton, James P.; Bloom, Marshall E.; Bresnahan, Wade A.; Best, Sonja M.

    2011-01-01

    In response to virus infection, type I interferons (IFNs) induce several genes, most of whose functions are largely unknown. Here we show that the tripartite motif (TRIM) protein, TRIM79α, is an IFN-stimulated gene (ISG) product that specifically targets tick-borne encephalitis virus (TBEV), a Flavivirus that causes encephalitides in humans. TRIM79α restricts TBEV replication by mediating lysosome-dependent degradation of the flavivirus NS5 protein, an RNA-dependent RNA polymerase essential for virus replication. NS5 degradation was specific to tick-borne flaviviruses as TRIM79α did not recognize NS5 from West Nile virus (WNV) or inhibit WNV replication. In the absence of TRIM79α, IFN-β was less effective in inhibiting tick-borne flavivirus infection of mouse macrophages, highlighting the importance of a single virus-specific ISG in establishing an antiviral state. The specificity of TRIM79α for TBEV reveals a remarkable ability of the innate IFN response to discriminate between closely related flaviviruses. PMID:21925107

  19. Powassan Virus and Other Arthropod-Borne Viruses in Wildlife and Ticks in Ontario, Canada.

    PubMed

    Smith, Kathryn; Oesterle, Paul T; Jardine, Claire M; Dibernardo, Antonia; Huynh, Chris; Lindsay, Robbin; Pearl, David L; Bosco-Lauth, Angela M; Nemeth, Nicole M

    2018-06-04

    Powassan virus (POWV) is a tick-borne zoonosis maintained in natural enzootic cycles between ixodid ticks and wild mammals. Reported human cases have increased in recent years; these infections can be fatal or lead to long-term neurologic sequelae. However, both the geographic distribution and the role of common, potential mammalian hosts in POWV transmission are poorly understood, creating challenges to public health surveillance. We looked for evidence of POWV infection among candidate wildlife host species and ticks collected from mammals and birds in southern Ontario. Tissues (including blood) and ticks from trapped wild mammals were collected in the summers of 2015 and 2016. Ticks removed from dogs in 2015-2016 and wildlife diagnostic cases from 2011 to 2013 were also included. Tissue and tick ( Ixodes spp.) homogenates were tested for POWV by reverse transcriptase-polymerase chain reaction (RT-PCR). In addition, sera from wild mammals were tested for antibodies to POWV, West Nile virus (WNV), and heartland virus (HRTV) by plaque reduction neutralization test. All 724 tissue samples were negative for POWV by RT-PCR. One of 53 pools of Ixodes cookei (among 98 total tick pools) was RT-PCR positive for deer tick virus (POWV) lineage. Antibodies to POWV and WNV were detected in 0.4% of 265 and 6.1% of 264 samples, respectively, and all of 219 serum samples tested negative for anti-HRTV antibodies. These results reveal low POWV detection rates in southern Ontario, while highlighting the challenges and need for continued efforts into understanding POWV epidemiology and targeted surveillance strategies.

  20. Tick borne illness-Lyme disease.

    PubMed

    Bush, Larry M; Vazquez-Pertejo, Maria T

    2018-05-01

    Lyme disease is the most commonly reported tick-borneillness in the United States. Thecausative spirochete, Borrelia burgdorferi is transmitted by 4 species of Ixodes tick species. Over 90% of US cases occur in northeasternstates from Maine to Virginia, and in Wisconsin, Minnesota, and Michigan. Infection also takes place in northern California and Oregon. Lyme borreliosis is also diagnosed in parts of Europe, China, and Japan. The white-footed mouse is the primary animal reservoir for B. burgdorferi in the U.S. and the preferred host for nymphal and larval forms of the deer tick. Deer are hosts for the adult ticks but do not carry the spirochete. Signs and symptomsof infection occur in 3 stages; early localized, typified by erythema migrans; early disseminated with a flu-like syndrome, neurologic, and cardiac manifestations; and late, characteristically with arthritis. Although, the term 'Chronic Lyme Disease' has been assigned to many patients with a variety of unexplained symptoms, experts in the field question the validity of this diagnosis and warn against prolonged unproven antimicrobial therapies. Diagnosis relies upon clinical evaluation and is supported by serologic testing using a 2-step process which requires careful interpretation. Treatmentvaries with stage of disease, but normally includes doxycycline, amoxicillin,and ceftriaxone. Currently, no preventative vaccine is available. In some geographic areas, patients may be confected with Babesia, Ehrlichia, and Anaplasma since the same Ixodes ticks transmit these pathogens. Copyright © 2018 Mosby, Inc. All rights reserved.

  1. Exploring knowledge and management practices on ticks and tick-borne diseases among agro-pastoral communities in Southern Highlands, Tanzania.

    PubMed

    Kerario, Isack Ibrahim; Simuunza, Martin; Laisser, Emmanuel L K; Chenyambuga, Sebastian

    2018-01-01

    The current study was conducted to assess the farmers' knowledge and management practices on ticks and tick-borne diseases (TBDs) through individual interview using a structured questionnaire in Mbarali and Momba districts of Mbeya region. A total of 240 households, 120 from each district were asked to mention TBDs of cattle which they thought were the most important in their localities and period of the year when the diseases occurred more frequently. In addition, farmers were asked to describe clinical signs and management practices associated with the common TBDs that they knew. The majority of respondents (46.2%) reported that East Coast fever (ECF) was the most important disease of cattle in the region, followed by anaplasmosis (33.8%), heartwater (15.4%), and babesiosis (4.6%). According to the farmers, ECF and anaplasmosis occurred more frequently during the dry season, while babesiosis and heartwater occurred more frequently during the rainy season. The majority of farmers were able to describe properly the signs of the common TBDs. Most farmers (80.4%) reported that they used acaricide to control ticks at a frequency of after every 2 weeks and a small proportion (15.8%) vaccinated their animals against ECF. It can be concluded that farmers in Mbeya have considerable knowledge on tick species and clinical signs of TBDs affecting their cattle. Based on the findings of the current study, it is recommended that integrated approach to the control of ticks and TBDs be adopted in the study area and many other areas that utilize agro-pastoral and pastoral cattle production systems.

  2. Cascading effect of economic globalization on human risks of scrub typhus and tick-borne rickettsial diseases.

    PubMed

    Kuo, Chi-Chien; Huang, Jing-Lun; Shu, Pei-Yun; Lee, Pei-Lung; Kelt, Douglas A; Wang, Hsi-Chieh

    2012-09-01

    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

  3. Vaccination and Tick-borne Encephalitis, Central Europe

    PubMed Central

    Stiasny, Karin; Holzmann, Heidemarie; Grgic-Vitek, Marta; Kriz, Bohumir; Essl, Astrid; Kundi, Michael

    2013-01-01

    Tick-borne encephalitis (TBE) is a substantial public health problem in many parts of Europe and Asia. To assess the effect of increasing TBE vaccination coverage in Austria, we compared incidence rates over 40 years for highly TBE-endemic countries of central Europe (Czech Republic, Slovenia, and Austria). For all 3 countries we found extensive annual and longer range fluctuations and shifts in distribution of patient ages, suggesting major variations in the complex interplay of factors influencing risk for exposure to TBE virus. The most distinctive effect was found for Austria, where mass vaccination decreased incidence to ≈16% of that of the prevaccination era. Incidence rates remained high for the nonvaccinated population. The vaccine was effective for persons in all age groups. During 2000–2011 in Austria, ≈4,000 cases of TBE were prevented by vaccination. PMID:23259984

  4. Rickettsiaceae and Anaplasmataceae infections in Ixodes ricinus ticks from urban and natural forested areas of Poland

    PubMed Central

    2014-01-01

    Background Ixodes ricinus is a major vector for a range of microbial pathogens and the most prevalent and widely distributed tick species on the European continent, occurring in both natural and urban habitats. Nevertheless, little is known about the relative density of ticks in these two ecologically distinct habitats and the diversity of tick-borne pathogens that they carry. Methods We compared densities of questing I. ricinus nymphs and adults in urban and natural habitats in Central and Northeastern Poland, assessed the prevalence and rate of co-infection with A. phagocytophilum, Rickettsia, Ehrlichia and ‘Ca. Neoehrlichia spp.’ in ticks, and compared the diversity of tick-borne pathogens using molecular assays (PCR). Results Of the 1325 adults and nymphs, 6.2% were infected with at least one pathogen, with 4.4%, 1.7% and less than 0.5% being positive for the DNA of Rickettsia spp., A. phagocytophilum, Ehrlichia spp. and Ca. N. mikurensis, respectively. Although tick abundance was higher in natural habitats, the prevalence of the majority of pathogens was higher in urban forested areas. Conclusion We conclude that: (i) zoonotic genetic variants of A. phagocytophilum are widely distributed in the Polish tick population, (ii) although the diversity of tick borne pathogens was higher in natural habitats, zoonotic species/strains were detected only in urban forests, (iii) and we provide the first description of Ca. N. mikurensis infections in ticks in Poland. PMID:24661311

  5. Exploring knowledge and management practices on ticks and tick-borne diseases among agro-pastoral communities in Southern Highlands, Tanzania

    PubMed Central

    Kerario, Isack Ibrahim; Simuunza, Martin; Laisser, Emmanuel L. K.; Chenyambuga, Sebastian

    2018-01-01

    Aim: The current study was conducted to assess the farmers’ knowledge and management practices on ticks and tick-borne diseases (TBDs) through individual interview using a structured questionnaire in Mbarali and Momba districts of Mbeya region. Materials and Methods: A total of 240 households, 120 from each district were asked to mention TBDs of cattle which they thought were the most important in their localities and period of the year when the diseases occurred more frequently. In addition, farmers were asked to describe clinical signs and management practices associated with the common TBDs that they knew. Results: The majority of respondents (46.2%) reported that East Coast fever (ECF) was the most important disease of cattle in the region, followed by anaplasmosis (33.8%), heartwater (15.4%), and babesiosis (4.6%). According to the farmers, ECF and anaplasmosis occurred more frequently during the dry season, while babesiosis and heartwater occurred more frequently during the rainy season. The majority of farmers were able to describe properly the signs of the common TBDs. Most farmers (80.4%) reported that they used acaricide to control ticks at a frequency of after every 2 weeks and a small proportion (15.8%) vaccinated their animals against ECF. Conclusion: It can be concluded that farmers in Mbeya have considerable knowledge on tick species and clinical signs of TBDs affecting their cattle. Based on the findings of the current study, it is recommended that integrated approach to the control of ticks and TBDs be adopted in the study area and many other areas that utilize agro-pastoral and pastoral cattle production systems. PMID:29479157

  6. A comparative analysis on the physicochemical properties of tick-borne encephalitis virus envelope protein residues that affect its antigenic properties.

    PubMed

    Bukin, Yu S; Dzhioev, Yu P; Tkachev, S E; Kozlova, I V; Paramonov, A I; Ruzek, D; Qu, Z; Zlobin, V I

    2017-06-15

    This work is dedicated to the study of the variability of the main antigenic envelope protein E among different strains of tick-borne encephalitis virus at the level of physical and chemical properties of the amino acid residues. E protein variants were extracted from then NCBI database. Four amino acid residues properties in the polypeptide sequences were investigated: the average volume of the amino acid residue in the protein tertiary structure, the number of amino acid residue hydrogen bond donors, the charge of amino acid residue lateral radical and the dipole moment of the amino acid residue. These physico-chemical properties are involved in antigen-antibody interactions. As a result, 103 different variants of the antigenic determinants of the tick-borne encephalitis virus E protein were found, significantly different by physical and chemical properties of the amino acid residues in their structure. This means that some strains among the natural variants of tick-borne encephalitis virus can potentially escape the immune response induced by the standard vaccine. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Veterinary entomology, colonial science and the challenge of tick-borne diseases in South Africa during the late nineteenth and early twentieth centuries.

    PubMed

    Brown, K

    2008-12-01

    This article provides an historical overview of developments in veterinary entomology during the late nineteenth and early twentieth centuries. During that period state employed entomologists and veterinary scientists discovered that ticks were responsible for transmitting a number of livestock diseases in South Africa. Diseases such as heartwater, redwater and gallsickness were endemic to the country. They had a detrimental effect on pastoral output, which was a mainstay of the national economy. Then in 1902 the decimating cattle disease East Coast fever arrived making the search for cures or preventatives all the more urgent. Vaccine technologies against tick-borne diseases remained elusive overall and on the basis of scientific knowledge, the South African state recommended regularly dipping animals in chemical solutions to destroy the ticks. Dipping along with quarantines and culls resulted in the eradication of East Coast fever from South Africa in the early 1950s. However, from the 1930s some ticks evolved a resistance to the chemical dips meaning that diseases like redwater were unlikely to be eliminated by that means. Scientists toiled to improve upon existing dipping technologies and also carried out ecological surveys to enhance their ability to predict outbreaks. Over the longer term dipping was not a panacea and ticks continue to present a major challenge to pastoral farming.

  8. Tick-borne rickettsiae in Guinea and Liberia.

    PubMed

    Mediannikov, Oleg; Diatta, Georges; Zolia, Yah; Balde, Mamadou Cellou; Kohar, Henry; Trape, Jean-François; Raoult, Didier

    2012-02-01

    While the high seroprevalence for the rickettsiae that cause spotted fevers and the multiple pathogenic rickettsiae is known, the data on the distribution of rickettsial diseases in Africa are often incomplete. We collected ticks from domestic or wild animals (generally a source of bushmeat) that were in contact with humans in 2 neighboring countries of tropical West Africa, Guinea and Liberia. In total, 382 ticks representing 6 species were collected in Liberia and 655 ticks representing 7 species were collected in Guinea. We found rickettsiae in 9 different species of ticks from both countries. Rickettsia africae was found in 93-100% of Amblyomma variegatum, in 14-93% of Rhipicephalus (B.) geigyi, Rh. (B.) annulatus, and Rh. (B.) decoloratus, and in several Hyalomma marginatum rufipes and Haemaphysalis paraleachi. A genetic variant of R. africae was found in Amblyomma compressum. R. massiliae was found in 10/61 (16%) of Rh. senegalensis ticks and in 2% of Haemaphysalis paraleachi ticks collected from dogs. We identified a new rickettsia in one of 44 (2%) Ixodes muniensis collected from a dog in Liberia. As this rickettsia is not yet isolated, we propose the provisional name "Candidatus Rickettsia liberiensis" (for the West African country where the host tick was collected). Copyright © 2011 Elsevier GmbH. All rights reserved.

  9. Prevention and control strategies for ticks and pathogen transmission.

    PubMed

    de La Fuente, J; Kocan, K M; Contreras, M

    2015-04-01

    Ticks and tick-borne pathogens have evolved together, resulting in a complex relationship in which the pathogen's life cycle is perfectly coordinated with the tick's feeding cycle, and the tick can harbour high pathogen levels without affecting its biology. Tick-borne diseases (TBDs) continue to emerge and/or spread, and pose an increasing threatto human and animal health. The disruptive impacts of global change have resulted in ecosystem instability and the future outcomes of management and control programmes for ticks and TBDs are difficult to predict. In particular, the selection of acaricide-resistant ticks has reduced the value of acaricides as a sole means of tick control. Vaccines provide an alternative control method, but the use of tick vaccines has not advanced since the first vaccines were registered in the early 1990s. An understanding of the complex molecular relationship between hosts, ticks and pathogens and the use of systems biology and vaccinomics approaches are needed to discover proteins with the relevant biological function in tick feeding, reproduction, development, immune response, the subversion of host immunity and pathogen transmission, all of which mediate tick and pathogen success. The same approaches will also be required to characterise candidate protective antigens and to validate vaccine formulations. Tick vaccines with a dual effect on tick infestations and pathogen transmission could reduce both tick infestations and their vector capacity for humans, animals and reservoir hosts. The development of integrated tick control strategies, including vaccines and synthetic and botanical acaricides, in combination with managing drug resistance and educating producers, should lead to the sustainable control of ticks and TBDs.

  10. Epidemiology of tick-borne encephalitis (TBE) in Europe and its prevention by available vaccines

    PubMed Central

    Amicizia, Daniela; Domnich, Alexander; Panatto, Donatella; Lai, Piero Luigi; Cristina, Maria Luisa; Avio, Ulderico; Gasparini, Roberto

    2013-01-01

    Tick-borne Encephalitis (TBE), which is caused by a Flavivirus, is the most common tick-transmitted disease in Central and Eastern Europe and Russia. Today, TBE is endemic in 27 European countries, and has become an international public health problem. The epidemiology of TBE is changing owing to various factors, such as improvements in diagnosis and case reporting, increased recreational activities in areas populated by ticks, and changes in climatic conditions affecting tick habitats. Vaccination remains the most effective protective measure against TBE for people living in risk zones, occupationally exposed subjects and travelers to endemic areas. The vaccines currently in use are FSME-Immun®, Encepur®, EnceVir® and TBE vaccine Moscow®. The numerous studies performed on the efficacy and safety of these vaccines have shown a high level of immunogenicity and an excellent safety profile. Several studies have also shown a high level of cross-protection among strains belonging to different subtypes.   In the present paper we attempted to describe the continuously changing epidemiology of TBE in European States and to overview clinical development of available vaccines paying particular attention on cross-protection elicited by the vaccines. PMID:23377671

  11. [The study of adaptation syndrome in mixed-infection of tick-borne encephalitis and borreliosis in children].

    PubMed

    Subbotin, A V; Poponnikova, T V; Zinchuk, S F

    2003-01-01

    Twenty two children with mixed-infection of tick-borne encephalitis (TBE) and ixodic tick borreliosis (ITB) were studied. Blood hydrocortisone level was changed in 94.5% of the cases. The most significant activation of hydrocortisone secretion in combination with the most pronounced and prolonged general brain manifestations, was detected in infants. Blood hydrocortisone level correlated with clinical symptoms of combined TBE and ITB infections. Along with higher hydrocortisone level, down-regulation of production of antibodies both to B. burgdorferi and to TBE virus was specific for all children studied.

  12. Animal Models of Tick-Borne Hemorrhagic Fever Viruses

    PubMed Central

    Zivcec, Marko; Safronetz, David; Feldmann, Heinz

    2013-01-01

    Tick-borne hemorrhagic fever viruses (TBHFV) are detected throughout the African and Eurasian continents and are an emerging or re-emerging threat to many nations. Due to the largely sporadic incidences of these severe diseases, information on human cases and research activities in general have been limited. In the past decade, however, novel TBHFVs have emerged and areas of endemicity have expanded. Therefore, the development of countermeasures is of utmost importance in combating TBHFV as elimination of vectors and interrupting enzootic cycles is all but impossible and ecologically questionable. As in vivo models are the only way to test efficacy and safety of countermeasures, understanding of the available animal models and the development and refinement of animal models is critical in negating the detrimental impact of TBHFVs on public and animal health. PMID:25437041

  13. [Sero-epidemiologic investigation on tick-borne diseases of humans and domestic animals in Zhejiang province].

    PubMed

    Chai, Cheng-liang; Lu, Qun-ying; Sun, Ji-min; Jiang, Li-ping; Ling, Feng; Zhang, Li-juan; Zheng, Shou-gui; Zhang, Hong; Ge, Jun-hua

    2010-10-01

    To investigate the seroprevalence of tick-borne diseases in humans and domestic animals from rural areas of Zhejiang province. Anji county, Jindong district and Tiantai county were selected for samples collection according to their geographic locations and historical prevalence of tick-borne diseases. Blood samples of humans and domestic animals were collected in the three sites. An indirect immuno-fluorescent antibody test was used to determine the presence of IgG antibodies of Rickettsiae heilongjiangii, Orientia tsutsugamushi, R. typhi, Anaplasma phagocytosis, Ehrlichia chaffeensis, Bartonella, R. hainan and Coxiella burnetii in these samples. Six hundred and eighty-three blood samples including 579 from humans and 104 from domestic animals (53 from cattles and 51 from sheep) were collected from the three sites. Antibody positive rates of Orientia tsutsugamushi, R. typhi, Ehrlichia chaffeensis and Coxiella burnetii were significantly different between these sites. IgG from all the 8 pathogens were detected in samples from humans. It was found that the sero-prevalence rates of R. typhi, Bartonella and C. burnetii (20.7%, 10.9%, 5.5%) of adults were higher than those of other Rickettsiae under investigation. The seroprevalence of R. typhi increased along with age. IgG from the 7 pathogens were detected in samples from domestic animals except for Anaplasma phagocytosis. The sero-prevalence rates of R. typhi, Bartonella and R. hainan (69.2%, 51.0%, 22.1%) of adults were higher than those of other Rickettsiae investigated. Tick-borne diseases did spread widely in humans and domestic animals from different rural areas of Zhejiang province. The sero-prevalence rates of R. typhi, B. henselae, R. hainan and C. burnetii were higher than that from other pathogens.

  14. Assessment of Climate Change and Vector-borne Diseases in the United States

    NASA Astrophysics Data System (ADS)

    Monaghan, A. J.; Beard, C. B.; Eisen, R. J.; Barker, C. M.; Garofalo, J.; Hahn, M.; Hayden, M.; Ogden, N.; Schramm, P.

    2016-12-01

    Vector-borne diseases are illnesses that are transmitted by vectors, which include mosquitoes, ticks, and fleas. The seasonality, distribution, and prevalence of vector-borne diseases are influenced significantly by climate factors, primarily high and low temperature extremes and precipitation patterns. In this presentation we summarize key findings from Chapter 5 ("Vector-borne Diseases") of the recently published USGCRP Scientific Assessment of the Impacts of Climate Change on Human Health in the United States. Climate change is expected to alter geographic and seasonal distributions of vectors and vector-borne diseases, leading to earlier activity and northward range expansion of ticks capable of carrying the bacteria that cause Lyme disease and other pathogens, and influencing the distribution, abundance and prevalence of infection in mosquitoes that transmit West Nile virus and other pathogens. The emergence or reemergence of vector-borne pathogens is also likely.

  15. Tick-borne Relapsing Fever in the Pacific Northwest: An Underdiagnosed Illness?

    PubMed Central

    Fihn, Stephan; Larson, Eric B.

    1980-01-01

    Some 30 cases of tick-borne relapsing fever due to Borrelia are known to have occurred between 1965 and 1978 in the Pacific Northwest. This disease was found more frequently in young men with a history of wilderness exposure during the summer months. Recurrent fever was the most common symptom with temperatures reaching higher than 39.5° C (103.1° F) in all cases, and many patients had three or more febrile episodes. Splenomegaly was the second most common finding reported. Diagnosis of relapsing fever was made in 20 cases by identifying spirochetes on peripheral blood smears. In ten remaining cases the diagnosis was made on clinical and epidemiologic grounds. Information regarding therapy was available in 21 cases. Ten patients received a tetracycline drug and all had a prompt response without relapse. Two of the patients died, a 68-year-old woman with possible myocardial involvement and a newborn infant with infection acquired in utero and meningeal involvement. The diagnosis was often delayed in spite of outpatient evaluation and admittance to hospital, probably because borreliosis was not considered in the differential diagnosis. Because tick-borne relapsing fever is eventually a self-limited disease in most patients, it is probably not recognized often enough. Awareness of this disease and examination of the peripheral blood smear for spirochetes will lead to earlier diagnosis. Prompt initiation of tetracycline therapy should reduce morbidity associated with borreliosis. ImagesFigure 3. PMID:7415171

  16. Tick-Borne Relapsing Fever

    MedlinePlus

    ... are usually found in higher elevations of the western states. Symptoms What are the symptoms of tick- ... Get Started About Support Us Copyright & Permissions Privacy Policy Contact familydoctor.org is powered by © 2018 American ...

  17. Tick-Borne Encephalitis Virus Structural Proteins Are the Primary Viral Determinants of Non-Viraemic Transmission between Ticks whereas Non-Structural Proteins Affect Cytotoxicity.

    PubMed

    Khasnatinov, Maxim A; Tuplin, Andrew; Gritsun, Dmitri J; Slovak, Mirko; Kazimirova, Maria; Lickova, Martina; Havlikova, Sabina; Klempa, Boris; Labuda, Milan; Gould, Ernest A; Gritsun, Tamara S

    2016-01-01

    Over 50 million humans live in areas of potential exposure to tick-borne encephalitis virus (TBEV). The disease exhibits an estimated 16,000 cases recorded annually over 30 European and Asian countries. Conventionally, TBEV transmission to Ixodes spp. ticks occurs whilst feeding on viraemic animals. However, an alternative mechanism of non-viraemic transmission (NVT) between infected and uninfected ticks co-feeding on the same transmission-competent host, has also been demonstrated. Here, using laboratory-bred I. ricinus ticks, we demonstrate low and high efficiency NVT for TBEV strains Vasilchenko (Vs) and Hypr, respectively. These virus strains share high sequence similarity but are classified as two TBEV subtypes. The Vs strain is a Siberian subtype, naturally associated with I. persulcatus ticks whilst the Hypr strain is a European subtype, transmitted by I. ricinus ticks. In mammalian cell culture (porcine kidney cell line PS), Vs and Hypr induce low and high cytopathic effects (cpe), respectively. Using reverse genetics, we engineered a range of viable Vs/Hypr chimaeric strains, with substituted genes. No significant differences in replication rate were detected between wild-type and chimaeric viruses in cell culture. However, the chimaeric strain Vs[Hypr str] (Hypr structural and Vs non-structural genomic regions) demonstrated high efficiency NVT in I. ricinus whereas the counterpart Hypr[Vs str] was not transmitted by NVT, indicating that the virion structural proteins largely determine TBEV NVT transmission efficiency between ticks. In contrast, in cell culture, the extent of cpe was largely determined by the non-structural region of the TBEV genome. Chimaeras with Hypr non-structural genes were more cytotoxic for PS cells when compared with Vs genome-based chimaeras.

  18. Tick-Borne Encephalitis Virus Structural Proteins Are the Primary Viral Determinants of Non-Viraemic Transmission between Ticks whereas Non-Structural Proteins Affect Cytotoxicity

    PubMed Central

    Khasnatinov, Maxim A.; Tuplin, Andrew; Gritsun, Dmitri J.; Slovak, Mirko; Kazimirova, Maria; Lickova, Martina; Havlikova, Sabina; Klempa, Boris; Gould, Ernest A.

    2016-01-01

    Over 50 million humans live in areas of potential exposure to tick-borne encephalitis virus (TBEV). The disease exhibits an estimated 16,000 cases recorded annually over 30 European and Asian countries. Conventionally, TBEV transmission to Ixodes spp. ticks occurs whilst feeding on viraemic animals. However, an alternative mechanism of non-viraemic transmission (NVT) between infected and uninfected ticks co-feeding on the same transmission-competent host, has also been demonstrated. Here, using laboratory-bred I. ricinus ticks, we demonstrate low and high efficiency NVT for TBEV strains Vasilchenko (Vs) and Hypr, respectively. These virus strains share high sequence similarity but are classified as two TBEV subtypes. The Vs strain is a Siberian subtype, naturally associated with I. persulcatus ticks whilst the Hypr strain is a European subtype, transmitted by I. ricinus ticks. In mammalian cell culture (porcine kidney cell line PS), Vs and Hypr induce low and high cytopathic effects (cpe), respectively. Using reverse genetics, we engineered a range of viable Vs/Hypr chimaeric strains, with substituted genes. No significant differences in replication rate were detected between wild-type and chimaeric viruses in cell culture. However, the chimaeric strain Vs[Hypr str] (Hypr structural and Vs non-structural genomic regions) demonstrated high efficiency NVT in I. ricinus whereas the counterpart Hypr[Vs str] was not transmitted by NVT, indicating that the virion structural proteins largely determine TBEV NVT transmission efficiency between ticks. In contrast, in cell culture, the extent of cpe was largely determined by the non-structural region of the TBEV genome. Chimaeras with Hypr non-structural genes were more cytotoxic for PS cells when compared with Vs genome-based chimaeras. PMID:27341437

  19. A Predictive Model Has Identified Tick-Borne Encephalitis High-Risk Areas in Regions Where No Cases Were Reported Previously, Poland, 1999–2012

    PubMed Central

    Rubikowska, Barbara; Bratkowski, Jakub; Ustrnul, Zbigniew; Vanwambeke, Sophie O.

    2018-01-01

    During 1999–2012, 77% of the cases of tick-borne encephalitis (TBE) were recorded in two out of 16 Polish provinces. However, historical data, mostly from national serosurveys, suggest that the disease could be undetected in many areas. The aim of this study was to identify which routinely-measured meteorological, environmental, and socio-economic factors are associated to TBE human risk across Poland, with a particular focus on areas reporting few cases, but where serosurveys suggest higher incidence. We fitted a zero-inflated Poisson model using data on TBE incidence recorded in 108 NUTS-5 administrative units in high-risk areas over the period 1999–2012. Subsequently we applied the best fitting model to all Polish municipalities. Keeping the remaining variables constant, the predicted rate increased with the increase of air temperature over the previous 10–20 days, precipitation over the previous 20–30 days, in forestation, forest edge density, forest road density, and unemployment. The predicted rate decreased with increasing distance from forests. The map of predicted rates was consistent with the established risk areas. It predicted, however, high rates in provinces considered TBE-free. We recommend raising awareness among physicians working in the predicted high-risk areas and considering routine use of household animal surveys for risk mapping. PMID:29617333

  20. Steps of the tick-borne encephalitis virus replication cycle that affect neuropathogenesis.

    PubMed

    Mandl, Christian W

    2005-08-01

    Tick-borne encephalitis virus (TBEV) is an important human pathogen that causes severe neurological illness in large areas of Europe and Asia. The neuropathogenesis of this disease agent is determined by its capacity to enter the central nervous system (CNS) after peripheral inoculation ("neuroinvasiveness") and its ability to replicate and cause damage within the CNS ("neurovirulence"). TBEV is a small, enveloped flavivirus with an unsegmented, positive-stranded RNA genome. Mutations affecting various steps of its natural replication cycle were shown to influence its neuropathogenic properties. This review describes experimental approaches and summarizes results on molecular determinants of neurovirulence and neuroinvasiveness that have been identified for this virus. It focuses on molecular mechanisms of three particular steps of the viral life cycle that have been studied in some detail for TBEV and two closely related tick-borne flaviviruses (Louping ill virus (LIV) and Langat virus (LGTV)), namely (i) the envelope protein E and its role in viral attachment to the cell surface, (ii) the 3'-noncoding region of the genome and its importance for viral RNA replication, and (iii) the capsid protein C and its role in the assembly process of infectious virus particles. Mutations affecting each of these three molecular targets significantly influence neuropathogenesis of TBEV, particularly its neuroinvasiveness. The understanding of molecular determinants of TBEV neuropathogenesis is relevant for vaccine development, also against other flaviviruses.

  1. Limited sharing of tick-borne hemoparasites between sympatric wild and domestic ungulates.

    PubMed

    Ghai, Ria R; Mutinda, Mathew; Ezenwa, Vanessa O

    2016-08-15

    Tick-borne hemoparasites (TBHs) are a group of pathogens of concern in animal management because they are associated with a diversity of hosts, including both wild and domestic species. However, little is known about how frequently TBHs are shared across the wildlife-livestock interface in natural settings. Here, we compared the TBHs of wild Grant's gazelle (Nanger granti) and domestic sheep (Ovis aries) in a region of Kenya where these species extensively overlap. Blood samples collected from each species were screened for piroplasm and rickettsial TBHs by PCR-based amplification of 18S/16S ribosomal DNA, respectively. Overall, 99% of gazelle and 66% of sheep were positive for Babesia/Theileria, and 32% of gazelle and 47% sheep were positive for Anaplasma/Ehrlichia. Sequencing a subset of positive samples revealed infections of Theileria and Anaplasma. Sequences sorted into seven phylogenetically distinct genotypes-two Theileria, and five Anaplasma. With the exception of a putatively novel Anaplasma lineage from Grant's gazelle, these genotypes appeared to be divergent forms of previously described species, including T. ovis, A. ovis, A. bovis, and A. platys. Only one genotype, which clustered within the A. platys clade, contained sequences from both gazelle and sheep. This suggests that despite niche, habitat, and phylogenetic overlap, the majority of circulating tick-borne diseases may not be shared between these two focal species. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Reducing Tick-Borne Disease in Alabama: Linking Health Risk Perception with Spatial Analysis Using the NASA Earth Observing System

    NASA Technical Reports Server (NTRS)

    Hemmings, S.; Renneboog, N.; Firsing, S.; Capilouto, E.; Harden, J.; Hyden, R.; Tipre, M.; Zhang, Y.

    2010-01-01

    Lyme disease (LD) accounts for most vector-borne disease reports in the U.S., and although its existence in Alabama remains controversial, other tick-borne illnesses (TBI) such as Southern Tick-Associated Rash Illness (STARI) pose a health concern in the state. Phase One of the Marshall Space Flight Center-UAB DEVELOP study of TBI identified the presence of the chain of infection for LD (Ixodes scapularis ticks carrying Borrelia burgdorferi bacteria) and STARI (Amblyomma americanum ticks and an as-yet-unconfirmed agent) in Alabama. Both LD and STARI are associated with the development of erythema migrans rashes around an infected tick bite, and while treatable with oral antibiotics, a review of educational resources available to state residents revealed low levels of prevention information. To improve prevention, recognition, and treatment of TBI in Alabama, Phase Two builds a health communication campaign based on vector habitat mapping and risk perception assessment. NASA Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) satellite imagery identified likely tick habitats using remotely sensed measurements of vegetation vigor (Normalized Difference Vegetation Index) and soil moisture. Likely tick habitats, identified as those containing both high vegetation density and soil moisture, included Oak Mountain State Park, Bankhead National Forest, and Talladega National Forest. To target a high-risk group -- outdoor recreation program participants at Alabama universities -- the study developed a behavior survey instrument based on existing studies of LD risk factors and theoretical constructs from the Social Ecological Model and Health Belief Model. The survey instrument was amended to include geographic variables in the assessment of TBI knowledge, attitudes, and prevention behaviors, and the vector habitat model will be expanded to incorporate additional environmental variables and in situ data. Remotely sensed environmental data combined with

  3. 76 FR 12959 - Promoting Community Integrated Pest Management To Prevent Tick-Borne Diseases; Notice of Public...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-09

    ...EPA will host a National Community Integrated Pest Management (IPM) for Preventing Tick-Borne Diseases Conference on March 30 and 31, 2011, under the auspices of EPA's Pesticide Program Dialog Committee (Public Health Work Group). The objectives of the conference are to identify knowledge gaps and barriers to effective community-wide tick control; propose the next steps in addressing knowledge gaps and eliminating barriers; and develop a framework for addressing the highest priority needs. The agenda for this conference will be posted at http://www.epa.gov/pestwise/ and placed in the docket in advance of the meeting.

  4. A review of reverse vaccinology approaches for the development of vaccines against ticks and tick borne diseases.

    PubMed

    Lew-Tabor, A E; Rodriguez Valle, M

    2016-06-01

    The field of reverse vaccinology developed as an outcome of the genome sequence revolution. Following the introduction of live vaccinations in the western world by Edward Jenner in 1798 and the coining of the phrase 'vaccine', in 1881 Pasteur developed a rational design for vaccines. Pasteur proposed that in order to make a vaccine that one should 'isolate, inactivate and inject the microorganism' and these basic rules of vaccinology were largely followed for the next 100 years leading to the elimination of several highly infectious diseases. However, new technologies were needed to conquer many pathogens which could not be eliminated using these traditional technologies. Thus increasingly, computers were used to mine genome sequences to rationally design recombinant vaccines. Several vaccines for bacterial and viral diseases (i.e. meningococcus and HIV) have been developed, however the on-going challenge for parasite vaccines has been due to their comparatively larger genomes. Understanding the immune response is important in reverse vaccinology studies as this knowledge will influence how the genome mining is to be conducted. Vaccine candidates for anaplasmosis, cowdriosis, theileriosis, leishmaniasis, malaria, schistosomiasis, and the cattle tick have been identified using reverse vaccinology approaches. Some challenges for parasite vaccine development include the ability to address antigenic variability as well the understanding of the complex interplay between antibody, mucosal and/or T cell immune responses. To understand the complex parasite interactions with the livestock host, there is the limitation where algorithms for epitope mining using the human genome cannot directly be adapted for bovine, for example the prediction of peptide binding to major histocompatibility complex motifs. As the number of genomes for both hosts and parasites increase, the development of new algorithms for pan-genomic mining will continue to impact the future of parasite and

  5. Tick-, mosquito-, and rodent-borne parasite sampling designs for the National Ecological Observatory Network

    USGS Publications Warehouse

    Springer, Yuri P.; Hoekman, David; Johnson, Pieter T. J.; Duffy, Paul A.; Hufft, Rebecca A.; Barnett, David T.; Allan, Brian F.; Amman, Brian R.; Barker, Christopher M.; Barrera, Roberto; Beard, Charles B.; Beati, Lorenza; Begon, Mike; Blackmore, Mark S.; Bradshaw, William E.; Brisson, Dustin; Calisher, Charles H.; Childs, James E.; Diuk-Wasser, Maria A.; Douglass, Richard J.; Eisen, Rebecca J.; Foley, Desmond H.; Foley, Janet E.; Gaff, Holly D.; Gardner, Scott L.; Ginsberg, Howard; Glass, Gregory E.; Hamer, Sarah A.; Hayden, Mary H.; Hjelle, Brian; Holzapfel, Christina M.; Juliano, Steven A.; Kramer, Laura D.; Kuenzi, Amy J.; LaDeau, Shannon L.; Livdahl, Todd P.; Mills, James N.; Moore, Chester G.; Morand, Serge; Nasci, Roger S.; Ogden, Nicholas H.; Ostfeld, Richard S.; Parmenter, Robert R.; Piesman, Joseph; Reisen, William K.; Savage, Harry M.; Sonenshine, Daniel E.; Swei, Andrea; Yabsley, Michael J.

    2016-01-01

    Parasites and pathogens are increasingly recognized as significant drivers of ecological and evolutionary change in natural ecosystems. Concurrently, transmission of infectious agents among human, livestock, and wildlife populations represents a growing threat to veterinary and human health. In light of these trends and the scarcity of long-term time series data on infection rates among vectors and reservoirs, the National Ecological Observatory Network (NEON) will collect measurements and samples of a suite of tick-, mosquito-, and rodent-borne parasites through a continental-scale surveillance program. Here, we describe the sampling designs for these efforts, highlighting sampling priorities, field and analytical methods, and the data as well as archived samples to be made available to the research community. Insights generated by this sampling will advance current understanding of and ability to predict changes in infection and disease dynamics in novel, interdisciplinary, and collaborative ways.

  6. Research on Piroplasmorida and other tick-borne agents: Are we going the right way?

    PubMed

    Uilenberg, Gerrit; Gray, Jeremy; Kahl, Olaf

    2018-05-01

    The use of molecular diagnostic techniques in the study of ticks and tick-borne agents has increased dramatically in the last few decades, and while conferring the advantages of rapidity, sensitivity and accuracy, they can also be misused by the research community, who have shown an increasing overreliance on the data they produce, often completely abandoning more traditional approaches such as microscopy and serology. In this short review examples are provided of 'findings' that are apparently at odds with well-established eco-epidemiological knowledge, ranging from descriptions of new species of pathogens to their detection in new hosts and ticks, often immediately incriminated as new reservoir hosts and vector ticks, respectively. Most examples have been taken from the Piroplasmorida or "piroplasm" species as they are often called. Researchers are urged to utilize molecular methods with as much awareness as possible of the system or systems they are investigating, and journal editors and their teams of reviewers should be encouraged to adopt a more critical approach to papers that contain data based solely on molecular methods without due regard to the underlying biology. Explanations for such findings should be offered and discussed. Copyright © 2018 Elsevier GmbH. All rights reserved.

  7. Tick-Borne Transmission of Two Genetically Distinct Anaplasma marginale Strains following Superinfection of the Mammalian Reservoir Host

    USDA-ARS?s Scientific Manuscript database

    Strain superinfection affects the dynamics of epidemiological spread of pathogens through a host population. Superinfection has recently been shown to occur for genetically distinct strains of the tick-borne pathogen Anaplasma marginale that encode distinctly different surface protein variants. Supe...

  8. Ticks infesting wild and domestic animals and humans of Sri Lanka with new host records.

    PubMed

    Liyanaarachchi, D R; Rajakaruna, R S; Dikkumbura, A W; Rajapakse, R P V J

    2015-02-01

    An island-wide collection of tick species infesting humans, domesticated and wild animals and questing ticks in domestic and peridomestic environments was carried out during 2009-2011. A total of 30,461 ticks were collected from 30 different hosts and free living stages from the ground. The collection consisted of 22 tick species from 30 different hosts recording 12 tick species from humans, 19 from domesticated animals and 21 from wild animals, with a total of 97 new host records. The most common tick species on humans were Dermacentor auratus and Amblyomma testudinairum, while Haemaphysalis intermedia, Rhipicephalus microplus and Rhipicephalus sanguineus were common in domesticated and wild animals sharing 20 host species. Among the questing ticks, immature D. auratus was the most abundant. Humans and domesticated animals were mostly infested by the nymphal stages while adult ticks were found on wild animals. High number of new host records could be due to domestic animals picking tick species from wildlife and vise versa at the human/animal interface. Habitat destruction due to forest fragmentation has lead to wild animals roaming in urban and semi-urban neighbourhoods increasing the interactions of wild animals with domesticated animals. Wild animals play a significant role as a reservoir of many tick borne infections which can easily be spread to domesticated animals and then to humans via tick infestations. Data in this paper are useful for those interested in tick infesting wild and domestic animals and humans in describing the zoonotic potential of tick borne infections. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Canine tick-borne pathogens and associated risk factors in dogs presenting with and without clinical signs consistent with tick-borne diseases in northern Australia.

    PubMed

    Hii, S F; Traub, R J; Thompson, M F; Henning, J; O'Leary, C A; Burleigh, A; McMahon, S; Rees, R L; Kopp, S R

    2015-03-01

    To estimate the proportion of canine tick-borne disease (CTBD) pathogens in dogs from northern states of Australia presenting with and without clinical signs/laboratory abnormalities suggestive of CTBD and to evaluate associated risk factors. Client-owned dogs presented to a general practice clinic in the Northern Territory (NT; n = 138) and five referral hospitals in south-east Queensland (SEQ; n = 100) were grouped into CTBD-suspect and -control groups based on clinical and laboratory criteria. Blood and sera were screened for haemotropic Mycoplasma spp., Babesia spp., Anaplasma spp., Ehrlichia spp. and Hepatozoon spp. using microscopic examination, in-clinic ELISA testing and PCR assays. Dog-specific risk factors associated with the presence of CTBD pathogens were evaluated. Overall, 24.4% of the suspect group and 12.2% of the control group dogs were infected. The proportions of M. haemocanis, B. vogeli, A. platys, Candidatus Mycoplasma haematoparvum, and C. Mycoplasma haemobos were 7.1%, 5.0%, 3.8%, 1.7% and 0.4%, respectively. Dogs originating from the NT were 3.6-fold (95% confidence interval (CI) 1.51-8.62; P = 0.004) more likely to be infected with CTBD pathogens than those from SEQ. Male dogs were 2.3-fold (95% CI 1.17-4.80, P = 0.024) more likely to be PCR-positive to CTBD pathogens than female dogs. Dogs presenting with clinical signs consistent with CTBD and thrombocytopenia were more likely to be infected by CTBD pathogens (odds ratio 2.85; 95% CI 1.16, 7.02; P = 0.019). Haemotropic mycoplasmas were the most common tick-borne pathogen infecting client-owned dogs. Subclinical cases were common in dogs from the NT. Veterinary practitioners should be aware of the proportion of CTBD pathogens and the presenting features of clinical and subclinical disease in their area. © 2015 Australian Veterinary Association.

  10. Ticks infesting domestic dogs in the UK: a large-scale surveillance programme.

    PubMed

    Abdullah, Swaid; Helps, Chris; Tasker, Severine; Newbury, Hannah; Wall, Richard

    2016-07-07

    Recent changes in the distribution of tick vectors and the incidence of tick-borne disease, driven variously by factors such as climate change, habitat modification, increasing host abundance and the increased movement of people and animals, highlight the importance of ongoing, active surveillance. This paper documents the results of a large-scale survey of tick abundance on dogs presented to veterinary practices in the UK, using a participatory approach that allows relatively cost- and time-effective extensive data collection. Over a period of 16 weeks (April-July 2015), 1094 veterinary practices were recruited to monitor tick attachment to dogs and provided with a tick collection and submission protocol. Recruitment was encouraged through a national publicity and communication initiative. Participating practices were asked to select five dogs at random each week and undertake a thorough, standardized examination of each dog for ticks. The clinical history and any ticks were then sent to the investigators for identification. A total of 12,000 and 96 dogs were examined and 6555 tick samples from infested dogs were received. Ixodes ricinus (Linnaeus) was identified on 5265 dogs (89 %), Ixodes hexagonus Leach on 577 (9.8 %) and Ixodes canisuga Johnston on 46 (0.8 %). Ten dogs had Dermacentor reticulatus (Fabricius), one had Dermacentor variabilis (Say), three had Haemaphysalis punctata Canesteini & Fanzago and 13 had Rhipicephalus sanguineus Latreille. 640 ticks were too damaged for identification. All the R. sanguineus and the single D. variabilis were on dogs with a recent history of travel outside the UK. The overall prevalence of tick attachment was 30 % (range 28-32 %). The relatively high prevalence recorded is likely to have been inflated by the method of participant recruitment. The data presented provide a comprehensive spatial understanding of tick distribution and species abundance in the UK against which future changes can be compared. Relative

  11. A tick-borne segmented RNA virus contains genome segments derived from unsegmented viral ancestors

    PubMed Central

    Qin, Xin-Cheng; Shi, Mang; Tian, Jun-Hua; Lin, Xian-Dan; Gao, Dong-Ya; He, Jin-Rong; Wang, Jian-Bo; Li, Ci-Xiu; Kang, Yan-Jun; Yu, Bin; Zhou, Dun-Jin; Xu, Jianguo; Plyusnin, Alexander; Holmes, Edward C.; Zhang, Yong-Zhen

    2014-01-01

    Although segmented and unsegmented RNA viruses are commonplace, the evolutionary links between these two very different forms of genome organization are unclear. We report the discovery and characterization of a tick-borne virus—Jingmen tick virus (JMTV)—that reveals an unexpected connection between segmented and unsegmented RNA viruses. The JMTV genome comprises four segments, two of which are related to the nonstructural protein genes of the genus Flavivirus (family Flaviviridae), whereas the remaining segments are unique to this virus, have no known homologs, and contain a number of features indicative of structural protein genes. Remarkably, homology searching revealed that sequences related to JMTV were present in the cDNA library from Toxocara canis (dog roundworm; Nematoda), and that shared strong sequence and structural resemblances. Epidemiological studies showed that JMTV is distributed in tick populations across China, especially Rhipicephalus and Haemaphysalis spp., and experiences frequent host-switching and genomic reassortment. To our knowledge, JMTV is the first example of a segmented RNA virus with a genome derived in part from unsegmented viral ancestors. PMID:24753611

  12. Environmental drivers of Ixodes ricinus abundance in forest fragments of rural European landscapes.

    PubMed

    Ehrmann, Steffen; Liira, Jaan; Gärtner, Stefanie; Hansen, Karin; Brunet, Jörg; Cousins, Sara A O; Deconchat, Marc; Decocq, Guillaume; De Frenne, Pieter; De Smedt, Pallieter; Diekmann, Martin; Gallet-Moron, Emilie; Kolb, Annette; Lenoir, Jonathan; Lindgren, Jessica; Naaf, Tobias; Paal, Taavi; Valdés, Alicia; Verheyen, Kris; Wulf, Monika; Scherer-Lorenzen, Michael

    2017-09-06

    The castor bean tick (Ixodes ricinus) transmits infectious diseases such as Lyme borreliosis, which constitutes an important ecosystem disservice. Despite many local studies, a comprehensive understanding of the key drivers of tick abundance at the continental scale is still lacking. We analyze a large set of environmental factors as potential drivers of I. ricinus abundance. Our multi-scale study was carried out in deciduous forest fragments dispersed within two contrasting rural landscapes of eight regions, along a macroclimatic gradient stretching from southern France to central Sweden and Estonia. We surveyed the abundance of I. ricinus, plant community composition, forest structure and soil properties and compiled data on landscape structure, macroclimate and habitat properties. We used linear mixed models to analyze patterns and derived the relative importance of the significant drivers. Many drivers had, on their own, either a moderate or small explanatory value for the abundance of I. ricinus, but combined they explained a substantial part of variation. This emphasizes the complex ecology of I. ricinus and the relevance of environmental factors for tick abundance. Macroclimate only explained a small fraction of variation, while properties of macro- and microhabitat, which buffer macroclimate, had a considerable impact on tick abundance. The amount of forest and the composition of the surrounding rural landscape were additionally important drivers of tick abundance. Functional (dispersules) and structural (density of tree and shrub layers) properties of the habitat patch played an important role. Various diversity metrics had only a small relative importance. Ontogenetic tick stages showed pronounced differences in their response. The abundance of nymphs and adults is explained by the preceding stage with a positive relationship, indicating a cumulative effect of drivers. Our findings suggest that the ecosystem disservices of tick-borne diseases, via the

  13. [Diseases transmitted by ticks locally and abroad].

    PubMed

    Gétaz, L; Loutan, L; Mezger, N

    2012-05-09

    This article provides a brief overview of some diseases transmitted by ticks. These vectors do not transmit only Lyme disease and tickborne-encephalitis, even in Switzerland. Several tick-borne diseases cause nonspecific flu-like symptoms. Nevertheless sometimes severe, some of these diseases can be treated with specific treatments. Repellents, appropriate clothes impregnated with permethrine and prompt removal of the tick are effective preventive measures to limit the risk of infection. There is an effective vaccine which protects against tick-borne encephalitis.

  14. Reconsidering the classification of tick-borne encephalitis virus within the Siberian subtype gives new insights into its evolutionary history.

    PubMed

    Kovalev, S Y; Mukhacheva, T A

    2017-11-01

    Tick-borne encephalitis is widespread in Eurasia and transmitted by Ixodes ticks. Classification of its causative agent, tick-borne encephalitis virus (TBEV), includes three subtypes, namely Far-Eastern, European, and Siberian (TBEV-Sib), as well as a group of 886-84-like strains with uncertain taxonomic status. TBEV-Sib is subdivided into three phylogenetic lineages: Baltic, Asian, and South-Siberian. A reason to reconsider TBEV-Sib classification was the analysis of 186 nucleotide sequences of an E gene fragment submitted to GenBank during the last two years. Within the South-Siberian lineage, we have identified a distinct group with prototype strains Aina and Vasilchenko as an individual lineage named East-Siberian. The analysis of reclassified lineages has promoted a new model of the evolutionary history of TBEV-Sib lineages and TBEV-Sib as a whole. Moreover, we present arguments supporting separation of 886-84-like strains into an individual TBEV subtype, which we propose to name Baikalian (TBEV-Bkl). Copyright © 2017 Elsevier B.V. All rights reserved.

  15. The International Scientific Working Group on Tick-Borne Encephalitis (ISW TBE): Review of 17 years of activity and commitment.

    PubMed

    Kunze, Ursula

    2016-04-01

    Tick-borne encephalitis (TBE) has been a growing public health problem in Europe and other parts of the world for the past 20 years. In 1999, in order to encourage the control of TBE, international experts created a new body: The International Scientific Working Group on Tick-Borne Encephalitis (ISW-TBE). This Working Group has been composed of internationally recognized scientific experts from tick-borne encephalitis virus (TBEv)-endemic and non-endemic regions with extensive personal expertise in the field and a high level of commitment to improve the knowledge of TBE and to increase the public awareness of TBE. Since the foundation of the Working Group, ISW-TBE members meet annually. Every meeting is dedicated to a specific topic, and since 2004 a yearly conference report has been published to inform the scientific community about the latest developments. Among the specific issues that have been extensively discussed over the years were the following: clinical aspects of the disease, TBE in children and golden agers, epidemiology, possible causes for the increase in TBE incidence in Europe, TBE and awareness, TBE and travel, (low) vaccination rates, and the cooperation with the European Centre for Disease Prevention and Control (ECDC). This paper gives an overview of the most important activities and achievements of the ISW-TBE over the past 17 years. Copyright © 2016 Elsevier GmbH. All rights reserved.

  16. Clusterons as a tool for monitoring populations of tick-borne encephalitis virus.

    PubMed

    Kovalev, Sergey Y; Mukhacheva, Tatyana A

    2014-02-01

    Tick-borne encephalitis (TBE) is a natural focal viral neuroinfection that is widespread in the temperate zone of Eurasia. Knowledge of the genetic structure of tick-borne encephalitis virus (TBEV) populations is important for understanding, not only the origin and evolution of the virus, but also the formation and maintenance of natural foci. A new approach to the differentiation of TBEV strains within subtype, with clusterons as the basis of analysis, has recently been proposed. In the present study, the genetic structure of TBEV-Sib populations has been investigated based on 387 strains isolated in the Middle Urals (Sverdlovsk region). Fourteen of the 18 currently known TBEV-Sib clusterons were identified. They belong to the Asian and Eastern European (Baltic) groups. It was shown that each TBE foci could be characterized by a unique clusteron profile. Three clusterons that emerged within the last 50 years have been identified which implies an active evolutionary process in the TBEV-Sib populations. The greatest diversity of clusterons was observed in the south of the Middle Urals along the Trans-Siberian Way. Such a pattern could reflect the history of colonization of the area and is closely related to the roads passing from Siberia to the European part of Russia through the Urals. In this article, the principles of continuous monitoring in the regional and local TBE foci are proposed, based on the quantitative and qualitative analysis of TBEV-Sib clusteron profiles. © 2013 Wiley Periodicals, Inc.

  17. Tick communities at the expanding wildlife/cattle interface in the Eastern Cape Province, South Africa: implications for Corridor disease.

    PubMed

    Smith, E R; Parker, D M

    2010-12-01

    Corridor disease, transmitted by the brown ear tick (Rhipicephalus appendiculatus), is one of Africa's most pathogenic tick-borne diseases for cattle. With a focus on this species, we investigated the community parameters (richness, diversity and abundance) of ticks in the Eastern Cape, South Africa, and how this may be linked to the increasing wildlife/cattle interface in the region. There were significantly more ticks of a greater diversity and richness at sites positioned at the wildlife/cattle interface ('treatment sites') compared to sites where wildlife was absent (controls). Significantly, R. appendiculatus was only found at the treatment sites. Therefore, it is believed that the wildlife/cattle interface may be playing a crucial role in increasing the occurrence, abundance and distribution of R. appendiculatus in the Eastern Cape. The implications of a Corridor disease outbreak in the region are discussed.

  18. Characterization of tick-borne encephalitis (TBE) foci in Germany and Latvia (1997-2000).

    PubMed

    Süss, Jochen; Schrader, Christina; Abel, Ulrich; Bormane, Antra; Duks, Arnis; Kalnina, Vaira

    2002-06-01

    Knowledge concerning the prevalence of the tick-borne encephalitis virus (TBEV) in wild living tick populations is very important for understanding the epidemiology of the disease and for immuno prophylactic strategy. In Germany high and low risk areas of TBE exist. In the years 1997-2000, 533 autochthonous clinical TBE cases were recorded, in the high-risk areas of Bavaria and Baden-Wuerttemberg 140 and 363, and in the low risk areas in Hesse (Odenwald) and Rhineland-Palatinate 22 and 8, respectively. Corresponding to these case reports we have measured the virus prevalence in free living ticks in these four risk areas and compared these findings with the situation in high-risk areas in Latvia. In the years 1997-2000, 2,797 clinical TBE cases were recorded in Latvia. For the studies in Germany, a total of 17,398 Ixodesricinus ticks (14,860 nymphs and 2,538 adults) were collected by flagging and examined for TBEV, in Latvia the corresponding numbers were 525 I. ricinus ticks (350 adults and 175 nymphs) and 281 I. persulcatus ticks (adults only). Information concerning annual and seasonal differences of the TBEV prevalence in natural TBE foci is not available in Germany. This paper is a continuation of the study (Süss et al., 1999), starting in 1997. We investigated every year, in May and September, the virus prevalence in ticks in high risk areas of Bavaria (8 foci) and Baden-Wuerttemberg (5 foci). A total of 15,400 ticks (13,100 nymphs and 2,300 adults) were examined for TBEV. The ticks were tested for the presence of TBEV-RNA using a sensitive, nested-RT-PCR. The virus prevalence in the Bavarian foci of the whole tick population ranged from 0.3 to 2.0% during these four years, in adults between 1.2 and 5.3% and in nymphs between 0.1 and 1.4%. In the high-risk areas of Baden-Wuerttemberg, in the Black Forest, the estimated virus prevalence rates of investigated ticks varied from 0.2 to 3.4%, in adults from 0 to 4.8%, and in nymphs from 0.2 to 3.4%. Using the same

  19. Effects of tick control by acaricide self-treatment of white-tailed deer on host-seeking tick infection prevalence and entomologic risk for Ixodes scapularis-borne pathogens.

    PubMed

    Hoen, Anne Gatewood; Rollend, Lindsay G; Papero, Michele A; Carroll, John F; Daniels, Thomas J; Mather, Thomas N; Schulze, Terry L; Stafford, Kirby C; Fish, Durland

    2009-08-01

    We evaluated the effects of tick control by acaricide self-treatment of white-tailed deer on the infection prevalence and entomologic risk for three Ixodes scapularis-borne bacteria in host-seeking ticks. Ticks were collected from vegetation in areas treated with the "4-Poster" device and from control areas over a 6-year period in five geographically diverse study locations in the Northeastern United States and tested for infection with two known agents of human disease, Borrelia burgdorferi and Anaplasma phagocytophilum, and for a novel relapsing fever-group spirochete related to Borrelia miyamotoi. Overall, 38.2% of adults and 12.5% of nymphs were infected with B. burgdorferi; 8.5% of adults and 4.2% of nymphs were infected with A. phagocytophilum; and 1.9% of adults and 0.8% of nymphs were infected with B. miyamotoi. In most cases, treatment with the 4-Poster device was not associated with changes in the prevalence of infection with any of these three microorganisms among nymphal or adult ticks. However, the density of nymphs infected with B. burgdorferi, and consequently the entomologic risk for Lyme disease, was reduced overall by 68% in treated areas compared to control areas among the five study sites at the end of the study. The frequency of bacterial coinfections in ticks was generally equal to the product of the proportion of ticks infected with a single bacterium, indicating that enzootic maintenance of these pathogens is independent. We conclude that controlling ticks on deer by self-application of acaricide results in an overall decrease in the human risk for exposure to these three bacterial agents, which is due solely to a reduction in tick density.

  20. What's eating you? lone star tick (Amblyomma americanum).

    PubMed

    Reynolds, H Harris; Elston, Dirk M

    2017-02-01

    Amblyomma americanum , also known as the lone star tick, is found in much of the eastern United States. Since the mid-20th century, the lone star tick has been implicated in human disease. Today, A americanum remains an important vector for tick-borne illness. In addition to others, species of Rickettsia , Ehrlichia , and Borrelia are all transmitted by the lone star tick. Recently described conditions such as Southern tick-associated rash illness and anaphylaxis to red meat following tick bites have been attributed to the lone star tick. Impressive local reactions also can result after bites from A americanum . Early treatment of tick-borne illness is crucial to ensure good patient outcomes. Tick-control measures also are an important part of disease management in endemic areas. We discuss the tick's biology, human illnesses associated with A americanum , and methods to control tick numbers and eliminate disease in local reservoirs.

  1. Goats as sentinel hosts for the detection of tick-borne encephalitis risk areas in the Canton of Valais, Switzerland.

    PubMed

    Rieille, Nadia; Klaus, Christine; Hoffmann, Donata; Péter, Olivier; Voordouw, Maarten J

    2017-07-11

    Tick-borne encephalitis (TBE) is an important tick-borne disease in Europe. Detection of the TBE virus (TBEV) in local populations of Ixodes ricinus ticks is the most reliable proof that a given area is at risk for TBE, but this approach is time-consuming and expensive. A cheaper and simpler approach is to use immunology-based methods to screen vertebrate hosts for TBEV-specific antibodies and subsequently test the tick populations at locations with seropositive animals. The purpose of the present study was to use goats as sentinel animals to identify new risk areas for TBE in the canton of Valais in Switzerland. A total of 4114 individual goat sera were screened for TBEV-specific antibodies using immunological methods. According to our ELISA assay, 175 goat sera reacted strongly with TBEV antigen, resulting in a seroprevalence rate of 4.3%. The serum neutralization test confirmed that 70 of the 173 ELISA-positive sera had neutralizing antibodies against TBEV. Most of the 26 seropositive goat flocks were detected in the known risk areas in the canton of Valais, with some spread into the connecting valley of Saas and to the east of the town of Brig. One seropositive site was 60 km to the west of the known TBEV-endemic area. At two of the three locations where goats were seropositive, the local tick populations also tested positive for TBEV. The combined approach of screening vertebrate hosts for TBEV-specific antibodies followed by testing the local tick population for TBEV allowed us to detect two new TBEV foci in the canton of Valais. The present study showed that goats are useful sentinel animals for the detection of new TBEV risk areas.

  2. Exploring of Primate Models of Tick-Borne Flaviviruses Infection for Evaluation of Vaccines and Drugs Efficacy

    PubMed Central

    Pripuzova, Natalia S.; Gmyl, Larissa V.; Romanova, Lidiya Iu.; Tereshkina, Natalia V.; Rogova, Yulia V.; Terekhina, Liubov L.; Kozlovskaya, Liubov I.; Vorovitch, Mikhail F.; Grishina, Karina G.; Timofeev, Andrey V.; Karganova, Galina G.

    2013-01-01

    Tick-borne encephalitis virus (TBEV) is one of the most prevalent and medically important tick-borne arboviruses in Eurasia. There are overlapping foci of two flaviviruses: TBEV and Omsk hemorrhagic fever virus (OHFV) in Russia. Inactivated vaccines exist only against TBE. There are no antiviral drugs for treatment of both diseases. Optimal animal models are necessary to study efficacy of novel vaccines and treatment preparations against TBE and relative flaviviruses. The models for TBE and OHF using subcutaneous inoculation were tested in Cercopithecus aethiops and Macaca fascicularis monkeys with or without prior immunization with inactivated TBE vaccine. No visible clinical signs or severe pathomorphological lesions were observed in any monkey infected with TBEV or OHFV. C. aethiops challenged with OHFV showed massive hemolytic syndrome and thrombocytopenia. Infectious virus or viral RNA was revealed in visceral organs and CNS of C. aethiops infected with both viruses; however, viremia was low. Inactivated TBE vaccines induced high antibody titers against both viruses and expressed booster after challenge. The protective efficacy against TBE was shown by the absence of virus in spleen, lymph nodes and CNS of immunized animals after challenge. Despite the absence of expressed hemolytic syndrome in immunized C. aethiops TBE vaccine did not prevent the reproduction of OHFV in CNS and visceral organs. Subcutaneous inoculation of M. fascicularis with two TBEV strains led to a febrile disease with well expressed viremia, fever, and virus reproduction in spleen, lymph nodes and CNS. The optimal terms for estimation of the viral titers in CNS were defined as 8–16 days post infection. We characterized two animal models similar to humans in their susceptibility to tick-borne flaviviruses and found the most optimal scheme for evaluation of efficacy of preventive and therapeutic preparations. We also identified M. fascicularis to be more susceptible to TBEV than C

  3. Molecular detection of Rickettsia conorii and other zoonotic spotted fever group rickettsiae in ticks, Romania.

    PubMed

    Ionita, Mariana; Silaghi, Cornelia; Mitrea, Ioan Liviu; Edouard, Sophie; Parola, Philippe; Pfister, Kurt

    2016-02-01

    The diverse tick fauna as well as the abundance of tick populations in Romania represent potential risks for both human and animal health. Spotted fever group (SFG) rickettsiae are recognized as important agents of emerging human tick-borne diseases worldwide. However, the epidemiology of rickettsial diseases has been poorly investigated in Romania. In urban habitats, companion animals which are frequently exposed to tick infestation, play a role in maintenance of tick populations and as reservoirs of tick-borne pathogens. Therefore, the aim of the present study was to investigate the occurrence of SFG rickettsiae in ticks infesting dogs in a greater urban area in South-eastern Romania. Adult ixodid ticks (n=205), including Rhipicephalus sanguineus sensu lato (n=120), Dermacentor reticulatus (n=76) and Ixodes ricinus (n=9) were collected from naturally infested dogs and were screened for SFG rickettsiae using conventional PCR followed by sequencing. Additionally, ticks were screened for DNA of Babesia spp., Hepatozoon spp., Ehrlichia canis, and Anaplasma platys. Four zoonotic SFG rickettsiae were identified: Rickettsia raoultii (16%) and Rickettsia slovaca (3%) in D. reticulatus, Rickettsia monacensis (11%) in I. ricinus, and Rickettsia conorii (0.8%) in Rh. sanguineus s.l. Moreover, pathogens of veterinary importance, such as B. canis (21%) in D. reticulatus and E. canis (7.5%) in Rh. sanguineus s.l. were identified. The findings expand the knowledge on distribution of SFG rickettsiae as well as canine pathogens in Romania. Additionally, this is the first report describing the molecular detection of R. conorii in ticks from Romania. Copyright © 2015 Elsevier GmbH. All rights reserved.

  4. Serological detection of Tick-Borne Relapsing Fever in Texan domestic dogs

    PubMed Central

    Snell, Chloe B.; Adetunji, Shakirat A.; Piccione, Julie

    2017-01-01

    Tick-Borne Relapsing Fever (TBRF) is caused by spirochetes in the genus Borrelia. Very limited information exists on the incidence of this disease in humans and domestic dogs in the United States. The main objective of this study is to evaluate exposure of dogs to Borrelia turicatae, a causative agent of TBRF, in Texas. To this end, 878 canine serum samples were submitted to Texas A&M Veterinary Medical Diagnostic Laboratory from October 2011 to September 2012 for suspected tick-borne illnesses. The recombinant Borrelial antigen glycerophosphodiester phosphodiesterase (GlpQ) was expressed, purified, and used as a diagnostic antigen in both ELISA assays and Immunoblot analysis. Unfortunately, due to significant background reaction, the use of GlpQ as a diagnostic marker in the ELISA assay was not effective in discriminating dogs exposed to B. turicatae. Nevertheless, immunoblot assays showed that 17 out of 853 samples tested were considered to be seropositive, which constitutes 1.99% of all Texas samples tested in this study. The majority of positive samples were from central and southern Texas. Exposure to TBRF spirochetes may be seasonal, with 70.59% (12 out of 17) of the cases detected between June and December. In addition, 2 out of the 17 sero-reactive cases (11.76%) showed reactivity to both B. burgdorferi (causative agent of Lyme disease) and B. turicatae (a causative agent of TBRF). This is the first report of TBRF sero-prevalence in companion animals in an endemic area. Our findings further indicate that B. turicatae is maintained in domestic canids in Texas in regions where human disease also occurs, suggesting that domestic dogs could serve as sentinels for this disease. PMID:29232415

  5. Widespread Rickettsia spp. Infections in Ticks (Acari: Ixodoidea) in Taiwan.

    PubMed

    Kuo, Chi-Chien; Shu, Pei-Yun; Mu, Jung-Jung; Lee, Pei-Lung; Wu, Yin-Wen; Chung, Chien-Kung; Wang, Hsi-Chieh

    2015-09-01

    Ticks are second to mosquitoes as the most important disease vectors, and recent decades have witnessed the emergence of many novel tick-borne rickettsial diseases, but systematic surveys of ticks and tick-borne rickettsioses are generally lacking in Asia. We collected and identified ticks from small mammal hosts between 2006 and 2010 in different parts of Taiwan. Rickettsia spp. infections in ticks were identified by targeting ompB and gltA genes with nested polymerase chain reaction. In total, 2,732 ticks were collected from 1,356 small mammals. Rhipicephalus haemaphysaloides Supino (51.8% of total ticks), Haemaphysalis bandicota Hoogstraal & Kohls (28.0%), and Ixodes granulatus Supino (20.0%) were the most common tick species, and Rattus losea Swinhoe (44.7% of total ticks) and Bandicota indica Bechstein (39.9%) were the primary hosts. The average Rickettsia infective rate in 329 assayed ticks was 31.9% and eight Rickettsia spp. or closely related species were identified. This study shows that rickettsiae-infected ticks are widespread in Taiwan, with a high diversity of Rickettsia spp. circulating in the ticks. Because notifiable rickettsial diseases in Taiwan only include mite-borne scrub typhus and flea-borne murine typhus, more studies are warranted for a better understanding of the real extent of human risks to rickettsioses in Taiwan. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. Detection and Differentiation of Lyme Spirochetes and Other Tick-Borne Pathogens from Blood Using Real-Time PCR with Molecular Beacons.

    PubMed

    Schlachter, Samantha; Chan, Kamfai; Marras, Salvatore A E; Parveen, Nikhat

    2017-01-01

    Real-time PCR assays have recently been implemented in diagnostics for many bacterial pathogens, allowing rapid and accurate detection, which ultimately results in improved clinical intervention. Here, we describe a sensitive method of detection for three common tick-borne pathogens Borrelia burgdorferi, Anaplasma phagocytophilum, and Babesia microti since coinfections with these pathogens have started occurring with increasing frequency over the last several years in both North America and Europe. A shared geographic region, the same tick vectors, and similar transmission cycle all favor simultaneous transmission of these three tick-borne pathogens. Furthermore, early symptoms of the diseases are often similar and somewhat nonspecific leading to poor clinical identification. The multiplex real-time PCR assay we describe here utilizes gene-specific primers, molecular beacon probes tagged with different fluorophores, and optimized PCR conditions to detect even small amounts of specific pathogen DNA without interference. Application of this detection method will offer better diagnostics for acute and persistent infection compared to the two-tier serological tests that are currently approved in North America and Europe, which do not necessarily detect active infection.

  7. Factors responsible for Ixodes ricinus nymph abundance: Are soil features indicators of tick abundance in a French region where Lyme borreliosis is endemic?

    PubMed

    Goldstein, Valérie; Boulanger, Nathalie; Schwartz, Dominique; George, Jean-Claude; Ertlen, Damien; Zilliox, Laurence; Schaeffer, Mickaël; Jaulhac, Benoît

    2018-05-01

    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. Copyright © 2018 Elsevier GmbH. All rights reserved.

  8. Coinfection by the tick-borne pathogens Babesia microti and Borrelia burgdorferi: ecological, epidemiological and clinical consequences

    PubMed Central

    Diuk-Wasser, Maria A.; Vannier, Edouard

    2015-01-01

    Ixodes ticks maintain a large and diverse array of human pathogens in the enzootic cycle, including Borrelia burgdorferi and Babesia microti. Despite the poor ecological fitness of B. microti, babesiosis has recently emerged in areas endemic for Lyme disease. Studies in ticks, reservoir hosts and humans indicate that coinfection with B. burgdorferi and B. microti is common, promotes transmission and emergence of B. microti in the enzootic cycle, and causes greater disease severity and duration in humans. These integrative studies may serve as a paradigm for the study of other vector-borne coinfections. Identifying ecological drivers of pathogen emergence and host factors that fuel disease severity will help guide the design of effective curative and prevention strategies. PMID:26613664

  9. The diversity and prevalence of hard ticks attacking human hosts in Eastern Siberia (Russian Federation) with first description of invasion of non-endemic tick species.

    PubMed

    Khasnatinov, Maxim Anatolyevich; Liapunov, Alexander Valeryevich; Manzarova, Ellina Lopsonovna; Kulakova, Nina Viktorovna; Petrova, Irina Viktorovna; Danchinova, Galina Anatolyevna

    2016-02-01

    Hard ticks are the vectors of many pathogens including tick-borne encephalitis virus and the Lyme disease agent Borrelia burgdorferi sensu lato. In Eastern Siberia, Ixodes persulcatus, Dermacentor nuttalli, Dermacentor silvarum and Haemaphysalis concinna are regarded as aggressive to humans. Recently, significant changes in world tick fauna have been reported and this affects the spread of tick-borne pathogens. We studied the current species diversity, population structure and prevalence of tick-borne pathogens of hard ticks (Acari: Ixodidae) that attacked humans in Eastern Siberia (Irkutsk region, Russia). In total, 31,892 individual ticks were identified and analysed during the years 2007-2014. The majority (85.4%) of victims was bitten by I. persulcatus, 14.55% of attacks on humans were caused by D. nuttalli and D. silvarum, whereas H. concinna was documented only in 15 cases (0.05%). The seasonal activity and the age/gender structure of the tick population were studied as well. Among all the studied ticks, three unconventional species, i.e. Rhipicephalus sanguineus, Dermacentor reticulatus and Amblyomma americanum, were identified. Analysis of tick bite histories indicates at least three events of invasion of non-endemic ticks into the ecosystems of northern Eurasia with harsh continental climates. Invading ticks are able to reach the adult life stage and are aggressive to the local human population. Phylogenetic analysis of mt 16S rRNA gene fragments suggests multiple independent routes of tick migration to Eastern Siberia. Possible implications to human health and epidemiology of tick-borne infections are discussed.

  10. Challenges Posed by Tick-Borne Rickettsiae: Eco-Epidemiology and Public Health Implications

    PubMed Central

    Eremeeva, Marina E.; Dasch, Gregory A.

    2015-01-01

    Rickettsiae are obligately intracellular bacteria that are transmitted to vertebrates by a variety of arthropod vectors, primarily by fleas and ticks. Once transmitted or experimentally inoculated into susceptible mammals, some rickettsiae may cause febrile illness of different morbidity and mortality, and which can manifest with different types of exhanthems in humans. However, most rickettsiae circulate in diverse sylvatic or peridomestic reservoirs without having obvious impacts on their vertebrate hosts or affecting humans. We have analyzed the key features of tick-borne maintenance of rickettsiae, which may provide a deeper basis for understanding those complex invertebrate interactions and strategies that have permitted survival and circulation of divergent rickettsiae in nature. Rickettsiae are found in association with a wide range of hard and soft ticks, which feed on very different species of large and small animals. Maintenance of rickettsiae in these vector systems is driven by both vertical and horizontal transmission strategies, but some species of Rickettsia are also known to cause detrimental effects on their arthropod vectors. Contrary to common belief, the role of vertebrate animal hosts in maintenance of rickettsiae is very incompletely understood. Some clearly play only the essential role of providing a blood meal to the tick while other hosts may supply crucial supplemental functions for effective agent transmission by the vectors. This review summarizes the importance of some recent findings with known and new vectors that afford an improved understanding of the eco-epidemiology of rickettsiae; the public health implications of that information for rickettsial diseases are also described. Special attention is paid to the co-circulation of different species and genotypes of rickettsiae within the same endemic areas and how these observations may influence, correctly or incorrectly, trends, and conclusions drawn from the surveillance of

  11. Challenges posed by tick-borne rickettsiae: eco-epidemiology and public health implications.

    PubMed

    Eremeeva, Marina E; Dasch, Gregory A

    2015-01-01

    Rickettsiae are obligately intracellular bacteria that are transmitted to vertebrates by a variety of arthropod vectors, primarily by fleas and ticks. Once transmitted or experimentally inoculated into susceptible mammals, some rickettsiae may cause febrile illness of different morbidity and mortality, and which can manifest with different types of exhanthems in humans. However, most rickettsiae circulate in diverse sylvatic or peridomestic reservoirs without having obvious impacts on their vertebrate hosts or affecting humans. We have analyzed the key features of tick-borne maintenance of rickettsiae, which may provide a deeper basis for understanding those complex invertebrate interactions and strategies that have permitted survival and circulation of divergent rickettsiae in nature. Rickettsiae are found in association with a wide range of hard and soft ticks, which feed on very different species of large and small animals. Maintenance of rickettsiae in these vector systems is driven by both vertical and horizontal transmission strategies, but some species of Rickettsia are also known to cause detrimental effects on their arthropod vectors. Contrary to common belief, the role of vertebrate animal hosts in maintenance of rickettsiae is very incompletely understood. Some clearly play only the essential role of providing a blood meal to the tick while other hosts may supply crucial supplemental functions for effective agent transmission by the vectors. This review summarizes the importance of some recent findings with known and new vectors that afford an improved understanding of the eco-epidemiology of rickettsiae; the public health implications of that information for rickettsial diseases are also described. Special attention is paid to the co-circulation of different species and genotypes of rickettsiae within the same endemic areas and how these observations may influence, correctly or incorrectly, trends, and conclusions drawn from the surveillance of

  12. Repellents and acaricides as personal protection measures in the prevention of tick-borne diseases.

    PubMed

    Cisak, Ewa; Wójcik-Fatla, Angelina; Zając, Violetta; Dutkiewicz, Jacek

    2012-01-01

    A number of preventive measures for the protection of humans against tick-borne diseases were evaluated. Measures involving the avoidance of tick bites with the use of protective clothing and insect repellents are the simplest and most effective. Repellents are applied directly to the skin or clothing and other fabrics, such as bednets, tents and anti-mosquito screens. Currently, DEET (N,N-diethyl-m-toluamide) is considered the most efficient arthropod repellent reference substance. The registered and recommended active repellent ingredients for skin and/or cloths application, among others, are: DEET, 1-methyl-propyl-2- (hydroxyethyl)-1-piperidinecarboxylate (picaridin), p-menthane-3,8-diol (PMD), ethyl butylactyloaminopropionate ( IR3535), 1S,2S-2-methylpiperidinyl-3-cyclohexene-1-carboxamide (SS220), racemic 2-methylpiperidinyl-3-cyclohexene-1-carboxamide (AI3-37220) and synthethic pyrethroid - 3-phenoxybenzyl-cis-trans-3(2,2 dichlorovinyl)-2,2-dimethylcyclopropancarboxylate (permethrin) - an acaricide with repellent properties. To achieve the protection from tick bites by avoiding attachment and/or engorgement by the arthropod, acaricides with repellent properties, such as synthetic pyrethroid-permethrin are used. This pyrethroid is an acaricide of choice used for clothing impregnation, which is effective for personal protection against all three parasitic stages of western black-legged ticks. Products based on natural compounds, e.g. eugenol from Ocimum basilicum, 2-undecanone originally derived from wild tomato, geraniol - a natural product extracted from plants, and many others, represent an interesting alternative to common synthetic repellents and/or acaricides.

  13. Tick microbiome: the force within

    PubMed Central

    Narasimhan, Sukanya; Fikrig, Erol

    2015-01-01

    Ticks are obligate blood-feeders and serve as vectors of human and livestock pathogens worldwide. Defining the tick microbiome and deciphering the interactions between the tick and its symbiotic bacteria in the context of tick development and pathogen transmission, will likely reveal new insights and spawn new paradigms to control tick-borne diseases. Descriptive observations on the tick microbiome that began almost a century ago serve as forerunners to the gathering momentum to define the tick microbiome in greater detail. This review will focus on the current efforts to address the microbiomes of diverse ticks, and the evolving understanding of tick microbiomes. There is hope that these efforts will bring a holistic understanding of pathogen transmission by ticks. PMID:25936226

  14. Tick-host conflict: immunoglobulin E antibodies to tick proteins in patients with anaphylaxis to tick bite

    PubMed Central

    Mateos-Hernández, Lourdes; Villar, Margarita; Moral, Angel; GarcíaRodríguez, Carmen; Arias, Teresa Alfaya; de la Osa, Verónica; Brito, Francisco Feo; Fernández de Mera, Isabel G.; Alberdi, Pilar; Ruiz-Fons, Francisco; Cabezas-Cruz, Alejandro; Estrada-Peña, Agustín; de la Fuente, José

    2017-01-01

    Tick-borne infectious diseases and allergies are a growing problem worldwide. Tick bite allergy has been associated with the direct effect of immunoglobulin E (IgE) response to tick salivary antigens, or secondary to the induction of allergy to red meat consumption through IgE antibodies against the carbohydrate α-Gal (Gal α 1-3Gal β 1-(3)4GlcNAc-R). However, despite the growing burden of this pathology, the proteins associated with anaphylaxis to tick bite have not been characterized. To address this question, a comparative proteomics approach was used to characterize tick proteins producing an IgE antibody response in a healthy individual with record of tick bites, which had not resulted in any allergic reactions, and two patients with anaphylactic reactions to Rhipicephalus bursa or Hyalomma marginatum tick bites. Both patients and the healthy individual were red meat tolerant. The results supported a patient-specific IgE antibody response to tick species responsible for the anaphylaxis to tick bite. Both patients and the healthy individual serologically recognized tick proteins with and without α-Gal modifications, with proteins differentially recognized by patients but not control sera. These proteins could be used as potential antigens for diagnostics, treatment and prevention of tick bite-induced allergies. PMID:28423486

  15. [Abundance of larvae and nymphs of the taiga tick Ixodes persuicatus (Acari: Ixodidae) on small mammals in the cut-over lands of the middle taiga subzone of Karelia].

    PubMed

    Bugmyrin, S V; Bespiatova, L A; Anikanova, V S; Ieshko, E P

    2009-01-01

    Data of long-term investigations (1998-2004) on the abundance of the taiga tick larvae and nymphs in the cut-over lands of different age in the middle taiga subzone of Karelia (62 degrees 04'S; 33 degrees 55'W) are presented. The investigation was carried out on three model cut-over lands of different age: 1) "young" cut-over land; age of cut-over in the beginning of investigation is 7 years; Betula-Deschampsia cespitosa-Agrostis tenuis; 2) "middle" cut-over land; age of cut-over is 12 years; Salix-Deschampsia cespitosa-Agrostis tenuis; 3) "old" cut-over land; age of cut-over 25 years; Alnus incana-Rubus idaeus-grass. The number of ticks was estimated by using common parasitological indices: prevalence, abundance, and index of feeding intensity (the tick abundance multiply by the number of small mammals per hundred traps-nights). In the beginning of investigation the "young" cut-over land was a typical meadow association. The lowest tick abundance was recorded here. That was a result of unfavorable abiotic conditions and low number of small mammals in the beginning of summer. "Middle" cut-over land is characterized by the highest number of the tick larvae, which is the evidence for high number of the hosts of tick imago. "Old" cut-over land has the optimum conditions for development of taiga ticks. High abundance of the ticks (larvae and nymphs) was recorded during the whole period of investigations. The number of preimaginal ticks is shown to be much higher in cut-over lands as compared with that in mixed and coniferous forests, due to the higher number of small mammals.

  16. Powassan encephalitis and Colorado tick fever.

    PubMed

    Romero, José R; Simonsen, Kari A

    2008-09-01

    This article discusses two tick-borne illnesses: Powassan encephalitis, a rare cause of central nervous system infection caused by the Powassan virus, and Colorado tick fever, an acute febrile illness caused by the Colorado tick fever virus common to the Rocky Mountain region of North America.

  17. Distribution pattern and number of ticks on lizards.

    PubMed

    Dudek, Krzysztof; Skórka, Piotr; Sajkowska, Zofia Anna; Ekner-Grzyb, Anna; Dudek, Monika; Tryjanowski, Piotr

    2016-02-01

    The success of ectoparasites depends primarily on the site of attachment and body condition of their hosts. Ticks usually tend to aggregate on vertebrate hosts in specific areas, but the distribution pattern may depend on host body size and condition, sex, life stage or skin morphology. Here, we studied the distribution of ticks on lizards and tested the following hypothesis: occurrence or high abundance of ticks is confined with body parts with smaller scales and larger interscalar length because such sites should provide ticks with superior attachment conditions. This study was performed in field conditions in central Poland in 2008-2011. In total, 500 lizards (Lacerta agilis) were caught and 839 ticks (Ixodes ricinus, larvae and nymphs) were collected from them. Using generalised linear mixed models, we found that the ticks were most abundant on forelimbs and their axillae, with 90% of ticks attached there. This part of the lizard body and the region behind the hindlimb were covered by the smallest scales with relatively wide gaps between them. This does not fully support our hypothesis that ticks prefer locations with easy access to skin between scales, because it does not explain why so few ticks were in the hindlimb area. We found that the abundance of ticks was positively correlated with lizard body size index (snout-vent length). Tick abundance was also higher in male and mature lizards than in female and young individuals. Autotomy had no effect on tick abundance. We found no correlation between tick size and lizard morphology, sex, autotomy and body size index. The probability of occurrence of dead ticks was positively linked with the total number of ticks on the lizard but there was no relationship between dead tick presence and lizard size, sex or age. Thus lizard body size and sex are the major factors affecting the abundance of ticks, and these parasites are distributed nearly exclusively on the host's forelimbs and their axillae. Copyright © 2015

  18. Identification of tick-borne pathogen diversity by metagenomic analysis in Haemaphysalis longicornis from Xinyang, China.

    PubMed

    Zhuang, Lu; Du, Juan; Cui, Xiao-Ming; Li, Hao; Tang, Fang; Zhang, Pan-He; Hu, Jian-Gong; Tong, Yi-Gang; Feng, Zhi-Chun; Liu, Wei

    2018-05-07

    A wide variety of pathogens could be maintained and transmitted by Haemaphysalis longicornis. The aim of this study is to systematically examine the variety of pathogens carried by Haemaphysalis longicornis, an importnatn vector, in tick-borne diseases epidemic area, and to estimate the risk of human infection imposed by tick bites. Adult questing ticks were collected in Xinyang, central China. Genomic DNA and RNA were extracted from 144 H. longicornis ticks individually, and sequenced respectively as the templates for high-throughput sequencing. Clean reads were compared against the database of NCBI nucleotide collection and specific PCR was performed to confirm the presence of pathogen. Phylogenetic analysis was performed to explore the evolutionary status of pathogens. The assignment of reads to taxa based on BLASTN results revealed the existence of several potential pathogens, including Anaplasma spp., Rickettsia spp., Babesia sp., as well as severe fever with thrombocytopenia syndrome bunyavirus (SFTSV). Comfirmantory PCR assays revealed the existence of Anaplasma bovis (13/144, 9.03%), Anaplasma centrale (2/144, 1.39%), Rickettsia heilongjiangensis (3/144, 2.08%), Rickettsia sp. LON-13 (1/144, 0.69%), Rickettsia raoultii (5/144, 3.47%), Babesia sp. (1/144, 0.69%). SFTSV accounted for the highest detected pathogen with a positive rate of 18.75% (27/144). Three of the ticks (2.08%) were co-infected with SFTSV and A. bovis. Our study provided a broadened list of microorganism that harbored by H. longicornis. In previously unrecognized endemic regions, prokaryotic and eukaryotic infection including Anaplasma spp., Rickettsiae spp., and Babesia spp. should be considered, along with the well-known SFTSV for patients with tick bites history. A novel Babesia species was identified in local natural foci, which needs further investigation in the future.

  19. Climate change influences on the potential geographic distribution of the disease vector tick Ixodes ricinus.

    PubMed

    Alkishe, Abdelghafar A; Peterson, A Townsend; Samy, Abdallah M

    2017-01-01

    Ixodes ricinus is a species of hard tick that transmits several important diseases in Europe and North Africa, including Lyme borreliosis and tick-borne encephalitis. Climate change is affecting the geographic distributions and abundances of arthropod vectors, which in turn influence the geographic distribution and epidemiology of associated vector-borne diseases. To date, few studies have investigated effects of climate change on the spatial distribution of I. ricinus at continental extents. Here, we assessed the potential distribution of I. ricinus under current and future climate conditions to understand how climate change will influence the geographic distribution of this important tick vector in coming decades. We used ecological niche modeling to estimate the geographic distribution of I. ricinus with respect to current climate, and then assessed its future potential distribution under different climate change scenarios. This approach integrates occurrence records of I. ricinus with six relevant environmental variables over a continental extent that includes Europe, North Africa, and the Middle East. Future projections were based on climate data from 17 general circulation models (GCMs) under 2 representative concentration pathway emissions scenarios (RCPs), for the years 2050 and 2070. The present and future potential distributions of I. ricinus showed broad overlap across most of western and central Europe, and in more narrow zones in eastern and northern Europe, and North Africa. Potential expansions were observed in northern and eastern Europe. These results indicate that I. ricinus populations could emerge in areas in which they are currently lacking, posing increased risks to human health in those areas. However, the future of I. ricinus ticks in some important regions such the Mediterranean was unclear owing to high uncertainty in model predictions.

  20. Detection of Borrelia miyamotoi and other tick-borne pathogens in human clinical specimens and Ixodes scapularis ticks in New York State, 2012-2015.

    PubMed

    Wroblewski, Danielle; Gebhardt, Linda; Prusinski, Melissa A; Meehan, Lisa J; Halse, Tanya A; Musser, Kimberlee A

    2017-03-01

    Borrelia miyamotoi (Bm) is a recently emerging bacterial agent transmitted by several species of ixodid ticks. Diagnosis of Bm infection can be challenging, as the organism is not easily cultivable. We have developed and validated a multiplex real-time PCR to simultaneously identify Bm infection and the agents causing human granulocytic anaplasmosis and human monocytic ehrlichiosis, Anaplasma phagocytophilum and Ehrlichia chaffeensis, respectively. The assay is 100% specific; highly sensitive, detecting 11 gene copies of Bm DNA in both whole blood and cerebral spinal fluid; and provides rapid results in less than two hours. A retrospective study of 796 clinical specimens collected between the years 2012 and 2014 and a prospective study of 366 clinical specimens were performed utilizing this novel assay to evaluate the frequency of Bm infection in New York State (NYS). Eight clinical specimens (1%) were found to be positive for Bm, 216 were positive for A. phagocytophilum, and 10 were positive for E. chaffeensis. Additionally, we tested 411 I. scapularis ticks collected in NYS during 2013 and 2014 in a separate multiplex real-time PCR to determine the prevalence of Bm, A. phagocytophilum, Borrelia burgdorferi s.s., and Borrelia species. Our results indicated rates of 1.5%, 27%, 19.7%, and 8.8% respectively. The ability to monitor both the frequency and geographic distribution of Bm cases and the prevalence and geographic distribution of Bm in ticks will help create a better understanding of this emerging tick-borne pathogen. Published by Elsevier GmbH.

  1. [Comparative analysis of virulence of the Siberian and Far-East subtypes of the tick-born encephalitis virus].

    PubMed

    Pogodina, V V; Bochkova, N G; Karan', L S; Frolova, M P; Trukhina, A G; Malenko, G V; Levina, L S; Platonov, A E

    2004-01-01

    The Siberian subtype of the tick-borne encephalitis virus (TEV) is different from the Far-East subtype by a moderate virulence observed in Siberian hamsters and by a low infection development rate (100 strains were compared). No differences were found in neuro-invasiveness. Clinical findings and experiments with monkeys denote the ability of the Siberian subtype to provoke severe forms of tick-borne encephalitis (TBE). The inflammation-and-degenerative changes were localized in the brain cortex, subcortical ganglions, nuclei of medulla oblongata, in the cortex and nuclei of the cerebellum as well as in the anterior horns of the spinal cord. 18 disease cases triggered by the Siberian TEV subtypes in residents of the Western and Eastern Siberia and of Central Russia (Yaroslavl Region), including 7 acute TBE cases (5 lethal outcomes), as well as 11 chronic TBE cases are analyzed. The viral RNA was found in the cortex, medulla oblongata, horn and in the cervical part of the spinal cord of those diseased of acute TBE. Sequences of genotyped strains were presented to Gen Bank, NCBI (AY363846-AY363865).

  2. [Mono- and mixed infection by the tick-borne encephalitis and Powassan viruses of tissue explants from ticks of the genus Hyalomma].

    PubMed

    Chunikhin, S P; Khozinskaia, G A; Stefutkina, L F; Korolev, M B

    1984-01-01

    The paper presents results of virusological and electron microscope studies of the reproduction of viruses of tick-borne encephalitis and Povassan at mono- and mixed persistent infection of explants of imaginal tissues of Hyalomma anatolicum and H. dromedarii with these viruses. The virus reproduction in explants was observed within 208 to 217 days after the infection. Joint reproduction of two model viruses within 1-2 months after the infection can take place and after that the inhibition of the reproduction of one of the viruses. This inhibition can be of cyclic character.

  3. The Willingness to Pay for Vaccination against Tick-Borne Encephalitis and Implications for Public Health Policy: Evidence from Sweden.

    PubMed

    Slunge, Daniel

    2015-01-01

    The increasing incidence of tick-borne encephalitis (TBE) in Sweden and several other European countries has sparked a discussion about the need for a public vaccination strategy. However, TBE vaccination coverage is incomplete and there is little knowledge about the factors influencing vaccination behavior. Based on a survey of 1,500 randomly selected respondents in Sweden, we estimate vaccination coverage in areas with different TBE risk levels and analyze the role of vaccine price and other factors influencing the demand for vaccination. First, we find that the average rate of TBE vaccination in Sweden is 33% in TBE risk areas and 18% elsewhere. Income, age and risk-related factors such as incidence of TBE in the area of residence, frequency of visits to areas with TBE risk, and experience with tick bites are positively associated with demand for TBE vaccine. Next, using contingent valuation methodology, we estimate the willingness to pay for TBE vaccination among the unvaccinated respondents and the effect of a possible subsidy. Among the unvaccinated respondents in TBE risk areas, we estimate the mean willingness to pay for the recommended three doses of TBE vaccine to be 465 SEK (approximately 46 euros or 40% of the current market price). We project that a subsidy making TBE vaccines free of charge could increase the vaccination rate in TBE risk areas to around 78%, with a larger effect on low-income households, whose current vaccination rate is only 15% in risk areas. However, price is not the only factor affecting demand. We find significant effects on vaccination behavior associated with trust in vaccine recommendations, perceptions about tick bite-related health risks and knowledge about ticks and tick-borne diseases. Hence, increasing knowledge and trust, as well as ease of access to vaccinations, can also be important measures for public health agencies that want to increase the vaccination rate.

  4. The Willingness to Pay for Vaccination against Tick-Borne Encephalitis and Implications for Public Health Policy: Evidence from Sweden

    PubMed Central

    Slunge, Daniel

    2015-01-01

    The increasing incidence of tick-borne encephalitis (TBE) in Sweden and several other European countries has sparked a discussion about the need for a public vaccination strategy. However, TBE vaccination coverage is incomplete and there is little knowledge about the factors influencing vaccination behavior. Based on a survey of 1,500 randomly selected respondents in Sweden, we estimate vaccination coverage in areas with different TBE risk levels and analyze the role of vaccine price and other factors influencing the demand for vaccination. First, we find that the average rate of TBE vaccination in Sweden is 33% in TBE risk areas and 18% elsewhere. Income, age and risk-related factors such as incidence of TBE in the area of residence, frequency of visits to areas with TBE risk, and experience with tick bites are positively associated with demand for TBE vaccine. Next, using contingent valuation methodology, we estimate the willingness to pay for TBE vaccination among the unvaccinated respondents and the effect of a possible subsidy. Among the unvaccinated respondents in TBE risk areas, we estimate the mean willingness to pay for the recommended three doses of TBE vaccine to be 465 SEK (approximately 46 euros or 40% of the current market price). We project that a subsidy making TBE vaccines free of charge could increase the vaccination rate in TBE risk areas to around 78%, with a larger effect on low-income households, whose current vaccination rate is only 15% in risk areas. However, price is not the only factor affecting demand. We find significant effects on vaccination behavior associated with trust in vaccine recommendations, perceptions about tick bite-related health risks and knowledge about ticks and tick-borne diseases. Hence, increasing knowledge and trust, as well as ease of access to vaccinations, can also be important measures for public health agencies that want to increase the vaccination rate. PMID:26641491

  5. Tick-borne encephalitis virus isolates from natural foci of the Irkutsk region: clarification of the genotype landscape.

    PubMed

    Mel'nikova, Ol'ga V; Adel'shin, R V; Korzun, V M; Trushina, Yu N; Andaev, E I

    The Irkutsk region is the unique territory where all known subtypes of tick-borne encephalitis virus (TBEV) circulate. In the last years, the phenomenon of changes in TBEV subtypes (substitution of the Far-Eastern subtype by the Siberian one) was noted in some regions of the Russian Federation. The results of individual investigation of 11522 Ixodes persulcatus ticks and brain specimens from 81 small mammals collected in natural foci of the Irkutsk region during 2006-2014 are presented in the article. More than 60 TBEV strains have been isolated and studied by virological methods; E gene fragments (1193 b.p.) of 68 isolates have been typed. The majority of the strains (irrespective of subtype) were of high virulence for laboratory mice (LM) in case of both intracerebral and subcutaneous inoculation of virus. All isolates from warm-blooded small mammals and humans were of high virulence for LM, but placed in the same clusters of the phylogenetic tree with ticks collected in the same area. Tick-borne strains of different virulence also did not form separate clusters on the tree. Phylogenetic analysis showed that modern TBEV genotypic landscape of the studied territory is changing toward absolute predominance of the Siberian subtype (94.1%). This subtype is represented by two groups with prototype strains “Zausaev” and “Vasilchenko”. The “Vasilchenko” group of strains is spread on the whole territory under study; the strains of “Zausaev” group were isolated previously in the Irkutsk suburbs. The European subtype of TBEV circulates in natural foci of Pribaikalie permanently (at least 5% of the random sampling); the strains are of high virulence for LM. The Far-Eastern TBEV subtype was not found within the group of isolates collected in 20062014. The phylogenetic relationship of the strains under study had a higher correlation with the place of isolation than with the year or source.

  6. The Tick Microbiome: Why Non-pathogenic Microorganisms Matter in Tick Biology and Pathogen Transmission

    PubMed Central

    Bonnet, Sarah I.; Binetruy, Florian; Hernández-Jarguín, Angelica M.; Duron, Olivier

    2017-01-01

    Ticks are among the most important vectors of pathogens affecting humans and other animals worldwide. They do not only carry pathogens however, as a diverse group of commensal and symbiotic microorganisms are also present in ticks. Unlike pathogens, their biology and their effect on ticks remain largely unexplored, and are in fact often neglected. Nonetheless, they can confer multiple detrimental, neutral, or beneficial effects to their tick hosts, and can play various roles in fitness, nutritional adaptation, development, reproduction, defense against environmental stress, and immunity. Non-pathogenic microorganisms may also play a role in driving transmission of tick-borne pathogens (TBP), with many potential implications for both human and animal health. In addition, the genetic proximity of some pathogens to mutualistic symbionts hosted by ticks is evident when studying phylogenies of several bacterial genera. The best examples are found within members of the Rickettsia, Francisella, and Coxiella genera: while in medical and veterinary research these bacteria are traditionally recognized as highly virulent vertebrate pathogens, it is now clear to evolutionary ecologists that many (if not most) Coxiella, Francisella, and Rickettsia bacteria are actually non-pathogenic microorganisms exhibiting alternative lifestyles as mutualistic ticks symbionts. Consequently, ticks represent a compelling yet challenging system in which to study microbiomes and microbial interactions, and to investigate the composition, functional, and ecological implications of bacterial communities. Ultimately, deciphering the relationships between tick microorganisms as well as tick symbiont interactions will garner invaluable information, which may aid in the future development of arthropod pest and vector-borne pathogen transmission control strategies. PMID:28642842

  7. The Tick Microbiome: Why Non-pathogenic Microorganisms Matter in Tick Biology and Pathogen Transmission.

    PubMed

    Bonnet, Sarah I; Binetruy, Florian; Hernández-Jarguín, Angelica M; Duron, Olivier

    2017-01-01

    Ticks are among the most important vectors of pathogens affecting humans and other animals worldwide. They do not only carry pathogens however, as a diverse group of commensal and symbiotic microorganisms are also present in ticks. Unlike pathogens, their biology and their effect on ticks remain largely unexplored, and are in fact often neglected. Nonetheless, they can confer multiple detrimental, neutral, or beneficial effects to their tick hosts, and can play various roles in fitness, nutritional adaptation, development, reproduction, defense against environmental stress, and immunity. Non-pathogenic microorganisms may also play a role in driving transmission of tick-borne pathogens (TBP), with many potential implications for both human and animal health. In addition, the genetic proximity of some pathogens to mutualistic symbionts hosted by ticks is evident when studying phylogenies of several bacterial genera. The best examples are found within members of the Rickettsia, Francisella , and Coxiella genera: while in medical and veterinary research these bacteria are traditionally recognized as highly virulent vertebrate pathogens, it is now clear to evolutionary ecologists that many (if not most) Coxiella, Francisella , and Rickettsia bacteria are actually non-pathogenic microorganisms exhibiting alternative lifestyles as mutualistic ticks symbionts. Consequently, ticks represent a compelling yet challenging system in which to study microbiomes and microbial interactions, and to investigate the composition, functional, and ecological implications of bacterial communities. Ultimately, deciphering the relationships between tick microorganisms as well as tick symbiont interactions will garner invaluable information, which may aid in the future development of arthropod pest and vector-borne pathogen transmission control strategies.

  8. Eradication and control of livestock ticks: biological, economic and social perspectives.

    PubMed

    Walker, Alan R

    2011-07-01

    Comparisons of successful and failed attempts to eradicate livestock ticks reveal that the social context of farming and management of the campaigns have greater influence than techniques of treatment. The biology of ticks is considered principally where it has contributed to control of ticks as practiced on farms. The timing of treatments by life cycle and season can be exploited to reduce numbers of treatments per year. Pastures can be managed to starve and desiccate vulnerable larvae questing on vegetation. Immunity to ticks acquired by hosts can be enhanced by livestock breeding. The aggregated distribution of ticks on hosts with poor immunity can be used to select animals for removal from the herd. Models of tick population dynamics required for predicting outcomes of control methods need better understanding of drivers of distribution, aggregation, stability, and density-dependent mortality. Changing social circumstances, especially of land-use, has an influence on exposure to tick-borne pathogens that can be exploited for disease control.

  9. Correlation between Tick Density and Pathogen Endemicity, New Hampshire

    PubMed Central

    Walk, Seth T.; Xu, Guang; Stull, Jason W.

    2009-01-01

    To assess the endemicity of tick-borne pathogens in New Hampshire, we surveyed adult tick vectors. Pathogens were more prevalent in areas of high tick density, suggesting a correlation between tick establishment and pathogen endemicity. Infection rates in ticks correlated with disease frequency in humans. PMID:19331738

  10. Anti-tick biological control agents: assessment and future perspectives

    USGS Publications Warehouse

    Samish, M.; Ginsberg, H.S.; Glazer, I.; Bowman, Alan. S.; Nuttall, Patricia A.

    2008-01-01

    Widespread and increasing resistance to most available acaracides threatens both global livestock industries and public health. This necessitates better understanding of ticks and the diseases they transmit in the development of new control strategies. Ticks: Biology, Disease and Control is written by an international collection of experts and covers in-depth information on aspects of the biology of the ticks themselves, various veterinary and medical tick-borne pathogens, and aspects of traditional and potential new control methods. A valuable resource for graduate students, academic researchers and professionals, the book covers the whole gamut of ticks and tick-borne diseases from microsatellites to satellite imagery and from exploiting tick saliva for therapeutic drugs to developing drugs to control tick populations. It encompasses the variety of interconnected fields impinging on the economically important and biologically fascinating phenomenon of ticks, the diseases they transmit and methods of their control.

  11. Molecular evidence of tick-borne hemoprotozoan-parasites (Theileria ovis and Babesia ovis) and bacteria in ticks and blood from small ruminants in Northern Algeria.

    PubMed

    Aouadi, Atef; Leulmi, Hamza; Boucheikhchoukh, Mehdi; Benakhla, Ahmed; Raoult, Didier; Parola, Philippe

    2017-02-01

    Using qPCR, standard PCR and/or sequencing, we investigated the presence of tick-associated microorganisms in ticks and blood from sheep and goats from Souk Ahras, Algeria. Borrelia theileri, was detected in (7/120, 5.8%) blood from sheep and (13/120, 10.8%) goats. Anaplasma ovis was screened in (38/73, 52%) Rhipicephalus bursa and (5/22, 22.7%) R. turanicus and in (74/120, 61.7%), (65/120, 54.2%) blood of sheep and goats respectively. Coxiella burnetii tested positive in R. bursa (4/73, 5.5%) and (7/120, 5.8%) blood of sheep and (2/120, 1.7%) goats. Theileria ovis was detected in (50/147, 34%) R. bursa and (3/22, 13.6%) R. turanicus and in (64/120, 53.3%) blood of sheep and (25/120, 20.8%) goats. Babesia ovis was screened positive in (23/147, 15.6%) R. bursa and (7/48, 14.6%) R. turanicus. Our findings expand knowledge about the repertoire of tick-borne microorganisms present in ectoparasites and/or the blood of small ruminants in Algeria. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Characterization of tick-borne encephalitis virus from Latvia.

    PubMed

    Mavtchoutko, V; Vene, S; Haglund, M; Forsgren, M; Duks, A; Kalnina, V; Hörling, J; Lundkvist, A

    2000-02-01

    Viruses of the tick-borne encephalitis (TBE) antigenic complex, within the family Flaviviridae, cause a variety of diseases including uncomplicated febrile illness, encephalitis, meningo-encephalitis, hemorrhagic fever and chronic disease in humans, domesticated animals or wildlife species. TBE is a serious problem in Latvia with up to a 1,000 patients confirmed serologically annually 1994-1995. No previous data had been reported on the causative agent of TBE in Latvia. In the present study, a virus was isolated from serum of a patient with clinical symptoms of an acute TBE infection. Nucleotide sequence information obtained by direct reverse transcription-polymerase chain reaction (RT-PCR) and the serological characteristics of the isolated virus strain, designated TBE-Latvia-1-96, indicated a closer relationship to the Vasilchenko strain, isolated in Novosibirsk (Siberia, Russia), as compared to the western European or far eastern subtypes of TBE viruses. In a mouse neurovirulence assay, a significant difference in survival rates (days) was shown between Latvia-1-96 and the western European TBE virus subtype. Copyright 2000 Wiley-Liss, Inc.

  13. Hepatozoon canis infection in ticks during spring and summer in Italy.

    PubMed

    Dantas-Torres, Filipe; Latrofa, Maria Stefania; Weigl, Stefania; Tarallo, Viviana Domenica; Lia, Riccardo Paolo; Otranto, Domenico

    2012-02-01

    Hepatozoon canis is a common protozoan of dogs, being among the most prevalent tick-borne pathogens infecting dogs around the world. It is primarily transmitted by Rhipicephalus sanguineus, the brown dog tick. In this study we tested ticks collected from dogs and from the environment in order to track the origin of an outbreak of H. canis infection detected in October 2009 in a private dog shelter in southern Italy. Ticks from dogs (n = 267) were collected during the spring of 2009, whereas ticks from environment (n = 300) were found on sticky traps placed in the same shelter during the summer of 2009. All ticks were tested by PCR for the detection of a H. canis 18S ribosomal RNA gene fragment. Four (1.5%, one female and three males) ticks collected from dogs were PCR positive. None of the larvae collected from the environment were positive, but a relatively high infection rate (8.0%) was detected in nymphs. These findings point out that dogs became infected during the summer, when ticks were abundant and highly infected by H. canis. Moreover, this study suggests that castor oil sticky traps might be useful to collect engorged immature ticks in highly infested environments (e.g., dog shelters). This might be particularly interesting to evaluate the level of infection by certain pathogens in free-ranging ticks R. sanguineus, as done in the present study.

  14. Coinfections acquired from ixodes ticks.

    PubMed

    Swanson, Stephen J; Neitzel, David; Reed, Kurt D; Belongia, Edward A

    2006-10-01

    The pathogens that cause Lyme disease (LD), human anaplasmosis, and babesiosis can coexist in Ixodes ticks and cause human coinfections. Although the risk of human coinfection differs by geographic location, the true prevalence of coinfecting pathogens among Ixodes ticks remains largely unknown for the majority of geographic locations. The prevalence of dually infected Ixodes ticks appears highest among ticks from regions of North America and Europe where LD is endemic, with reported prevalences of < or =28%. In North America and Europe, the majority of tick-borne coinfections occur among humans with diagnosed LD. Humans coinfected with LD and babesiosis appear to have more intense, prolonged symptoms than those with LD alone. Coinfected persons can also manifest diverse, influenza-like symptoms, and abnormal laboratory test results are frequently observed. Coinfecting pathogens might alter the efficiency of transmission, cause cooperative or competitive pathogen interactions, and alter disease severity among hosts. No prospective studies to assess the immunologic effects of coinfection among humans have been conducted, but animal models demonstrate that certain coinfections can modulate the immune response. Clinicians should consider the likelihood of coinfection when pursuing laboratory testing or selecting therapy for patients with tick-borne illness.

  15. Ixodid Tick Infestation in Cattle and Wild Animals in Maswa and Iringa, Tanzania

    PubMed Central

    Kwak, You Shine; Kim, Tae Yun; Nam, Sung-Hyun; Lee, In-Yong; Kim, Hyung-Pyo; Mduma, Simon; Keyyu, Julius; Fyumagwa, Robert

    2014-01-01

    Ticks and tick-borne diseases are important in human and livestock health worldwide. In November 2012, ixodid ticks were collected and identified morphologically from cattle and wild animals in the Maswa district and Iringa urban, Tanzania. Amblyomma gemma, A. lepidum, and A. variegatum were identified from Maswa cattle, and A. variegatum was the predominant species. A. marmoreum, Hyalomma impeltatum, and Rhipicephalus pulchellus were identified from Iringa cattle in addition to the above 3 Amblyomma species, and A. gemma was the most abundant species. Total 4 Amblyomma and 6 Rhipicephalus species were identified from wild animals of the 2 areas. A. lepidum was predominant in Maswa buffaloes, whereas A. gemma was predominant in Iringa buffaloes. Overall, A. variegatum in cattle was predominant in the Maswa district and A. gemma was predominant in Iringa, Tanzania. PMID:25352709

  16. Ixodid tick infestation in cattle and wild animals in Maswa and Iringa, Tanzania.

    PubMed

    Kwak, You Shine; Kim, Tae Yun; Nam, Sung-Hyun; Lee, In-Yong; Kim, Hyung-Pyo; Mduma, Simon; Keyyu, Julius; Fyumagwa, Robert; Yong, Tai-Soon

    2014-10-01

    Ticks and tick-borne diseases are important in human and livestock health worldwide. In November 2012, ixodid ticks were collected and identified morphologically from cattle and wild animals in the Maswa district and Iringa urban, Tanzania. Amblyomma gemma, A. lepidum, and A. variegatum were identified from Maswa cattle, and A. variegatum was the predominant species. A. marmoreum, Hyalomma impeltatum, and Rhipicephalus pulchellus were identified from Iringa cattle in addition to the above 3 Amblyomma species, and A. gemma was the most abundant species. Total 4 Amblyomma and 6 Rhipicephalus species were identified from wild animals of the 2 areas. A. lepidum was predominant in Maswa buffaloes, whereas A. gemma was predominant in Iringa buffaloes. Overall, A. variegatum in cattle was predominant in the Maswa district and A. gemma was predominant in Iringa, Tanzania.

  17. Comparative genome analysis of Alkhumra hemorrhagic fever virus with Kyasanur forest disease and tick-borne encephalitis viruses by the in silico approach.

    PubMed

    Palanisamy, Navaneethan; Akaberi, Dario; Lennerstrand, Johan; Lundkvist, Åke

    2018-05-10

    Alkhumra hemorrhagic fever virus (AHFV), a relatively new member of the Flaviviruses, was discovered in Saudi Arabia 23 years ago. AHFV is classified in the tick-borne encephalitis virus serocomplex, along with the Kyasanur forest disease virus (KFDV) and tick-borne encephalitis virus (TBEV). Currently, very little is known about the pathologies of AHFV. In this study, using the available genome information of AHFV, KFDV and TBEV, we have predicted and compared the following aspects of these viruses: evolution, nucleotide and protein compositions, recombination, codon frequency, substitution rate, N- and O-glycosylation sites, signal peptide and cleavage site, transmembrane region, secondary structure of 5' and 3' UTRs and RNA-RNA interactions. Additionally, we have modeled the 3D protease and RNA-dependent RNA polymerase structures for AHFV, KFDV and TBEV. Recombination analysis showed no evidence of recombination in the AHFV genome with that of either KFDV or TBEV, although single break point analysis showed that nucleotide position 7399 (in the NS4B) is a breakpoint location. AHFV, KFDV and TBEV are very similar in terms of codon frequency, the number of transmembrane regions, properties of the polyprotein, RNA-RNA interaction sequences, NS3 protease and NS5 polymerase structures and 5' UTR structure. Using genome sequences, we showed the similarities between these closely- related viruses on several different areas.

  18. Kissing-loop interaction between 5′ and 3′ ends of tick-borne Langat virus genome ‘bridges the gap’ between mosquito- and tick-borne flaviviruses in mechanisms of viral RNA cyclization: applications for virus attenuation and vaccine development

    PubMed Central

    Tsetsarkin, Konstantin A.; Liu, Guangping; Shen, Kui; Pletnev, Alexander G.

    2016-01-01

    Insertion of microRNA target sequences into the flavivirus genome results in selective tissue-specific attenuation and host-range restriction of live attenuated vaccine viruses. However, previous strategies for miRNA-targeting did not incorporate a mechanism to prevent target elimination under miRNA-mediated selective pressure, restricting their use in vaccine development. To overcome this limitation, we developed a new approach for miRNA-targeting of tick-borne flavivirus (Langat virus, LGTV) in the duplicated capsid gene region (DCGR). Genetic stability of viruses with DCGR was ensured by the presence of multiple cis-acting elements within the N-terminal capsid coding region, including the stem-loop structure (5′SL6) at the 3′ end of the promoter. We found that the 5′SL6 functions as a structural scaffold for the conserved hexanucleotide motif at its tip and engages in a complementary interaction with the region present in the 3′ NCR to enhance viral RNA replication. The resulting kissing-loop interaction, common in tick-borne flaviviruses, supports a single pair of cyclization elements (CYC) and functions as a homolog of the second pair of CYC that is present in the majority of mosquito-borne flaviviruses. Placing miRNA targets into the DCGR results in superior attenuation of LGTV in the CNS and does not interfere with development of protective immunity in immunized mice. PMID:26850640

  19. Tick salivary compounds: their role in modulation of host defences and pathogen transmission

    PubMed Central

    Kazimírová, Mária; Štibrániová, Iveta

    2013-01-01

    Ticks require blood meal to complete development and reproduction. Multifunctional tick salivary glands play a pivotal role in tick feeding and transmission of pathogens. Tick salivary molecules injected into the host modulate host defence responses to the benefit of the feeding ticks. To colonize tick organs, tick-borne microorganisms must overcome several barriers, i.e., tick gut membrane, tick immunity, and moulting. Tick-borne pathogens co-evolved with their vectors and hosts and developed molecular adaptations to avoid adverse effects of tick and host defences. Large gaps exist in the knowledge of survival strategies of tick-borne microorganisms and on the molecular mechanisms of tick-host-pathogen interactions. Prior to transmission to a host, the microorganisms penetrate and multiply in tick salivary glands. As soon as the tick is attached to a host, gene expression and production of salivary molecules is upregulated, primarily to facilitate feeding and avoid tick rejection by the host. Pathogens exploit tick salivary molecules for their survival and multiplication in the vector and transmission to and establishment in the hosts. Promotion of pathogen transmission by bioactive molecules in tick saliva was described as saliva-assisted transmission (SAT). SAT candidates comprise compounds with anti-haemostatic, anti-inflammatory and immunomodulatory functions, but the molecular mechanisms by which they mediate pathogen transmission are largely unknown. To date only a few tick salivary molecules associated with specific pathogen transmission have been identified and their functions partially elucidated. Advanced molecular techniques are applied in studying tick-host-pathogen interactions and provide information on expression of vector and pathogen genes during pathogen acquisition, establishment and transmission. Understanding the molecular events on the tick-host-pathogen interface may lead to development of new strategies to control tick-borne diseases. PMID

  20. Two Cases of Severe Tick-Borne Encephalitis in Rituximab-Treated Patients in Germany: Implications for Diagnosis and Prevention.

    PubMed

    Steininger, Philipp A; Bobinger, Tobias; Dietrich, Wenke; Lee, De-Hyung; Knott, Michael; Bogdan, Christian; Korn, Klaus; Lang, Roland

    2017-01-01

    Rituximab (RTX) has become a standard therapy for certain B cell malignancies and autoimmune diseases. We report 2 RTX-treated patients who developed severe tick-borne encephalitis virus (TBEV) infection. The inability to generate new antibody responses renders RTX-treated patients susceptible to TBEV, impedes laboratory diagnosis, and necessitates preventive vaccination in endemic areas.

  1. Full genome sequences and molecular characterization of tick-borne encephalitis virus strains isolated from human patients.

    PubMed

    Formanová, Petra; Černý, Jiří; Bolfíková, Barbora Černá; Valdés, James J; Kozlova, Irina; Dzhioev, Yuri; Růžek, Daniel

    2015-02-01

    Tick-borne encephalitis virus (TBEV) causes tick-borne encephalitis (TBE), one of the most important human neuroinfections across Eurasia. Up to date, only three full genome sequences of human European TBEV isolates are available, mostly due to difficulties with isolation of the virus from human patients. Here we present full genome characterization of an additional five low-passage TBEV strains isolated from human patients with severe forms of TBE. These strains were isolated in 1953 within Central Bohemia in the former Czechoslovakia, and belong to the historically oldest human TBEV isolates in Europe. We demonstrate here that all analyzed isolates are distantly phylogenetically related, indicating that the emergence of TBE in Central Europe was not caused by one predominant strain, but rather a pool of distantly related TBEV strains. Nucleotide identity between individual sequenced TBEV strains ranged from 97.5% to 99.6% and all strains shared large deletions in the 3' non-coding region, which has been recently suggested to be an important determinant of virulence. The number of unique amino acid substitutions varied from 3 to 9 in individual isolates, but no characteristic amino acid substitution typical exclusively for all human TBEV isolates was identified when compared to the isolates from ticks. We did, however, correlate that the exploration of the TBEV envelope glycoprotein by specific antibodies were in close proximity to these unique amino acid substitutions. Taken together, we report here the largest number of patient-derived European TBEV full genome sequences to date and provide a platform for further studies on evolution of TBEV since the first emergence of human TBE in Europe. Copyright © 2014 Elsevier GmbH. All rights reserved.

  2. Differential Antagonism of Human Innate Immune Responses by Tick-Borne Phlebovirus Nonstructural Proteins

    PubMed Central

    Rezelj, Veronica V.; Li, Ping; Chaudhary, Vidyanath; Elliott, Richard M.

    2017-01-01

    ABSTRACT In recent years, several newly discovered tick-borne viruses causing a wide spectrum of diseases in humans have been ascribed to the Phlebovirus genus of the Bunyaviridae family. The nonstructural protein (NSs) of bunyaviruses is the main virulence factor and interferon (IFN) antagonist. We studied the molecular mechanisms of IFN antagonism employed by the NSs proteins of human apathogenic Uukuniemi virus (UUKV) and those of Heartland virus (HRTV) and severe fever with thrombocytopenia syndrome virus (SFTSV), both of which cause severe disease. Using reporter assays, we found that UUKV NSs weakly inhibited the activation of the beta interferon (IFN-β) promoter and response elements. UUKV NSs weakly antagonized human IFN-β promoter activation through a novel interaction with mitochondrial antiviral-signaling protein (MAVS), confirmed by coimmunoprecipitation and confocal microscopy studies. HRTV NSs efficiently antagonized both IFN-β promoter activation and type I IFN signaling pathways through interactions with TBK1, preventing its phosphorylation. HRTV NSs exhibited diffused cytoplasmic localization. This is in comparison to the inclusion bodies formed by SFTSV NSs. HRTV NSs also efficiently interacted with STAT2 and impaired IFN-β-induced phosphorylation but did not affect STAT1 or its translocation to the nucleus. Our results suggest that a weak interaction between STAT1 and HRTV or SFTSV NSs may explain their inability to block type II IFN signaling efficiently, thus enabling the activation of proinflammatory responses that lead to severe disease. Our findings offer insights into how pathogenicity may be linked to the capacity of NSs proteins to block the innate immune system and illustrate the plethora of viral immune evasion strategies utilized by emerging phleboviruses. IMPORTANCE Since 2011, there has been a large expansion in the number of emerging tick-borne viruses that have been assigned to the Phlebovirus genus. Heartland virus (HRTV) and

  3. Identification of Tick Species Collected from Wild Boars and Habitats of Wild Boars and Domestic Pigs in the Republic of Korea.

    PubMed

    Chae, Jeong-Byoung; Kang, Jun-Gu; Kim, Heung-Chul; Chong, Sung-Tae; Lee, In-Yong; Shin, Nam-Shik; Chae, Joon-Seok

    2017-04-01

    Tick is one of the most important arthropods in the transmission of vector-borne diseases. In this study, we investigated the abundance and species of ticks associated with swine and their habitats to assess the risk of spread of tick-borne diseases in host species, such as wild boars. Ticks were collected from 24 grazing or traditionally reared domestic pig farms and 8 habitats of wild boars in 8 provinces and 1 city in the Republic of Korea, by using the dragging and flagging methods. Ticks were also collected directly from 49 wild boars by using fine forceps. A total of 9,846 hard ticks were collected, including 4,977 Haemaphysalis longicornis , 4,313 Haemaphysalis flava , 508 Ixodes nipponensis , 1 Ixodes turdus , and 47 Amblyomma testudinarium . A total of 240 hard ticks were collected from 49 wild boars, including 109 H. flava , 84 H. longicornis , and 47 A. testudinarium . A total of 578 hard ticks were collected from areas around domestic pig farms. Only 2 hard tick species, 546 H. longicornis and 32 H. flava , were collected from these areas. A total of 9,028 hard ticks were collected from wild boars of 8 habitats, including 4,347 H. longicornis , 4,172 H. flava , 508 I. nipponensis , and 1 I. turdus . A. testudinarium was collected only from wild boars, and I. nipponensis and I. turdus were collected only from the habitats of wild boars.

  4. Climate change influences on the potential geographic distribution of the disease vector tick Ixodes ricinus

    PubMed Central

    Peterson, A. Townsend; Samy, Abdallah M.

    2017-01-01

    Background Ixodes ricinus is a species of hard tick that transmits several important diseases in Europe and North Africa, including Lyme borreliosis and tick-borne encephalitis. Climate change is affecting the geographic distributions and abundances of arthropod vectors, which in turn influence the geographic distribution and epidemiology of associated vector-borne diseases. To date, few studies have investigated effects of climate change on the spatial distribution of I. ricinus at continental extents. Here, we assessed the potential distribution of I. ricinus under current and future climate conditions to understand how climate change will influence the geographic distribution of this important tick vector in coming decades. Method We used ecological niche modeling to estimate the geographic distribution of I. ricinus with respect to current climate, and then assessed its future potential distribution under different climate change scenarios. This approach integrates occurrence records of I. ricinus with six relevant environmental variables over a continental extent that includes Europe, North Africa, and the Middle East. Future projections were based on climate data from 17 general circulation models (GCMs) under 2 representative concentration pathway emissions scenarios (RCPs), for the years 2050 and 2070. Result The present and future potential distributions of I. ricinus showed broad overlap across most of western and central Europe, and in more narrow zones in eastern and northern Europe, and North Africa. Potential expansions were observed in northern and eastern Europe. These results indicate that I. ricinus populations could emerge in areas in which they are currently lacking, posing increased risks to human health in those areas. However, the future of I. ricinus ticks in some important regions such the Mediterranean was unclear owing to high uncertainty in model predictions. PMID:29206879

  5. Tick infestation in birds and prevalence of pathogens in ticks collected from different places in Germany.

    PubMed

    Klaus, Christine; Gethmann, Jörn; Hoffmann, Bernd; Ziegler, Ute; Heller, Martin; Beer, Martin

    2016-07-01

    The importance of ticks and tick-borne pathogens for human and animal health has been increasing over the past decades. For their transportation and dissemination, birds may play a more important role than wingless hosts. In this study, tick infestation of birds in Germany was examined. Eight hundred ninety-two captured birds were infested with ticks and belonged to 48 different species, of which blackbirds (Turdus merula) and song thrushes (Turdus philomelos) were most strongly infested. Ground feeders were more strongly infested than non-ground feeders, sedentary birds more strongly than migratory birds, and short-distance migratory birds more strongly than long-distance migratory birds. Mean tick infestation per bird ranged between 2 (long-distance migratory bird) and 4.7 (sedentary bird), in some single cases up to 55 ticks per bird were found. With the exception of three nymphs of Haemaphysalis spp., all ticks belonged to Ixodes spp., the most frequently detected tick species was Ixodes ricinus. Birds were mostly infested by nymphs (65.1 %), followed by larvae (32.96 %). Additionally, ticks collected from birds were examined for several pathogens: Tick-borne encephalitis virus (TBEV) and Sindbisvirus with real-time RT-PCR, Flaviviruses, Simbuviruses and Lyssaviruses with broad-range standard RT-PCR-assays, and Borrelia spp. with a Pan-Borrelia real-time PCR. Interestingly, no viral pathogens could be detected, but Borrelia spp. positive ticks were collected from 76 birds. Borrelia (B.) garinii, B. valaisiaina, B. burgdorferi s.s. and B. afzelii were determined. The screening of ticks and birds for viral pathogens with broad range PCR-assays was tested and the use as an "early warning system" is discussed.

  6. Tick control: trapping, biocontrol, host management and other alternative strategies

    USGS Publications Warehouse

    Ginsberg, Howard S.; Edited by Sonenshine, Daniel E.; Roe, R. Michael

    2014-01-01

    Biology of Ticks is the most comprehensive work on tick biology and tick-borne diseases. This second edition is a multi-authored work, featuring the research and analyses of renowned experts across the globe. Spanning two volumes, the book examines the systematics, biology, structure, ecological adaptations, evolution, genomics and the molecular processes that underpin the growth, development and survival of these important disease-transmitting parasites. Also discussed is the remarkable array of diseases transmitted (or caused) by ticks, as well as modern methods for their control. This book should serve as a modern reference for students, scientists, physicians, veterinarians and other specialists. Volume I covers the biology of the tick and features chapters on tick systematics, tick life cycles, external and internal anatomy, and others dedicated to specific organ systems, specifically, the tick integument, mouthparts and digestive system, salivary glands, waste removal, salivary glands, respiratory system, circulatory system and hemolymph, fat body, the nervous and sensory systems and reproductive systems. Volume II includes chapters on the ecology of non-nidicolous and nidicolous ticks, genetics and genomics (including the genome of the Lyme disease vector Ixodes scapularis) and immunity, including host immune responses to tick feeding and tick-host interactions, as well as the tick's innate immune system that prevents and/or controls microbial infections. Six chapters cover in depth the many diseases caused by the major tick-borne pathogens, including tick-borne protozoa, viruses, rickettsiae of all types, other types of bacteria (e.g., the Lyme disease agent) and diseases related to tick paralytic agents and toxins. The remaining chapters are devoted to tick control using vaccines, acaricides, repellents, biocontrol, and, finally, techniques for breeding ticks in order to develop tick colonies for scientific study.

  7. The presence of tick-borne diseases in domestic dogs and cats living on Iriomote-jima and Tsushima islands

    PubMed Central

    JIKUYA, Mao; TATENO, Morihiro; TAKAHASHI, Masashi; ENDO, Yasuyuki

    2017-01-01

    The Iriomote cat and Tsushima leopard cat are endangered wildcats in Japan and inhabit only Iriomote-jima and Tsushima islands, respectively. Domestic dogs and cats living on Iriomote-jima and Tsushima islands were surveyed to clarify the interrelationship between wildcats and domestic animals regarding tick-borne disease transmission. Pathogen-derived DNA in blood samples was detected by polymerase chain reaction. Babesia gibsoni was detected in dogs of Iriomote-jima, and Hepatozoon felis and hemoplasmas were detected in domestic cats of Tsushima. Because the H. felis detected in this study was closely related to that isolated from wildcats, we suspect that common H. felis is harbored and transmitted among wildcats and domestic cats via ticks in Tsushima. PMID:28484147

  8. The presence of tick-borne diseases in domestic dogs and cats living on Iriomote-jima and Tsushima islands.

    PubMed

    Jikuya, Mao; Tateno, Morihiro; Takahashi, Masashi; Endo, Yasuyuki

    2017-06-29

    The Iriomote cat and Tsushima leopard cat are endangered wildcats in Japan and inhabit only Iriomote-jima and Tsushima islands, respectively. Domestic dogs and cats living on Iriomote-jima and Tsushima islands were surveyed to clarify the interrelationship between wildcats and domestic animals regarding tick-borne disease transmission. Pathogen-derived DNA in blood samples was detected by polymerase chain reaction. Babesia gibsoni was detected in dogs of Iriomote-jima, and Hepatozoon felis and hemoplasmas were detected in domestic cats of Tsushima. Because the H. felis detected in this study was closely related to that isolated from wildcats, we suspect that common H. felis is harbored and transmitted among wildcats and domestic cats via ticks in Tsushima.

  9. A database of human genes and a gene network involved in response to tick-borne encephalitis virus infection.

    PubMed

    Ignatieva, Elena V; Igoshin, Alexander V; Yudin, Nikolay S

    2017-12-28

    Tick-borne encephalitis is caused by the neurotropic, positive-sense RNA virus, tick-borne encephalitis virus (TBEV). TBEV infection can lead to a variety of clinical manifestations ranging from slight fever to severe neurological illness. Very little is known about genetic factors predisposing to severe forms of disease caused by TBEV. The aims of the study were to compile a catalog of human genes involved in response to TBEV infection and to rank genes from the catalog based on the number of neighbors in the network of pairwise interactions involving these genes and TBEV RNA or proteins. Based on manual review and curation of scientific publications a catalog comprising 140 human genes involved in response to TBEV infection was developed. To provide access to data on all genes, the TBEVhostDB web resource ( http://icg.nsc.ru/TBEVHostDB/ ) was created. We reconstructed a network formed by pairwise interactions between TBEV virion itself, viral RNA and viral proteins and 140 genes/proteins from TBEVHostDB. Genes were ranked according to the number of interactions in the network. Two genes/proteins (CCR5 and IFNAR1) that had maximal number of interactions were revealed. It was found that the subnetworks formed by CCR5 and IFNAR1 and their neighbors were a fragments of two key pathways functioning during the course of tick-borne encephalitis: (1) the attenuation of interferon-I signaling pathway by the TBEV NS5 protein that targeted peptidase D; (2) proinflammation and tissue damage pathway triggered by chemokine receptor CCR5 interacting with CD4, CCL3, CCL4, CCL2. Among nine genes associated with severe forms of TBEV infection, three genes/proteins (CCR5, IL10, ARID1B) were found to have protein-protein interactions within the network, and two genes/proteins (IFNL3 and the IL10, that was just mentioned) were up- or down-regulated in response to TBEV infection. Based on this finding, potential mechanisms for participation of CCR5, IL10, ARID1B, and IFNL3 in the host

  10. Records of ticks on humans in Rio Grande do Sul state, Brazil.

    PubMed

    Reck, José; Souza, Ugo; Souza, Getúlio; Kieling, Eduardo; Dall'Agnol, Bruno; Webster, Anelise; Michel, Thais; Doyle, Rovaina; Martins, Thiago F; Labruna, Marcelo B; Marks, Fernanda; Ott, Ricardo; Martins, João Ricardo

    2018-05-18

    More than seventy tick species have been reported in Brazil. Despite the emergence of tick-borne diseases in Neotropical region, there are still limited data available on tick species parasitizing humans in Brazil. Rio Grande do Sul is the southernmost state of Brazil, comprising the only part of Brazilian territory inside the Pampa biome, as well as the transition between subtropical and temperate zones. Here, we report on human parasitism by ticks in Rio Grande do Sul state between 2004 and 2017. Seventy cases of human parasitism by ticks were recorded, with a total of 81 tick specimens collected. These included 11 tick species belonging to three genera of Ixodidae (hard-ticks), Amblyomma, Haemaphysalis and Rhipicephalus; and one genus of Argasidae, Ornithodoros. The most prevalent tick species associated to cases of human parasitism were Amblyomma parkeri (24%), Rhipicephalus sanguineus sensu lato (22%), Amblyomma aureolatum (15%) and Amblyomma ovale (12%). A spatial analysis showed two major hot spots of human parasitism by ticks in Rio Grande do Sul state. The findings of this study highlight the need for permanent monitoring of human parasitism by ticks in order to provide a better understanding of tick and tick-borne disease eco-epidemiology, and the early identification of potential cases of tick-borne diseases, particularly in spotted fever endemic regions. Copyright © 2018 Elsevier GmbH. All rights reserved.

  11. Molecular detection of tick-borne pathogens in cattle from Southwestern Ethiopia.

    PubMed

    Hailemariam, Zerihun; Krücken, Jürgen; Baumann, Maximilian; Ahmed, Jabbar S; Clausen, Peter-Henning; Nijhof, Ard M

    2017-01-01

    Tick-borne diseases (TBDs) cause significant losses among livestock and impact the livelihoods of resource-poor farming communities worldwide. In Ethiopia, detailed studies on the epidemiology of tick-borne pathogens (TBPs) in cattle using sensitive molecular detection methods are scarce. The objective of this study was to determine the prevalence and species composition of bovine TBPs of veterinary significance in local cattle populations. A comprehensive cross-sectional epidemiological study was conducted in cattle populations of Illubabor zone in Southwestern Ethiopia from June to August 2013. For this purpose, blood samples were collected from 392 cattle. A combination of polymerase chain reaction (PCR) and a Reverse Line Blot (RLB) hybridization assay was employed for the detection of TBPs in these samples. The PCR/RLB results of the 392 blood samples indicated a high overall prevalence of 96.9% for TBPs, including Theileria mutans (66.1%), Theileria orientalis (51.8%), Anaplasma sp. Omatjenne (25.5%), Anaplasma marginale (14.5%), Babesia bigemina (14.0%) and Theileria velifera (13.0%) and minor occurrences of Ehrlichia ruminantium (0.5%) and Ehrlichia minasensis (0.26%). Moreover, three novel Anaplasma genotypes were detected in bovine blood samples. A phylogenetic analysis revealed that they most likely represent three, but at least two, new species. The prevalence of the three novel Anaplasma species, preliminary designated as Anaplasma sp. Hadesa, Anaplasma sp. Saso and Anaplasma sp. Dedessa, was 12.5%, 14.3% and 5.6%, respectively. Overall, a total of 227 cattle (57.9%) were found to be co-infected with two or more TBPs simultaneously and 86 different species combinations were observed. The findings show a very high burden of infection of cattle with TBPs in Ethiopia. The high frequency of co-infections suggests that clinical manifestations might be complex. Further research is required to determine the pathogenicity, host cell types and vector of the

  12. Molecular detection of tick-borne pathogens in cattle from Southwestern Ethiopia

    PubMed Central

    Hailemariam, Zerihun; Krücken, Jürgen; Baumann, Maximilian; Ahmed, Jabbar S.; Clausen, Peter-Henning

    2017-01-01

    Tick-borne diseases (TBDs) cause significant losses among livestock and impact the livelihoods of resource-poor farming communities worldwide. In Ethiopia, detailed studies on the epidemiology of tick-borne pathogens (TBPs) in cattle using sensitive molecular detection methods are scarce. The objective of this study was to determine the prevalence and species composition of bovine TBPs of veterinary significance in local cattle populations. A comprehensive cross-sectional epidemiological study was conducted in cattle populations of Illubabor zone in Southwestern Ethiopia from June to August 2013. For this purpose, blood samples were collected from 392 cattle. A combination of polymerase chain reaction (PCR) and a Reverse Line Blot (RLB) hybridization assay was employed for the detection of TBPs in these samples. The PCR/RLB results of the 392 blood samples indicated a high overall prevalence of 96.9% for TBPs, including Theileria mutans (66.1%), Theileria orientalis (51.8%), Anaplasma sp. Omatjenne (25.5%), Anaplasma marginale (14.5%), Babesia bigemina (14.0%) and Theileria velifera (13.0%) and minor occurrences of Ehrlichia ruminantium (0.5%) and Ehrlichia minasensis (0.26%). Moreover, three novel Anaplasma genotypes were detected in bovine blood samples. A phylogenetic analysis revealed that they most likely represent three, but at least two, new species. The prevalence of the three novel Anaplasma species, preliminary designated as Anaplasma sp. Hadesa, Anaplasma sp. Saso and Anaplasma sp. Dedessa, was 12.5%, 14.3% and 5.6%, respectively. Overall, a total of 227 cattle (57.9%) were found to be co-infected with two or more TBPs simultaneously and 86 different species combinations were observed. The findings show a very high burden of infection of cattle with TBPs in Ethiopia. The high frequency of co-infections suggests that clinical manifestations might be complex. Further research is required to determine the pathogenicity, host cell types and vector of the

  13. The prevalence of Anaplasma phagocytophilum in questing Ixodes ricinus ticks in SW Poland.

    PubMed

    Kiewra, Dorota; Zaleśny, Grzegorz; Czułowska, Aleksandra

    2014-01-01

    Ticks constitute important vectors of human and animal pathogens. Besides the Lyme borreliosis and tick-borne encephalitis, other pathogens such as Babesia spp., Rickettsia spp., and Anaplasma phagocytophilum, are of increasing public health interest. In Poland, as in other European countries, Ixodes ricinus, the most prevalent tick species responsible for the majority of tick bites in humans, is the main vector of A. phagocytophilum. The aim of the study was to estimate the infection level of I. ricinus with A. phagocytophilum in selected districts, not previously surveyed for the presence of this agent. Sampling of questing ticks was performed in 12 forested sites, located in four districts (Legnica, Milicz, Lubań, and Oława) in SW Poland. Altogether, 792 ticks (151 females, 101 males, and 540 nymphs) representing I. ricinus were checked for the presence of A. phagocytophilum. The average infection level was 4.3%, with higher rate reported for adult ticks. The highest percentage of infected adults was observed in Milicz (17.4%) and the lowest in Oława (6.8%). The abundance of questing I. ricinus in all examined sites as well as the infection with A. phagocytophilum indicate for the first time the risk for HGA transmission in SW Poland.

  14. [Pain syndromes in tick-borne neuroborreliosis. Clinical aspects and differential diagnosis.].

    PubMed

    Kohler, J; Thoden, U

    1987-09-01

    Tick-borne borreliosis (Borrelia burgdorferi) is a common and complex disorder affecting the skin, the joints and the nervous system. It progresses through different clinical stages. The clinical spectrum of neuroborreliosis has expanded since the introduction and widespread application of specific serological tests. We have investigated 41 patients with Bannwarth's meningopolyneuritis (MPN) as the classical form of neuroborreliosis, in a prospective (26 patients) and a retrospective (15 patients) study. When questioned, 19/41 patients reported a tick bite and only 15/41, erythema migrans as the characteristic early skin lesion. In 34/41 patients typical MPN characterized by painful radiculoneuritis and/or cranial neuritis, especially facial palsy, were seen. Among these, 3 had a complicated form with a progressive remitting relapsing course or focal central nervous system involvement (hemiparesis, cerebellar syndrome); 2 had mild meningitis and facial nerve palsy bilaterally without radicular pain; and in 5 radicular pain was the only symptom. MPN associated with Lyme arthritis was observed only once. In 2 patients in the retrospective study (no antibiotics in the acute stage) we saw a chronic spinal cord disorder with spastic paresis several years after uncomplicated MPN, accompanied in 1 of them by acrodermatitis chronica atrophicans (ACA), the typical late-onset borrelia-induced dermatosis. In the acute stage of the disease 40/41 patients had a cerebrospinal fluid (CSF) syndrome compatible with MPN (mononuclear pleocytosis, blood-brain barrier dysfunction, elevated IgG and/or oligoclonal bands). IgG antibody titers against borrelia antigen were elevated in all patients in the serum and in 21/30 also in the CSF. In all patients pain was an early and prominent symptom; the first symptoms are usually felt in the region of the tick bite or the erythema, initially as diffuse myalgia, arthralgia or pain in the connective tissue. In the further course the migrating

  15. Chemical ecology of tick-host interactions

    USDA-ARS?s Scientific Manuscript database

    Ticks impact the health of livestock and humans world-wide through their roles as pests and vectors of diseases such as heartwater, theileriosis, anaplasmosis, babesiosis, Lyme disease, erhlichiosis, tick-borne encephalitis and Crimean Congo Haemorrhagic fever. Intrinsic to their capacity to serve ...

  16. Distinction between serological responses following tick-borne encephalitis virus (TBEV) infection vs vaccination, Sweden 2017.

    PubMed

    Albinsson, Bo; Vene, Sirkka; Rombo, Lars; Blomberg, Jonas; Lundkvist, Åke; Rönnberg, Bengt

    2018-01-01

    Tick-borne encephalitis virus (TBEV) is an important European vaccine-preventable pathogen. Discrimination of vaccine-induced antibodies from those elicited by infection is important. We studied anti-TBEV IgM/IgG responses, including avidity and neutralisation, by multiplex serology in 50 TBEV patients and 50 TBEV vaccinees. Infection induced antibodies reactive to both whole virus (WV) and non-structural protein 1 (NS1) in 48 clinical cases, whereas 47 TBEV vaccinees had WV, but not NS1 antibodies, enabling efficient discrimination of infection/vaccination.

  17. Ticks collected from humans, domestic animals, and wildlife in Yucatan, Mexico.

    PubMed

    Rodríguez-Vivas, R I; Apanaskevich, D A; Ojeda-Chi, M M; Trinidad-Martínez, I; Reyes-Novelo, E; Esteve-Gassent, M D; Pérez de León, A A

    2016-01-15

    Domestic animals and wildlife play important roles as reservoirs of zoonotic pathogens that are transmitted to humans by ticks. Besides their role as vectors of several classes of microorganisms of veterinary and public health relevance, ticks also burden human and animal populations through their obligate blood-feeding habit. It is estimated that in Mexico there are around 100 tick species belonging to the Ixodidae and Argasidae families. Information is lacking on tick species that affect humans, domestic animals, and wildlife through their life cycle. This study was conducted to bridge that knowledge gap by inventorying tick species that infest humans, domestic animals and wildlife in the State of Yucatan, Mexico. Amblyomma ticks were observed as euryxenous vertebrate parasites because they were found parasitizing 17 animal species and human. Amblyomma mixtum was the most eryxenous species found in 11 different animal species and humans. Both A. mixtum and A. parvum were found parasitizing humans. Ixodes near affinis was the second most abundant species parasitizing six animal species (dogs, cats, horses, white-nosed coati, white-tail deer and black vulture) and was found widely across the State of Yucatan. Ixodid tick populations may increase in the State of Yucatan with time due to animal production intensification, an increasing wildlife population near rural communities because of natural habitat reduction and fragmentation. The diversity of ticks across host taxa documented here highlights the relevance of ecological information to understand tick-host dynamics. This knowledge is critical to inform public health and veterinary programs for the sustainable control of ticks and tick-borne diseases. Copyright © 2015. Published by Elsevier B.V.

  18. Lyme disease risk in southern California: abiotic and environmental drivers of Ixodes pacificus (Acari: Ixodidae) density and infection prevalence with Borrelia burgdorferi.

    PubMed

    MacDonald, Andrew J; Hyon, David W; Brewington, John B; O'Connor, Kerry E; Swei, Andrea; Briggs, Cheryl J

    2017-01-05

    Tick-borne diseases, particularly Lyme disease, are emerging across the northern hemisphere. In order to manage emerging diseases and predict where emergence will likely occur, it is necessary to understand the factors influencing the distribution, abundance and infection prevalence of vector species. In North America, Lyme disease is the most common vector-borne disease and is transmitted by blacklegged ticks. This study aimed to explore the abiotic and environmental drivers of density and infection prevalence of western blacklegged ticks (Ixodes pacificus) in southern California, an understudied and densely populated region of North America. Over the course of this two-year study, densities of I. pacificus adults were consistently positively associated with host availability for juvenile ticks and dense oak woodland habitat. Densities of nymphal and larval I. pacificus, on the other hand were primarily predicted by host availability for juvenile ticks in the first year of the study, and by habitat characteristics such as dense leaf litter in the second year. Infection with the causative agent of Lyme disease, Borrelia burgdorferi (sensu stricto), and related spirochetes was not predicted by the abiotic conditions promoting I. pacificus populations, but rather by diversity of the tick community, and in particular by the presence of two Ixodes tick species that do not generally feed on humans (Ixodes spinipalpis and Ixodes peromysci). Borrelia spp. infection was not detected in the I. pacificus populations sampled, but was detected in other vector species that may maintain enzootic transmission of the pathogen on the landscape. This study identified dense oak woodlands as high-risk habitats for I. pacificus tick encounter in southern California. The shift in relative importance of host availability to habitat characteristics in predicting juvenile tick abundance occurred as California's historic drought intensified, suggesting that habitat providing suitable

  19. An Emerging Tick-Borne Disease of Humans Is Caused by a Subset of Strains with Conserved Genome Structure

    PubMed Central

    Barbet, Anthony F.; Al-Khedery, Basima; Stuen, Snorre; Granquist, Erik G.; Felsheim, Roderick F.; Munderloh, Ulrike G.

    2013-01-01

    The prevalence of tick-borne diseases is increasing worldwide. One such emerging disease is human anaplasmosis. The causative organism, Anaplasma phagocytophilum, is known to infect multiple animal species and cause human fatalities in the U.S., Europe and Asia. Although long known to infect ruminants, it is unclear why there are increasing numbers of human infections. We analyzed the genome sequences of strains infecting humans, animals and ticks from diverse geographic locations. Despite extensive variability amongst these strains, those infecting humans had conserved genome structure including the pfam01617 superfamily that encodes the major, neutralization-sensitive, surface antigen. These data provide potential targets to identify human-infective strains and have significance for understanding the selective pressures that lead to emergence of disease in new species. PMID:25437207

  20. Two Stochastic Phases of Tick-wise Price Fluctuation and the Price Prediction Generator

    NASA Astrophysics Data System (ADS)

    Tanaka-Yamawaki, Mieko; Tokuoka, Seiji

    2007-07-01

    We report in this paper the existence of two different stochastic phases in the tick-wise price fluctuations. Based on this observation, we improve our old method of developing the evolutional strategy to predict the direction of the tick-wise price movements. We obtain a stable predictive power even in the region where the old method had a difficulty.

  1. Tick-borne diseases in North Carolina: is "Rickettsia amblyommii" a possible cause of rickettsiosis reported as Rocky Mountain spotted fever?

    PubMed

    Apperson, Charles S; Engber, Barry; Nicholson, William L; Mead, Daniel G; Engel, Jeffrey; Yabsley, Michael J; Dail, Kathy; Johnson, Joey; Watson, D Wesley

    2008-10-01

    Cases of Rocky Mountain spotted fever (RMSF) in North Carolina have escalated markedly since 2000. In 2005, we identified a county in the Piedmont region with high case numbers of RMSF. We collected ticks and examined them for bacterial pathogens using molecular methods to determine if a novel tick vector or spotted fever group rickettsiae (SFGR) might be emerging. Amblyomma americanum, the lone star tick, comprised 99.6% of 6,502 specimens collected in suburban landscapes. In contrast, Dermacentor variabilis, the American dog tick, a principal vector of Rickettsia rickettsii, comprised < 1% of the ticks collected. Eleven of 25 lone star tick pools tested were infected with "Rickettsia amblyommii," an informally named SFGR. Sera from patients from the same county who were presumptively diagnosed by local physicians with a tick-borne illness were tested by an indirect immunofluorescence antibody (IFA) assay to confirm clinical diagnoses. Three of six patients classified as probable RMSF cases demonstrated a fourfold or greater rise in IgG class antibody titers between paired acute and convalescent sera to "R. amblyommii" antigens, but not to R. rickettsii antigens. White-tailed deer, Odocoileus virginianus, are preferred hosts of lone star ticks. Blood samples collected from hunter-killed deer from the same county were tested by IFA test for antibodies to Ehrlichia chaffeensis and "R. amblyommii." Twenty-eight (87%) of 32 deer were positive for antibodies to E. chaffeensis, but only 1 (3%) of the deer exhibited antibodies to "R. amblyommii," suggesting that deer are not the source of "R. amblyommii" infection for lone star ticks. We propose that some cases of rickettsiosis reported as RMSF may have been caused by "R. amblyommii" transmitted through the bite of A. americanum.

  2. [Genetic characterisation of Powassan virus (POWV) isolated from Haemophysalis longicornis ticks in Primorye and two strains of Tick-borne encephalitis virus (TBEV) (Flaviviridae, Flavivirus): Alma-Arasan virus (AAV) isolated from Ixodes persulcatus ticks in Kazakhstan and Malyshevo virus isolated from Aedes vexans nipponii mosquitoes in Khabarovsk kray].

    PubMed

    L'vov, D K; Al'khovskiĭ, S V; Shchelkanov, M Iu; Deriabin, P G; Gitel'man, A K; Botikov, A G; Aristova, V A

    2014-01-01

    The complete genomes of the three tick-borne flaviviruses (genus Flavivirus, fam. Bunyaviridae) were sequenced: Povassan virus (POWV, strain LEIV-3070Prm, isolated from Haemophysalis logicornis in Primorsky Krai, Russia in 1977), Alma-Arasan virus (AAV, strain LEIV-1380Kaz, isolated from Ixodes persulcatus ticks in Kazakhstan in 1977) and Malyshevo virus (isolated from a pool of Aedes vexans nipponii mosquitoes, in the Khabarovsk Krai, Russia in 1978). It is shown that AAV and Malyshevo virus are the strains of Tick-borne encephalitis virus (TBEV) and belong to Sibirian and Far-Eastern genotypes, respectively (GenBank ID: AAV KJ744033; strain Malyshevo KJ744034). Phylogenetically AAV is closest related (94,6% nt and 98,3% aa identity) to TBEV strains, isolated in Sibiria (Vasilchenko, Aino, Chita-653, Irkutsk-12). Malyshevo virus is closest related (96,4% nt and 98,3% nt identity) to strains of TBEV, isolated in Far Eastern part of Russia (1230, Spassk-72, Primorye-89). POWV LEIV-3070Prm has 99.7% identity with the prototype strain POWV LB, isolated in Canada and 99.5% of isolates with Far-Eastern strains of POWV (Spassk-9 and Nadezdinsk-1991).

  3. Tick-Borne Relapsing Fever Outbreak Among a High School Football Team at an Outdoor Education Camping Trip, Arizona, 2014.

    PubMed

    Jones, Jefferson M; Hranac, Carter R; Schumacher, Mare; Horn, Kim; Lee, Darlene M; Terriquez, Joel; Engelthaler, David M; Peoples, Marie; Corrigan, Jennifer; Replogle, Adam; Souders, Nina; Komatsu, Kenneth K; Nieto, Nathan C

    2016-09-07

    During August 2014, five high school students who had attended an outdoor education camp were hospitalized with a febrile illness, prompting further investigation. Ten total cases of tick-borne relapsing fever (TBRF) were identified-six cases confirmed by culture or visualization of spirochetes on blood smear and four probable cases with compatible symptoms (attack rate: 23%). All patients had slept in the campsite's only cabin. Before the camp, a professional pest control company had rodent proofed the cabin, but no acaricides had been applied. Cabin inspection after the camp found rodents and Ornithodoros ticks, the vector of TBRF. Blood samples from a chipmunk trapped near the cabin and from patients contained Borrelia hermsii with identical gene sequences (100% over 630 base pairs). Health departments in TBRF endemic areas should consider educating cabin owners and pest control companies to apply acaricides during or following rodent proofing, because ticks that lack rodents for a blood meal might feed on humans. © The American Society of Tropical Medicine and Hygiene.

  4. Importance of Common Wall Lizards in the Transmission Dynamics of Tick-Borne Pathogens in the Northern Apennine Mountains, Italy.

    PubMed

    Tomassone, Laura; Ceballos, L A; Ragagli, C; Martello, E; De Sousa, R; Stella, M C; Mannelli, A

    2017-11-01

    During the investigations on ticks and tick-borne pathogens (TBP) range expansion in the Northern Apennines, we captured 107 Podarcis muralis lizards. Sixty-eight animals were infested by immature Ixodes ricinus, Haemaphysalis sulcata and H. punctata. Borrelia burgdorferi s.l. was detected in 3.7% of I. ricinus larvae and 8.0% of nymphs. Together with the species-specific B. lusitaniae, we identified B. garinii, B. afzelii and B. valaisiana. Rickettsia spp. (18.1% larvae, 12.0% nymphs), namely R. monacensis, R. helvetica and R. hoogstraalii, were also found in I. ricinus. R. hoogstraalii was detected in H. sulcata nymphs as well, while the two H. punctata did not harbour any bacteria. One out of 16 lizard tail tissues was positive to R. helvetica. Our results support the hypothesis that lizards are involved in the epidemiological cycles of TBP. The heterogeneity of B. burgdorferi genospecies mirrors previous findings in questing ticks in the area, and their finding in attached I. ricinus larvae suggests that lizards may contribute to the maintenance of different genospecies. The rickettsiae are new findings in the study area, and R. helvetica infection in a tail tissue indicates a systemic infection. R. hoogstraalii is reported for the first time in I. ricinus ticks. Lizards seem to favour the bacterial exchange among different tick species, with possible public health consequences.

  5. Tick-borne bacteria in free-living jaguars (Panthera onca) in Pantanal, Brazil.

    PubMed

    Widmer, Cynthia E; Azevedo, Fernando C C; Almeida, Aliny P; Ferreira, Fernando; Labruna, Marcelo B

    2011-08-01

    Tick-borne bacteria were investigated in 10 free-living jaguars and their ticks in the Pantanal biome, Brazil. Jaguar sera were tested by indirect fluorescent antibody assays using Rickettsia rickettsii, Rickettsia parkeri, Rickettsia amblyommii, Rickettsia rhipicephali, Rickettsia felis, Rickettsia bellii, Ehrlichia canis, and Coxiella burnetii as crude antigens. All 10 jaguar sera reacted (titer ≥ 64) to at least one Rickettsia species; 4 and 3 sera reacted with E. canis and C. burnetii, respectively. One jaguar presented antibody titer to R. parkeri at least fourfold higher than those to any of the other five Rickettsia antigens, suggesting that this animal was infected by R. parkeri. Ticks collected from jaguars included the species Amblyomma cajennense, Amblyomma triste, and Rhipicephalus (Boophilus) microplus. No Rickettsia DNA was detected in jaguar blood samples, but an A. triste specimen collected on a jaguar was shown by PCR to be infected by R. parkeri. The blood of two jaguars and samples of A. triste, A. cajennense, and Amblyomma sp. yielded Ehrlichia DNA by PCR targeting the ehrlichial genes 16S rRNA and dsb. Partial DNA sequences obtained from PCR products resulted in a new ehrlichial strain, here designated as Ehrlichia sp. strain Jaguar. A partial DNA sequence of the 16S rRNA gene of this novel strain showed to be closest (99.0%) to uncultured strains of Ehrlichia sp. from Japan and Russia and 98.7% identical to different strains of Ehrlichia ruminantium. The ehrlichial dsb partial sequence of strain jaguar showed to be at most 80.7% identical to any Ehrlichia species or genotype available in GenBank. Through phylogenetic analysis, Ehrlichia sp. strain jaguar grouped in a cluster, albeit distantly, with different genotypes of E. ruminantium. Results highlight risks for human and animal health, considering that cattle ranching and ecotourism are major economic activities in the Pantanal region of Brazil.

  6. Tick parasites of rodents in Romania: host preferences, community structure and geographical distribution.

    PubMed

    Mihalca, Andrei D; Dumitrache, Mirabela O; Sándor, Attila D; Magdaş, Cristian; Oltean, Miruna; Györke, Adriana; Matei, Ioana A; Ionică, Angela; D'Amico, Gianluca; Cozma, Vasile; Gherman, Călin M

    2012-11-21

    Ticks are among the most important vectors of zoonotic diseases in temperate regions of Europe, with widespread distribution and high densities, posing an important medical risk. Most ticks feed on a variety of progressively larger hosts, with a large number of small mammal species typically harbouring primarily the immature stages. However, there are certain Ixodidae that characteristically attack micromammals also during their adult stage. Rodents are widespread hosts of ticks, important vectors and competent reservoirs of tick-borne pathogens. Micromammal-tick associations have been poorly studied in Romania, and our manuscript shows the results of a large scale study on tick infestation epidemiology in rodents from Romania. Rodents were caught using snap-traps in a variety of habitats in Romania, between May 2010 and November 2011. Ticks were individually collected from these rodents and identified to species and development stage. Frequency, mean intensity, prevalence and its 95% confidence intervals were calculated using the EpiInfo 2000 software. A p value of <0.05 was considered statistically significant. We examined 423 rodents (12 species) collected from six counties in Romania for the presence of ticks. Each collected tick was identified to species level and the following epidemiological parameters were calculated: prevalence, mean intensity and mean abundance. The total number of ticks collected from rodents was 483, with eight species identified: Ixodes ricinus, I. redikorzevi, I. apronophorus, I. trianguliceps, I. laguri, Dermacentor marginatus, Rhipicephalus sanguineus and Haemaphysalis sulcata. The overall prevalence of tick infestation was 29.55%, with a mean intensity of 3.86 and a mean abundance of 1.14. Only two polyspecific infestations were found: I. ricinus + I. redikorzevi and I. ricinus + D. marginatus. Our study showed a relatively high diversity of ticks parasitizing rodents in Romania. The most common tick in rodents was I. ricinus

  7. Tick parasites of rodents in Romania: host preferences, community structure and geographical distribution

    PubMed Central

    2012-01-01

    Background Ticks are among the most important vectors of zoonotic diseases in temperate regions of Europe, with widespread distribution and high densities, posing an important medical risk. Most ticks feed on a variety of progressively larger hosts, with a large number of small mammal species typically harbouring primarily the immature stages. However, there are certain Ixodidae that characteristically attack micromammals also during their adult stage. Rodents are widespread hosts of ticks, important vectors and competent reservoirs of tick-borne pathogens. Micromammal-tick associations have been poorly studied in Romania, and our manuscript shows the results of a large scale study on tick infestation epidemiology in rodents from Romania. Methods Rodents were caught using snap-traps in a variety of habitats in Romania, between May 2010 and November 2011. Ticks were individually collected from these rodents and identified to species and development stage. Frequency, mean intensity, prevalence and its 95% confidence intervals were calculated using the EpiInfo 2000 software. A p value of <0.05 was considered statistically significant. Results We examined 423 rodents (12 species) collected from six counties in Romania for the presence of ticks. Each collected tick was identified to species level and the following epidemiological parameters were calculated: prevalence, mean intensity and mean abundance. The total number of ticks collected from rodents was 483, with eight species identified: Ixodes ricinus, I. redikorzevi, I. apronophorus, I. trianguliceps, I. laguri, Dermacentor marginatus, Rhipicephalus sanguineus and Haemaphysalis sulcata. The overall prevalence of tick infestation was 29.55%, with a mean intensity of 3.86 and a mean abundance of 1.14. Only two polyspecific infestations were found: I. ricinus + I. redikorzevi and I. ricinus + D. marginatus. Conclusions Our study showed a relatively high diversity of ticks parasitizing rodents in Romania. The most

  8. Acarologic risk of exposure to emerging tick-borne bacterial pathogens in a semirural community in northern California.

    PubMed

    Lane, R S; Foley, J E; Eisen, L; Lennette, E T; Peot, M A

    2001-01-01

    An acarologic study was conducted in a semirural community in northern California to determine the relative abundance of, and the prevalence of infection with, three emerging bacterial pathogens in the western black-legged tick (Ixodes pacificus). These included the agents causing Lyme disease (Borrelia burgdorferi), human granulocytic ehrlichiosis [Ehrlichia phagocytophila (formerly Ehrlichia equi)], and human monocytic ehrlichiosis (Ehrlichia chaffeensis). The study area in Sonoma County consisted of two properties each with four residents and an uninhabited adjacent comparison area. Six of the eight residents had been either physician-diagnosed or serodiagnosed previously with Lyme disease, and, of these, one also had been serodiagnosed with human monocytic ehrlichiosis. Direct immunofluorescent/culture assays and bacterial species-specific polymerase chain reaction assays were used to test whole ticks individually for presence of B. burgdorferi and Ehrlichia spp., respectively. Overall, 6.5% of the nymphal (n = 589) and 1.6% of the adult ticks (n = 318) from the same generational cohort were found to contain B. burgdorferi. In contrast, none of 465 nymphs and 9.9% of 202 adults were infected with E. phagocytophila. Excised tissues from another 95 adult ticks yielded a comparable E. phagocytophila infection prevalence of 13.7%. E. chaffeensis was not detected in either nymphal or adult ticks. Using a combination of culture and polymerase chain reaction assays, coinfection of I. pacificus adults with B. burgdorferi and E. phagocytophila was demonstrated for the first time. The marked disparity in the infection prevalence of these pathogens in nymphal and adult ticks suggests that their maintenance cycles are inherently different.

  9. Comparison of Preferred Bite Sites between Mites and Ticks on Humans in Korea

    PubMed Central

    Jang, Mi-Sun; Kim, Choon-Mee; Kim, Dong-Min; Yoon, Na Ra; Han, Mi Ah; Kim, Hyun-Kuk; Oh, Won Sup; Yoon, Hee-Jung; Wie, Seong-Heon; Hur, Jian

    2016-01-01

    Identification of mite and tick bite sites provides important clinical information. The predominant mite species in Korea associated with scrub typhus are Leptotrombidium pallidum and Leptotrombidium scutellare. The most abundant tick species is Haemaphysalis longicornis. To date, there has been no comparative study on preferred bite sites between mites and ticks in humans. This study included a review of medical records and a field study. For mite bite sites, eschars were checked on 506 patients with scrub typhus, confirmed by indirect immunofluorescence assay or nested polymerase chain reaction on the 56-kDa type-specific antigen gene of Orientia tsutsugamushi. Tick bite sites were identified and marked on a diagram for 91 patients who experienced tick bites within the previous year through a field epidemiological investigation. The mite and tick bite sites in Koreans were compared. The most frequently observed mite bite sites were the anterior chest, including the axillae (29.1%) and the abdominal region, including the inguinal area (26.1%). Tick bite sites were most frequent on the lower extremities (33.0%), followed by the abdominal region, including the inguinal area (26.4%), and upper extremities (26.4%). The distribution was significantly different between mite and tick bite sites (P < 0.001). There was a statistically significant difference in the mite bite (P = 0.001), but not tick bite sites (P = 0.985), between men and women. This is the first report on the differences between tick and mite bite sites, and may help clinicians reach a rapid diagnosis of mite- or tick-borne infection. PMID:27645781

  10. Molecular Ecological Insights into Neotropical Bird–Tick Interactions

    PubMed Central

    Esser, Helen J.; Loaiza, Jose R.; Herre, Edward Allen; Aguilar, Celestino; Quintero, Diomedes; Alvarez, Eric; Bermingham, Eldredge

    2016-01-01

    In the tropics, ticks parasitize many classes of vertebrate hosts. However, because many tropical tick species are only identifiable in the adult stage, and these adults usually parasitize mammals, most attention on the ecology of tick-host interactions has focused on mammalian hosts. In contrast, immature Neotropical ticks are often found on wild birds, yet difficulties in identifying immatures hinder studies of birds’ role in tropical tick ecology and tick-borne disease transmission. In Panama, we found immature ticks on 227 out of 3,498 individually–sampled birds representing 93 host species (24% of the bird species sampled, and 13% of the Panamanian land bird fauna). Tick parasitism rates did not vary with rainfall or temperature, but did vary significantly with several host ecological traits. Likewise, Neotropical–Nearctic migratory birds were significantly less likely to be infested than resident species. Using a molecular library developed from morphologically–identified adult ticks specifically for this study, we identified eleven tick species parasitizing birds, indicating that a substantial portion of the Panamanian avian species pool is parasitized by a diversity of tick species. Tick species that most commonly parasitized birds had the widest diversity of avian hosts, suggesting that immature tick species are opportunistic bird parasites. Although certain avian ecological traits are positively associated with parasitism, we found no evidence that individual tick species show specificity to particular avian host ecological traits. Finally, our data suggest that the four principal vectors of Rocky Mountain Spotted Fever in the Neotropics rarely, if ever, parasitize Panamanian birds. However, other tick species that harbor newly–discovered rickettsial parasites of unknown pathogenicity are frequently found on these birds. Given our discovery of broad interaction between Panamanian tick and avian biodiversity, future work on tick ecology and the

  11. Molecular identification of tick-borne pathogens infecting cattle in Mymensingh district of Bangladesh reveals emerging species of Anaplasma and Babesia.

    PubMed

    Roy, B C; Krücken, J; Ahmed, J S; Majumder, S; Baumann, M P; Clausen, P-H; Nijhof, A M

    2018-04-01

    Tick-borne diseases are considered a major hindrance to the health and productive performance of cattle in Bangladesh. To elucidate the epidemiology of tick-borne pathogens (TBPs) in local cattle, a cross-sectional study was performed in the 12 subdistricts (Upazilas) of Mymensingh district in Bangladesh. Blood samples and ticks were collected from 384 clinically healthy cattle kept by 135 farmers from 96 randomly selected villages. DNA extracted from the blood samples was subsequently screened by polymerase chain reaction (PCR) and a Reverse Line Blot (RLB) hybridization assay using an in-house prepared chemiluminescence solution for the presence of Anaplasma, Ehrlichia, Rickettsia, Babesia and Theileria spp. A total of 2,287 ticks were collected from 232 infested cattle (60.4%, 232/384) and identified morphologically as Rhipicephalus (Boophilus) microplus (n = 1,432, 62.6%) and Haemaphysalis bispinosa (n = 855; 37.4%). The RLB results demonstrated that the majority of the cattle (62.2%) were infected with at least one TBP. Theileria orientalis infections were most common (212/384, 55.2%) followed by infections with Anaplasma bovis (137/384, 35.67%), Anaplasma marginale (16/384, 4.17%), Babesia bigemina (4/384, 1.04%) and Babesia bovis (2/384, 0.52%). A previously uncharacterized Anaplasma sp. (Anaplasma sp. Mymensingh) and Babesia sp. (Babesia sp. Mymensingh), which are genetically closely related to Anaplasma platys and B. bigemina, were detected in 50 of 384 (13.0%) and 1 of 384 (0.3%) of the blood samples, respectively. Key risk factors for the occurrence of T. orientalis, A. marginale and Anaplasma sp. Mymensingh were identified. In conclusion, this study revealed that cattle in Mymensingh district are mainly infested with R. microplus and H. bispinosa ticks and may carry multiple TBPs. In addition, two previously uncharacterized pathogens were detected in the bovine blood samples. The pathogenicity of these species remains to be determined. © 2017

  12. Heterogeneity of 3’-Untraslated Region of Genome RNA of the Tick-Borne Encephalitis Virus (TBEV) Strains Isolated from Ticks in the Western Siberia, Russia

    PubMed Central

    Morozova, Olga V.; Bakhvalova, Valentina N.; Morozov, Igor V.

    2007-01-01

    The tick-borne encephalitis virus (TBEV) strains have been isolated from unfed adult ticks Ixodes persulcatus Schulze in Novosibirsk region (South-Western Siberia, Russia) beginning from 1980 till 2006. The TBEV 3’-untraslated region (3’UTR) variable fragment was amplified with primers corresponding to conserved flanking areas. The RT-PCR product lengths varied in range from 100 to 400 bp. Comparative analysis of 3’UTR nucleotide sequences revealed a few groups of the TBEV strains within Siberian genetic subtype with significant intra-group homology and essential differences between groups. Correlation between lengths of the 3’UTR fragments and hemagglutination (HA) titers for subsequent passages of the TBEV strains was not found. However, for the viral strains with shorter 3’UTR (less than 200 nucleotides) incubation period for suckling mice was longer than 5 days. It might be resulted from decreased RNA synthesis or reduced neuroinvasiveness. PMID:23675045

  13. Importation of exotic ticks and tick-borne spotted fever group rickettsiae into the United States by migrating songbirds.

    PubMed

    Mukherjee, Nabanita; Beati, Lorenza; Sellers, Michael; Burton, Laquita; Adamson, Steven; Robbins, Richard G; Moore, Frank; Karim, Shahid

    2014-03-01

    Birds are capable of carrying ticks and, consequently, tick-transmitted microorganisms over long distances and across geographical barriers such as oceans and deserts. Ticks are hosts for several species of spotted fever group rickettsiae (SFGR), which can be transmitted to vertebrates during blood meals. In this study, the prevalence of this group of rickettsiae was examined in ticks infesting migratory songbirds by using polymerase chain reaction (PCR). During the 2009 and 2010 spring migration season, 2064 northward-migrating passerine songbirds were examined for ticks at Johnson Bayou, Louisiana. A total of 91 ticks was removed from 35 individual songbirds for tick species identification and spotted fever group rickettsia detection. Ticks were identified as Haemaphysalis juxtakochi (n=38, 42%), Amblyomma longirostre (n=22, 24%), Amblyomma nodosum (n=17, 19%), Amblyomma calcaratum (n=11, 12%), Amblyomma maculatum (n=2, 2%), and Haemaphysalis leporispalustris (n=1, 1%) by comparing their 12S rDNA gene sequence to homologous sequences in GenBank. Most of the identified ticks were exotic species originating outside of the United States. The phylogenetic analysis of the 71 ompA gene sequences of the rickettsial strains detected in the ticks revealed the occurrence of 6 distinct rickettsial genotypes. Two genotypes (corresponding to a total of 28 samples) were included in the Candidatus Rickettsia amblyommii clade (less than 1% divergence), 2 of them (corresponding to a total of 14 samples) clustered with Rickettsia sp. "Argentina" with less than 0.2% sequence divergence, and 2 of them (corresponding to a total of 27 samples), although closely related to the R. parkeri-R. africae lineage (2.50-3.41% divergence), exhibited sufficient genetic divergence from its members to possibly constitute a new rickettsial genotype. Overall, there does not seem to be a specific relationship between exotic tick species, the rickettsiae they harbor, or the reservoir competence of the

  14. Vector-Borne Diseases in Stray Dogs in Peninsular Malaysia and Molecular Detection of Anaplasma and Ehrlichia spp. from Rhipicephalus sanguineus (Acari: Ixodidae) Ticks.

    PubMed

    Koh, Fui Xian; Panchadcharam, Chandrawathani; Tay, Sun Tee

    2016-01-01

    Little data are available on the prevalence and transmission of vector-borne diseases in stray dogs in Peninsular Malaysia. This study was designed to determine the occurrence of vector-borne pathogens in Malaysian stray dogs using serological and molecular approaches. In total, 48 dog blood samples were subjected to serological analysis using SNAP 4Dx kit (IDEXX Laboratories, Westbrook, ME). The presence of Ehrlichia and Anaplasma DNA in the dog blood samples and Rhipicephalus sanguineus (Latreille) ticks was detected using nested polymerase chain reaction assays. Positive serological findings against Ehrlichia canis and Anaplasma phagocytophilum were obtained in 17 (39.5%) and four (9.3%) of 43 dog samples, respectively. None of the dog blood samples were positive for Borrelia burgdorferi and Dirofilaria immitis. DNA of E. canis and A. phagocytophilum was detected in 12 (25.5%) and two (4.3%) of 47 dog blood samples, and 17 (51.5%) and one (3.0%) of 33 R. sanguineus ticks, respectively. Additionally, DNA of Ehrlichia spp. closely related to Ehrlichia chaffeensis was detected in two (6.1%) R. sanguineus ticks. This study highlights the prevalence of anaplasmosis and ehrlichiosis in dogs in Malaysia. Due to the zoonotic potential of Ehrlichia and Anaplasma spp., appropriate measures should be instituted for prevention and control of vector-borne diseases in dogs. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  15. Laboratory aspects of tick-borne diseases: lyme, human granulocytic ehrlichiosis and babesiosis.

    PubMed

    Aguero-Rosenfeld, Marie E

    2003-05-01

    Lyme disease, human granulocytic ehrlichiosis (HGE) and babesiosis are emerging infections in the northeastern and midwestern United States, where Ixodes scapularis ticks are prevalent. Lyme disease and babesiosis have also been reported on the West Coast, but less frequently. Lyme disease presents frequently with a skin lesion known as erythema migrans (EM), and diagnostic tests are not necessary if the lesion is classical. Those patients presenting without EM or with atypical skin lesions may need laboratory confirmation. The most frequently used laboratory modality consists of the 2-step serological assays, employing a sensitive ELISA as a first step, followed by IgG and/or IgM immunoblots. Current guidelines for interpretation are those recommended by the CDC. HGE and babesiosis are febrile illnesses with non-specific signs and symptoms. Both infections may present with routine laboratory abnormalities, including leukopenia and/or thrombocytopenia in HGE and anemia in babesiosis. Moderate elevations of liver enzymes may occur in all three tick-borne infections. Specific diagnostic modalities for acute-phase HGE include buffy coat smear examination, culture and PCR. Culture appears to have the greatest sensitivity of the three tests. Babesiosis can be diagnosed by peripheral blood examination for the intraerythrocytic parasites, PCR or serology. Co-infections with these agents exist, but they should be documented by detection of the organisms rather than by serology, since seroprevalence rates are high in endemic areas.

  16. Development of a tick-borne pathogen QPCR panel for detection of Anaplasma, Ehrlichia, Rickettsia, and Lyme disease Borrelia in animals.

    PubMed

    Shen, Zhenyu; Zhang, Michael Z; Stich, Roger W; Mitchell, William J; Zhang, Shuping

    2018-05-23

    Anaplasma spp., Ehrlichia spp., Rickettsia spp., and Lyme disease associated Borrelia spp. are the most common tick-borne pathogens reported to infect human beings worldwide and other animals, such as dogs and horses. In the present study, we developed a broad-coverage SYBR Green QPCR panel consisting of four individual assays for the detection and partial differentiation of the aforementioned pathogens. All assays were optimized to the same thermocycling condition and had a detection limit of 10 copies per reaction. The assays remained sensitive when used to test canine and equine blood DNA samples spiked with known amounts of synthetic DNA (gBlock) control template. The assays were specific, as evidenced by lack of cross reaction to non-target gBlock or other pathogens commonly tested in veterinary diagnostic labs. With appropriate Ct cutoff values for positive samples and negative controls and the melting temperature (TM) ranges established in the present study, the QPCR panel is suitable for accurate, convenient and rapid screening and confirmation of tick-borne pathogens in animals. Copyright © 2017. Published by Elsevier B.V.

  17. Biosurveillance in Central Asia: Successes and Challenges of Tick-Borne Disease Research in Kazakhstan and Kyrgyzstan.

    PubMed

    Hay, John; Yeh, Kenneth B; Dasgupta, Debanjana; Shapieva, Zhanna; Omasheva, Gulnara; Deryabin, Pavel; Nurmakhanov, Talgat; Ayazbayev, Timur; Andryushchenko, Alexei; Zhunushov, Asankadyr; Hewson, Roger; Farris, Christina M; Richards, Allen L

    2016-01-01

    Central Asia is a vast geographic region that includes five former Soviet Union republics: Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan. The region has a unique infectious disease burden, and a history that includes Silk Road trade routes and networks that were part of the anti-plague and biowarfare programs in the former Soviet Union. Post-Soviet Union biosurveillance research in this unique area of the world has met with several challenges, including lack of funding and resources to independently conduct hypothesis driven, peer-review quality research. Strides have been made, however, to increase scientific engagement and capability. Kazakhstan and Kyrgyzstan are examples of countries where biosurveillance research has been successfully conducted, particularly with respect to especially dangerous pathogens. In this review, we describe in detail the successes, challenges, and opportunities of conducting biosurveillance in Central Asia as exemplified by our recent research activities on ticks and tick-borne diseases in Kazakhstan and Kyrgyzstan.

  18. Biosurveillance in Central Asia: Successes and Challenges of Tick-Borne Disease Research in Kazakhstan and Kyrgyzstan

    PubMed Central

    Hay, John; Yeh, Kenneth B.; Dasgupta, Debanjana; Shapieva, Zhanna; Omasheva, Gulnara; Deryabin, Pavel; Nurmakhanov, Talgat; Ayazbayev, Timur; Andryushchenko, Alexei; Zhunushov, Asankadyr; Hewson, Roger; Farris, Christina M.; Richards, Allen L.

    2016-01-01

    Central Asia is a vast geographic region that includes five former Soviet Union republics: Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan. The region has a unique infectious disease burden, and a history that includes Silk Road trade routes and networks that were part of the anti-plague and biowarfare programs in the former Soviet Union. Post-Soviet Union biosurveillance research in this unique area of the world has met with several challenges, including lack of funding and resources to independently conduct hypothesis driven, peer-review quality research. Strides have been made, however, to increase scientific engagement and capability. Kazakhstan and Kyrgyzstan are examples of countries where biosurveillance research has been successfully conducted, particularly with respect to especially dangerous pathogens. In this review, we describe in detail the successes, challenges, and opportunities of conducting biosurveillance in Central Asia as exemplified by our recent research activities on ticks and tick-borne diseases in Kazakhstan and Kyrgyzstan. PMID:26870722

  19. Molecular and serological detection of tick-borne pathogens in donkeys (Equus asinus) in Italy.

    PubMed

    Veronesi, Fabrizia; Morganti, Giulia; Ravagnan, Silvia; Laus, Fulvio; Spaterna, Andrea; Diaferia, Manuela; Moretti, Annabella; Fioretti, Daniela Piergili; Capelli, Gioia

    2014-10-10

    Donkeys, owing to the frequent outdoor activity, are exposed to a high risk of infection with tick-borne pathogens. This work aimed to detect exposure to Theileria equi, Babesia caballi, Anaplasma phagocytophilum and Borrelia burgdorferi s.l. of donkeys reared in Central Italy. For this purpose 122 adult donkeys were selected within 11 herds and submitted to blood collection. IgG antibodies to T. equi, B. caballi, A. phagocytophilum and B. burgdorferi s.l. were detected by IFAT. Conventional PCRs targeting the genes MSP2 and the flagellin were used for the detection of A. phagocytophilum and B. burgdorferi s.l. respectively and a Real Time PCR Sybr Green was used to detect Babesia/Theileria spp…. The species identity was determined by amplicons sequencing. Forty eight (39.3%) and 58 (47.5%) animals tested positive for T. equi and B. caballi antibodies, respectively; nine animals (7.4%) were found positive for antibodies against A. phagocytophilum whereas negative results were obtained for B. burgdorferi s.l. Twenty-six (21.3%) animals showed antibodies for both T. equi and B. caballi. Twenty-three (18.8%) donkeys were positive to Babesia/Theileria spp. PCR assay. Out of 21 sequenced amplicons, 20 were identified as T. equi, belonging to three main groups designated A, B and D and one as B. caballi group A. Neither A. phagocytophilum nor B. burgdorferi PCR results were positive. The study showed a high exposure of donkeys to tick-borne pathogens and provides information on the genetic identity of the T. equi strains circulating in Central Italy. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Historical review and insights on the livestock tick-borne disease research of a developing country: The Philippine scenario.

    PubMed

    Ybañez, Adrian P; Mingala, Claro N; Ybañez, Rochelle Haidee D

    2018-04-01

    Tick-borne diseases (TBDs) remain to be a global animal health threat. Developing countries like the Philippines is not exempt to this. Despite the potential impact TBDs can give to these countries, local government initiatives and researches remain to be limited. In the Philippines, most epidemiological studies were confined only to specific areas, and predominantly in the Northern Area. Due to its unique geography and limited studies, the current nationwide status of most TBDs could not be clearly established. This review mainly covered published studies and presented challenges in the conduct of TBD research in the Philippines, which may be similar to other Southeast Asian or developing countries. To date, reported livestock TBD pathogens in the Philippines include Anaplasma, Babesia, Theileria, and Mycoplasma spp. With the ubiquitous presence of the Rhipicephalus microplus ticks in the country, it is highly probable that other pathogens transmitted by these vectors could be present. Despite studies on different TBDs in the livestock sector, the Philippine government has not yet heightened its efforts to implement tick control measures as part of the routine animal health program for local farmers. Further studies might be needed to determine the nationwide prevalence of TBDs and the presence of other possible tick species and TBD pathogens. The Philippine scenario may present situations that are similar to other developing countries. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. A cross-sectional study of small mammals for tick-borne pathogen infection in northern Mongolia.

    PubMed

    Pulscher, Laura A; Moore, Thomas C; Caddell, Luke; Sukhbaatar, Lkhagvatseren; von Fricken, Michael E; Anderson, Benjamin D; Gonchigoo, Battsetseg; Gray, Gregory C

    2018-01-01

    Background : Tick-borne pathogens (TBPs) are frequently studied in developed nations but are often neglected in emerging countries. In Mongolia, TBP research is especially sparse, with few research reports focusing upon human and domestic animal disease and tick ecology. However, little information exists on TBPs in small mammals. Methods : In this 2016 cross-sectional pilot study, we sought to uniquely study wildlife for TBPs. We live-trapped small mammals, and tested their whole blood, serum and ear biopsy samples for molecular or serological evidence of Borrelia spp., Rickettsia spp., and Anaplasma spp. /Ehrlichia spp. Results : Of 64 small mammals collected, 56.0%, 39.0% and 0.0% of animals were positive by molecular assays for Borrelia spp., Rickettsia spp., and Anaplasma spp. /Erhlicia spp., respectively. 41.9% were seropositive for A. phagocytophilum and 24.2% of animals were seropositive for Rickettsia rickettsii . Conclusion : This pilot data demonstrates evidence of a number of TBPs among small mammal populations in northern Mongolia and suggests the need to further investigate what role these mammals play in human and domestic animal disease.

  2. Managing Japanese barberry (Ranunculales: Berberidaceae) infestations reduces blacklegged tick (Acari: Ixodidae) abundance and infection prevalence with Borrelia burgdorferi (Spirochaetales: Spirochaetaceae).

    PubMed

    Williams, Scott C; Ward, Jeffrey S; Worthley, Thomas E; Stafford, Kirby C

    2009-08-01

    In many Connecticut forests with an overabundance of white-tailed deer (Odocoileus virginianus Zimmermann), Japanese barberry (Berberis thunbergii DC) has become the dominant understory shrub, which may provide a habitat favorable to blacklegged tick (Ixodes scapularis Say) and white-footed mouse (Peromyscus leucopus Rafinesque) survival. To determine mouse and larval tick abundances at three replicate sites over 2 yr, mice were trapped in unmanipulated dense barberry infestations, areas where barberry was controlled, and areas where barberry was absent. The number of feeding larval ticks/mouse was recorded. Adult and nymphal ticks were sampled along 200-m draglines in each treatment, retained, and were tested for Borrelia burgdorferi (Johnson, Schmid, Hyde, Steigerwalt, and Brenner) presence. Total first-captured mouse counts did not differ between treatments. Mean number of feeding larval ticks per mouse was highest on mice captured in dense barberry. Adult tick densities in dense barberry were higher than in both controlled barberry and no barberry areas. Ticks sampled from full barberry infestations and controlled barberry areas had similar infection prevalence with B. burgdorferi the first year. In areas where barberry was controlled, infection prevalence was reduced to equal that of no barberry areas the second year of the study. Results indicate that managing Japanese barberry will have a positive effect on public health by reducing the number of B. burgdorferi-infected blacklegged ticks that can develop into motile life stages that commonly feed on humans.

  3. Crimean-Congo Hemorrhagic Fever Virus: Genetic Analysis and Tick Survey in Turkey

    PubMed Central

    Tonbak, Sukru; Aktas, Munir; Altay, Kursat; Azkur, Ahmet K.; Kalkan, Ahmet; Bolat, Yusuf; Dumanli, Nazir; Ozdarendeli, Aykut

    2006-01-01

    Crimean-Congo hemorrhagic fever virus (CCHFV) is a tick-borne virus in the family Bunyaviridae, genus Nairovirus. The virus is transmitted to humans through infected tick bites or from direct contact with viremic animals or humans. In the present study, a total of 1,015 adult ticks were collected from cattle (603 specimens), sheep (17 specimens), and goats (395 specimens) in the Kelkit Valley in Turkey. Four tick species were recognized on the animals in the surveyed region. The most abundant species were Rhipicephalus bursa and Hyalomma marginatum marginatum, at 47.68% (484/1,015) and 46.40% (471/1,015), respectively. Reverse transcriptase PCR was used to recover partial sequences of the CCHFV small (S) genome segment. The presence of CCHFV was determined in 3 of 33 (9.09%) R. bursa pools and in 1 of 31 (3.22%) H. m. marginatum pools. Virus sequences from R. bursa were extremely different from those of the Greek CCHFV strain (U04958) isolated from an R. bursa tick. Phylogenetic analysis indicated that the CCHFV isolates obtained in this study clustered in group 5, whose range encompasses southwestern Russian and Kosovo. This is the first evidence of CCHFV in ticks from Turkey. Even though Hyalomma is the main vector for CCHFV, R. bursa may play a role in CCHFV transmission. PMID:17088370

  4. The Tick Cell Biobank: A global resource for in vitro research on ticks, other arthropods and the pathogens they transmit.

    PubMed

    Bell-Sakyi, Lesley; Darby, Alistair; Baylis, Matthew; Makepeace, Benjamin L

    2018-05-31

    Tick cell lines are increasingly used in many fields of tick and tick-borne disease research. The Tick Cell Biobank was established in 2009 to facilitate the development and uptake of these unique and valuable resources. As well as serving as a repository for existing and new ixodid and argasid tick cell lines, the Tick Cell Biobank supplies cell lines and training in their maintenance to scientists worldwide and generates novel cultures from tick species not already represented in the collection. Now part of the Institute of Infection and Global Health at the University of Liverpool, the Tick Cell Biobank has embarked on a new phase of activity particularly targeted at research on problems caused by ticks, other arthropods and the diseases they transmit in less-developed, lower- and middle-income countries. We are carrying out genotypic and phenotypic characterisation of selected cell lines derived from tropical tick species. We continue to expand the culture collection, currently comprising 63 cell lines derived from 18 ixodid and argasid tick species and one each from the sand fly Lutzomyia longipalpis and the biting midge Culicoides sonorensis, and are actively engaging with collaborators to obtain starting material for primary cell cultures from other midge species, mites, tsetse flies and bees. Outposts of the Tick Cell Biobank will be set up in Malaysia, Kenya and Brazil to facilitate uptake and exploitation of cell lines and associated training by scientists in these and neighbouring countries. Thus the Tick Cell Biobank will continue to underpin many areas of global research into biology and control of ticks, other arthropods and vector-borne viral, bacterial and protozoan pathogens. Copyright © 2018 The Authors. Published by Elsevier GmbH.. All rights reserved.

  5. Influence of microhabitat use and behavior of Amblyomma sculptum and Amblyomma dubitatum nymphs (Acari: Ixodidae) on human risk for tick exposure, with notes on Rickettsia infection.

    PubMed

    Pajuaba Neto, Adalberto Albuquerque; Ramos, Vanessa do Nascimento; Martins, Maria Marlene; Osava, Carolina Fonseca; Pascoal, Jamile de Oliveira; Suzin, Adriane; Yokosawa, Jonny; Szabó, Matias Pablo Juan

    2018-01-01

    Brazilian spotted fever (BSF) is a potentially lethal human disease caused by Rickettsia rickettsii transmitted by ticks, including Amblyomma sculptum. However, in Southeast Brazil, where most BSF cases occur, capybaras are key hosts for both A. sculptum and Amblyomma dubitatum. We therefore compared the risk of human exposure to these ticks at a non-endemic anthropogenic site in Southeast Brazil where both tick species are maintained by capybaras and occur at high abundance. Cloth dragging, human baits and CO 2 traps were used to assess tick abundance and risk for human exposure. The two tick species displayed profound differences in behavior and microhabitat use. Notably, A. sculptum but not A. dubitatum quested for hosts openly from vegetation (ambush behavior) and infested human baits. Furthermore, A. dubitatum was more aggregated at a specific site whereas A. sculptum was more widespread along differing and drier microhabitats. Adults and nymphs of both species were infected with Rickettsia bellii. Overall, the results indicate that even though both species co-existed in the same area, A. sculptum posed a greater risk for biting humans and thus also for transmitting tick-borne pathogens. Copyright © 2017 Elsevier GmbH. All rights reserved.

  6. Changes in Black-legged Tick Population in New England with Future Climate Change

    NASA Astrophysics Data System (ADS)

    Krishnan, S.; Huber, M.

    2015-12-01

    Lyme disease is one of the most frequently reported vector-borne diseases in the United States. In the Northeastern United States, vector transmission is maintained in a horizontal transmission cycle between the vector, the black-legged ticks, and the vertebrate reservoir hosts, which include white-tailed deer, rodents and other medium to large sized mammals. Predicting how vector populations change with future climate change is critical to understanding disease spread in the future, and for developing suitable regional adaptation strategies. For the United States, these predictions have mostly been made using regressions based on field and lab studies, or using spatial suitability studies. However, the relation between tick populations at various life-cycle stages and climate variables are complex, necessitating a mechanistic approach. In this study, we present a framework for driving a mechanistic tick population model with high-resolution regional climate modeling projections. The goal is to estimate changes in black-legged tick populations in New England for the 21st century. The tick population model used is based on the mechanistic approach of Ogden et al., (2005) developed for Canada. Dynamically downscaled climate projections at a 3-kms resolution using the Weather and Research Forecasting Model (WRF) are used to drive the tick population model.

  7. Prevalence of tick-borne encephalitis virus (TBEV) in samples of raw milk taken randomly from cows, goats and sheep in eastern Poland.

    PubMed

    Cisak, Ewa; Wójcik-Fatla, Angelina; Zając, Violetta; Sroka, Jacek; Buczek, Alicja; Dutkiewicz, Jacek

    2010-01-01

    A total of 119 unpasteurized milk samples taken from 63 cows, 29 goats and 27 sheep bred on 8 farms situated on the territory of the Lublin province (eastern Poland), an area of risk of tick-borne encephalitis (TBE), were examined for the presence of RNA of tick-borne encephalitis virus (TBEV) by the nested RT-PCR method. Milk samples were also tested for the presence of anti-TBEV antibodies by ELISA test. By RT-PCR, the greatest prevalence of TBE virus was found in the milk of sheep (22.2%), followed by milk of goats (20.7%) and cows (11.1%). By ELISA, the greatest prevalence of anti- TBEV antibodies was found also in the milk of sheep (14.8%), followed by milk of cows (3.2%) and goats (0%). The results suggest a potential risk of infection with TBEV by drinking raw milk on endemic areas of TBE, and indicate a need for milk pasteurization before consumption.

  8. [Activating effect of cyclophosphane at late stages of persistence of the tick-borne encephalitis virus].

    PubMed

    Frolova, T V; Pogodina, V V; Larina, G I; Frolova, M P; Karmysheva, V Ia

    1982-01-01

    Conditions of activation of persistent infection caused by subcutaneous inoculation of Syrian hamsters with the B-383 and Vasilchenko strains of tick-borne encephalitis virus (TBE) were studied. After 2 administrations of cyclophosphane (CP) on day 170 of infection clinically manifest disease developed in some animals with increasingly severe pathomorphological lesions in the CNS. Several variants of activated TBE virus were isolated from brains and spleens of CP-treated hamsters. The activation of persistent infection was observed in the presence of marked decreased of humoral immunity level, weight of the thymus, and values of spontaneous rosette-formation.

  9. Evidence of Powassan/deer tick virus in adult black-legged ticks (Ixodes scapularis) recovered from hunter-harvested white-tailed deer (Odocoileus virginianus) in Pennsylvania: A public health perspective.

    PubMed

    Campagnolo, E R; Tewari, D; Farone, T S; Livengood, J L; Mason, K L

    2018-04-29

    Studies reporting tick infection rates for Powassan virus (POWV), an emerging zoonotic arthropod-borne pathogen responsible for POWV disease in the Commonwealth of Pennsylvania, are limited. To determine the presence and ascertain a statewide prevalence of POWV, ticks were collected from 9,912 hunter-harvested white-tailed deer (Odocoileus virginianus) heads presented to six regional Pennsylvania Game Commission Chronic Wasting Disease sampling stations in early December of 2013, 2014 and 2015. Of the 2,973 ticks recovered, 1,990 (66.9%) were identified as adult Ixodes scapularis (black-legged tick). The 1,990 I. scapularis ticks were PCR-tested for the presence of POWV. The ticks had a statewide Powassan/deer tick virus infection rate of 0.05%, providing evidence of this pathogen in Pennsylvania's adult I. scapularis ticks and supporting the need for more comprehensive pathogen prevalence assessment strategies, as well as increased public health awareness for this emerging zoonotic arthropod-borne pathogen of public health concern. © 2018 Blackwell Verlag GmbH.

  10. The Essential Role of Tick Salivary Glands and Saliva in Tick Feeding and Pathogen Transmission.

    PubMed

    Šimo, Ladislav; Kazimirova, Maria; Richardson, Jennifer; Bonnet, Sarah I

    2017-01-01

    As long-term pool feeders, ticks have developed myriad strategies to remain discreetly but solidly attached to their hosts for the duration of their blood meal. The critical biological material that dampens host defenses and facilitates the flow of blood-thus assuring adequate feeding-is tick saliva. Saliva exhibits cytolytic, vasodilator, anticoagulant, anti-inflammatory, and immunosuppressive activity. This essential fluid is secreted by the salivary glands, which also mediate several other biological functions, including secretion of cement and hygroscopic components, as well as the watery component of blood as regards hard ticks. When salivary glands are invaded by tick-borne pathogens, pathogens may be transmitted via saliva, which is injected alternately with blood uptake during the tick bite. Both salivary glands and saliva thus play a key role in transmission of pathogenic microorganisms to vertebrate hosts. During their long co-evolution with ticks and vertebrate hosts, microorganisms have indeed developed various strategies to exploit tick salivary molecules to ensure both acquisition by ticks and transmission, local infection and systemic dissemination within the vertebrate host.

  11. The Essential Role of Tick Salivary Glands and Saliva in Tick Feeding and Pathogen Transmission

    PubMed Central

    Šimo, Ladislav; Kazimirova, Maria; Richardson, Jennifer; Bonnet, Sarah I.

    2017-01-01

    As long-term pool feeders, ticks have developed myriad strategies to remain discreetly but solidly attached to their hosts for the duration of their blood meal. The critical biological material that dampens host defenses and facilitates the flow of blood—thus assuring adequate feeding—is tick saliva. Saliva exhibits cytolytic, vasodilator, anticoagulant, anti-inflammatory, and immunosuppressive activity. This essential fluid is secreted by the salivary glands, which also mediate several other biological functions, including secretion of cement and hygroscopic components, as well as the watery component of blood as regards hard ticks. When salivary glands are invaded by tick-borne pathogens, pathogens may be transmitted via saliva, which is injected alternately with blood uptake during the tick bite. Both salivary glands and saliva thus play a key role in transmission of pathogenic microorganisms to vertebrate hosts. During their long co-evolution with ticks and vertebrate hosts, microorganisms have indeed developed various strategies to exploit tick salivary molecules to ensure both acquisition by ticks and transmission, local infection and systemic dissemination within the vertebrate host. PMID:28690983

  12. [Streptomycin--an activator of persisting tick-borne encephalitis virus].

    PubMed

    Malenko, G V; Pogodina, V V; Karmysheva, V Ia

    1984-01-01

    The effect of streptomycin (C) on persistence of tick-borne encephalitis (TBE) virus in Syrian hamsters infected with 3 strains of the virus (41/65, Aina/1448, Vasilchenko ) intracerebrally or subcutaneously was studied. In the animals not given C the infectious virus could be detected in the brain for 8-14 days but not later although their organs (mostly brains and spleens) contained the hemagglutinating antigen and viral antigen detectable by immunofluorescence. Intramuscularly C was given twice daily for 13-35 days in a daily dose of 200 mg/kg. The C-treated hamsters yielded 7 virulent TBE virus strains: 3 from the brain, 3 from the spleen, and one from the blood. No virus could be isolated from the liver, kidneys, or lungs despite the use of various methods for isolation including tissue explantation. The activating effect of C was observed against the background of 4-fold decrease in the titre of complement-fixing and antihemagglutinating antibodies. C exerted its activating effect both at early (70 days) and late (9 months) stages of TBE virus persistence. The activating effect of C appears to be due to its immunosuppressive properties and neurotoxic action on the CNS.

  13. Detection of West Nile virus and tick-borne encephalitis virus in birds in Slovakia, using a universal primer set.

    PubMed

    Csank, Tomáš; Bhide, Katarína; Bencúrová, Elena; Dolinská, Saskia; Drzewnioková, Petra; Major, Peter; Korytár, Ľuboš; Bocková, Eva; Bhide, Mangesh; Pistl, Juraj

    2016-06-01

    West Nile virus (WNV) is a mosquito-borne neurotropic pathogen that presents a major public health concern. Information on WNV prevalence and circulation in Slovakia is insufficient. Oral and cloacal swabs and bird brain samples were tested for flavivirus RNA by RT-PCR using newly designed generic primers. The species designation was confirmed by sequencing. WNV was detected in swab and brain samples, whereas one brain sample was positive for tick-borne encephalitis virus (TBEV). The WNV sequences clustered with lineages 1 and 2. These results confirm the circulation of WNV in birds in Slovakia and emphasize the risk of infection of humans and horses.

  14. The bacterial microbiome of dermacentor andersoni ticks influences pathogen susceptibility

    USDA-ARS?s Scientific Manuscript database

    Ticks are of medical and veterinary importance due to their ability to transmit pathogens to humans and animals. The Rocky Mountain wood tick, Dermacentor andersoni, is a vector of a number of pathogens, including Anaplasma marginale, which is the most widespread tick-borne pathogen of livestock. Al...

  15. The Blacklegged Tick, Ixodes scapularis: An Increasing Public Health Concern.

    PubMed

    Eisen, Rebecca J; Eisen, Lars

    2018-04-01

    In the United States, the blacklegged tick, Ixodes scapularis, is a vector of seven human pathogens, including those causing Lyme disease, anaplasmosis, babesiosis, Borrelia miyamotoi disease, Powassan virus disease, and ehrlichiosis associated with Ehrlichia muris eauclarensis. In addition to an accelerated rate of discovery of I. scapularis-borne pathogens over the past two decades, the geographic range of the tick, and incidence and range of I. scapularis-borne disease cases, have increased. Despite knowledge of when and where humans are most at risk of exposure to infected ticks, control of I. scapularis-borne diseases remains a challenge. Human vaccines are not available, and we lack solid evidence for other prevention and control methods to reduce human disease. The way forward is discussed. Published by Elsevier Ltd.

  16. Comprehensive molecular detection of tick-borne phleboviruses leads to the retrospective identification of taxonomically unassigned bunyaviruses and the discovery of a novel member of the genus phlebovirus.

    PubMed

    Matsuno, Keita; Weisend, Carla; Kajihara, Masahiro; Matysiak, Colette; Williamson, Brandi N; Simuunza, Martin; Mweene, Aaron S; Takada, Ayato; Tesh, Robert B; Ebihara, Hideki

    2015-01-01

    Until the recent emergence of two human-pathogenic tick-borne phleboviruses (TBPVs) (severe fever with thrombocytopenia syndrome virus [SFTSV] and Heartland virus), TBPVs have been neglected as causative agents of human disease. In particular, no studies have addressed the global distribution of TBPVs, and consequently, our understanding of the mechanism(s) underlying their evolution and emergence remains poor. In order to provide a useful tool for the ecological and epidemiological study of TBPVs, we have established a simple system that can detect all known TBPVs, based on conventional reverse transcription-PCR (RT-PCR) with degenerate primer sets targeting conserved regions of the viral L genome segment. Using this system, we have determined that several viruses that had been isolated from ticks decades ago but had not been taxonomically identified are novel TBPVs. Full-genome sequencing of these viruses revealed a novel fourth TBPV cluster distinct from the three known TBPV clusters (i.e., the SFTS, Bhanja, and Uukuniemi groups) and from the mosquito/sandfly-borne phleboviruses. Furthermore, by using tick samples collected in Zambia, we confirmed that our system had enough sensitivity to detect a new TBPV in a single tick homogenate. This virus, tentatively designated Shibuyunji virus after the region of tick collection, grouped into a novel fourth TBPV cluster. These results indicate that our system can be used as a first-line screening approach for TBPVs and that this kind of work will undoubtedly lead to the discovery of additional novel tick viruses and will expand our knowledge of the evolution and epidemiology of TBPVs. Tick-borne phleboviruses (TBPVs) have been largely neglected until the recent emergence of two virulent viruses, severe fever with thrombocytopenia syndrome virus and Heartland virus. Little is known about the global distribution of TBPVs or how these viruses evolved and emerged. A major hurdle to study the distribution of TBPVs is the

  17. Exploring the use of anti-tick vaccine as tool for integrated eradication of the cattle fever tick, Rhipicephalus (Boophilus) annulatus

    USDA-ARS?s Scientific Manuscript database

    Bovine babesiosis, also known as cattle fever, is a tick-borne protozoal disease foreign to the United States. It was eradicated by eliminating the vector species, Rhipicephalus (Boophilus) annulatus and R. (B.) microplus, through the efforts of the Cattle Fever Tick Eradication Program (CFTEP), wit...

  18. Effect of Climate and Land Use on the Spatio-Temporal Variability of Tick-Borne Bacteria in Europe

    PubMed Central

    Tagliapietra, Valentina; Baráková, Ivana; Hauffe, Heidi Christine; Rosso, Fausta; Blaňarová, Lucia; Bona, Martin; Derdáková, Marketa; Hamšíková, Zuzana; Kazimírová, Maria; Kraljik, Jasna; Kocianová, Elena; Mahríková, Lenka; Minichová, Lenka; Mošanský, Ladislav; Slovák, Mirko; Stanko, Michal; Špitalská, Eva; Ducheyne, Els; Hubálek, Zdenek; Rudolf, Ivo; Venclikova, Kristyna; Silaghi, Cornelia; Overzier, Evelyn; Farkas, Robert; Hornok, Sándor; Takács, Nóra

    2018-01-01

    The incidence of tick-borne diseases caused by Borrelia burgdorferi sensu lato, Anaplasma phagocytophilum and Rickettsia spp. has been rising in Europe in recent decades. Early pre-assessment of acarological hazard still represents a complex challenge. The aim of this study was to model Ixodes ricinus questing nymph density and its infection rate with B. burgdorferi s.l., A. phagocytophilum and Rickettsia spp. in five European countries (Italy, Germany, Czech Republic, Slovakia, Hungary) in various land cover types differing in use and anthropisation (agricultural, urban and natural) with climatic and environmental factors (Normalized Difference Vegetation Index (NDVI), Normalized Difference Water Index (NDWI), Land Surface Temperature (LST) and precipitation). We show that the relative abundance of questing nymphs was significantly associated with climatic conditions, such as higher values of NDVI recorded in the sampling period, while no differences were observed among land use categories. However, the density of infected nymphs (DIN) also depended on the pathogen considered and land use. These results contribute to a better understanding of the variation in acarological hazard for Ixodes ricinus transmitted pathogens in Central Europe and provide the basis for more focused ecological studies aimed at assessing the effect of land use in different sites on tick–host pathogens interaction. PMID:29649132

  19. Susceptibility to Ticks and Lyme Disease Spirochetes Is Not Affected in Mice Coinfected with Nematodes.

    PubMed

    Maaz, Denny; Rausch, Sebastian; Richter, Dania; Krücken, Jürgen; Kühl, Anja A; Demeler, Janina; Blümke, Julia; Matuschka, Franz-Rainer; von Samson-Himmelstjerna, Georg; Hartmann, Susanne

    2016-05-01

    Small rodents serve as reservoir hosts for tick-borne pathogens, such as the spirochetes causing Lyme disease. Whether natural coinfections with other macroparasites alter the success of tick feeding, antitick immunity, and the host's reservoir competence for tick-borne pathogens remains to be determined. In a parasitological survey of wild mice in Berlin, Germany, approximately 40% of Ixodes ricinus-infested animals simultaneously harbored a nematode of the genus Heligmosomoides We therefore aimed to analyze the immunological impact of the nematode/tick coinfection as well as its effect on the tick-borne pathogen Borrelia afzelii Hosts experimentally coinfected with Heligmosomoides polygyrus and larval/nymphal I. ricinus ticks developed substantially stronger systemic type 2 T helper cell (Th2) responses, on the basis of the levels of GATA-3 and interleukin-13 expression, than mice infected with a single pathogen. During repeated larval infestations, however, anti-tick Th2 reactivity and an observed partial immunity to tick feeding were unaffected by concurrent nematode infections. Importantly, the strong systemic Th2 immune response in coinfected mice did not affect susceptibility to tick-borne B. afzelii An observed trend for decreased local and systemic Th1 reactivity against B. afzelii in coinfected mice did not result in a higher spirochete burden, nor did it facilitate bacterial dissemination or induce signs of immunopathology. Hence, this study indicates that strong systemic Th2 responses in nematode/tick-coinfected house mice do not affect the success of tick feeding and the control of the causative agent of Lyme disease. Copyright © 2016 Maaz et al.

  20. Detection and genetic characterization of tick-borne encephalitis virus (TBEV) derived from ticks removed from red foxes (Vulpes vulpes) and isolated from spleen samples of red deer (Cervus elaphus) in Croatia.

    PubMed

    Jemeršić, Lorena; Dežđek, Danko; Brnić, Dragan; Prpić, Jelena; Janicki, Zdravko; Keros, Tomislav; Roić, Besi; Slavica, Alen; Terzić, Svjetlana; Konjević, Dean; Beck, Relja

    2014-02-01

    Tick-borne encephalitis (TBE) is a growing public health concern in central and northern European countries. Even though TBE is a notifiable disease in Croatia, there is a significant lack of information in regard to vector tick identification, distribution as well as TBE virus prevalence in ticks or animals. The aim of our study was to identify and to investigate the viral prevalence of TBE virus in ticks removed from red fox (Vulpes vulpes) carcasses hunted in endemic areas in northern Croatia and to gain a better insight in the role of wild ungulates, especially red deer (Cervus elaphus) in the maintenance of the TBE virus in the natural cycle. We identified 5 tick species (Ixodes ricinus, Ixodes hexagonus, Haemaphysalis punctata, Dermacentor reticulatus, Rhipicephalus sanguineus) removed from 40 red foxes. However, TBE virus was isolated only from adult I. ricinus and I. hexagonus ticks showing a viral prevalence (1.6%) similar to or higher than reported in endemic areas of other European countries. Furthermore, 2 positive spleen samples from 182 red deer (1.1%) were found. Croatian TBE virus isolates were genetically analyzed, and they were shown to be closely related, all belonging to the European TBE virus subgroup. However, on the basis of nucleotide and amino acid sequence analysis, 2 clusters were identified. Our results show that further investigation is needed to understand the clustering of isolates and to identify the most common TBE virus reservoir hosts in Croatia. Sentinel surveys based on wild animal species would give a better insight in defining TBE virus-endemic and possible risk areas in Croatia. Copyright © 2013. Published by Elsevier GmbH.

  1. Tick-borne encephalitis virus in arthropod vectors in the Far East of Russia.

    PubMed

    Pukhovskaya, Natalia M; Morozova, Olga V; Vysochina, Nelya P; Belozerova, Nadejda B; Bakhmetyeva, Svetlana V; Zdanovskaya, Nina I; Seligman, Stephen J; Ivanov, Leonid I

    2018-05-01

    Isolates of tick-borne encephalitis virus (TBEV) from arthropod vectors (ticks and mosquitoes) in the Amur, the Jewish Autonomous and the Sakhalin regions as well as on the Khabarovsk territory of the Far East of Russia were studied. Different proportions of four main tick species of the family Ixodidae: Ixodes persulcatus P. Schulze, 1930; Haemaphysalis concinna Koch, 1844; Haemaphysalis japonica douglasi Nuttall et Warburton, 1915 and Dermacentor silvarum Olenev, 1932 were found in forests and near settlements. RT-PCR of TBEV RNA in adult ticks collected from vegetation in 1999-2014 revealed average infection rates of 7.9 ± 0.7% in I. persulcatus, of 5.6 ± 1.0% in H. concinna, of 2.0 ± 2.0% in H. japonica, and of 1.3 ± 1.3% in D. silvarum. Viral loads varied in a range from 10 2 to 10 9 TBEV genome-equivalents per a tick with the maximal values in I. persulcatus and H. japonica. Molecular typing using reverse transcription with subsequent real time PCR with subtype-specific fluorescent probes demonstrated that the Far Eastern (FE) subtype of TBEV predominated both in mono-infections and in mixed infection with the Siberian (Sib) subtype in I. persulcatus pools. TBEV strains of the FE subtype were isolated from I. persulcatus, H. concinna and from a pool of Aedes vexans mosquitoes. Ten TBEV strains isolated from I. persulcatus from the Khabarovsk territory and the Jewish Autonomous region between 1985 and 2013 cluster with the TBEV vaccine strain Sofjin of the FE subtype isolated from human brain in 1937. A TBEV strain from H. concinna collected in the Amur region (GenBank accession number KF880803) is similar to the vaccine strain 205 isolated in 1973 from I. persulcatus collected in the Jewish Autonomous region. The TBEV strain Lazo MP36 of the FE subtype isolated from a pool of A. vexans in the Khabarovsk territory in 2014 (KT001073) differs from strains isolated from 1) I. persulcatus (including the vaccine strain 205) and H. concinna; 2

  2. Spatially heterogeneous land cover/land use and climatic risk factors of tick-borne feline cytauxzoonosis.

    PubMed

    Raghavan, Ram K; Almes, Kelli; Goodin, Doug G; Harrington, John A; Stackhouse, Paul W

    2014-07-01

    Feline cytauxzoonosis is a highly fatal tick-borne disease caused by a hemoparasitic protozoan, Cytauxzoon felis. This disease is a leading cause of mortality for cats in the Midwestern United States, and no vaccine or effective treatment options exist. Prevention based on knowledge of risk factors is therefore vital. Associations of different environmental factors, including recent climate were evaluated as potential risk factors for cytauxzoonosis using Geographic Information Systems (GIS). There were 69 cases determined to be positive for cytauxzoonosis based upon positive identification of C. felis within blood film examinations, tissue impression smears, or histopathologic examination of tissues. Negative controls totaling 123 were selected from feline cases that had a history of fever, malaise, icterus, and anorexia but lack of C. felis within blood films, impression smears, or histopathologic examination of tissues. Additional criteria to rule out C. felis among controls were the presence of regenerative anemia, cytologic examination of blood marrow or lymph node aspirate, other causative agent diagnosed, or survival of 25 days or greater after testing. Potential environmental determinants were derived from publicly available sources, viz., US Department of Agriculture (soil attributes), US Geological Survey (land-cover/landscape, landscape metrics), and NASA (climate). Candidate variables were screened using univariate logistic models with a liberal p value (0.2), and associations with cytauxzoonosis were modeled using a global multivariate logistic model (p<0.05). Spatial heterogeneity among significant variables in the study region was modeled using a geographically weighted regression (GWR) approach. Total Edge Contrast Index (TECI), grassland-coverage, humidity conditions recorded during the 9(th) week prior to case arrival, and an interaction variable, "diurnal temperature range × percent mixed forest area" were significant risk factors for

  3. Ixodes scapularis Tick Saliva Proteins Sequentially Secreted Every 24 h during Blood Feeding

    PubMed Central

    Pinto, Antônio F. M.; Moresco, James; Yates, John R.; da Silva Vaz, Itabajara; Mulenga, Albert

    2016-01-01

    Ixodes scapularis is the most medically important tick species and transmits five of the 14 reportable human tick borne disease (TBD) agents in the USA. This study describes LC-MS/MS identification of 582 tick- and 83 rabbit proteins in saliva of I. scapularis ticks that fed for 24, 48, 72, 96, and 120 h, as well as engorged but not detached (BD), and spontaneously detached (SD). The 582 tick proteins include proteases (5.7%), protease inhibitors (7.4%), unknown function proteins (22%), immunity/antimicrobial (2.6%), lipocalin (3.1%), heme/iron binding (2.6%), extracellular matrix/ cell adhesion (2.2%), oxidant metabolism/ detoxification (6%), transporter/ receptor related (3.2%), cytoskeletal (5.5%), and housekeeping-like (39.7%). Notable observations include: (i) tick saliva proteins of unknown function accounting for >33% of total protein content, (ii) 79% of proteases are metalloproteases, (iii) 13% (76/582) of proteins in this study were found in saliva of other tick species and, (iv) ticks apparently selectively inject functionally similar but unique proteins every 24 h, which we speculate is the tick's antigenic variation equivalent strategy to protect important tick feeding functions from host immune system. The host immune responses to proteins present in 24 h I. scapularis saliva will not be effective at later feeding stages. Rabbit proteins identified in our study suggest the tick's strategic use of host proteins to modulate the feeding site. Notably fibrinogen, which is central to blood clotting and wound healing, was detected in high abundance in BD and SD saliva, when the tick is preparing to terminate feeding and detach from the host. A remarkable tick adaptation is that the feeding lesion is completely healed when the tick detaches from the host. Does the tick concentrate fibrinogen at the feeding site to aide in promoting healing of the feeding lesion? Overall, these data provide broad insight into molecular mechanisms regulating different tick

  4. A Geographical Information System Based Approach for Integrated Strategies of Tick Surveillance and Control in the Peri-Urban Natural Reserve of Monte Pellegrino (Palermo, Southern Italy).

    PubMed

    Torina, Alessandra; Blanda, Valeria; Blanda, Marcellocalogero; Auteri, Michelangelo; La Russa, Francesco; Scimeca, Salvatore; D'Agostino, Rosalia; Disclafani, Rosaria; Villari, Sara; Currò, Vittoria; Caracappa, Santo

    2018-02-27

    Ticks (Acari: Ixodidae) are bloodsucking arthropods involved in pathogen transmission in animals and humans. Tick activity depends on various ecological factors such as vegetation, hosts, and temperature. The aim of this study was to analyse the spatial/temporal distribution of ticks in six sites within a peri-urban area of Palermo (Natural Reserve of Monte Pellegrino) and correlate it with field data using Geographical Information System (GIS) data. A total of 3092 ticks were gathered via dragging method from June 2012 to May 2014. The species collected were: Ixodes ventalloi (46.09%), Hyalomma lusitanicum (19.99%), Rhipicephalus sanguineus (17.34%), Rhipicephalus pusillus (16.11%), Haemaphisalis sulcata (0.36%), Dermacentor marginatus (0.10%), and Rhipicephalus turanicus (0.03%). GIS analysis revealed environmental characteristics of each site, and abundance of each tick species was analysed in relation to time (monthly trend) and space (site-specific abundance). A relevant presence of I. ventalloi in site 2 and H. lusitanicum in site 5 was observed, suggesting the possible exposure of animals and humans to tick-borne pathogens. Our study shows the importance of surveillance of ticks in peri-urban areas and the useful implementation of GIS analysis in vector ecology; studies on temporal and spatial distribution of ticks correlated to GIS-based ecological analysis represent an integrated strategy for decision support in public health.

  5. A Geographical Information System Based Approach for Integrated Strategies of Tick Surveillance and Control in the Peri-Urban Natural Reserve of Monte Pellegrino (Palermo, Southern Italy)

    PubMed Central

    Torina, Alessandra; Blanda, Marcellocalogero; Auteri, Michelangelo; La Russa, Francesco; Scimeca, Salvatore; D’Agostino, Rosalia; Disclafani, Rosaria; Currò, Vittoria; Caracappa, Santo

    2018-01-01

    Ticks (Acari: Ixodidae) are bloodsucking arthropods involved in pathogen transmission in animals and humans. Tick activity depends on various ecological factors such as vegetation, hosts, and temperature. The aim of this study was to analyse the spatial/temporal distribution of ticks in six sites within a peri-urban area of Palermo (Natural Reserve of Monte Pellegrino) and correlate it with field data using Geographical Information System (GIS) data. A total of 3092 ticks were gathered via dragging method from June 2012 to May 2014. The species collected were: Ixodes ventalloi (46.09%), Hyalomma lusitanicum (19.99%), Rhipicephalus sanguineus (17.34%), Rhipicephalus pusillus (16.11%), Haemaphisalis sulcata (0.36%), Dermacentor marginatus (0.10%), and Rhipicephalus turanicus (0.03%). GIS analysis revealed environmental characteristics of each site, and abundance of each tick species was analysed in relation to time (monthly trend) and space (site-specific abundance). A relevant presence of I. ventalloi in site 2 and H. lusitanicum in site 5 was observed, suggesting the possible exposure of animals and humans to tick-borne pathogens. Our study shows the importance of surveillance of ticks in peri-urban areas and the useful implementation of GIS analysis in vector ecology; studies on temporal and spatial distribution of ticks correlated to GIS-based ecological analysis represent an integrated strategy for decision support in public health. PMID:29495440

  6. The role of particular ticks developmental stages in the circulation of tick-borne pathogens in Central Europe. 4. Anaplasmataceae

    PubMed

    Karbowiak, Grzegorz; Biernat, Beata; Stańczak, Joanna; Werszko, Joanna; Wróblewski, Piotr; Szewczyk, Tomasz; Sytykiewicz, Hubert

    In Central European conditions, two species of Anaplasmataceae have epidemiological significance – Candidatus Neoehrlichia micurensis and Anaplasma phagocytophilum. Tick Ixodes ricinus is considered as their main vector, wild mammals as the animal reservoir. There is presented the transstadial transmission in ticks, due to the lack of transovarial mode the circulation goes mainly between immature ticks and hosts; pathogen circulates primarily in the cycle: infected rodent → the tick larva → the nymph → the mammal reservoir → the larva of the tick. The tick stages able to effectively infect human are nymphs and adult females, males do not participate in the follow transmission. The summary of available data of different A. phagocytophilum strains associations with different hosts revealed at least few distinct enzootic cycle, concern the same ticks species and different mammal hosts. It is possible to reveal in Central Europe the existence of at least three different epidemiological transmission cycles of A. phagocytophilum. The first cycle involves strains pathogenic for human and identical strains from horses, dogs, cats, wild boars, hedgehogs, possibly red foxes. The second cycle involves deer, European bison and possibly domestic ruminants. The third cycle contains strains from voles, shrew and possibly Apodemus mice. In Western Europe voles might be involved in separate enzootic cycle with Ixodes trianguliceps as the vector.

  7. Geographical Environment Factors and Risk Assessment of Tick-Borne Encephalitis in Hulunbuir, Northeastern China.

    PubMed

    Li, Yifan; Wang, Juanle; Gao, Mengxu; Fang, Liqun; Liu, Changhua; Lyu, Xin; Bai, Yongqing; Zhao, Qiang; Li, Hairong; Yu, Hongjie; Cao, Wuchun; Feng, Liqiang; Wang, Yanjun; Zhang, Bin

    2017-05-26

    Tick-borne encephalitis (TBE) is one of natural foci diseases transmitted by ticks. Its distribution and transmission are closely related to geographic and environmental factors. Identification of environmental determinates of TBE is of great importance to understanding the general distribution of existing and potential TBE natural foci. Hulunbuir, one of the most severe endemic areas of the disease, is selected as the study area. Statistical analysis, global and local spatial autocorrelation analysis, and regression methods were applied to detect the spatiotemporal characteristics, compare the impact degree of associated factors, and model the risk distribution using the heterogeneity. The statistical analysis of gridded geographic and environmental factors and TBE incidence show that the TBE patients mainly occurred during spring and summer and that there is a significant positive spatial autocorrelation between the distribution of TBE cases and environmental characteristics. The impact degree of these factors on TBE risks has the following descending order: temperature, relative humidity, vegetation coverage, precipitation and topography. A high-risk area with a triangle shape was determined in the central part of Hulunbuir; the low-risk area is located in the two belts next to the outside edge of the central triangle. The TBE risk distribution revealed that the impact of the geographic factors changed depending on the heterogeneity.

  8. Virome Analysis of Amblyomma americanum, Dermacentor variabilis, and Ixodes scapularis Ticks Reveals Novel Highly Divergent Vertebrate and Invertebrate Viruses

    PubMed Central

    Williams, Simon Hedley; Sameroff, Stephen; Sanchez Leon, Maria; Jain, Komal; Lipkin, W. Ian

    2014-01-01

    ABSTRACT A wide range of bacterial pathogens have been identified in ticks, yet the diversity of viruses in ticks is largely unexplored. In the United States, Amblyomma americanum, Dermacentor variabilis, and Ixodes scapularis are among the principal tick species associated with pathogen transmission. We used high-throughput sequencing to characterize the viromes of these tick species and identified the presence of Powassan virus and eight novel viruses. These included the most divergent nairovirus described to date, two new clades of tick-borne phleboviruses, a mononegavirus, and viruses with similarity to plant and insect viruses. Our analysis revealed that ticks are reservoirs for a wide range of viruses and suggests that discovery and characterization of tick-borne viruses will have implications for viral taxonomy and may provide insight into tick-transmitted diseases. IMPORTANCE Ticks are implicated as vectors of a wide array of human and animal pathogens. To better understand the extent of tick-borne diseases, it is crucial to uncover the full range of microbial agents associated with ticks. Our current knowledge of the diversity of tick-associated viruses is limited, in part due to the lack of investigation of tick viromes. In this study, we examined the viromes of three tick species from the United States. We found that ticks are hosts to highly divergent viruses across several taxa, including ones previously associated with human disease. Our data underscore the diversity of tick-associated viruses and provide the foundation for further studies into viral etiology of tick-borne diseases. PMID:25056893

  9. Seroprevalence of Borrelia burgdorferi sensu lato and tick-borne encephalitis virus in zoo animal species in the Czech Republic.

    PubMed

    Sirmarová, Jana; Tichá, Lucie; Golovchenko, Marina; Salát, Jiří; Grubhoffer, Libor; Rudenko, Nataliia; Nowotny, Norbert; Růžek, Daniel

    2014-09-01

    This study was conducted to evaluate the prevalence of antibodies against Borrelia bugdorferi (Bb) s.l. and tick-borne encephalitis virus (TBEV) in zoo animals in the Czech Republic. We collected 133 serum samples from 69 animal species from 5 zoos located in different parts of the country. The samples were obtained from even-toed ungulates (n=78; 42 species), odd-toed ungulates (n=32; 11 species), carnivores (n=13; 9 species), primates (n=2, 2 species), birds (n=3; 2 species), and reptiles (n=5; 3 species). A high antibody prevalence (60%) was observed for Bb s.l. On the other hand, only two animals had TBEV-specific antibodies: a markhor (Capra falconeri) and a reindeer (Rangifer tarandus), both from the same zoo, located in an area endemic for TBEV. Both of these animals were also positive for Bb s.l. antibodies. Our results indicate that a high number of animal species in the Czech zoos were exposed to Bb s.l. and that TBEV infection occurred at least in one of the investigated zoos. Considering the pathogenic potential of these two tick-borne pathogens, clinical and serological monitoring should be continued, and therapeutic and preventive measures should be taken when necessary. Copyright © 2014 Elsevier GmbH. All rights reserved.

  10. Visualization of Microbiota in Tick Guts by Whole-mount In Situ Hybridization.

    PubMed

    Moss, Caitlin E; Robson, Andrew; Fikrig, Erol; Narasimhan, Sukanya

    2018-06-01

    Infectious diseases transmitted by arthropod vectors continue to pose a significant threat to human health worldwide. The pathogens causing these diseases, do not exist in isolation when they colonize the vector; rather, they likely engage in interactions with resident microorganisms in the gut lumen. The vector microbiota has been demonstrated to play an important role in pathogen transmission for several vector-borne diseases. Whether resident bacteria in the gut of the Ixodes scapularis tick, the vector of several human pathogens including Borrelia burgdorferi, influence tick transmission of pathogens is not determined. We require methods for characterizing the composition of the bacteria associated with the tick gut to facilitate a better understanding of potential interspecies interactions in the tick gut. Using whole-mount in situ hybridization to visualize RNA transcripts associated with particular bacterial species allows for the collection of qualitative data regarding the abundance and distribution of the microbiota in intact tissue. This technique can be used to examine changes in the gut microbiota milieu over the course of tick feeding and can also be applied to analyze expression of tick genes. Staining of whole tick guts yield information about the gross spatial distribution of target RNA in the tissue without the need for three-dimensional reconstruction and is less affected by environmental contamination, which often confounds the sequencing-based methods frequently used to study complex microbial communities. Overall, this technique is a valuable tool that can be used to better understand vector-pathogen-microbiota interactions and their role in disease transmission.

  11. Quantifying the Availability of Vertebrate Hosts to Ticks: A Camera-Trapping Approach

    PubMed Central

    Hofmeester, Tim R.; Rowcliffe, J. Marcus; Jansen, Patrick A.

    2017-01-01

    The availability of vertebrate hosts is a major determinant of the occurrence of ticks and tick-borne zoonoses in natural and anthropogenic ecosystems and thus drives disease risk for wildlife, livestock, and humans. However, it remains challenging to quantify the availability of vertebrate hosts in field settings, particularly for medium-sized to large-bodied mammals. Here, we present a method that uses camera traps to quantify the availability of warm-bodied vertebrates to ticks. The approach is to deploy camera traps at questing height at a representative sample of random points across the study area, measure the average photographic capture rate for vertebrate species, and then correct these rates for the effective detection distance. The resulting “passage rate” is a standardized measure of the frequency at which vertebrates approach questing ticks, which we show is proportional to contact rate. A field test across twenty 1-ha forest plots in the Netherlands indicated that this method effectively captures differences in wildlife assemblage composition between sites. Also, the relative abundances of three life stages of the sheep tick Ixodes ricinus from drag sampling were correlated with passage rates of deer, which agrees with the known association with this group of host species, suggesting that passage rate effectively reflects the availability of medium- to large-sized hosts to ticks. This method will facilitate quantitative studies of the relationship between densities of questing ticks and the availability of different vertebrate species—wild as well as domesticated species—in natural and anthropogenic settings. PMID:28770219

  12. Microbial Invasion vs. Tick Immune Regulation.

    PubMed

    Sonenshine, Daniel E; Macaluso, Kevin R

    2017-01-01

    Ticks transmit a greater variety of pathogenic agents that cause disease in humans and animals than any other haematophagous arthropod, including Lyme disease, Rocky Mountain spotted fever, human granulocytic anaplasmosis, babesiosis, tick-borne encephalitis, Crimean Congo haemorhagic fever, and many others (Gulia-Nuss et al., 2016). Although diverse explanations have been proposed to explain their remarkable vectorial capacity, among the most important are their blood feeding habit, their long term off-host survival, the diverse array of bioactive molecules that disrupt the host's natural hemostatic mechanisms, facilitate blood flow, pain inhibitors, and minimize inflammation to prevent immune rejection (Hajdušek et al., 2013). Moreover, the tick's unique intracellular digestive processes allow the midgut to provide a relatively permissive microenvironment for survival of invading microbes. Although tick-host-pathogen interactions have evolved over more than 300 million years (Barker and Murrell, 2008), few microbes have been able to overcome the tick's innate immune system, comprising both humoral and cellular processes that reject them. Similar to most eukaryotes, the signaling pathways that regulate the innate immune response, i.e., the Toll, IMD (Immunodeficiency) and JAK-STAT (Janus Kinase/ Signal Transducers and Activators of Transcription) also occur in ticks (Gulia-Nuss et al., 2016). Recognition of pathogen-associated molecular patterns (PAMPs) on the microbial surface triggers one or the other of these pathways. Consequently, ticks are able to mount an impressive array of humoral and cellular responses to microbial challenge, including anti-microbial peptides (AMPs), e.g., defensins, lysozymes, microplusins, etc., that directly kill, entrap or inhibit the invaders. Equally important are cellular processes, primarily phagocytosis, that capture, ingest, or encapsulate invading microbes, regulated by a primordial system of thioester-containing proteins

  13. Climate, niche, ticks, and models: what they are and how we should interpret them.

    PubMed

    Estrada-Peña, Agustín

    2008-12-01

    Ticks spend most of their life cycle in the environment, and all tick life cycle stages are dependent on a complex combination of climate variables. Furthermore, host availability and vegetation significantly modulate the dynamics of tick populations. Tick recruitment is dependent on successful reproduction, which in turn requires sufficient adult tick densities, available blood meal sources, and egg survival. Though many animals can serve as hosts, there are several determinants of host suitability. For example, host availability in time and space is an important determinant of tick bionomics. Shelter and protection from environmental extremes are critical to tick survival. Questing and diapausing ticks are vulnerable to extremes of temperature and humidity. There are concerns about how predicted climate change may alter several critical features of host-parasite relationships of ticks, the potential for invasion of new areas or alteration of patterns of pathogen transmission in particular. However, modeling approaches that relate known occurrences of tick species to climate (and/or landscape) features and predict geographic occurrences are not completely fulfilling our needs to understand how the "tick panorama" can change as a consequence of these climate trends. This is a short review about the concept of ecological niche as applied to ticks, as well as some raised concerns about its evaluation and strict definition, and its usefulness to map geographical suitability for ticks. Comments about how climate, hosts, and landscape configuration are briefly discussed regarding its applicability to tick mapping and with reference about their impact on tick abundance. I will further comment on already published observations about observed changes in the geographical range of ticks in parts of Europe.

  14. Effects of an invasive forest pathogen on abundance of ticks and their vertebrate hosts in a California Lyme disease focus.

    PubMed

    Swei, Andrea; Ostfeld, Richard S; Lane, Robert S; Briggs, Cheryl J

    2011-05-01

    Invasive species, including pathogens, can have important effects on local ecosystems, including indirect consequences on native species. This study focuses on the effects of an invasive plant pathogen on a vertebrate community and Ixodes pacificus, the vector of the Lyme disease pathogen (Borrelia burgdorferi) in California. Phytophthora ramorum, the causative agent of sudden oak death, is a non-native pathogen killing trees in California and Oregon. We conducted a multi-year study using a gradient of SOD-caused disturbance to assess the impact on the dusky-footed woodrat (Neotoma fuscipes) and the deer mouse (Peromyscus maniculatus), two reservoir hosts of B. burgdorferi, as well as the impact on the Columbian black-tailed deer (Odocoileus hemionus columbianus) and the western fence lizard (Sceloporus occidentalis), both of which are important hosts for I. pacificus but are not pathogen reservoirs. Abundances of P. maniculatus and S. occidentalis were positively correlated with greater SOD disturbance, whereas N. fuscipes abundance was negatively correlated. We did not find a change in space use by O. hemionus. Our data show that SOD has a positive impact on the density of nymphal ticks, which is expected to increase the risk of human exposure to Lyme disease all else being equal. A positive correlation between SOD disturbance and the density of nymphal ticks was expected given increased abundances of two important hosts: deer mice and western fence lizards. However, further research is needed to integrate the direct effects of SOD on ticks, for example via altered abiotic conditions with host-mediated indirect effects.

  15. Detection of tick-borne bacteria and babesia with zoonotic potential in Argas (Carios) vespertilionis (Latreille, 1802) ticks from British bats.

    PubMed

    Lv, Jizhou; Fernández de Marco, Maria Del Mar; Goharriz, Hooman; Phipps, L Paul; McElhinney, Lorraine M; Hernández-Triana, Luis M; Wu, Shaoqiang; Lin, Xiangmei; Fooks, Anthony R; Johnson, Nicholas

    2018-01-30

    Ticks host a wide range of zoonotic pathogens and are a significant source of diseases that affect humans and livestock. However, little is known about the pathogens associated with bat ticks. We have collected ectoparasites from bat carcasses over a seven year period. Nucleic acids (DNA and RNA) were extracted from 296 ticks removed from bats and the species designation was confirmed in all ticks as Argas (Carios) vespertilionis. A subset of these samples (n = 120) were tested for the presence of zoonotic pathogens by molecular methods. Babesia species, Rickettsia spp., within the spotted fever group (SFG), and Ehrlichia spp. were detected in ticks removed from 26 bats submitted from 14 counties across England. The prevalence of Rickettsia spp. was found to be highest in Pipistrellus pipistrellus from southern England. This study suggests that the tick species that host B. venatorum may include the genus Argas in addition to the genus Ixodes. As A. vespertilionis has been reported to feed on humans, detection of B. venatorum and SFG Rickettsia spp. could present a risk of disease transmission in England. No evidence for the presence of flaviviruses or Issyk-Kul virus (nairovirus) was found in these tick samples.

  16. Higher sika deer density is associated with higher local abundance of Haemaphysalis longicornis nymphs and adults but not larvae in central Japan.

    PubMed

    Tsukada, Hideharu; Nakamura, Yoshio; Kamio, Tsugihiko; Inokuma, Hisashi; Hanafusa, Yasuko; Matsuda, Naoko; Maruyama, Tetsuya; Ohba, Takahiro; Nagata, Koji

    2014-02-01

    Haemaphysalis longicornis (Acari: Ixodidae) is one of the most common and important arthropod disease vectors in Japan, carrying Japanese spotted fever and bovine theileriosis. The recent expansion of sika deer (Cervus nippon, Artiodactyla: Cervidae) populations, the most common wild host of H. longicornis, has also caused concern about increasing the risk of vector-borne diseases in Japan. We used generalized linear mixed model analysis to determine the relative contribution of deer density and other biological and abiotic factors on the abundance of H. longicornis ticks questing at each developmental stage. A total of 6223 H. longicornis adults, nymphs, and larvae were collected from 70 sites in three regions of central Japan. The abundance of questing adult and nymphal ticks was associated with deer density and other biotic and abiotic factors. However, the abundance of questing larvae showed no association with deer density but did show an association with other biotic and abiotic factors. These findings show that a high density of deer along with other biotic and abiotic factors is associated with increased risk of vector-borne diseases through amplified local abundance of questing nymphal and adult H. longicornis. Further, questing larvae abundance is likely regulated by environmental conditions and is likely correlated with survival potential or the distribution of other host species.

  17. Distribution of ticks infesting ruminants and risk factors associated with high tick prevalence in livestock farms in the semi-arid and arid agro-ecological zones of Pakistan.

    PubMed

    Rehman, Abdul; Nijhof, Ard M; Sauter-Louis, Carola; Schauer, Birgit; Staubach, Christoph; Conraths, Franz J

    2017-04-19

    Tick infestation is the major problem for animal health that causes substantial economic losses, particularly in tropical and subtropical countries. To better understand the spatial distribution of tick species and risk factors associated with tick prevalence in livestock in Pakistan, ticks were counted and collected from 471 animals, including 179 cattle, 194 buffaloes, 80 goats and 18 sheep, on 108 livestock farms in nine districts, covering both semi-arid and arid agro-ecological zones. In total, 3,807 ticks representing four species were collected: Hyalomma anatolicum (n = 3,021), Rhipicephalus microplus (n = 715), Hyalomma dromedarii (n = 41) and Rhipicephalus turanicus (n = 30). The latter species is reported for the first time from the study area. Rhipicephalus microplus was the predominant species in the semi-arid zone, whereas H. anatolicum was the most abundant species in the arid zone. The overall proportion of tick-infested ruminants was 78.3% (369/471). It was highest in cattle (89.9%), followed by buffaloes (81.4%), goats (60.0%) and sheep (11.1%). The median tick burden significantly differed among animal species and was highest in cattle (median 58), followed by buffaloes (median 38), goats (median 19) and sheep (median 4.5). Female animals had significantly higher tick burdens than males and, in large ruminants, older animals carried more ticks than younger animals. The intensity of infestation was significantly lower in indigenous animals compared to exotic and crossbred cows. Analysis of questionnaire data revealed that the absence of rural poultry, not using any acaricides, traditional rural housing systems and grazing were potential risk factors associated with a higher tick prevalence in livestock farms. Absence of rural poultry, not performing acaricide treatments, traditional rural housing systems and grazing were important risk factors associated with higher tick prevalence in livestock farms. Age, gender, breed and animal

  18. The impact of climate change on the expansion of Ixodes persulcatus habitat and the incidence of tick-borne encephalitis in the north of European Russia

    PubMed Central

    Tokarevich, Nikolay K.; Tronin, Andrey A.; Blinova, Olga V.; Buzinov, Roman V.; Boltenkov, Vitaliy P.; Yurasova, Elena D.; Nurse, Jo

    2011-01-01

    Background The increase in tick-borne encephalitis (TBE) incidence is observed in recent decades in a number of subarctic countries. The reasons of it are widely discussed in scientific publications. The objective of this study was to understand if the climate change in Arkhangelsk Oblast (AO) situated in the north of European subarctic zone of Russia has real impact on the northward expansion of Ixodid ticks and stipulates the increase in TBE incidence. Methods This study analyzes: TBE incidence in AO and throughout Russia, the results of Ixodid ticks collecting in a number of sites in AO, and TBE virus prevalence in those ticks, the data on tick bite incidence in AO, and meteorological data on AO mean annual air temperatures and precipitations. Results It is established that in recent years TBE incidence in AO tended to increase contrary to its apparent decrease nationwide. In last 10 years, there was nearly 50-fold rise in TBE incidence in AO when compared with 1980–1989. Probably, the increase both in mean annual air temperatures and temperatures during tick active season resulted in the northward expansion of Ixodes Persulcatus, main TBE virus vector. The Ixodid ticks expansion is confirmed both by the results of ticks flagging from the surface vegetation and by the tick bite incidence in the population of AO locations earlier free from ticks. Our mathematical (correlation and regression) analysis of available data revealed a distinct correlation between TBE incidence and the growth of mean annual air temperatures in AO in 1990–2009. Conclusion Not ruling out other factors, we conclude that climate change contributed much to the TBE incidence increase in AO. PMID:22028678

  19. Inhibitors of the tick-borne, hemorrhagic fever-associated flaviviruses.

    PubMed

    Flint, Mike; McMullan, Laura K; Dodd, Kimberly A; Bird, Brian H; Khristova, Marina L; Nichol, Stuart T; Spiropoulou, Christina F

    2014-06-01

    No antiviral therapies are available for the tick-borne flaviviruses associated with hemorrhagic fevers: Kyasanur Forest disease virus (KFDV), both classical and the Alkhurma hemorrhagic fever virus (AHFV) subtype, and Omsk hemorrhagic fever virus (OHFV). We tested compounds reported to have antiviral activity against members of the Flaviviridae family for their ability to inhibit AHFV replication. 6-Azauridine (6-azaU), 2'-C-methylcytidine (2'-CMC), and interferon alpha 2a (IFN-α2a) inhibited the replication of AHFV and also KFDV, OHFV, and Powassan virus. The combination of IFN-α2a and 2'-CMC exerted an additive antiviral effect on AHFV, and the combination of IFN-α2a and 6-azaU was moderately synergistic. The combination of 2'-CMC and 6-azaU was complex, being strongly synergistic but with a moderate level of antagonism. The antiviral activity of 6-azaU was reduced by the addition of cytidine but not guanosine, suggesting that it acted by inhibiting pyrimidine biosynthesis. To investigate the mechanism of action of 2'-CMC, AHFV variants with reduced susceptibility to 2'-CMC were selected. We used a replicon system to assess the substitutions present in the selected AHFV population. A double NS5 mutant, S603T/C666S, and a triple mutant, S603T/C666S/M644V, were more resistant to 2'-CMC than the wild-type replicon. The S603T/C666S mutant had a reduced level of replication which was increased when M644V was also present, although the replication of this triple mutant was still below that of the wild type. The S603 and C666 residues were predicted to lie in the active site of the AHFV NS5 polymerase, implicating the catalytic center of the enzyme as the binding site for 2'-CMC. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  20. Inhibitors of the Tick-Borne, Hemorrhagic Fever-Associated Flaviviruses

    PubMed Central

    Flint, Mike; McMullan, Laura K.; Dodd, Kimberly A.; Bird, Brian H.; Khristova, Marina L.; Nichol, Stuart T.

    2014-01-01

    No antiviral therapies are available for the tick-borne flaviviruses associated with hemorrhagic fevers: Kyasanur Forest disease virus (KFDV), both classical and the Alkhurma hemorrhagic fever virus (AHFV) subtype, and Omsk hemorrhagic fever virus (OHFV). We tested compounds reported to have antiviral activity against members of the Flaviviridae family for their ability to inhibit AHFV replication. 6-Azauridine (6-azaU), 2′-C-methylcytidine (2′-CMC), and interferon alpha 2a (IFN-α2a) inhibited the replication of AHFV and also KFDV, OHFV, and Powassan virus. The combination of IFN-α2a and 2′-CMC exerted an additive antiviral effect on AHFV, and the combination of IFN-α2a and 6-azaU was moderately synergistic. The combination of 2′-CMC and 6-azaU was complex, being strongly synergistic but with a moderate level of antagonism. The antiviral activity of 6-azaU was reduced by the addition of cytidine but not guanosine, suggesting that it acted by inhibiting pyrimidine biosynthesis. To investigate the mechanism of action of 2′-CMC, AHFV variants with reduced susceptibility to 2′-CMC were selected. We used a replicon system to assess the substitutions present in the selected AHFV population. A double NS5 mutant, S603T/C666S, and a triple mutant, S603T/C666S/M644V, were more resistant to 2′-CMC than the wild-type replicon. The S603T/C666S mutant had a reduced level of replication which was increased when M644V was also present, although the replication of this triple mutant was still below that of the wild type. The S603 and C666 residues were predicted to lie in the active site of the AHFV NS5 polymerase, implicating the catalytic center of the enzyme as the binding site for 2′-CMC. PMID:24663025

  1. Ixodid ticks in the megapolis of Kyiv, Ukraine.

    PubMed

    Rogovskyy, Artem S; Nebogatkin, Igor V; Scoles, Glen A

    2017-01-01

    The Ixodidae include the most common tick species encountered in Europe. The ticks transmit a variety of bacterial and protozoan agents of medical and veterinary significance. The aim of the current work was to investigate distribution of Ixodes ricinus and Dermacentor reticulatus ticks in Kyiv, the largest and most densely populated megapolis of Ukraine. Ticks were collected at various recreational areas by flagging during May, the month that showed the highest tick abundance in the past. Sex distribution among I. ricinus ticks was relatively equal, whereas females were collected in higher numbers for D. reticulatus. As opposed to western and central Europe where nymphal ticks had been more abundant, the nymph:adult ratio for I. ricinus was reversed. Also, this report documents detection of Rhipicephalus sanguineus sensu lato (s.l.) in Kyiv region, well outside of its historically documented distribution area. Previously thought to be restricted to the southern Ukraine, a single male specimen of R. sanguineus s.l. was collected just outside the city limits. Data on tick diversity over the past 30 years, however, indicates that this finding may only be incidental. Published by Elsevier GmbH.

  2. Emerging Tick-borne Rickettsia and Ehrlichia at Joint Base Langley-Eustis, Fort Eustis, Virginia.

    PubMed

    Miller, Melissa K; Jiang, Ju; Truong, Melissa; Yarina, Tamasin; Evans, Holly; Christensen, Timothy P; Richards, Allen L

    2016-01-01

    Four species of ticks known to parasitize humans (Amblyomma americanum (lone star tick), Dermacentor variabilis (American dog tick), Amblyomma maculatum (Gulf Coast tick), and Ixodes scapularis (black-legged tick)) were collected at Joint Base Langley-Eustis, Fort Eustis, Virginia during 2009. These ticks were tested individually (adults and nymphs) and in pools of 15 (larvae) for pathogens of public health importance within the genera: Rickettsia, Borrelia, and Ehrlichia, by quantitative real-time polymerase chain reaction (qPCR) assays and, where appropriate, multilocus sequence typing (MLST). Of the 340 A americanum ticks tested, a minimum of 65 (19%), 4 (1%), 4 (1%), and one (<1%) were positive for Rickettsia amblyommii, B lonestari, E ewingii and E chaffeensis, respectively. One of 2 (50%) A maculatum ticks collected was found to be positive for R parkeri by MLST and qPCR analyses. All 33 D variabilis ticks were negative for evidence of rickettsial infections. Likewise, no pathogenic organisms were detected from the single Ixodes scapularis tick collected. Pathogenic rickettsiae and ehrlichiae are likely emerging and cause under-recognized diseases, which threaten people who live, work, train, or otherwise engage in outdoor activities at, or in the vicinity of, Fort Eustis, Virginia.

  3. Detection of Ehrlichia chaffeensis in adult and nymphal stage lone star ticks (Amblyomma americanum) from Long Island, New York

    USGS Publications Warehouse

    Mixson, T.R.; Ginsberg, H.S.; Campbell, S.R.; Sumner, J.W.; Paddock, C.D.

    2004-01-01

    The lone star tick, Amblyomma americanum (L.), has increased in abundance in several regions of the northeastern United States, including areas of Long Island, NY. Adult and nymphal stage A. americanum collected from several sites on Long Island were evaluated for infection with Ehrlichia chaffeensis, the causative agent of human monocytic ehrlichiosis (HME), by using a nested polymerase chain reaction assay. Fifty-nine (12.5%) of ,17.3 adults and eight of 11.3 pools of five nymphs each (estimated minimum prevalence of infection 1.4%) contained DNA of E. chaffeensis. These data, coupled with the documented expansion of lone star tick populations in the northeastern United States, confirm that E. chaffeensis is endemic to many areas of Long Island and that HME should be considered among the differential diagnoses of the many distinct tick-borne diseases that occur in this region.

  4. Molecular detection of tick-borne bacteria and protozoa in cervids and wild boars from Portugal.

    PubMed

    Pereira, André; Parreira, Ricardo; Nunes, Mónica; Casadinho, Afonso; Vieira, Maria Luísa; Campino, Lenea; Maia, Carla

    2016-05-10

    Wildlife can act as reservoir of different tick-borne pathogens, such as bacteria, parasites and viruses. The aim of the present study was to assess the presence of tick-borne bacteria and protozoa with veterinary and zoonotic importance in cervids and wild boars from the Centre and South of Portugal. One hundred and forty one blood samples from free-ranging ungulates including 73 red deer (Cervus elaphus), 65 wild boars (Sus scrofa) and three fallow deer (Dama dama) were tested for the presence of Anaplasma marginale/A. ovis, A. phagocytophilum, Anaplasma/Ehrlichia spp., Babesia/Theileria spp., Borrelia burgdorferi (sensu lato) (s.l.), and Rickettsia spp. DNA by PCR. Anaplasma spp. DNA was detected in 33 (43.4 %) cervids (31 red deer and two fallow deer) and in two (3.1 %) wild boars while Theileria spp. were found in 34 (44.7 %) cervids (32 red deer and two fallow deer) and in three (4.6 %) wild boar blood samples. Sequence analysis of msp4 sequences identified A. marginale, A. ovis, while the analysis of rDNA sequence data disclosed the presence of A. platys and A. phagocytophilum and T. capreoli and Theileria sp. OT3. Anaplasma spp./Theileria spp. mixed infections were found in 17 cervids (22.4 %) and in two wild boars (3.1 %). All samples were negative for Babesia sp., B. burgdorferi (s.l.), Ehrlichia sp. or Rickettsia sp. This is the first detection of Anaplasma marginale, A. ovis, A. phagocytophilum, A. platys, Theileria capreoli and Theileria sp. OT3 in cervids and wild boars from Portugal. Further studies concerning the potential pathogenicity of the different species of  Anaplasma and Theileria infecting wild ungulates, the identification of their vector range, and their putative infectivity to domestic livestock and humans should be undertaken.

  5. [Modeling of mixed infection by tick-borne encephalitis and Powassan viruses in mice].

    PubMed

    Khozinskaia, G A; Pogodina, V V

    1982-01-01

    Simultaneous inoculation of mice with tick-borne and Powassan viruses was shown, depending on experimental conditions, to result either in stimulation of infection or its unchanged course as compared with monoinfection and inoculation with the viruses at 2--3-week intervals in cross protection of mice against the superinfecting virus. Simultaneous inoculation of mice with the two viruses was accompanied by their multiplication in the blood and brains of mice and formation of antihemagglutinating antibodies to each of them. In the virus population in the brains of mice there was either formation of a mixture of two viruses or their phenotypic mixing. In cross protection, multiplication of the superinfecting virus in the blood and brain of mice was slightly inhibited, the antihemagglutinating antibody to a second virus either did not form or appeared in low titres.

  6. The tick biocontrol agent Metarhizium brunneum (= M. anisopliae) (strain F52) does not reduce non-target arthropods

    PubMed Central

    Keesing, Felicia; Ostfeld, Richard S.

    2017-01-01

    Previous studies have found that Met52®, which contains the entomopathogenic fungus Metarhizium brunneum, is effective in reducing the abundance of Ixodes scapularis, the tick vector for the bacterium causing Lyme disease and for other tick-borne pathogens. Given widespread interest in effective, safe methods for controlling ticks, Met52 has the potential to be used at increasing scales. The non-target impacts of Met52, as applied for tick control, have not yet been assessed. A Before-After-Control-Impact experiment was conducted to assess the effects of Met52 on non-target arthropods in lawn and forest habitats typical of residential yards. Ground-dwelling arthropods were collected using bulk sampling of soil and litter, and pitfall sampling. Arthropods were sampled once before and twice after treatment of plots with either Met52 or water (control). Multivariate general linear models were used to jointly model the abundance of arthropod orders. For each sampling method and post-spray sampling occasion, Akaike Information Criterion values were used to compare the fits of two alternative models: one that included effects of period (before vs. after spray), habitat (lawn vs. forest), and treatment (Met52 vs. control), versus a nested null model that included effects of period, and habitat, but no treatment effect. The null model was consistently better supported by the data. Significant effects were found of period and habitat but not treatment. Retrospective power analysis indicated the study had 80% power to detect a 50% reduction in arthropod abundance, as measured by bulk samples taken before versus one week after treatment. The deployment of Met52 in suburban settings is unlikely to cause meaningful reductions in the abundance of non-target arthropods. PMID:29155838

  7. The molecular biology of nairoviruses, an emerging group of tick-borne arboviruses.

    PubMed

    Lasecka, Lidia; Baron, Michael D

    2014-06-01

    The nairoviruses are a rapidly emerging group of tick-borne bunyaviruses that includes pathogens of humans (Crimean-Congo hemorrhagic fever virus [CCHFV]) and livestock (Nairobi sheep disease virus [NSDV], also known as Ganjam virus), as well as a large number of viruses for which the normal vertebrate host has not been established. Studies on this group of viruses have been fairly limited, not least because CCHFV is a BSL4 human pathogen, restricting the number of labs able to study the live virus, while NSDV, although highly pathogenic in naive animals, is not seen as a threat in developed countries, making it a low priority. Nevertheless, recent years have seen significant progress in our understanding of the biology of these viruses, particularly that of CCHFV, and this article seeks to draw together our existing knowledge to generate an overall picture of their molecular biology, underlining areas of particular ignorance for future studies.

  8. Molecular analysis of tick-borne protozoan and rickettsial pathogens in small ruminants from two South African provinces.

    PubMed

    Ringo, Aaron Edmond; Adjou Moumouni, Paul Franck; Taioe, Moeti; Jirapattharasate, Charoonluk; Liu, Mingming; Wang, Guanbo; Gao, Yang; Guo, Huanping; Lee, Seung-Hun; Zheng, Weiqing; Efstratiou, Artemis; Li, Jixu; Inoue, Noboru; Suzuki, Hiroshi; Thekisoe, Oriel; Xuan, Xuenan

    2018-04-01

    Tick-borne protozoan and rickettsial diseases are a major threat to livestock in tropical and sub-tropical regions of Africa. In this study we investigated the presence and distribution of Theileria spp., Babesia ovis, Anaplasma ovis, Anaplasma phagocytophilum, Ehrlichia ruminantium and SFG Rickettsia in sheep and goats from Free State and KwaZulu-Natal provinces. A total of 91 blood samples were screened in this study, 61 from goats and 30 from sheep. PCR assay was conducted using primers based on Theileria spp. 18S rRNA, Babesia ovis (BoSSU rRNA), Anaplasma ovis (AoMSP4), Anaplasma phagocytophilum epank1, Ehrlichia ruminantium pCS20 and SFG Rickettsia OmpA. Overall infection rates of Theileria spp., Anaplasma ovis and Ehrlichia ruminantium were 18 (19.8%), 33 (36.3%) and 13 (14.3%), respectively. The co-infection of two pathogens were detected in 17/91 (18.7%) of all samples, goats having higher rates of co-infection compared to sheep. Phylogenetic tree analysis sequence of pCS20 gene of E. ruminantium of this study was found to be in the same clade with Kumm2 and Riverside strains both from South Africa. The phylogram of SSU rRNA of Theileria ovis had longer branch length compared to all other sequences most of which were from Asia and Middle East. This study provides important data for understanding the tick-borne diseases occurrence in the study area and it is expected to improve the approach for the diagnosis and control of these diseases. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Scouts, forests, and ticks: Impact of landscapes on human-tick contacts.

    PubMed

    De Keukeleire, Mathilde; Vanwambeke, Sophie O; Somassè, Elysée; Kabamba, Benoît; Luyasu, Victor; Robert, Annie

    2015-07-01

    Just as with forest workers or people practicing outdoor recreational activities, scouts are at high risk for tick bites and tick-borne infections. The risk of a tick bite is shaped not only by environmental and climatic factors but also by land management. The aim of this study was to assess which environmental conditions favour scout-tick contacts, and thus to better understand how these factors and their interactions influence the two components of risk: hazard (related to vector and host ecology) and exposure of humans to disease vectors. A survey was conducted in the summer of 2009 on the incidence of tick bites in scout camps taking place in southern Belgium. Joint effects of landscape composition and configuration, weather, climate, forest and wildlife management were examined using a multiple gamma regression with a log link. The landscape was characterized by buffers of varying sizes around the camps using a detailed land use map, and accounting for climate and weather variables. Landscape composition and configuration had a significant influence on scout-tick contacts: the risk was high when the camp was surrounded by a low proportion of arable land and situated in a complex and fragmented landscape. The distance to the nearest forest patch, the composition of the forest ecotone as well as weather and climatic factors were all significantly associated with scout-tick contacts. Both hazard- and exposure-related variables significantly contributed to the frequency of scout-tick contact. Our results show that environmental conditions favour scout-tick contacts. For example, we emphasize the impact of accessibility of environments suitable for ticks on the risk of contact. We also highlight the significant effect of both hazard and exposure. Our results are consistent with current knowledge, but further investigations on the effect of forest management, e.g. through its impact on forest structure, on the tick-host-pathogen system, and on humans exposure, is

  10. Emergence of tick-borne encephalitis in new endemic areas in Austria: 42 years of surveillance.

    PubMed

    Heinz, F X; Stiasny, K; Holzmann, H; Kundi, M; Sixl, W; Wenk, M; Kainz, W; Essl, A; Kunz, C

    2015-04-02

    Human infections with tick-borne encephalitis (TBE)virus are a public health concern in certain regions of Europe, central and eastern Asia. Expansions of endemic areas and increased incidences have been associated with different factors including ecological changes supporting tick reproduction, socioeconomic changes increasing human outdoor activities and climatic changes favouring virus circulation in natural foci. Austria is among the most strongly affected countries in Central Europe, but the annual number of cases has strongly declined due to vaccination. Here,we have analysed changes of the incidence of TBE in the unvaccinated population of all federal states of Austria over a period of 42 years. The overall incidence in Austria has remained constant, but new strongly affected endemic regions have emerged in alpine valleys in the west of Austria. In parallel, the incidence in low-land regions in the north-east of the country is decreasing. There is no evidence for a shift to higher altitudes of infection sites in the traditional TBE zones,but the average altitudes of some newly established endemic areas in the west are significantly higher. Our analyses underscore the focal nature of TBE endemic areas and the potential of TBE virus to emerge in previously unaffected regions.

  11. Research Strategies to Reduce Tick Densities and the Risk of Tick-borne Disease Transmission through Host-Targeted Control

    USDA-ARS?s Scientific Manuscript database

    While white-tailed deer are not reservoir hosts for the Lyme disease agent, Borrelia burgdorferi, they are the keystone host animal on which adult female blacklegged ticks engorge on blood that is essential to production of tick eggs and completion of the life cycle. This session explores current re...

  12. New evidence on tick-borne rickettsioses in the Altai region of Russia using primary lesions, serum and blood clots of molecular and serological study.

    PubMed

    Granitov, Vladimir; Shpynov, Stanislav; Beshlebova, Olga; Arsenjeva, Irina; Dedkov, Vladimir; Safonova, Marina; Stukolova, Olga; Pantjukhina, Anna; Tarasevich, Irina

    2015-01-01

    Tick-borne rickettsioses (TBRs) have similar clinical symptoms and can give serological cross-reaction. We firstly found that in the natural foci of North Asian tick typhus (NATT) in the Altai region of Russia, TBRs can be caused by two Rickettsia species: Rickettsia sibirica subsp. sibirica (causative agent of NATT) and Rickettsia heilongjiangensis. Rickettsial DNA was detected in primary lesions, serum samples and blood clots using real-time PCR. Therefore, each case of TBRs should be verified by using molecular typing. TBR caused by R. sibirica subsp. sibirica - NATT dominates on the territory of Altai region. Copyright © 2015 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  13. Species interactions in occurrence data for a community of tick-transmitted pathogens

    PubMed Central

    Estrada-Peña, Agustín; de la Fuente, José

    2016-01-01

    Interactions between tick species, their realized range of hosts, the pathogens they carry and transmit, and the geographic distribution of species in the Western Palearctic were determined based on evidence published between 1970–2014. These relationships were linked to remotely sensed features of temperature and vegetation and used to extract the network of interactions among the organisms. The resulting datasets focused on niche overlap among ticks and hosts, species interactions, and the fraction of the environmental niche in which tick-borne pathogens may circulate as a result of interactions and overlapping environmental traits. The resulting datasets provide a valuable resource for researchers interested in tick-borne pathogens, as they conciliate the abiotic and biotic sides of their niche, allowing exploration of the importance of each host species acting as a vertebrate reservoir in the circulation of tick-transmitted pathogens in the environmental niche. PMID:27479213

  14. Critical Evaluation of the Linkage Between Tick-Based Risk Measures and the Occurrence of Lyme Disease Cases

    PubMed Central

    Eisen, Lars; Eisen, Rebecca J.

    2018-01-01

    The nymphal stage of the blacklegged tick, Ixodes scapularis Say, is considered the primary vector to humans in the eastern United States of the Lyme disease spirochete Borrelia burgdorferi sensu stricto. The abundance of infected host-seeking nymphs is commonly used to estimate the fundamental risk of human exposure to B. burgdorferi, for the purpose of environmental risk assessment and as an outcome measure when evaluating environmentally based tick or pathogen control methods. However, as this tick-based risk measure does not consider the likelihoods of either human encounters with infected ticks or tick bites resulting in pathogen transmission, its linkage to the occurrence of Lyme disease cases is worth evaluating. In this Forum article, we describe different tick-based risk measures, discuss their strengths and weaknesses, and review the evidence for their capacity to predict the occurrence of Lyme disease cases. We conclude that: 1) the linkage between abundance of host-seeking B. burgdorferi-infected nymphs and Lyme disease occurrence is strong at community or county scales but weak at the fine spatial scale of residential properties where most human exposures to infected nymphs occur in Northeast, 2) the combined use of risk measures based on infected nymphs collected from the environment and ticks collected from humans is preferable to either one of these risk measures used singly when assessing the efficacy of environmentally based tick or pathogen control methods aiming to reduce the risk of human exposure to B. burgdorferi, 3) there is a need for improved risk assessment methodology for residential properties that accounts for both the abundance of infected nymphs and the likelihood of human–tick contact, and 4) we need to better understand how specific human activities conducted in defined residential microhabitats relate to risk for nymphal exposures and bites. PMID:27330093

  15. Infections and Coinfections of Questing Ixodes ricinus Ticks by Emerging Zoonotic Pathogens in Western Switzerland

    PubMed Central

    Lommano, Elena; Bertaiola, Luce; Dupasquier, Christèle

    2012-01-01

    In Europe, Ixodes ricinus is the vector of many pathogens of medical and veterinary relevance, among them Borrelia burgdorferi sensu lato and tick-borne encephalitis virus, which have been the subject of numerous investigations. Less is known about the occurrence of emerging tick-borne pathogens like Rickettsia spp., Babesia spp., “Candidatus Neoehrlichia mikurensis,” and Anaplasma phagocytophilum in questing ticks. In this study, questing nymph and adult I. ricinus ticks were collected at 11 sites located in Western Switzerland. A total of 1,476 ticks were analyzed individually for the simultaneous presence of B. burgdorferi sensu lato, Rickettsia spp., Babesia spp., “Candidatus Neoehrlichia mikurensis,” and A. phagocytophilum. B. burgdorferi sensu lato, Rickettsia spp., and “Candidatus Neoehrlichia mikurensis” were detected in ticks at all sites with global prevalences of 22.5%, 10.2%, and 6.4%, respectively. Babesia- and A. phagocytophilum-infected ticks showed a more restricted geographic distribution, and their prevalences were lower (1.9% and 1.5%, respectively). Species rarely reported in Switzerland, like Borrelia spielmanii, Borrelia lusitaniae, and Rickettsia monacensis, were identified. Infections with more than one pathogenic species, involving mostly Borrelia spp. and Rickettsia helvetica, were detected in 19.6% of infected ticks. Globally, 34.2% of ticks were infected with at least one pathogen. The diversity of tick-borne pathogens detected in I. ricinus in this study and the frequency of coinfections underline the need to take them seriously into consideration when evaluating the risks of infection following a tick bite. PMID:22522688

  16. Bird ticks in Hungary reflect western, southern, eastern flyway connections and two genetic lineages of Ixodes frontalis and Haemaphysalis concinna.

    PubMed

    Hornok, S; Flaisz, B; Takács, N; Kontschán, J; Csörgő, T; Csipak, Á; Jaksa, B R; Kováts, D

    2016-02-24

    Birds play an important role in short- and long-distance transportation of ticks and tick-borne pathogens. The aim of the present study was to provide comprehensive information on the species and genetic diversity of ixodid ticks transported by migratory and non-migratory bird species in Central Europe, and to evaluate relevant data in a geographical, as well as in an ecological context. During a three year period (2012-2014), altogether 3339 ixodid ticks were collected from 1167 passerine birds (representatives of 47 species) at ringing stations in Hungary. These ticks were identified, and the tick-infestations of bird species were compared according to various traits. In addition, PCR and sequencing of part of the cytochrome oxidase subunit-I (COI) and 16S rDNA genes were performed from representatives of five tick species. The most abundant tick species found were Ixodes ricinus and Haemaphysalis concinna (with 2296 and 989 immature stages, respectively). In addition, 48 I. frontalis (all stages), three Hyalomma rufipes nymphs, one I. lividus and two I. festai females were collected. The majority of I. ricinus and I. frontalis specimens occurred on ground-feeding bird species, as contrasted to Ha. concinna. Hy. rufipes showed the highest degree of sequence identity to an Ethiopian hybrid of the same tick species. Based on both COI and 16S rDNA gene analyses, two genetic lineages of I. frontalis were recognized (with only 91.4 % identity in their partial COI gene). These were highly similar to South-Western European isolates of the same tick species. Phylogenetic analysis of Ha. concinna specimens collected from birds in Hungary also revealed two genetic lineages, one of which showed high (≥99 %) degree of 16S rDNA sequence identity to conspecific East Asian isolates. Two genetic lineages of I. frontalis and Ha. concinna are transported by birds in Central Europe, which reflect a high degree of sequence identity to South-Western European and East Asian isolates

  17. Nucleoside Inhibitors of Tick-Borne Encephalitis Virus

    PubMed Central

    Eyer, Luděk; Valdés, James J.; Gil, Victor A.; Nencka, Radim; Hřebabecký, Hubert; Šála, Michal; Salát, Jiří; Černý, Jiří; Palus, Martin; De Clercq, Erik

    2015-01-01

    Tick-borne encephalitis virus (TBEV) is a leading cause of human neuroinfections in Europe and Northeast Asia. There are no antiviral therapies for treating TBEV infection. A series of nucleoside analogues was tested for the ability to inhibit the replication of TBEV in porcine kidney cells and human neuroblastoma cells. The interactions of three nucleoside analogues with viral polymerase were simulated using advanced computational methods. The nucleoside analogues 7-deaza-2′-C-methyladenosine (7-deaza-2′-CMA), 2′-C-methyladenosine (2′-CMA), and 2′-C-methylcytidine (2′-CMC) inhibited TBEV replication. These compounds showed dose-dependent inhibition of TBEV-induced cytopathic effects, TBEV replication (50% effective concentrations [EC50]of 5.1 ± 0.4 μM for 7-deaza-2′-CMA, 7.1 ± 1.2 μM for 2′-CMA, and 14.2 ± 1.9 μM for 2′-CMC) and viral antigen production. Notably, 2′-CMC was relatively cytotoxic to porcine kidney cells (50% cytotoxic concentration [CC50] of ∼50 μM). The anti-TBEV effect of 2′-CMA in cell culture diminished gradually after day 3 posttreatment. 7-Deaza-2′-CMA showed no detectable cellular toxicity (CC50 > 50 μM), and the antiviral effect in culture was stable for >6 days posttreatment. Computational molecular analyses revealed that compared to the other two compounds, 7-deaza-2′-CMA formed a large cluster near the active site of the TBEV polymerase. High antiviral activity and low cytotoxicity suggest that 7-deaza-2′-CMA is a promising candidate for further investigation as a potential therapeutic agent in treating TBEV infection. PMID:26124166

  18. Cattle Tick Rhipicephalus microplus-Host Interface: A Review of Resistant and Susceptible Host Responses

    PubMed Central

    Tabor, Ala E.; Ali, Abid; Rehman, Gauhar; Rocha Garcia, Gustavo; Zangirolamo, Amanda Fonseca; Malardo, Thiago; Jonsson, Nicholas N.

    2017-01-01

    Ticks are able to transmit tick-borne infectious agents to vertebrate hosts which cause major constraints to public and livestock health. The costs associated with mortality, relapse, treatments, and decreased production yields are economically significant. Ticks adapted to a hematophagous existence after the vertebrate hemostatic system evolved into a multi-layered defense system against foreign invasion (pathogens and ectoparasites), blood loss, and immune responses. Subsequently, ticks evolved by developing an ability to suppress the vertebrate host immune system with a devastating impact particularly for exotic and crossbred cattle. Host genetics defines the immune responsiveness against ticks and tick-borne pathogens. To gain an insight into the naturally acquired resistant and susceptible cattle breed against ticks, studies have been conducted comparing the incidence of tick infestation on bovine hosts from divergent genetic backgrounds. It is well-documented that purebred and crossbred Bos taurus indicus cattle are more resistant to ticks and tick-borne pathogens compared to purebred European Bos taurus taurus cattle. Genetic studies identifying Quantitative Trait Loci markers using microsatellites and SNPs have been inconsistent with very low percentages relating phenotypic variation with tick infestation. Several skin gene expression and immunological studies have been undertaken using different breeds, different samples (peripheral blood, skin with tick feeding), infestation protocols and geographic environments. Susceptible breeds were commonly found to be associated with the increased expression of toll like receptors, MHC Class II, calcium binding proteins, and complement factors with an increased presence of neutrophils in the skin following tick feeding. Resistant breeds had higher levels of T cells present in the skin prior to tick infestation and thus seem to respond to ticks more efficiently. The skin of resistant breeds also contained higher

  19. Relatively low prevalence of Babesia microti and Anaplasma phagocytophilum in Ixodes scapularis ticks collected in the Lehigh Valley region of eastern Pennsylvania.

    PubMed

    Edwards, Marten J; Barbalato, Laura A; Makkapati, Amulya; Pham, Katerina D; Bugbee, Louise M

    2015-09-01

    Several human pathogens are transmitted by the blacklegged tick, Ixodes scapularis. These include the spirochetes that cause Lyme disease (Borrelia burgdorferi) which is endemic to the Lehigh Valley region of eastern Pennsylvania. Emerging and currently rare tick-borne diseases have been of increasing concern in this region, including tick-borne relapsing fever (caused by Borrelia miyamotoi), human granulocytic anaplasmosis (caused by Anaplasma phagocytophilum), and human babesiosis (caused by Babesia microti). Real-time PCR assays and in some instances, conventional PCR followed by DNA sequencing, were used to screen 423 DNA samples that were prepared from questing adult and nymph stage I. scapularis ticks for infection with four tick-borne human pathogens. B. burgdorferi was detected in 23.2% of the sampled ticks, while B. miyamotoi, B. microti and a human variant of A. phagocytophilum were detected in less than 0.5% of the ticks. Our results are consistent with those expected in a region where Lyme disease is prevalent and human cases of tick-borne relapsing fever, babesiosis and human granulocytic anaplasmosis are not currently widespread. It is expected that this study will serve as a baseline for future studies of tick-borne pathogens in an area that is in close proximity to regions of high endemicity for Lyme disease, human granulocytic anaplasmosis and human babesiosis. Copyright © 2015 Elsevier GmbH. All rights reserved.

  20. Tick-borne encephalitis in a child with previous history of completed primary vaccination.

    PubMed

    Zlamy, Manuela; Haberlandt, Edda; Brunner, Jürgen; Dozcy, Ludwig; Rostasy, Kevin

    2016-01-01

    We report the case of a 13-year-old girl who presented with fever, headache, nausea and pain behind the right ear. Cerebrospinal fluid (CSF; leukocytes 227/μL), electroencephalogram and cerebral magnetic resonance imaging were indicative of meningoencephalitis. Despite intensive therapy the general condition worsened and the patient was admitted to the intensive care unit. Serological analysis of CSF and serum indicated acute tick-borne encephalitis virus (TBEV) infection (IgG and IgM positive). TBEV infection has been reported after incomplete and complete vaccination. TBEV vaccination breakthrough in childhood has been shown to cause severe disease. It has been suggested that immunized patients develop more severe disease due to altered immune response, but the exact mechanism is unknown. In the presence of typical symptoms and a history of vaccination, possible vaccination breakthrough or missing booster vaccination should be considered. © 2015 Japan Pediatric Society.

  1. Ticks and Fleas Infestation on East Hedgehogs (Erinaceus concolor) in Van Province, Eastern Region of Turkey

    PubMed Central

    Goz, Yaşar; Yilmaz, Ali Bilgin; Aydin, Abdulalim; Dicle, Yalçın

    2016-01-01

    Background: Ixodid ticks (Acari: İxodidae) and fleas (Siphonaptera) are the major vectors of pathogens threatening animals and human healths. The aim of our study was to detect the infestation rates of East Hedgehogs (Erinaceus concolor) with ticks and fleas in Van Province, eastern region of Turkey. Methods: We examined fleas and ticks infestation patterns in 21 hedgehogs, collected from three suburbs with the greater of number gardens. In order to estimate flea and tick infestation of hedgehogs, we immobilized the ectoparasites by treatment the body with a insecticide trichlorphon (Neguvon®-Bayer). Results: On the hedgehogs, 60 ixodid ticks and 125 fleas were detected. All of the ixodid ticks were Rhipicephalus turanicus and all of the fleas were Archaeopsylla erinacei. Infestation rate for ticks and fleas was detected 66.66 % and 100 %, respectively. Conclusion: We detected ticks (R. turanicus) and fleas (A. erinacei) in hedgehogs at fairly high rates. Since many ticks and fleas species may harbor on hedgehogs and transmit some tick-borne and flea-borne patogens, this results are the important in terms of veterinary and public health. PMID:27047971

  2. Tularaemia in southwest Germany: Three cases of tick-borne transmission.

    PubMed

    Boone, I; Hassler, D; Nguyen, T; Splettstoesser, W D; Wagner-Wiening, C; Pfaff, G

    2015-07-01

    Tularaemia, caused by Francisella tularensis, is an endemic zoonosis frequently occurring in southwest Germany. Since 2005 there is an increase in the number of reported cases of tularaemia in Germany. We report on two cases of ulceroglandular tularaemia and one case of glandular tularaemia that occurred in the summer of 2012 and 2013 in two counties in the Federal State of Baden-Wuerttemberg. Bacteria were transmitted through tick bites, which to date has only rarely been reported in Germany. Inadequate treatment of the patients and an aggravation of clinical symptoms were caused by a delay between disease onset and the detection of the pathogen. Although contact to or consumption of infected hares are the most often reported transmission routes of tularaemia in Germany, tick-bites should also be taken into account. Health professionals should include Francisella tularensis in the differential diagnosis of patients with fever and/or ulcerative lymphadenopathy following a tick bite. Copyright © 2015 Elsevier GmbH. All rights reserved.

  3. Tick-borne encephalitis in Japan, Republic of Korea and China

    PubMed Central

    Yoshii, Kentaro; Song, Joon Young; Park, Seong-Beom; Yang, Junfeng; Schmitt, Heinz-Josef

    2017-01-01

    Tick-borne encephalitis virus (TBEV) causes mild or moderate febrile illness in humans that may progress to encephalitis, leading to severe long-term complications and sometimes death. TBEV is prevalent in the Eurasian continent and has been isolated in China, Japan and Republic of Korea (ROK). The TBEV isolates from Japan are of the Far-Eastern subtype; in ROK, the isolates are of the Western subtype; and all TBEV isolates in China are of the Far-Eastern subtype, except one strain that was identified most recently as the Siberian subtype. TBE is endemic to the northeast, northwest and southeast of China; only two confirmed TBE cases have been reported in Japan to date; and no TBE case has been confirmed in ROK. For TBE patients in China, the onset of disease is acute with no biphasic course for disease presentation. The clinical spectrum of disease phenotypes may be wider than currently understood, since serological evidence suggests the presence of TBEV infections in healthy people, indicating that asymptomatic or unspecific manifestations of TBEV infection may exist. The current treatment for TBE is supportive care. In China, vaccines against TBEV have been developed and are available with demonstrated immunogenicity and safety, although efficacy data are lacking. No vaccines are available in ROK or Japan. PMID:28928417

  4. Prevalence, risk factors, and genetic diversity of veterinary important tick-borne pathogens in cattle from Rhipicephalus microplus-invaded and non-invaded areas of Benin.

    PubMed

    Adjou Moumouni, Paul Franck; Aplogan, Gilbert Luc; Katahira, Hirotaka; Gao, Yang; Guo, Huanping; Efstratiou, Artemis; Jirapattharasate, Charoonluk; Wang, Guanbo; Liu, Mingming; Ringo, Aaron Edmond; Umemiya-Shirafuji, Rika; Suzuki, Hiroshi; Xuan, Xuenan

    2018-03-01

    Babesiosis, theileriosis, anaplasmosis, and heartwater are tick-borne diseases (TBD) that threaten livestock production in sub-Saharan Africa including Benin. This country has been faced with an invasion of Rhipicephalus microplus, a major vector for babesiosis, theileriosis, and anaplasmosis over the last decade. Yet, data on TBD and the impact of the invasive ticks are lacking, making risk level evaluation and disease control arduous. In this study, epidemiological features of Babesia bovis, B. bigemina, Theileria spp., Anaplasma marginale and Ehrlichia ruminantium infections in Benin cattle were investigated in R. microplus-invaded and non-invaded areas. Detection of pathogens was based on species-specific PCR assays and resulting data were used to identify risk factors. Genetic diversity and phylogenies were then evaluated using several markers. Out of 207 samples examined, 170 (82.1%), 109 (52.7%), 42 (20.3%) 24 (11.6%) and 1 (0.5%) were positive for T. mutans, A. marginale, B. bigemina, B. bovis and E. ruminantium, respectively. Animal gender (for B. bovis), exposure to R. microplus (for B. bigemina and A. marginale), animal age (for B. bigemina and A. marginale) and cattle breed and/or antiprotozoal treatment (for T. mutants) significantly modulated pathogen occurrence. In addition, R. microplus exposure was significantly related to co-infection patterns and cases of clinical theileriosis and/or anaplasmosis were recorded among cattle highly exposed to the tick. In the genetic characterization, Theileria spp. and E. ruminantium sequences were conserved. Babesia spp. and A. marginale, however, showed high sequence polymorphisms that indicate the presence of several strains and may be linked to R. microplus invasion. Taken together, these results ascertain the endemicity of tick-borne infections in Benin and suggest that the characteristics of Babesia spp. and A. marginale infections in R. microplus-invaded and non-invaded areas are different. Copyright

  5. Reverse transcription PCR-based detection of Crimean-Congo hemorrhagic fever virus isolated from ticks of domestic ruminants in Kurdistan province of Iran.

    PubMed

    Fakoorziba, Mohammad Reza; Golmohammadi, Parvaneh; Moradzadeh, Rahmatollah; Moemenbellah-Fard, Mohammad Djaefar; Azizi, Kourosh; Davari, Behrooz; Alipour, Hamzeh; Ahmadnia, Sara; Chinikar, Sadegh

    2012-09-01

    Crimean-Congo hemorrhagic fever (CCHF) is a potentially fatal viral vector-borne zoonosis which has a mortality rate of up to 30% without treatment in humans. CCHF virus is transmitted to humans by ticks, predominantly from the Hyalomma genus. Following the report of two confirmed and one suspected death due to CCHF virus in Kurdistan province of Iran in 2007, this study was undertaken to determine the fauna of hard ticks on domestic ruminants (cattle, sheep, and goats) and their possible infection with CCHF virus using reverse transcription PCR technique. This is the first detection of CCHF virus in ticks from the Kurdistan province of Iran. Overall, 414 ixodid ticks were collected from two districts in this province. They represented four genera from which 10 separate species were identified. The Hyalomma genus was the most abundant tick genus (70%). It was the only genus shown to be infected with the CCHF virus using RT-PCR technique. The number of ticks positive for CCHF virus was 5 out of 90 (5.6%) adult ticks. The three remaining genera (Haemaphysalis, Rhipicephalus, and Dermacentor) were all negative following molecular survey. Four of the five virally-infected ticks were from cattle mainly in the Sanandaj district. We concluded that CCHF virus is present in the Hyalomma ticks on domestic ruminants (cattle) in Kurdistan province of Iran.

  6. Report of the 19th Annual Meeting of the International Scientific Working Group on Tick-Borne Encephalitis (ISW-TBE) - TBE in a changing world.

    PubMed

    Kunze, Ursula

    2018-02-01

    The 19th meeting of the International Scientific Working Group on Tick-Borne Encephalitis (ISW-TBE) - a group of neurologists, general practitioners, clinicians, travel physicians, virologists, pediatricians and epidemiologists-was held under the title "TBE in a changing world". Key topics within virology, current epidemiological developments and investigations, expansion of risk areas, clinical aspects and cases, traveling and mobility, vaccination rates, and latest news on vaccination were presented and extensively discussed. Over the past four decades, TBE has become a growing public health challenge in Europe and parts of Asia. It may be considered a complex eco-epidemiological system, characterized by an intricate interplay between the virus, ticks and tick hosts on the one hand and human exposure strongly influenced by socioeconomic conditions on the other hand. Although the facts are simple - vaccination is the best prevention - the socioeconomic conditions keep changing, and with them the ability or willingness of people to get vaccinated. Copyright © 2017 Elsevier GmbH. All rights reserved.

  7. A tiny tick can cause a big health problem.

    PubMed

    John, Manuel; Raman, M; Ryan, Keith

    2017-11-01

    Ticks are tiny crawling bugs in the spider family that feed by sucking blood from animals. They are second only to mosquitoes as vectors of human disease, both infectious and toxic. Infected ticks spread over a hundred diseases, some of which are fatal if undetected. They spread the spirochete (which multiplies in the insect's gut) with a subsequent bite to the next host. We describe the only reported cases of peri ocular tick bite from India that presented to us within a span of 3 days and its management. Due suspicion and magnification of the lesions revealed the ticks which otherwise masqueraded as small skin tags/moles on gross examination. The ticks were firmly latched on to the skin and careful removal prevented incarceration of the mouth parts. Rickettsial diseases that were believed to have disappeared from India are reemerging and their presence has recently been documented in at least 11 states in the country. Among vector borne diseases, the most common, Lyme disease, also known as the great mimicker, can present with rheumatoid arthritis, fibromyalgia, depression, attention deficit hyperactivity disorder, multiple sclerosis, chronic fatigue syndrome, cardiac manifestations, encephalitis, and mental illness, to name some of the many associations. Common ocular symptoms and signs include conjunctivitis, keratitis, uveitis, and retinitis. Early detection and treatment of tick borne diseases is important to prevent multi system complications that can develop later in life.

  8. Borrelia miyamotoi: a widespread tick-borne relapsing fever spirochete.

    PubMed

    Wagemakers, Alex; Staarink, Pieter J; Sprong, Hein; Hovius, Joppe W R

    2015-06-01

    Borrelia miyamotoi is a relapsing fever spirochete that has only recently been identified as a human pathogen. Borrelia miyamotoi is genetically and ecologically distinct from Borrelia burgdorferi sensu lato, while both are present in Ixodes ticks. Over 50 patients with an acute febrile illness have been described with a B. miyamotoi infection, and two infected immunocompromised patients developed a meningoencephalitis. Seroprevalence studies indicate exposure in the general population and in specific risk groups, such as patients initially suspected of having human granulocytic anaplasmosis. Here, we review the available literature on B. miyamotoi, describing its presence in ticks, reservoir hosts, and humans, and discussing its potential impact on public health. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. 3'-O-Substituted 5-(perylen-3-ylethynyl)-2'-deoxyuridines as tick-borne encephalitis virus reproduction inhibitors.

    PubMed

    Proskurin, Gleb V; Orlov, Alexey A; Brylev, Vladimir A; Kozlovskaya, Liubov I; Chistov, Alexey A; Karganova, Galina G; Palyulin, Vladimir A; Osolodkin, Dmitry I; Korshun, Vladimir A; Aralov, Andrey V

    2018-05-26

    A series of analogues of potent antiviral perylene nucleoside dUY11 with methylthiomethyl (MTM), azidomethyl (AZM) and HO-C 1-4 -alkyl-1,2,3-triazol-1,4-diyl groups at 3'-O-position as well as the two products of copper-free alkyne-azide cycloaddition of the AZM derivative were prepared and evaluated against tick-borne encephalitis virus (TBEV). Four compounds (4, 6, 8a, 8b) showed EC 50  ≤ 10 nM, thus appearing the most potent TBEV inhibitors to date. Moreover, these nucleosides have higher lipophilicity (clogP) and increased solubility in aq. DMSO vs. parent compound dUY11. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  10. Comparative Metagenomic Profiling of Symbiotic Bacterial Communities Associated with Ixodes persulcatus, Ixodes pavlovskyi and Dermacentor reticulatus Ticks.

    PubMed

    Kurilshikov, Alexander; Livanova, Natalya N; Fomenko, Nataliya V; Tupikin, Alexey E; Rar, Vera A; Kabilov, Marsel R; Livanov, Stanislav G; Tikunova, Nina V

    2015-01-01

    Ixodes persulcatus, Ixodes pavlovskyi, and Dermacentor reticulatus ticks inhabiting Western Siberia are responsible for the transmission of a number of etiological agents that cause human and animal tick-borne diseases. Because these ticks are abundant in the suburbs of large cities, agricultural areas, and popular tourist sites and frequently attack people and livestock, data regarding the microbiomes of these organisms are required. Using metagenomic 16S profiling, we evaluate bacterial communities associated with I. persulcatus, I. pavlovskyi, and D. reticulatus ticks collected from the Novosibirsk region of Russia. A total of 1214 ticks were used for this study. DNA extracted from the ticks was pooled according to tick species and sex. Sequencing of the V3-V5 domains of 16S rRNA genes was performed using the Illumina Miseq platform. The following bacterial genera were prevalent in the examined communities: Acinetobacter (all three tick species), Rickettsia (I. persulcatus and D. reticulatus) and Francisella (D. reticulatus). B. burgdorferi sensu lato and B. miyamotoi sequences were detected in I. persulcatus and I. pavlovskyi but not in D. reticulatus ticks. The pooled samples of all tick species studied contained bacteria from the Anaplasmataceae family, although their occurrence was low. DNA from A. phagocytophilum and Candidatus Neoehrlichia mikurensis was first observed in I. pavlovskyi ticks. Significant inter-species differences in the number of bacterial taxa as well as intra-species diversity related to tick sex were observed. The bacterial communities associated with the I. pavlovskyi ticks displayed a higher biodiversity compared with those of the I. persulcatus and D. reticulatus ticks. Bacterial community structure was also diverse across the studied tick species, as shown by permutational analysis of variance using the Bray-Curtis dissimilarity metric (p = 0.002). Between-sex variation was confirmed by PERMANOVA testing in I. persulcatus (p = 0

  11. Modelling and mapping tick dynamics using volunteered observations.

    PubMed

    Garcia-Martí, Irene; Zurita-Milla, Raúl; van Vliet, Arnold J H; Takken, Willem

    2017-11-14

    Tick populations and tick-borne infections have steadily increased since the mid-1990s posing an ever-increasing risk to public health. Yet, modelling tick dynamics remains challenging because of the lack of data and knowledge on this complex phenomenon. Here we present an approach to model and map tick dynamics using volunteered data. This approach is illustrated with 9 years of data collected by a group of trained volunteers who sampled active questing ticks (AQT) on a monthly basis and for 15 locations in the Netherlands. We aimed at finding the main environmental drivers of AQT at multiple time-scales, and to devise daily AQT maps at the national level for 2014. Tick dynamics is a complex ecological problem driven by biotic (e.g. pathogens, wildlife, humans) and abiotic (e.g. weather, landscape) factors. We enriched the volunteered AQT collection with six types of weather variables (aggregated at 11 temporal scales), three types of satellite-derived vegetation indices, land cover, and mast years. Then, we applied a feature engineering process to derive a set of 101 features to characterize the conditions that yielded a particular count of AQT on a date and location. To devise models predicting the AQT, we use a time-aware Random Forest regression method, which is suitable to find non-linear relationships in complex ecological problems, and provides an estimation of the most important features to predict the AQT. We trained a model capable of fitting AQT with reduced statistical metrics. The multi-temporal study on the feature importance indicates that variables linked to water levels in the atmosphere (i.e. evapotranspiration, relative humidity) consistently showed a higher explanatory power than previous works using temperature. As a product of this study, we are able of mapping daily tick dynamics at the national level. This study paves the way towards the design of new applications in the fields of environmental research, nature management, and public

  12. Ecology of the Tick-Borne Phlebovirus Causing Severe Fever with Thrombocytopenia Syndrome in an Endemic Area of China.

    PubMed

    Li, Zhifeng; Bao, Changjun; Hu, Jianli; Liu, Wendong; Wang, Xiaochen; Zhang, Lei; Ji, Zhengmin; Feng, Zhi; Li, Luxun; Shen, Aihua; Liu, Xuejian; Zhao, Hongjun; Tan, Wenwen; Zhou, Jiangang; Qi, Xian; Zhu, Yefei; Tang, Fenyang; Cardona, Carol J; Xing, Zheng

    2016-04-01

    Severe fever with thrombocytopenia syndrome (SFTS) is caused by SFTS virus (SFTSV), a tick-borne phlebovirus in family Bunyaviridae. Studies have found that humans, domestic and wildlife animals can be infected by SFTSV. However, the viral ecology, circulation, and transmission remain largely unknown. Sixty seven human SFTS cases were reported and confirmed by virus isolation or immunofluorescence assay between 2011 and 2014. In 2013-2014 we collected 9,984 ticks from either vegetation or small wild mammals in the endemic area in Jiangsu, China, and detected SFTSV-RNA by real-time RT-PCR in both questing and feeding Haemaphysalis longicornis and H. flava. Viral RNA was identified in larvae of H. longicornis prior to a first blood meal, which has never been confirmed previously in nature. SFTSV-RNA and antibodies were also detected by RT-PCR and ELISA, respectively, in wild mammals including Erinaceus europaeus and Sorex araneus. A live SFTSV was isolated from Erinaceus europaeus captured during the off tick-feeding season and with a high SFTSV antibody titer. Furthermore, SFTSV antibodies were detected in the migratory birds Anser cygnoides and Streptopelia chinensis using ELISA. The detection of SFTSV-RNA in non-engorged larvae indicated that vertical transmission of SFTSV in H. longicornis might occur in nature, which suggests that H. longicornis is a putative reservoir host of SFTSV. Small wild mammals such as Erinaceus europaeus and Sorex araneus could be infected by SFTSV and may serve as natural amplifying hosts. Our data unveiled that wild birds could be infected with SFTSV or carry SFTSV-infected ticks and thus might contribute to the long-distance spread of SFTSV via migratory flyways. These findings provide novel insights for understanding SFTSV ecology, reservoir hosts, and transmission in nature and will help develop new measures in preventing its rapid spread both regionally and globally.

  13. Clinical Presentation, Convalescence, and Relapse of Rocky Mountain Spotted Fever in Dogs Experimentally Infected via Tick Bite

    PubMed Central

    Levin, Michael L.; Killmaster, Lindsay F.; Zemtsova, Galina E.; Ritter, Jana M.; Langham, Gregory

    2014-01-01

    Rocky Mountain spotted fever (RMSF) is a tick-borne disease caused by R. rickettsii in North and South America. Domestic dogs are susceptible to infection and canine RMSF can be fatal without appropriate treatment. Although clinical signs of R. rickettsii infection in dogs have been described, published reports usually include descriptions of either advanced clinical cases or experimental infections caused by needle-inoculation of cultured pathogen rather than by tick bite. The natural progression of a tick-borne R. rickettsii infection has not been studied in sufficient detail. Here, we provide a detailed description of clinical, hematological, molecular, and serological dynamics of RMSF in domestic dogs from the day of experimental exposure to infected ticks through recovery. Presented data indicate that neither the height/duration of fever nor detection of rickettsial DNA in dogs' blood by PCR are good indicators for clinical prognosis. Only the apex and subsequent subsidence of neutrophilia seem to mark the beginning of recovery and allow predicting a favorable outcome in Rickettsia-infected dogs, even despite the continuing persistence of mucosal petechiae and skin rash. On the other hand the appropriate (doxycycline) antibiotic therapy of sufficient duration is crucial in prevention of RMSF relapses in dogs. PMID:25542001

  14. Clinical presentation, convalescence, and relapse of rocky mountain spotted fever in dogs experimentally infected via tick bite.

    PubMed

    Levin, Michael L; Killmaster, Lindsay F; Zemtsova, Galina E; Ritter, Jana M; Langham, Gregory

    2014-01-01

    Rocky Mountain spotted fever (RMSF) is a tick-borne disease caused by R. rickettsii in North and South America. Domestic dogs are susceptible to infection and canine RMSF can be fatal without appropriate treatment. Although clinical signs of R. rickettsii infection in dogs have been described, published reports usually include descriptions of either advanced clinical cases or experimental infections caused by needle-inoculation of cultured pathogen rather than by tick bite. The natural progression of a tick-borne R. rickettsii infection has not been studied in sufficient detail. Here, we provide a detailed description of clinical, hematological, molecular, and serological dynamics of RMSF in domestic dogs from the day of experimental exposure to infected ticks through recovery. Presented data indicate that neither the height/duration of fever nor detection of rickettsial DNA in dogs' blood by PCR are good indicators for clinical prognosis. Only the apex and subsequent subsidence of neutrophilia seem to mark the beginning of recovery and allow predicting a favorable outcome in Rickettsia-infected dogs, even despite the continuing persistence of mucosal petechiae and skin rash. On the other hand the appropriate (doxycycline) antibiotic therapy of sufficient duration is crucial in prevention of RMSF relapses in dogs.

  15. Diversity of ticks (Acari: Ixodidae) infesting cheetahs (Acinoyx jubatus) at three breeding centres in South Africa and activity patterns of questing ticks.

    PubMed

    Golezardy, Habib; Oosthuizen, Marinda C; Penzhorn, Barend L

    2016-07-01

    Ticks were collected from 191 cheetahs at three breeding centres in North West and Limpopo Provinces, South Africa. Haemaphysalis elliptica, a common tick of large felids, was the most abundant species collected, while Amblyomma hebraeum and Rhipicephalus simus occurred in lower numbers. In addition to these three species, drag-sampling of the vegetation revealed the presence of Amblyomma marmoreum, Rhipicephalus (B.) decoloratus and Rhipicephalus zambeziensis. The presence of free-ranging antelopes, murid rodents and tortoises at the breeding centres probably contributed to the availability of immature tick stages on the vegetation. Diurnal and seasonal questing patterns of ixodid ticks were investigated at monthly intervals at the largest cheetah-breeding centre. Questing ticks were most abundant on the vegetation during the warm summer months. Most questing H. elliptica larvae and nymphs were collected from the vegetation in the early morning and late afternoon and fewest during the middle of the day. Copyright © 2016 Elsevier GmbH. All rights reserved.

  16. Identification and molecular characterization of spotted fever group rickettsiae in ticks collected from farm ruminants in Lebanon.

    PubMed

    Fernández de Mera, Isabel G; Blanda, Valeria; Torina, Alessandra; Dabaja, Mayssaa Fawaz; El Romeh, Ali; Cabezas-Cruz, Alejandro; de la Fuente, José

    2018-01-01

    Tick-borne diseases have become a world health concern, emerging with increasing incidence in recent decades. Spotted fever group (SFG) rickettsiae are tick-borne pathogens recognized as important agents of human tick-borne diseases worldwide. In this study, 88 adult ticks from the species Hyalomma anatolicum, Rhipicephalus annulatus, Rh. bursa, Rh. sanguineus sensu lato, and Rh. turanicus, were collected from farm ruminants in Lebanon, and SFG rickettsiae were molecularly identified and characterized in these ticks. The screening showed a prevalence of 68% for Rickettsia spp., including the species R. aeschlimannii, R. africae, R. massiliae and Candidatus R. barbariae, the latter considered an emerging member of the SFG rickettsiae. These findings contribute to a better knowledge of the distribution of these pathogens and demonstrate that SFG rickettsiae with public health relevance are found in ticks collected in Lebanon, where the widespread distribution of tick vectors and possible livestock animal hosts in contact with humans may favor transmission to humans. Few reports exist for some of the tick species identified here as being infected with SFG Rickettsia. Some of these tick species are proven vectors of the hosted rickettsiae, although this information is unknown for other of these species. Therefore, these results suggested further investigation on the vector competence of the tick species with unknown role in transmission of some of the pathogens identified in this study. Copyright © 2017 Elsevier GmbH. All rights reserved.

  17. Seasonal dynamics of ixodid ticks on wild rabbits Oryctolagus cuniculus (Leporidae) from Central Spain.

    PubMed

    González, J; Valcárcel, F; Pérez-Sánchez, J L; Tercero-Jaime, J M; Olmeda, A S

    2016-11-01

    Rabbit Hemorrhagic Disease and Myxomatosis caused a decline in the rabbit population in the second half of the last century. Despite some recovery, the risk of vector-borne disease is present and thus the importance of controlling vector populations. In the current study, we describe the ixodid tick fauna in wild rabbit in a natural reserve in Ciudad Real (Central Spain) during the course of two 3-year periods (2007-2009 and 2012-2014). Of all the ticks collected on average 72.5 % were larvae, 24.4 % nymphs and 3.1 % adults, although the percentage varied monthly. Seven tick species were identified: Hyalomma lusitanicum Koch (Parasitic indicator [PI] = number of ticks per examined rabbit = 96.47), Rhipicephalus pusillus Gil Collado (PI = 47.37), Haemaphysalis hispanica Gil Collado (PI = 12.15), Ixodes ventalloi Gil Collado (PI = 0.65), R. bursa Canestrini and Fanzago (PI = 0.18), R. sanguineus Latreille (PI = 0.11), Dermacentor marginatus Sulzer (PI = 0.01). In spring and summer, most abundant were larvae of H. lusitanicum, followed by immature stages of R. pusillus and Ha. hispanica. In autumn, the main tick species were nymphs of I. ventalloi whereas in winter adults of Ha. hispanica were more numerous. Rhipicephalus pusillus was present all year long, although not always in high percentage. PI of other species (R. bursa, R. sanguineus and D. marginatus) were too low to be representative. The seasonal dynamics of ticks on wild rabbit defined in this study could be useful to design species-specific control strategies.

  18. Brain perfusion alterations in tick-borne encephalitis-preliminary report.

    PubMed

    Tyrakowska-Dadełło, Zuzanna; Tarasów, Eugeniusz; Janusek, Dariusz; Moniuszko-Malinowska, Anna; Zajkowska, Joanna; Pancewicz, Sławomir

    2018-03-01

    Magnetic resonance imaging (MRI) changes in tick-borne encephalitis (TBE) are non-specific and the pathophysiological mechanisms leading to their formation remain unclear. This study investigated brain perfusion in TBE patients using dynamic susceptibility-weighted contrast-enhanced magnetic resonance perfusion imaging (DSC-MRI perfusion). MRI scans were performed for 12 patients in the acute phase, 3-5days after the diagnosis of TBE. Conventional MRI and DSC-MRI perfusion studies were performed. Cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), and time to peak (TTP) parametric maps were created. The bilateral frontal, parietal, and temporal subcortical regions and thalamus were selected as regions of interest. Perfusion parameters of TBE patients were compared to those of a control group. There was a slight increase in CBF and CBV, with significant prolongation of TTP in subcortical areas in the study subjects, while MTT values were comparable to those of the control group. A significant increase in thalamic CBF (p<0.001) and increased CBV (p<0.05) were observed. Increased TTP and a slight reduction in MTT were also observed within this area. The DSC-MRI perfusion study showed that TBE patients had brain perfusion disturbances, expressed mainly in the thalami. These results suggest that DSC-MRI perfusion may provide important information regarding the areas affected in TBE patients. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  19. Ticks imported to Europe with exotic reptiles.

    PubMed

    Mihalca, Andrei Daniel

    2015-09-30

    It is known that traded exotic animals carry with them an immense number of associated symbionts, including parasites. Reptiles are no exception. Most of the imported reptiles originate from tropical countries and their possibility to carry potentially dangerous pathogens is high. According to CITES, Europe is currently the main reptile importer in the world. Despite this, there is no review or analysis available for the risk related to the importation of tick-borne diseases with traded reptile to the EU. The main aim of the manuscript is to provide a review on the available literature on ticks introduced to and exchanged between European countries via the live reptile trade. So far, the published reports of ticks imported on reptiles are limited to few European countries: Italy, Poland, Spain, Netherlands, Belgium, Slovenia and UK. The following species have been reported: Hyalomma aegyptium, Amblyomma dissimile, Amblyomma exornatum, Amblyomma flavomaculatum, Amblyomma fuscolineatum, Amblyomma latum, Amblyomma quadricavum, Amblyomma marmoreum, Amblyomma nuttalli, Amblyomma sparsum, Amblyomma sphenodonti, Amblyomma transversale and Amblyomma varanense. The majority of species are of African origin, followed by American and Asian species. All groups of reptiles (chelonians, snakes, lizards, crocodiles, tuataras) were involved. However, it seems that certain groups (i.e. tortoises of genus Testudo, monitor lizards of genus Varanus, snakes of genus Python) are more important as host for imported ticks, but this may be related to higher levels of international trade. Even fewer are the reports of tick-borne pathogens associated with imported reptile ticks. Despite the diversity of tick species reported on imported reptiles, the situations of truly invasive species are atypical and are limited in natural environments to maximum two cases where H. aegyptium was involved. Otherwise, the risk associated with reptile trade for introduction of invasive tick to Europe is low

  20. Arthropods and associated arthropod-borne diseases transmitted by migrating birds. The case of ticks and tick-borne pathogens.

    PubMed

    Sparagano, Olivier; George, David; Giangaspero, Annunziata; Špitalská, Eva

    2015-09-30

    Geographic spread of parasites and pathogens poses a constant risk to animal health and welfare, particularly given that climate change is expected to potentially expand appropriate ranges for many key species. The spread of deleterious organisms via trade routes and human travelling is relatively closely controlled, though represents only one possible means of parasite/pathogen distribution. The transmission via natural parasite/pathogen movement between geographic locales, is far harder to manage. Though the extent of such movement may be limited by the relative inability of many parasites and pathogens to actively migrate, passive movement over long distances may still occur via migratory hosts. This paper reviews the potential role of migrating birds in the transfer of ectoparasites and pathogens between geographic locales, focusing primarily on ticks. Bird-tick-pathogen relationships are considered, and evidence provided of long-range parasite/pathogen transfer from one location to another during bird migration events. As shown in this paper not only many different arthropod species are carried by migrating birds but consequently these pests carry many different pathogens species which can be transmitted to the migrating birds or to other animal species when those arthropods are dropping during these migrations. Data available from the literature are provided highlighting the need to understand better dissemination paths and disease epidemiology. Copyright © 2015 Elsevier B.V. All rights reserved.