Browsing by Author "Sprong, H."
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- Bridging of cryptic Borrelia cycles in European songbirdsPublication . Heylen, D.; Krawczyk, A.; Lopes de Carvalho, I.; N uncio, M.S.; Sprong, H.; Norte, A.C.The principal European vector for Borrelia burgdorferi s.l., the causative agents of Lyme disease, is the host-generalist tick Ixodes ricinus. Almost all terrestrial host-specialist ticks have been supposed not to contribute to the terrestrial Borrelia transmission cycles. Through an experiment with blackbirds, we show successful transmission by the widespread I. frontalis, an abundant bird-specialized tick that infests a broad range of songbirds. In the first phase of the experiment, we obtained Borrelia-infected I. frontalis (infection rate: 19%) and I. ricinus (17%) nymphs by exposing larvae to wild blackbirds that carried several genospecies (Borrelia turdi, B. valaisiana, B. burgdorferi s.s.). In the second phase, pathogen-free blackbirds were exposed to these infected nymphs. Both tick species were able to infect the birds, as indicated by the analysis of xenodiagnostic I. ricinus larvae which provided evidence for both co-feeding and systemic transmission (infection rates: 10%-60%). Ixodes frontalis was shown to transmit B. turdi spirochetes, while I. ricinus transmitted both B. turdi and B. valaisiana. Neither species transmitted B. burgdorferi s.s. European enzootic cycles of Borrelia between songbirds and their ornithophilic ticks do exist, with I. ricinus potentially acting as a bridging vector towards mammals, including man.
- A comparative test of ixodid tick identification by a network of European researchersPublication . Estrada-Peña, A.; D'Amico, G.; Palomar, A.M.; Dupraz, M.; Fonville, M.; Heylen, D.; Habela, M.A.; Hornok, S.; Lempereur, L.; Madder, M.; Núncio, M.S.; Otranto, D.; Pfaffle, M.; Plantard, O.; Santos-Silva, M.M.; Sprong, H.; Vatansever, Z.; Vial, L.; Mihalca, A.D.This study reports the results of a comparative test of identification of ticks occurring in Western Europe and Northern Africa. A total of 14 laboratories were voluntarily enrolled in the test. Each participant received between 22 and 25 specimens of adult and nymphal ticks of 11 species: Dermacentor marginatus, D. reticulatus, Haemaphysalis punctata, Hyalomma lusitanicum, Hy. marginatum, Ixodes ricinus, I. hexagonus, Rhipicephalus annulatus, R. bursa, R. rossicus, and/or R. sanguineus s.l. Ticks were morphologically identified by three of the co-authors and the identification confirmed by a fourth co-author who used molecular methods based on several genes. Then ticks were randomly selected and blindly distributed among participants, together with a questionnaire. Only specimens collected while questing and, if possible, in the same survey, were circulated. Because of the random nature of the test, a participant could receive several specimens of the same species. Species in the different genera had variable misidentification rates (MR) of 7% (Dermacentor), 14% (Ixodes), 19% (Haemaphysalis), 36% (Hyalomma), and 54% (Rhipicephalus). Within genera, the MR was also variable ranging from 5.4% for I. ricinus or 7.4% for D. marginatus or D. reticulatus to 100% for R. rossicus. The test provided a total misidentification rate of 29.6% of the species of ticks. There are no significant differences in MR according to the sex of the tick. Participants were requested to perform a second round of identifications on the same set of ticks, using only purposely prepared keys (without illustrations), circulated to the enrolled participants, including 2 species of the genus Dermacentor, 8 of Haemaphysalis, 10 of Hyalomma, 23 of Ixodes, and 6 of Rhipicephalus. The average MR in the second round was 28%: 0% (Dermacentor), 33% (Haemaphysalis), 30% (Hyalomma) 18% (Ixodes), and 50% (Rhipicephalus). Species which are not reported in the countries of a participating laboratory had always highest MR, i.e. purely Mediterranean species had highest MR by laboratories in Central and Northern Europe. Participants expressed their concerns about a correct identification for almost 50% of the ticks of the genera Hyalomma and Rhipicephalus. The results revealed less than total confidence in identifying the most prominent species of ticks in the Western Palearctic, and underpin the need for reference libraries for specialists involved in this task. Results also showed that a combination of certain genes may adequately identify the target species of ticks.
- Detection of Anaplasma phagocytophilum, Candidatus Neoehrlichia sp., Coxiella burnetii and Rickettsia spp. in questing ticks from a recreational park, PortugalPublication . Santos, A.S.; de Bruin, A.; Veloso, A.R.; Marques, C.; Pereira da Fonseca, I.; De Sousa, R.; Sprong, H.; Santos-Silva, M.M.Tick-borne agents with medical relevance have been recorded in Portugal but little is known about their oc-currence in urban outdoor leisure areas. This study aimed to investigate ticks and tick-borne agents in threepublic parks of Lisbon’s metropolitan area. A total of 234 questing ticks belonging to eight species were found inParque Florestal de Monsanto (PFM). Ixodes ventalloi represented 40% of collections. Mitochondrial genesconfirmed Ixodes morphological identification, evidencing the intraspecific variability of I. ricinus and particu-larly I. frontalis populations. Regarding tick-borne agents, Rickettsia massiliae DNA were found in 21 (9.0%) ticks,Coxiella burnetii in 15 (6.4%), Anaplasma phagocytophilum in five (2.1%), an agent closely related to CandidatusNeoehrlichia mikurensis in two (0.9%), Rickettsia sibirica mongolitimonae and Rickettsia monacensis each in one(0.4%). Active enzootic cycles were suggested for these agents by the detection of positives in different timeperiods. Five tick species were founded with C. burnetii, including I. ventalloi which seems to be a new associationrecord. This tick was also the only species found positive for A. phagocytophilum and the Candidatus Neoehrlichiamikurensis-like agent. Two A. phagocytophilum variants were detected in PFM, one of them representing a po-tentially new ecotype already found in I. ventalloi from another Portuguese area. To the authors´ knowledge, thisis also the first report of such a Candidatus Neoehrlichia mikurensis-like microorganism. These data show aninteresting diversity of ticks and tick-borne agents with potential public health relevance in PFM, an urbanrecreational area commonly frequented by humans and their pets.
- Driving forces for changes in geographical distribution of Ixodes ricinus ticks in EuropePublication . Medlock, J.M.; Hansford, K.M.; Bormane, A.; Derdakova, M.; Estrada-Peña, A.; George, J-C; Golovljova, I.; Jaenson, T.G.; Jensen, J-K; Jensen, P.M.; Kazimirova, M.; Oteo, J.A.; Papa, A.; Pfister, K.; Plantard, O.; Randolph, S.E.; Rizzoli, A.; Santos-Silva, M.M.; Sprong, H.; Vial, L.; Hendrickx, G.; Zeller, H.; Van Bortel, W.Many factors are involved in determining the latitudinal and altitudinal spread of the important tick vector Ixodes ricinus (Acari: Ixodidae) in Europe, as well as in changes in the distribution within its prior endemic zones. This paper builds on published literature and unpublished expert opinion from the VBORNET network with the aim of reviewing the evidence for these changes in Europe and discusses the many climatic, ecological, landscape and anthropogenic drivers. These can be divided into those directly related to climatic change, contributing to an expansion in the tick's geographic range at extremes of altitude in central Europe, and at extremes of latitude in Scandinavia; those related to changes in the distribution of tick hosts, particularly roe deer and other cervids; other ecological changes such as habitat connectivity and changes in land management; and finally, anthropogenically induced changes. These factors are strongly interlinked and often not well quantified. Although a change in climate plays an important role in certain geographic regions, for much of Europe it is non-climatic factors that are becoming increasingly important. How we manage habitats on a landscape scale, and the changes in the distribution and abundance of tick hosts are important considerations during our assessment and management of the public health risks associated with ticks and tick-borne disease issues in 21st century Europe. Better understanding and mapping of the spread of I. ricinus (and changes in its abundance) is, however, essential to assess the risk of the spread of infections transmitted by this vector species. Enhanced tick surveillance with harmonized approaches for comparison of data enabling the follow-up of trends at EU level will improve the messages on risk related to tick-borne diseases to policy makers, other stake holders and to the general public.
- Guidelines for the Direct Detection of Anaplasma spp. in Diagnosis and Epidemiological StudiesPublication . Silaghi, C.; Santos, A.S.; Gomes, J.; Christova, I.; Matei, I.A.; Walder, G.; Domingos, A.; Bell-Sakyi, L.; Sprong, H.; von Loewenich, F.D.; Oteo, J.A.; de la Fuente, J.; Dumler, J.S.The genus Anaplasma (Rickettsiales: Anaplasmataceae) comprises obligate intracellular Gram-negative bacteria that are mainly transmitted by ticks, and currently includes six species: Anaplasma bovis, Anaplasma centrale, Anaplasma marginale, Anaplasma phagocytophilum, Anaplasma platys, and Anaplasma ovis. These have long been known as etiological agents of veterinary diseases that affect domestic and wild animals worldwide. A zoonotic role has been recognized for A. phagocytophilum, but other species can also be pathogenic for humans. Anaplasma infections are usually challenging to diagnose, clinically presenting with nonspecific symptoms that vary greatly depending on the agent involved, the affected host, and other factors such as immune status and coinfections. The substantial economic impact associated with livestock infection and the growing number of human cases along with the risk of transfusion-transmitted infections, determines the need for accurate laboratory tests. Because hosts are usually seronegative in the initial phase of infection and serological cross-reactions with several Anaplasma species are observed after seroconversion, direct tests are the best approach for both case definition and epidemiological studies. Blood samples are routinely used for Anaplasma spp. screening, but in persistently infected animals with intermittent or low-level bacteremia, other tissues might be useful. These guidelines have been developed as a direct outcome of the COST action TD1303 EURNEGVEC ("European Network of Neglected Vectors and Vector-Borne Diseases"). They review the direct laboratory tests (microscopy, nucleic acid-based detection and in vitro isolation) currently used for Anaplasma detection in ticks and vertebrates and their application.
- Host dispersal shapes the population structure of a tick-borne bacterial pathogenPublication . Norte, A.C.; Margos, G.; Becker, N.S.; Albino Ramos, J.; Núncio, M.S.; Fingerle, V.; Araújo, P.M.; Adamík, P.; Alivizatos, H.; Barba, E.; Barrientos, R.; Cauchard, L; Csörgő, T.; Diakou, A.; Dingemanse, N.J.; Doligez, B.; Dubiec, A.; Eeva, T.; Flaisz, B.; Grim, T.; Hau, M.; Hornok, S.; Kazantzidis, S.; Kováts, D.; Krause, F.; Literak, I.; Mänd, R.; Mentesana, L.; Morinay, J.; Mutanen, M.; Neto, J.M.; Nováková, M.; Sanz, J.J.; Pascoal da Silva, L.; Sprong, H.; Tirri, I.S.; Török, J.; Trilar, T.; Tyller, Z.; Visser, M.E.; Lopes de Carvalho, I.f ticks and their associated pathogens. The life cycle of tick-borne pathogens is complex and their evolutionary ecology is shaped by the interactions with vertebrate hosts and tick vectors (Kurtenbach et al., 2006). This study focused on the ecology and genetic diversity of B. burgdorferi s.l. as a model to investigate the drivers of the population structure and to understand the role of host- associated dispersal on the evolution of tick-borne pathogens. This represents a consequential question in the ecology and evolution of any pathogen. Borrelia burgdorferi s.l. is a bacterial complex of over 20 known genospecies, including the etiologic agents of Lyme borreliosis (Casjens et al., 2011; Margos et al., 2015), whose main vectors are ticks of the genus Ixodes (Eisen & Lane, 2002). These bacteria are widespread in Europe, Asia and North America and are also present in North Africa (Margos, Vollmer, Ogden, & Fish, 2011; Zhioua et al., 1999). Different Borrelia genospecies have different patterns of association with vertebrate reservoir hosts (Humair & Gern, 2000; Kurtenbach, Peacey, et al., 1998) because of the immunological host response, mediated by the action of the host's complement system (Kurtenbach et al., 2002). While B. burgdorferi sensu stricto (s.s.) is a generalist genospecies, Borrelia afzelii is mostly associated with mammalian hosts such as rodents, whereas Borrelia valaisiana, Borrelia garinii and Borrelia turdi are mostly associated with birds (Heylen, 2016; Margos et al., 2011). Because tick vectors cannot move large distances independent of hosts, it has been suggested that host specialization determines the spread and dispersal of B. burgdorferi s.l. genospecies (Kurtenbach et al., 2010; Sonenshine & Mather, 1994). Because birds are both important hosts for some Borrelia genospecies and for various species of vector ticks, they act as a driving force shaping B. burgdorferi s.l. distribution and phylogeographical patterns (Margos et al., 2011; Vollmer et al., 2011). Here, we assessed the role of passerine birds as hosts and dispersers of B. burgdorferi s.l. We tested the hypothesis that infection prevalence with Borrelia genospecie
- Host-parasite interactions between Borrelia burgdorferi s.l. and its avian reservoir hostsPublication . Norte, A.C.; Heylen, D.; Margos, G.; Fingerle, V.; Becker, N.; Araújo, P.M.; da Silva, L.P.; Sprong, H.; Krawczyk, A.; Costantini, D.; Eens, M.; Núncio, M.S.; Ramos, J.A.; Lopes de Carvalho, I.Borrelia burgdorferi sensu lato (s.l.) is maintained in enzootic cycles in nature by vertebrate reservoir hosts, including mammals, lizards and birds. To understand the eco-epidemiology of Lyme borreliosis it is necessary to evaluate the relationships among Borrelia genospecies, their tick vectors and vertebrate reservoir hosts. We surveyed infection prevalence in avian hosts and using wild birds as models, we performed transmission experiments, assessed the physiological impact of infection in reservoir hosts and how exposure to stress could affect the host’s infectivity to vector ticks. Additionally, we evaluated the population structure of an avian-associated Borrelia genospecies.
- Ixodes ventalloi: a vector role to be exploredPublication . Santos, A.S.; de Bruin, A.; Veloso, R.; Marques, C.; Pereira da Fonseca, I.; de Sousa, R.; Sprong, H.; Santos-Silva, M.M.Ixodes ventalloi is still a poorly studied tick and its public health relevance largely unknown. In Portugal it is known to share habitats with Ixodes ricinus in mainland littoral areas and to parasitize a variety of wild and domesticated animals and also humans. The potential involvement of I. ventalloi in the natural cycle of tick‐borne agents was first suggested by the detection of a new variant of Anaplasma phagocytophilum in questing and cat‐feeding ticks from Setúbal and Santarém, and is again questioned here. In this study we present the detection of A. phagocytophilum, Candidatus Neoehrlichia mikurensis and Coxiella burnetii in questing I. ventalloi collected from Parque Florestal de Monsanto (PFM), a Lisbon recreational park.
- Neglected vector-borne zoonoses in Europe: Into the wildPublication . Tomassone, L.; Berriatua, E; De Sousa, R.; Duscher, G.G.; Mihalca, A.D.; Silaghi, C.; Sprong, H.; Zintl, A.Wild vertebrates are involved in the transmission cycles of numerous pathogens. Additionally, they can affect the abundance of arthropod vectors. Urbanization, landscape and climate changes, and the adaptation of vectors and wildlife to human habitats represent complex and evolving scenarios, which affect the interface of vector, wildlife and human populations, frequently with a consequent increase in zoonotic risk. While considerable attention has focused on these interrelations with regard to certain major vector-borne pathogens such as Borrelia burgdorferi s.l. and tick-borne encephalitis virus, information regarding many other zoonotic pathogens is more dispersed. In this review, we discuss the possible role of wildlife in the maintenance and spread of some of these neglected zoonoses in Europe. We present case studies on the role of rodents in the cycles of Bartonella spp., of wild ungulates in the cycle of Babesia spp., and of various wildlife species in the life cycle of Leishmania infantum, Anaplasma phagocytophilum and Rickettsia spp. These examples highlight the usefulness of surveillance strategies focused on neglected zoonotic agents in wildlife as a source of valuable information for health professionals, nature managers and (local) decision-makers. These benefits could be further enhanced by increased collaboration between researchers and stakeholders across Europe and a more harmonised and coordinated approach for data collection.
- Pandora's flying box - Borrelia burgdorferi sensu lato prevalence in Ixodes species from birds throughout EuropePublication . Norte, A. C.; Ramos, J.A.; Núncio, M.S.; Margos, G.; Fingerle, V.; Adamik, P.; Alivizatos, H.; Barba, E.; Barrientos, R.; Cauchard, L.; Csörgo, T.; Diakou, A.; Dingemanse, N.J.; Doligez, B.; Dubiec, A.; Eeva, T.; Flaisz, B.; Grim, T.; Hau, M.; Heylen, D.; Hornok, S.; Kazantzidis, S.; Kováts, D.; Krause, F.; Literak, I.; Mänd, R.; Mentesana, L.; Morinay, J.; Mutanen, M.; Neto, J.; Nováková, M.; Sanz, J.J.; Silva, L.P.; Sprong, H.; Tirri, I.S.; Török, J.; Trilar, T.; Tyller, Z.; Visser, M.E.; Lopes de Carvalho, I.Birds are important hosts for ticks and may act as reservoirs for several zoonotic pathogens. Because of their high mobility, especially of the long distance migratory species, they can act as dispersers for ticks and pathogens, ultimately affecting their distribution and phylogeography.