The α-Gal syndrome (AGS) is a type of allergy characterized by an IgE antibody (Ab) response against the carbohydrate Galα1-3Galβ1-4GlcNAc-R (α-Gal), which is present in glycoproteins from tick saliva and tissues of non-catarrhine mammals. Recurrent tick bites induce high levels of anti-α-Gal IgE Abs that mediate delayed hypersensitivity to consumed red meat products in humans. This was the first evidence that tick glycoproteins play a major role in allergy development with the potential to cause fatal delayed anaphylaxis to α-Gal-containing foods and drugs and immediate anaphylaxis to tick bites. Initially, it was thought that the origin of tick-derived α-Gal was either residual blood meal mammalian glycoproteins containing α-Gal or tick gut bacteria producing this glycan. However, recently tick galactosyltransferases were shown to be involved in α-Gal synthesis with a role in tick and tick-borne pathogen life cycles. The tick-borne pathogen Anaplasma phagocytophilum increases the level of tick α-Gal, which potentially increases the risk of developing AGS after a bite by a pathogen-infected tick. Two mechanisms might explain the production of anti-α-Gal IgE Abs after tick bites. The first mechanism proposes that the α-Gal antigen on tick salivary proteins is presented to antigen-presenting cells and B-lymphocytes in the context of Th 2 cell-mediated immunity induced by tick saliva. The second mechanism is based on the possibility that tick salivary prostaglandin E2 triggers Immunoglobulin class switching to anti-α-Gal IgE-producing B cells from preexisting mature B cells clones producing anti-α-Gal IgM and/or IgG. Importantly, blood group antigens influence the capacity of the immune system to produce anti-α-Gal Abs which in turn impacts individual susceptibility to AGS. The presence of blood type B reduces the capacity of the immune system to produce anti-α-Gal Abs, presumably due to tolerance to α-Gal, which is very similar in structure to blood group B antigen. Therefore, individuals with blood group B and reduced levels of anti-α-Gal Abs have lower risk to develop AGS. Specific immunity to tick α-Gal is linked to host immunity to tick bites. Basophil activation and release of histamine have been implicated in IgE-mediated acquired protective immunity to tick infestations and chronic itch. Basophil reactivity was also found to be higher in patients with AGS when compared to asymptomatic α-Gal sensitized individuals. In addition, host resistance to tick infestation is associated with resistance to tick-borne pathogen infection. Anti-α-Gal IgM and IgG Abs protect humans against vector-borne pathogens and blood group B individuals seem to be more susceptible to vector-borne diseases. The link between blood groups and anti-α-Gal immunity which in turn affects resistance to vector-borne pathogens and susceptibility to AGS, suggests a trade-off between susceptibility to AGS and protection to some infectious diseases. The understanding of the environmental and mole...

BackgroundAlveolar echinococcosis (AE) is a severe helminth disease affecting humans, which is caused by the fox tapeworm Echinococcus multilocularis. AE represents a serious public health issue in larger regions of China, Siberia, and other regions in Asia. In Europe, a significant increase in prevalence since the 1990s is not only affecting the historically documented endemic area north of the Alps but more recently also neighbouring regions previously not known to be endemic. The genetic diversity of the parasite population and respective distribution in Europe have now been investigated in view of generating a fine-tuned map of parasite variants occurring in Europe. This approach may serve as a model to study the parasite at a worldwide level.Methodology/Principal FindingsThe genetic diversity of E. multilocularis was assessed based upon the tandemly repeated microsatellite marker EmsB in association with matching fox host geographical positions. Our study demonstrated a higher genetic diversity in the endemic areas north of the Alps when compared to other areas.Conclusions/SignificanceThe study of the spatial distribution of E. multilocularis in Europe, based on 32 genetic clusters, suggests that Europe can be considered as a unique global focus of E. multilocularis, which can be schematically drawn as a central core located in Switzerland and Jura Swabe flanked by neighbouring regions where the parasite exhibits a lower genetic diversity. The transmission of the parasite into peripheral regions is governed by a “mainland–island” system. Moreover, the presence of similar genetic profiles in both zones indicated a founder event.

BackgroundRed foxes (Vulpes vulpes) have recently been recognized as potential reservoirs of several vector-borne pathogens and a source of infection for domestic dogs and humans, mostly due to their close vicinity to urban areas and frequent exposure to different arthropod vectors. The aim of this study was to investigate the presence and distribution of Babesia spp., Hepatozoon canis, Anaplasma spp., Bartonella spp., ‘Candidatus Neoehrlichia mikurensis’, Ehrlichia canis, Rickettsia spp. and blood filaroid nematodes in free-ranging red foxes from Bosnia and Herzegovina.MethodsSpleen samples from a total of 119 red foxes, shot during the hunting season between October 2013 and April 2014 throughout Bosnia and Herzegovina, were examined for the presence of blood vector-borne pathogens by conventional PCRs and sequencing.ResultsIn the present study, three species of apicomplexan parasites were molecularly identified in 73 red foxes from the entire sample area, with an overall prevalence of 60.8%. The DNA of B. canis, B. cf. microti and H. canis was found in 1 (0.8%), 38 (31.9%) and 46 (38.6%) spleen samples, respectively. In 11 samples (9.2%) co-infections with B. cf. microti and H. canis were detected and one fox harboured all three parasites (0.8%). There were no statistically significant differences between geographical region, sex or age of the host in the infection prevalence of B. cf. microti, although females (52.9%; 18/34) were significantly more infected with H. canis than males (32.9%; 28/85). The presence of vector-borne bacteria and filaroid nematodes was not detected in our study.ConclusionThis is the first report of B. canis, B. cf. microti and H. canis parasites in foxes from Bosnia and Herzegovina and the data presented here provide a first insight into the distribution of these pathogens among the red fox population. Moreover, the relatively high prevalence of B. cf. microti and H. canis reinforces the assumption that this wild canid species might be a possible reservoir and source of infection for domestic dogs.

BackgroundDirofilaria repens and D. immitis are filarioid helminths with domestic and wild canids as main hosts and mosquitoes as vectors. Both species are known to cause zoonotic diseases, primarily pulmonary (D. immitis), ocular (D. repens), and subcutaneous (D. repens) dirofilariosis. Both D. immitis and D. repens are known as invasive species, and their distribution seems associated with climate change. Until very recently, both species were known to be nonendemic in Austria.Methodology and Principal FindingsMetadata on introduced and possibly autochthonous cases of infection with Dirofilaria sp. in dogs and humans in Austria are analysed, together with analyses of mosquito populations from Austria in ongoing studies.In Austria, most cases of Dirofilaria sp. in humans (30 cases of D. repens—six ocular and 24 subcutaneous) and dogs (approximately 50 cases—both D. immitis and D. repens) were most likely imported. However, occasionally infections with D. repens were discussed to be autochthonous (one human case and seven in dogs). The introduction of D. repens to Austria was confirmed very recently, as the parasite was detected in Burgenland (eastern Austria) for the first time in mosquito vectors during a surveillance program. For D. immitis, this could not be confirmed yet, but data from Germany suggest that the successful establishment of this nematode species in Austria is a credible scenario for the near future.ConclusionsThe first findings of D. repens in mosquito vectors indicate that D. repens presumably invaded in eastern Austria. Climate analyses from central Europe indicate that D. immitis also has the capacity to establish itself in the lowland regions of Austria, given that both canid and culicid hosts are present.

BackgroundIn Europe, hard ticks of the subgenus Pholeoixodes (Ixodidae: Ixodes) are usually associated with burrow-dwelling mammals and terrestrial birds. Reports of Pholeoixodes spp. from carnivores are frequently contradictory, and their identification is not based on key diagnostic characters. Therefore, the aims of the present study were to identify ticks collected from dogs, foxes and badgers in several European countries, and to reassess their systematic status with molecular analyses using two mitochondrial markers.ResultsBetween 2003 and 2017, 144 Pholeoixodes spp. ticks were collected in nine European countries. From accurate descriptions and comparison with type-materials, a simple illustrated identification key was compiled for adult females, by focusing on the shape of the anterior surface of basis capituli. Based on this key, 71 female ticks were identified as I. canisuga, 21 as I. kaiseri and 21 as I. hexagonus. DNA was extracted from these 113 female ticks, and from further 31 specimens. Fragments of two mitochondrial genes, cox1 (cytochrome c oxidase subunit 1) and 16S rRNA, were amplified and sequenced. Ixodes kaiseri had nine unique cox1 haplotypes, which showed 99.2–100% sequence identity, whereas I. canisuga and I. hexagonus had eleven and five cox1 haplotypes, respectively, with 99.5–100% sequence identity. The distribution of cox1 haplotypes reflected a geographical pattern. Pholeoixodes spp. ticks had fewer 16S rRNA haplotypes, with a lower degree of intraspecific divergence (99.5–100% sequence identity) and no geographical clustering. Phylogenetic analyses were in agreement with morphology: I. kaiseri and I. hexagonus (with the similar shape of the anterior surface of basis capituli) were genetically more closely related to each other than to I. canisuga. Phylogenetic analyses also showed that the subgenus Eschatocephalus (bat ticks) clustered within the subgenus Pholeoixodes.ConclusionsA simple, illustrated identification key is provided for female Pholeoixodes ticks of carnivores (including I. hexagonus and I. rugicollis) to prevent future misidentification of these species. It is also shown that I. kaiseri is more widespread in Europe than previously thought. Phylogenetic analyses suggest that the subgenus Pholeoixodes is not monophyletic: either the subgenus Eschatocephalus should be included in Pholeoixodes, or the latter subgenus should be divided, which is a task for future studies.

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.

The neozoan species raccoon dog (Nyctereutes procyonoides) and raccoon (Procyon lotor) are widespread in Europe and potential vectors of many diseases that can threaten human and domestic animal health. Facing a further spread of these species, it is important to know about (i) pathogens imported and/or (ii) pathogens acquired in the new habitat. Thus, we investigated the parasite fauna of wild raccoon dogs and raccoons from Austria, at the edge of their new distribution range. The eight examined raccoons were nearly free of pathogens including Baylisascaris procyonis, and thus assumed to have a low epidemiological impact, so far. Out of ten raccoon dog specimens, we found one from western Austria to be infected with Echinococcus multilocularis and another three from the eastern wetland regions to harbour adults of Alaria alata. Furthermore, we detected Babesia cf. microti in five of eight raccoon dogs all over Austria but none of our samples were tested positive for Trichinella spp. Nevertheless, the raccoon dog seems to be a relevant host, at least for the zoonotic pathogens E. multilocularis and A. alata, and we suggest to further monitor the raccoon dogs parasite fauna.

BackgroundEffective control of tick infestation and pathogen transmission requires profound knowledge of tick biology in view of their vector function. The particular time of the year when the different tick species start to quest and the favoured sites on the canine host are of major interest. The efficacy of acaricides/repellents to control ticks in the field requires observation.MethodsTo address these issues, 90 dogs, grouped in “untreated”, “acaricide/repellent” (permethrin) and “acaricide only” (fipronil) animals and subjected to tick infestation under natural conditions in Burgenland (Eastern Austria), were examined. The number and species of ticks occurring during and outside the protection time was evaluated during a period of 11 months and the biting location on the dogs’ skin was recorded.ResultsOf the 700 ticks collected, the most common species in that particular walking area was Ixodes ricinus, followed by Dermacentor reticulatus and Haemaphysalis concinna. Regarding the on-host activity, D. reticulatus displayed more infestations in early spring and late autumn, whereas I. ricinus occurred almost one month later in spring and one month earlier in autumn. H. concinna followed a monophasic pattern of activity with a peak in summer. The preferred feeding sites of the ticks on the dogs were on the head, neck, shoulder and chest. This distribution over the dog’s body was not influenced by the use of the drugs, although on the whole fewer ticks (22.5% of all ticks) were found during the protection time. Interestingly, differences occurred with the use of drugs compared to non-protected dogs with regard to the infestation over the year. Acaricide-treated dogs displayed a higher prevalence in April, May and September, whereas dogs of the acaricide/repellent group showed a higher infestation in March, July, October and November.ConclusionThe different tick species display different on-dog activity peaks over the year, during which particular canine diseases can be expected and predicted, considering the specific incubation times for each pathogen.The tick species occurring in this study do not seem to choose particular sites on the dogs. Their arrival place seems to represent the attachment and consequently the feeding sites. The use of acaricides leads to a significantly (p<0.01) lower number of infesting ticks but no change of the distribution pattern on the dogs was observed.