Wild animals are obviously important for the maintenance of ticks and the long-term persistence of pathogens, often serving as a blood meal resource and reservoirs or amplification hosts, respectively ( Lorusso et al., 2011 ; Rizzoli et al., 2014). Among others, red foxes are the most monitored wild carnivorous species in Europe, mainly due to their high population densities and wide distribution (Mitková et al., 2017). Say no to plagiarism. Get Custom Essay on “Why Violent Video Games Should Not Be Banned”?Get Original Essay As a result, they have been suggested as reservoirs of several PADs, including those affecting pets and humans (Cardoso et al., 2015; Hodžić et al., 2015; Liesner et al., 2016; Ebani et al., 2017), but their reservoir status has not yet been proven (Lorusso et al., 2011). The main objective of the present project was to study the presence and genetic diversity of tick-associated pathogens in foxes and to estimate their reservoir competence based on the data obtained here and those available in the published scientific literature . To test our hypothesis (H1), we analyzed blood and spleen samples from 506 foxes from two westernmost Austrian provinces, Tyrol and Vorarlberg, for common arthropod-derived pathogens. vectors (Publication 1). Following an in-depth molecular study, it was found that Austrian foxes harbor a significant number of pathogens of veterinary and public health importance, including: Babesia Canis, Babesia cf. microti (syn. Theileria annae, Babesia microti-like, Babesia vulpes), Hepatozoon canis, Anaplasma phagocytophilum, Candidatus Neoehrlichia sp. (FU98) and Bartonella rochalimae. In accordance with the results of other European studies (Duscher et al., 2014; Hodžić et al., 2015; Tolnai et al., 2015; Ebani et al., 2017), Babesia cf. microti and H. Cranes were the most prevalent pathogens in the foxes studied. The high prevalence and wide geographical distribution of these two hematozoan parasites infecting foxes almost everywhere in Europe are the main reasons why they have been proposed as the main candidate reservoir. However, the high rate of infections itself does not necessarily qualify the host as a reservoir (Rizzoli et al., 2014; Alvarado-Rybak et al., 2016; Hodo and Hamer, 2017) and only indicates exposure to the pathogen or its pathogen. carrier status (Estrada-Peña and de la Fuente, 2014; Hodo and Hamer, 2017). Therefore, the reservoir role of a certain animal species can only be unequivocally demonstrated through xenodiagnosis and transmission experiments (Rizzoli et al., 2014). Unfortunately, such studies are rare and have not been carried out for most PBTs, so the reservoir status of wild animals, especially carnivores, involved in their natural transmission cycles still remains unknown (Rizzoli et al ., 2014). This mainly reflects the difficulties associated with maintaining long-term colonies of wild animals in captivity for experimental transmission studies (Roque and Jansen, 2014). However, prevalence, combined with other data, provides a constructive framework for estimating reservoir potential in the absence of such experimental studies (Gürtler and Cardinal, 2015; Hodo and Hamer, 2017). The conceptual approach has already been used to assess the competence of reservoir hosts and the role of domestic and wild species in the transmission of Trypanosoma cruzi (Kinetoplastida:Trypanosomatidae), and it can be applicable to any multi-host pathogen transmission system (Gürtler and Cardinal, 2015; Hodo and Hamer, 2017), including Babesia cf. microti and H. canis. Therefore, the results of the thesis are discussed in light of the following criteria: (1) host susceptibility, (2) contagiousness of the host to the tick vector, (3) tick-host contact and (4) host-parasite haplotype associations. Relative host susceptibility is defined as the proportion or probability that the exposed animal host is infected, and it can be calculated from epidemiological studies reporting the prevalence of infections (Hodo and Hamer, 2017). Babesia cf. microti and H. canis are evidently the most common parasites harbored by red foxes in Europe, with overall detection rates ranging from 1% (Zanet et al., 2014) to 69.2% (Cardoso et al., 2013 ) and 7.8% (Farkas et al., 2014) to 100% (Criado-Fornelio et al., 2003), respectively (Supplementary Material). The large discrepancy in prevalence between studies may be attributed to geographic locality, abundance and density of tick vectors, red fox population size, and sensitivity of PCR tests (Cardoso et al ., 2013). However, the results of our study revealed that the infection rate is highly dependent on the tissue used for molecular detection. We observed that blood is statistically more frequently infected with Babesia cf. microti compared to the spleen, while the spleen has a higher level of H. canis infection than the blood. Therefore, an overall global prevalence of infection, i.e. total number of positive animals/total number of animals tested in all published reports, should be used for comparison (Hodo and Hamer, 2017) instead of direct comparison of prevalence, as it is often misleading (Gürtler and Cardinal, 2015). An overall infection rate greater than 20% has been proposed as one of the criteria used for reservoir host identification (Gürtler and Cardinal, 2015). The overall overall prevalence of Babesia cf. microti and H. canis in foxes in Europe, calculated from available molecular genetic studies, are estimated at 23.9% and 28.4%, respectively (Supplementary Material). Nevertheless, golden jackals (Canis aureus) and raccoon dogs (Nyctereutes procyonoides) are two other wild carnivore species recently recognized as suitable hosts and potential reservoirs for Babesia cf. microti (Mitková et al., 2017; Duscher et al., 2017) and H. canis (Duscher et al., 2013; Farkas et al., 2014; Mitková et al., 2017). However, their role in the eco-epidemiology of blood parasites is uncertain and requires further studies involving a larger number of samples from different geographical regions. Furthermore, the ability of a suspected reservoir host to infect a tick vector (host infectivity) is not evenly distributed in the host population, and the mode of transmission is primarily determined by the host ( for example, genetic makeup, body mass, sex, behavior) and by environment. factors (Hersh et al., 2012; Roque and Jansen, 2014). As a result, the reservoir capacity of a given host animal may be different across localities and times (Estrada-Peña and de la Fuente, 2014). In the absence of xenodiagnostic investigations, the presence of a parasite in the blood observed by cytology or PCR can be used as an indicator to calculate the infectivity index (Hodo and Hamer, 2017). The number of studies in which blood has been used for parasite detection in foxes is considerably smaller than that using spleens and has shown an overall infectivity index for Babesia cf. microti and H. canis by 39.1% and 19.5%,..