Over eco-epidemiology of TBDs, and this mainly comes

Over the past
few decades, the incidence, diversity and geographic range of tick-borne
diseases (TBDs) have rapidly increased, and this mostly coincides with the
upsurge of scientific awareness and anthropogenic influence on biotic and
abiotic components of natural ecosystems (Aguirre, 2009; Estrada-Peña et al.,
2012; Alvarado-Rybak et al., 2016). Global warming, socio-demographic factors,
deforestation and reduction of wildlife habitats are believed to be the main underlying
factors facilitating the geographic expansion of ticks and emergence of
tick-borne pathogens (TBPs) (Estrada-Peña and de la Fuente, 2014; Tomassone et
al., 2018). However, many aspects of the pathogen and tick ecology depend on
vertebrate hosts (Sobrino et al., 2012; Pfäffle et al., 2013). Ticks are
wingless arthropods and their dispersal and distribution exclusively rely on
the host movement, often culminating in the introduction of pathogens into new
areas and non-resistant populations of wild animals (Aguirre, 2009). In this
manner, ticks may open new disease foci in environments where other arthropod
vectors (e.g. mosquitoes) are unable to transmit pathogenic microorganisms due
to the limiting abiotic factors (Pfäffle et al., 2013). Among terrestrial
vertebrates, wild carnivores seem to play a very important role in the
eco-epidemiology of TBDs, and this mainly comes from the fact that they have a
broad distribution range, and thus are commonly exposed to different ticks and
the associated pathogens (Labruna et al., 2005; Lorusso et al., 2011).
Moreover, wild carnivores serve as a food resource and maintenance hosts for
ticks, and as potential reservoirs they are essential for the pathogens
long-term persistence in natural and periurban settings (Rizzoli et al., 2014).
However, host abundance and wildlife community composition directly influence
the circulation of TBPs. Therefore, a risk of infections in both animals and
humans is proportional to the density of competent tick vectors and infected
reservoir hosts (Estrada-Peña and de la Fuente, 2014).

Europe has a
very rich diversity of terrestrial wild carnivores with 26 native species
divided into six families: Canidae (5 species), Felidae (4 species), Herpestidae
(1 species), Mustelidae (13 species), Ursidae (2 species) and Viverridae (1
species) (Temple and Terry, 2007). However, for the actual research project we
have chosen red fox (Vulpes vulpes Linnaeus,
1758) as an ideal research model system for testing our hypotheses because of
its biological and ecological plasticity. Foremost, the red fox has the widest
geographical distribution among the members of the order Carnivora and it is
highly adapted for living in urban and periurban areas (Hoffmann and
Sillero-Zubiri, 2016). Even with the constant hunting pressure, number of foxes
in Europe has been increasing, and they conservation status is classified as “Least
Concern” according to the IUCN Red List of Threatened Species (Hoffmann and
Sillero-Zubiri, 2016). Furthermore, the relatively wide home range, predatory behaviour
and dietary preference to small mammals and rodents, which may serve as
intermediate hosts, make foxes highly susceptible and frequently exposed to
many pathogenic agents (Duscher et al., 2015). Finally, as peridomestic
animals, foxes may pose a risk of infections for companion animals and humans (Otranto
et al., 2015).

Therewith,
European wild cat (Felis silvestris
silvestris Schreber, 1777) is another wild carnivore species with a wide
geographic range, but very limited population size in Europe (Otranto et al.,
2015). From an epidemiological standpoint, the wild cat merits attention as it
shares habitats and often interbreed with domestic cats producing fertile
hybrids (Otranto et al., 2015; Mattucci et al., 2016). The close interface
between these two genetically associated felids can lead to the bidirectional
exchange of arthropod vectors and pathogens they transmit (Otranto et al.,
2015). However, the scientific data on diversity of TBPs hosted by European
wild cats are scarce and limited to a very few reports.