Spotted fever group rickettsiae in Dermacentor marginatus from wild boars in Italy

Abstract

Tick-borne diseases (TBDs) are of increasing concern in public health worldwide (Otranto et al., 2015). Several sociodemographic factors, as agricultural strategies and wildlife management, deforestation and global warming are strongly involved in the alteration of ecosystems, affecting the tick-host interaction and the circulation of tick-borne pathogens (TBPs) (Dantas-Torres et al., 2013;Estrada-Peña & de la Fuente, 2014). Due to the restriction of natural habitats, urbanization may seriously change the composition of wildlife communities and their associated tick populations (Faeth et al., 2011). Human-induced environmental changes may inadvertently select for synanthropic wild mammals, driving the rise of emerging infectious diseases (EIDs) (McFarlane et al., 2012). In this scenario, wild boars (Sus scrofa) have increased in terms of density throughout Europe, with high occurrence in several countries, including Italy (Pittiglio et al., 2018). The abundance of this mammal may seriously contribute to the maintenance of ticks in the environment in urban and peri-urban areas (Rizzoli et al., 2014) leading to a high risk of human exposure to them and the pathogens they transmit (Pfäffle et al., 2013).

Rickettsiales in Italy

“…R. raoultii [46,51,61,72,[83][84][85][86][87] and R. rioja [88], were both found in Italy in D. marginatus and, R. raoultii in other ticks like Ixodes spp. [48,52,62], Rhipicephalus spp.…”

“…Dermacentor ticks infected with the above rickettsiae were found prevalently in Tyrrhenian coast and western alps and have a period of activity cold season (from late fall to mid spring [186]). The tick species found infected were D. reticulatus [89] and D. marginatus [32,34,40,42,43,45,46,51,61,72,80,[83][84][85][86][87][88]90,92], the first was found only once in the western alps on a wild boar, the second was more commonly found. Other ticks involved in ecology of R. slovaca are Ha.…”

“…punctata [40], Hy. sulcata [34], I. ricinus [48,80,87], I. hexagonus [48], and R. sanguineus [42,51]. Wild boar appears to be the favorite host for infected Dermacentor spp., nonetheless R. slovaca was not found in ticks collected more often from one animal than others.…”

“…In consideration of the spread of flea infection found in Italy, it is possible that the disease may be present in Italy even if it is generally not sought. [32,43,47], Candidatus R. siciliensis [89], Candidatus R. mendelii [74], R. honei [40], R. tamurae [42], R. rioja [88], R. limoniae [70], R. raoultii [41,46,48,51,52,61,62,72,[83][84][85][86][87]. R. belli, interestingly, was identified in Crataerina pallida, an Hippoboscidae hematophagous dipter [54].…”

Hard Ticks (Ixodidae) from Wildlife in Liguria, Northwest Italy: Tick Species Diversity and Tick-Host Associations

“…Wild animals may be useful for characterizing and monitoring tick populations, and surveys on wildlife ticks' abundance and spatial distribution have been conducted in Europe and Italy [3,11,20,21]. However, data often rely on surveys concerning single tick species and their pathogens [15,22] or on ticks collected from the environment [9,10,12,14]. Data regarding hard-tick diversity and tick-host associations are particularly scarce in wild carnivores [3], and only sporadic data are available for some areas of southeastern Europe [9,23].…”