Ticks are more suitable than red foxes for monitoring zoonotic tick-borne pathogens in northeastern Italy

Abstract

BackgroundNortheastern Italy is a hotspot for several tick-borne pathogens, transmitted to animals and humans mainly by Ixodes ricinus. Here we compare the results of molecular monitoring of ticks and zoonotic TBPs over a six-year period, with the monitoring of red foxes (Vulpes vulpes) in an endemic area.ResultsIn the period 2011–2016, 2,578 ticks were collected in 38 sites of 20 municipalities of Belluno Province. Individual adults (264), pooled larvae (n = 330) and nymphs (n = 1984) were screened for tick-borne encephalitis virus, Borrelia burgdorferi (s.l.), Rickettsia spp., Babesia spp., Anaplasma phagocytophilum and “Candidatus Neoehrlichia mikurensis” by specific SYBR green real-time PCR assays and sequencing. The spleens of 97 foxes, culled in the period 2015–2017 during sport hunting or population control programs, were also screened. Overall, nine different pathogens were found in I. ricinus nymph and adult ticks: Rickettsia helvetica (3.69%); R. monacensis (0.49%); four species of the B. burgdorferi (s.l.) complex [B. afzelii (1.51%); B. burgdorferi (s.s.) (1.25%); B. garinii (0.18%); and B. valaisiana (0.18%)]; A. phagocytophilum (3.29%); “Candidatus N. mikurensis” (1.73%); and Babesia venatorum (0.04%). Larvae were collected and screened in the first year only and two pools (0.6%) were positive for R. helvetica. Tick-borne encephalitis virus was not found in ticks although human cases do occur in the area. The rate of infection in ticks varied widely according to tick developmental stage, site and year of collection. As expected, adults were the most infected, with 27.6% harboring at least one pathogen compared to 7.3% of nymphs. Pathogens with a minimum infection rate above 1% were recorded every year. None of the pathogens found in ticks were detectable in the foxes, 52 (54%) of which were instead positive for Babesia cf. microti (also referred to as Babesia microti-like, “Theileria annae”, “Babesia annae” and “Babesia vulpes”).ConclusionsThe results show that foxes cannot be used as sentinel animals to monitor tick-borne pathogens in the specific epidemiological context of northeastern Italy. The high prevalence of Babesia cf. microti in foxes and its absence in ticks strongly suggests that I. ricinus is not the vector of this pathogen.Electronic supplementary materialThe online version of this article (10.1186/s13071-018-2726-7) contains supplementary material, which is available to authorized users.

Molecular Survey on Vector-Borne Pathogens in Alpine Wild Carnivorans

“…Lower prevalence has been detected in Spain (40), Germany (41), Hungary (42) and Slovakia (43) (72.2, 46.4, 20, and 9.7%, respectively). In Italy, previous findings have showed variable results depending on the geographical area, ranging from <1 to 54% (21)(22)(23)44). Most of the foxes in the present study were found to be infected with B. vulpes, as already reported in Spain (45), Italy (46), Croatia (47), Germany (41), Portugal (39), and Austria (31).…”

Diversity of Anaplasma and Ehrlichia/Neoehrlichia Agents in Terrestrial Wild Carnivores Worldwide: Implications for Human and Domestic Animal Health and Wildlife Conservation

“…Even though wild carnivores have been incriminated as sentinels for Anaplasmataceae agents in natural environments, as well as in degraded and periurban areas ( 29 , 31 ) emphasized that the molecular screening of TBPs in vector ticks represents a more efficient system than the screening of foxes as sentinel animals in the specific epidemiological context of northeastern Italy (Belluno Province). Despite the detection of A. phagocytophilum and “ Candidatus Neoehrlichia mikurensis” in Ixodes ricinus nymphs and adults, all sampled foxes ( n = 97) were negative to Anaplasmataceae agents.…”

Sequencing-based phylogenetic-study of Babesia spp detected in tick tissues in Al-Diwaniyah province, Iraq

“…Babesia-species members are globally recognized for their huge damages that they cause to the world industries of herds (2). Babesiosis is a tick-borne disease that generates a blood-based disease in different animals such as cows (3). Different genera and species of ticks such as Hyalomma and Rhipicephalus are well-known for their enhancement to transmit Babesia species to different animals (4).…”