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

BACKGROUND: Northeastern 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. RESULTS: In 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"). CONCLUSIONS: The 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.

First report in Italy of the exotic mosquito species Aedes (Finlaya) koreicus, a potential vector of arboviruses and filariae.

BACKGROUND: In the Veneto region (north-eastern Italy) an entomological surveillance system has been implemented since the introduction of the Asian tiger mosquito (Aedes albopictus) in 1991. During the routine monitoring activity in a tiger mosquito-free area, an unexpected mosquito was noticed, which clearly did not belong to the recorded Italian fauna. FINDINGS: At the end of May 2011, twelve larvae and pupae were collected in a small village in Belluno province (Veneto region) from a single manhole. Ten adults reared in the laboratory were morphologically and genetically identified as Aedes (Finlaya) koreicus (Edwards, 1917), a species native to Southeast Asia. The subsequent investigations carried out in the following months in the same village provided evidence that this species had become established locally. Entomological and epidemiological investigations are currently ongoing in the surrounding area, to verify the eventual extension of the species outside the village and to trace back the route of entry into Italy. CONCLUSIONS: This is the first report in Italy of the introduction of the exotic mosquito Ae. koreicus. This species has been shown experimentally to be competent in the transmission of the Japanese encephalitis virus and of the dog heartworm Dirofilaria immitis and is considered a potential vector of other arboviruses. Thus, the establishment of this species may increase the current risk or pose new potential threats, for human and animal health. This finding considerably complicates the entomological monitoring of the Asian tiger mosquito Ae. albopictus in Italy and stresses the importance of implementing the entomological surveillance for the early detection of and the rapid response against invasive mosquito species.