Ticks (Acari: Ixodidae) on birds migrating to the island of Ponza, Italy, and the tick-borne pathogens they carry

Seasonal migration of birds between breeding and wintering areas can facilitate the spread of tick species and tick-borne diseases. In this study, 151 birds representing 10 different bird species were captured on Ponza Island, an important migratory stopover off the western coast of Italy and screened for tick infestation. Ticks were collected and identified morphologically. Morphological identification was supported through sequencing a fragment of the 16S mitochondrial gene. In total, 16 captured birds carried ticks from four tick species: Hyalomma rufipes(n = 14), Amblyomma variegatum(n = 1), Amblyommasp. (n = 1), and Ixodes ventalloi(n = 2). All specimens were either larvae (n = 2) or nymphs (n = 16). All ticks were investigated for tick-borne pathogens using published molecular methods. Rickettsia aeschlimanniiwas detected in six of the 14 collected H. rufipesticks. Additionally, the singular A. variegatumnymph tested positive for R. africae. In all 14 H. rufipesspecimens (2 larvae and 12 nymphs), Francisella-like endosymbionts were detected. Four H. rufipesticks tested positive for Borrelia burgdorferisensu lato in a screening PCR but did not produce sufficient amplicon amounts for species identification. All ticks tested negative for tick-borne encephalitis virus, Crimean-Congo hemorrhagic fever virus, Coxiella burnetii, Coxiella-like organisms, Babesiaspp., and Theileriaspp. This study confirms the role of migratory birds in the spread and establishment of both exotic tick species and tick-borne pathogens outside their endemic range.