Geographical Distribution of Tick Species and Tick-Borne Pathogens in Italy (2000–2022): A Systematic Review

Background: Italy hosts a wide diversity of tick species and tick-borne pathogens (TBPs), with documented expansions in their distribution driven by environmental, ecological, and climatic changes. Although numerous studies have investigated their presence, available data remain fragmented and heterogeneous, limiting a comprehensive national overview. Materials and Methods: This systematic review searched for studies published between January 2000 and December 2022 reporting the presence, prevalence, or geographical distribution of ticks and/or TBPs in Italy. A two-level screening process was conducted by 24 reviewers working in pairs, with conflicts resolved by a third reviewer. Eligible studies included primary field investigations on wild or domestic animals, humans, or the environment, with morphological or molecular identification of tick species and laboratory-confirmed detection of TBPs. Data were extracted into a structured database, analyzed using R software, and synthesized descriptively with spatial mapping of tick and pathogen distribution. Results: Of 12,017 records identified, 356 studies met the inclusion criteria, reporting 43 tick species, with Ixodes ricinus, Rhipicephalus sanguineus s.l., Hyalomma marginatum , and Dermacentor marginatus being the most widely distributed. The most frequently reported pathogens were Anaplasma phagocytophilum , Rickettsia spp., and Borrelia burgdorferi s.l. Substantial heterogeneity in study design and geographic coverage limited quantitative comparisons, although the dataset covered 78.5% of Italian provinces. This review provides a comprehensive overview of ticks and TBPs in Italy and identifies priority areas for future surveillance and research within a One Health framework.