Surveillance of Tick-Borne Pathogens in Ticks from Humans in the Province of Verona, Italy (2018-2022): A Prospective Study

Microorganisms. 2025 Apr 23;13(5):965. doi: 10.3390/microorganisms13050965.

Abstract

In Italy, the epidemiology of tick-borne pathogens is still poorly characterized. This prospective study was conducted at the IRCCS Sacro Cuore Don Calabria Hospital in Negrar di Valpolicella (Verona), northeastern Italy, from 2018 to 2022. Ticks from asymptomatic individuals visiting the hospital after a recent tick bite were characterized using microscopy and tested for pathogens using molecular tests. A total of 317 ticks collected from 280 subjects were analyzed, with most identified as Ixodes species (95.6%), followed by Rhipicephalus spp. (0.6%) and Dermacentor spp. (0.3%). Molecular analysis was performed on 257 single ticks and 23 pooled samples. Overall, 15.4% tested positive for at least one pathogen. The most frequently detected pathogen was Borrelia spp. (n = 22, 7.8%), including B. afzeli (n = 8), B. miyamotoi (n = 6), B. valaisiana (n = 2), B. garinii (n = 2), Borrelia spp. (n = 2), B. burgdorferi sensu stricto (n = 1), and B. spielmanii (n = 1). Rickettsia spp. was detected in 20 samples (7.1%), comprising R. helvetica (n = 11), R. monacensis (n = 7), and Rickettsia spp. (n = 2). Other pathogens included Anaplasma phagocytophilum (n = 5, 1.8%), Babesia venatorum (n = 2, 0.7%), and tick-borne encephalitis virus (n = 1, 0.4%). This study calls for enhanced surveillance in the province of Verona to clarify these pathogens' clinical impact.

Keywords: Anaplasma; Babesia; Borrelia; Northern Italy; Rickettsia; TBE virus; human infection; zoonosis.