Borrelia miyamotoi is a relapsing fever spirochete, first identified in Japan and later detected in various Ixodes species across the northern hemisphere. The pathogen was linked to human infections in North America, Europe, Asia, and Russia, causing symptoms ranging from flu-like illness to severe neurological damage. This study aimed to assess the presence of B. miyamotoi in Ixodes ricinus ticks collected from wildlife, dogs, and humans in Lombardy, Northern Italy, between 2020 and 2023. A total of 3,886 ticks were sampled, with a 1% positivity rate. The spirochete was detected in all life stages of ticks, with sequences 100% identical to European strains. The pathogen was found mostly in northern mountain regions. Although no human cases have been reported in Italy, these areas pose a potential risk due to high tourist activity.
CrowderCD, CarolanHE, RoundsMA, et al.Prevalence of Borrelia miyamotoi in Ixodes ticks in Europe and the United States. Emerg Infect Dis, 2014; 20(10):1678–1682.
3.
CutlerSJ, Vayssier-TaussatM, Estrada-PeñaA, et al.A new Borrelia on the block: Borrelia miyamotoi - a human health risk? Euro Surveill, 2019; 24(18):1800170; doi: 10.2807/1560-7917.ES.2019.24.18.1800170
4.
FukunagaM, TakahashiY, TsurutaY, et al.Genetic and phenotypic analysis of Borrelia miyamotoi sp. nov., isolated from the ixodid tick Ixodes persulcatus, the vector for Lyme disease in Japan. Int J Syst Evol Microbiol, 1995; 45(4):804–810.
5.
HoornstraD, AzagiT, van EckJA, et al.Prevalence and clinical manifestation of Borrelia miyamotoi in Ixodes ticks and humans in the northern hemisphere: A systematic review and meta-analysis. Lancet Microbe, 2022; 3(10):e772–e786.
6.
HoviusJW, de WeverB, SohneM, et al.A case of meningoencephalitis by the relapsing fever spirochaete Borrelia miyamotoi in Europe. Lancet, 2013; 382(9892):658.
7.
Iwabu-ItohY, BazartserenB, NaranbaatarO, et al.Tick surveillance for Borrelia miyamotoi and phylogenetic analysis of isolates in Mongolia and Japan. Ticks Tick Borne Dis, 2017; 8(6):850–857.
8.
KrausePJ, FishD, NarasimhanS, et al.Borrelia miyamotoi infection in nature and in humans. Clin Microbiol Infect, 2015; 21(7):631–639; doi: 10.1016/j.cmi.2015.02.006
9.
KubiakK, SzczotkoM, DmitryjukM. Borrelia miyamotoi—an emerging human tick-borne pathogen in Europe. Microorganisms, 2021; 9(1): 113–154; doi: 10.3390/microorganisms9010154
10.
LiberskaJA, MichalikJF, DabertM. Exposure of dogs and cats to Borrelia miyamotoi infected Ixodes ricinus ticks in urban areas of the city of Poznań, west-central Poland. Ticks Tick Borne Dis, 2023; 14(4):102188.
PlatonovAE, KaranLS, KolyasnikovaNM, et al.Humans infected with relapsing fever spirochete Borrelia miyamotoi, Russia. Emerg Infect Dis, 2011; 17(10):1816–1823; doi: 10.3201/eid1710.101474
13.
RavagnanS, TomassoneL, MontarsiF, et al.First detection of Borrelia miyamotoi in Ixodes ricinus ticks from northern Italy. Parasit Vectors, 2018; 11(1):130–2019; doi: 10.1186/s13071-018-2713-z
14.
Vayssier-TaussatM, MoutaillerS, MicheletL, et al.Next generation sequencing uncovers unexpected bacterial pathogens in ticks in western Europe. PLoS One, 2013; 8(11):e81439.
