<i>Borrelia miyamotoi</i> in <i>Ixodes ricinus</i> Ticks Removed from Hosts in Northern Italy

<i>Borrelia miyamotoi</i> is a relapsing fever spirochete, first identified in Japan and later detected in various <i>Ixodes</i> 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 <i>B. miyamotoi</i> in <i>Ixodes ricinus</i> 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.