Molecular detection of Borrelia burgdorferi sensu lato in questing ticks: One year of sampling in Bologna (Northern Italy)

Borrelia burgdorferi sensu lato (s.l.) includes several genospecies responsible for Lyme borreliosis (LB), a major zoonotic disease transmitted by Ixodes spp. ticks. In Western Europe, LB incidence has risen in recent decades, with documented expansion into previously non-endemic regions. A cross-sectional study was conducted in peri-urban areas of Bologna, Emilia-Romagna (north-eastern Italy), from February to November 2024 to assess the presence of B. burgdorferi s.l. in questing ticks using real-time PCR. A total of 887 ticks were collected by dragging across 24 sites, including urban parks, school gardens, and forested areas. The 887 ticks were pooled into 130 samples and screened for B. burgdorferi s.l., resulting in an overall estimated prevalence of 10% in nymphs (95% CI 6.6–13.5) and 8% in adults (95% CI 1.4–22.7). This study provides the first prevalence estimate of B. burgdorferi s.l. in ticks within the municipality of Bologna. Pathogen detection in highly frequented peri-urban sites indicates a concrete exposure risk for human and animals. These findings support the need for strengthen local surveillance and targeted prevention strategies in line with One Health principles.