Prevalence and Risk Factors of Borrelia burgdorferi Sensu Lato IgG Antibodies Among Blood Donors in Western Romania.

Borrelia burgdorferi sensu lato is a complex of spirochetes that includes the main pathogenic species B. burgdorferi sensu stricto, B. afzelii, and B. garinii, the causative agents of Lyme disease. Our aim was to determine the seroprevalence of anti-Borrelia IgG antibodies and assess associated risk factors among blood donors from Western Romania. We conducted a cross-sectional study of 1347 consecutive donors at the Regional Blood Transfusion Center in Timisoara, Western Romania, between November and December 2018. Participants completed an epidemiological questionnaire and serum samples were tested for IgG antibodies against B. burgdorferi sensu lato using the VIDAS® Lyme IgG assay. The overall seroprevalence was 2.08% (28/1347). Individuals aged 46-55 years had the highest prevalence (3.79%) and a more than fivefold increased risk compared to those aged 18-25 years (aOR = 4.77; 95% CI: 1.24-18.27; p = 0.023). Soil exposure was also independently associated with higher seropositivity (aOR = 2.37; 95% CI: 1.10-5.09; p = 0.027). Other factors, including residence, gender, and pet ownership, showed no significant associations. Our findings provide new epidemiological data for Romania and emphasize the importance of environmental exposures in shaping Borrelia seroprevalence.