Detection of Anti-<i>Borrelia burgdorferi</i> IgG Antibodies Among at Risk Workers in Iran; Time for Re-consideration?

Background: Lyme borreliosis is a significant zoonotic disease with global prevalence, and due to its severe complications, early diagnosis is crucial. Limited information is available about the disease in Iran. Objectives: Therefore, this study aimed to determine the frequency of IgG antibodies against Borrelia burgdorferi among high-risk personnel. Methods: In this cross-sectional study, serum samples were collected from 91 out of 450 employees working at the main industrial slaughterhouse in Mashhad, northeast Iran. Relevant information from the participants was recorded using a pre-prepared checklist. The presence of anti- B. burgdorferi IgG antibodies was evaluated using the EUROIMMUN ELISA kit, following the manufacturer’s instructions. The data were analyzed using SPSS software. Results: According to ELISA results, 10 out of 91 individuals (11%) tested positive for IgG antibodies against B. burgdorferi. Based on optical density (OD) values, 9 participants (9.9%) were categorized as borderline, while 72 workers tested negative. The rate of positive cases was significantly higher among workers who had contact with sheep compared to those who worked with cattle (chi-square test: P = 0.03; OR = 8.97; 95% CI: 1.06 - 75.56). Conclusions: Based on the ELISA technique, 11% of slaughterhouse workers tested positive for anti- B. burgdorferi antibodies, with the majority of these individuals working with sheep. While the possibility of cross-reactivity should be considered, this study highlights a health concern for high-risk occupations. Comprehensive diagnostic evaluations should be performed in cases of clinical suspicion.