Unseen Threats to Meat Safety: Exposing the Hidden Epidemic to Bovine Tuberculosis in Slaughterhouses

A total of 600 cattle (200 from each New Valley, Qena, and Aswan) were verified by a single intradermal cervical tuberculin test (SICTT), and the positive reactors were slaughtered at the central abattoirs of each governorate. Additionally, the tissues of the affected carcasses were inspected by Ziehl-Neelsen (ZN) staining and culturing, and confirmation of results was achieved through ELISA and PCR techniques. The findings revealed that 2.3% of inspected animals tested positive for the SICTT test. Qena recorded the highest rate of tuberculin-positive animals at 3.5%, followed by Aswan at 2% and New Valley at 1.5%. BTB was found to be statistically related to sex, body condition, age, breed, and yard density (p<0.05), and the thoracic organs and their lymph nodes were mostly affected. All culture-prepared samples on Lowenstein-Jensen media yielded Mycobacterium spp. isolates. ZN staining identified only 85.7% of the isolates as acid-fast bacilli. ELISA results indicated that 78.6% of positive tuberculin reactors were also positive for bovine-purified protein derivative antigen and 71.4% were positive for commercial polypeptide antigen. Furthermore, there was no significant correlation between the molecular identification of M. bovis using tissue samples or isolates and the PCR results confirmed the occurrence of M. bovis DNA in 8 of each examined category. The findings underscore the crucial role of slaughterhouses in providing essential data for monitoring BTB epidemiology within specific regions. These insights are pivotal for informing strategies and implementing effective regulation and prevention measures.