HISTOPATHOLOGICAL EVALUATION OF LYMPH NODES IN CATTLE WITH TUBERCULOSIS: CORRELATION WITH INTRAVITAL DIAGNOSTIC METHODS (TUBERCULIN TEST AND PCR)

Abstract

Objective: To evaluate the main diagnostic methods used in the detection of bovine tuberculosis, focusing on the combination of histopathological techniques, such as Hematoxylin-Eosin (H&E) and Ziehl-Neelsen (ZN), with the polymerase chain reaction (PCR), and to correlate them with the results of the intradermal tuberculin test. Bovine tuberculosis, caused by Mycobacterium bovis, is a zoonotic disease with a major economic and public health impact and is difficult to diagnose, especially in the early stages of infection. The tuberculin test is widely used, but has limitations in terms of specificity and sensitivity. Histopathological and molecular techniques, such as H&E, ZN and PCR, have shown efficacy in identifying granulomatous lesions and detecting the pathogen, even in more advanced stages of the disease. This literature review analyzed national and international studies on the application of these methodologies in the diagnosis of bovine tuberculosis, highlighting the clinical protocols, the effectiveness of the methods and the limitations associated with each technique. The results show that the combination of these diagnostic methods offers a more sensitive and accurate approach to the detection of M. bovis, with the need for further research into the standardization of protocols and validation at different stages of the disease.