Comparison of a capture ELISA and Intradermal test for diagnosis of Bovine Tuberculosis in Mexico

Resumen

Objective: A comparative study was conducted to evaluate two immunodiagnostic techniques capture ELISA and the intradermal test for detecting bovine tuberculosis, aiming to establish the optimal test for early diagnosis in cattle. Design/Methodology/Scope: Initially, the intradermal test was used as a screening tool in cattle, after which reactor animals underwent the comparative cervical test. Reactor animals (positive to the intradermal test) were then evaluated using a capture ELISA for bovine IFNγ. Intradermal testing is widely used in Mexico; however, its application presents several limitations. Identifying a faster and more accessible diagnostic test would significantly enhance disease control efficiency.

Results: The prevalence of bovine tuberculosis detected by the intradermal test was 4.9%, whereas the capture ELISA test identified 8.95%, showing a significant difference in the identification of positive cases between the two methods. The likelihood ratio met the standard parameters (LR+ >10 and LR- <0.5), confirming that the capture ELISA test for bIFNγ is a valuable diagnostic tool. Additionally, the capture immunoassay detected a higher number of infected cattle compared to the intradermal test.

Conclusions/Limitations: The capture ELISA technique for bovine IFNγ proves to be a more effective diagnostic test. However, further studies are required, including a larger study population and expanded geographical coverage within the country.