Background: This study aimed to screen the sera of goats and sheep from flocks suspected of Mycobacterium avium subsp. paratuberculosis (MAP) infection by a newly standardized Mce-truncated ELISA (Mt-ELISA) kit for the detection of antibodies against MAP. Four diagnostic applied tests were evaluated including Indigenous plate-ELISA (IP-ELISA), Mt-ELISA, fecal Polymerase Chain Reaction (f-PCR) and fecal culture (FC).
Materials and methods: Assuming the absence of a gold standard, latent-class models in a Bayesian framework were used to estimate the diagnostic accuracy of the four tests for MAP.
Results: Mt-ELISA had higher Sensitivity (Se) in sheep (posterior median: 0.68 (95% Probability Interval (PI): 0.43-0.95), while IP-ELISA recorded the highest Se in goats as 0.83 (95% PI, 0.61-0.97). The f-PCR Se estimate slightly differed between species [sheep 0.36 (0.19-0.58), goats 0.19 (0.08-0.35)], while the Se of FC was similar between species [sheep 0.29 (0.15-0.51), goats 0.27 (0.13-0.45)]. The specificity estimates for all tests were high, close to unity, and similar between species.
Conclusion: Overall, the results showed that the Mt-ELISA method can be used for MAP detection in small ruminants' flocks.
Keywords: Bayesian latent class models; Culture; IP-ELISA; Mt-ELISA; PCR-IS900/413; Paratuberculosis; Small ruminants; Test evaluation.
© 2022. The Author(s).