Evaluation of a commercial ELISA for diagnosis of paratuberculosis in cattle

Objective-To evaluate sensitivity and specificity of a new ELISA for antibo dies against Mycobacterium avium subsp paratuberculosis. Design-Cross-sectional observational survey. Sample Population-Serum samples from 590 cattle that were infected with M a vium subsp paratuberculosis and 723 cattle that were not infected. Procedure-Serum samples were tested by use of an ELISA for antibodies again st M avium subsp paratuberculosis. Results-Sensitivity of the test varied from 15.4 to 88.1%, depending on the clinical stage and bacterial shedding status of the cattle. Conclusions and Clinical Relevance-Results obtained with use of the new ELI SA agreed favorably with those of a previous ELISA. Practitioners must be a ware of variability in the sensitivity of the test, which depends on the cl inical and shedding status of the cattle, because this may affect interpret ation of test results.