FIG. 1.

Comparison of the sensitivities of the Bovigam IGRA and the Enferplex TB multiplex immunoassay. The analysis is based on the testing of 30 animals with confirmed bTB. The interpretation of the Bovigam assay is based on the differences between the OD₄₅₀ values obtained after stimulation with bovine versus avian PPD. The following cutoffs were used to determine the relative sensitivity of the Bovigam IGRA: 79.6% specificity corresponds to a difference of 0.016 OD₄₅₀ unit; 91.4% specificity, to a >0.045-OD₄₅₀ difference; 94.6% specificity, to a >0.076-OD₄₅₀ difference; 97% specificity, to a >0.110-OD₄₅₀ difference; 97.8% specificity, to a >0.178-OD difference; and 100% specificity, to a >1.903-OD₄₅₀ difference.