Table 3 IGRAa test results for DST and MDT reagents.

From: A molecularly defined skin test reagent for the diagnosis of bovine tuberculosis compatible with vaccination against Johne’s Disease

Animal group

Test performance

DSTb

MDTb

B–Ac

Experimentally infected (n = 19)

% Sensitivity [95% CI]

63 [41, 81]

100 [83, 100]*

100 [83, 100]

Naturally infected (n = 22)

% Sensitivity [95% CI]

68 [47, 84]

100 [85, 100]*

100 [85, 100]

Non-infected controls (n = 59)

% Specificity [95% CI]

100 [94, 100]

97 [88, 99]

97 [88, 99]

Gudair vaccinated (n = 29)

% Specificity [95% CI]

100 [88, 100]

97 [83, 100]

100 [88,100]

  1. *p < 0.05, McNemar’s test (compared to DST).
  2. aIGRA, interferon-gamma release assay using the BOVIGAM IFN-γ EIA kit.
  3. bDST (DIVA Skin Test) or MDT (Molecularly Defined Tuberculin) induced IFN-γ production. Cut-off for positivity = OD450 nm with MDT or DST minus nil antigen control > 0.1.
  4. cB–A, comparison of IFN-γ induced by stimulation with PPD-B and PPD-A. Cut-off for positivity = OD450 for PPD-B minus PPD-A > 0.1.
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