Table 3 Relative sensitivity and specificity estimates for DST-F.

From: Test performance data demonstrates utility of a cattle DIVA skin test reagent (DST-F) compatible with BCG vaccination

Animal group

Test performance

DST-Fa

SICCTb

SITc

M. bovis infected

% Sensitivity [95% CI]

(n/N)d

95 [88, 98]

(80/84)

89 [81, 94] (75/84)

99 [94, 100] (83 / 84)

BCG vaccinated / M. bovis infected

% Sensitivity [95% CI]

(n/N)

90 [81, 95]e

(65/72)

85 [75, 91]

(61/72)

100 [95, 100]

(72/72)

Non-infected controls

% Specificity [95% CI]

(n/N)

100 [92, 100]

(0/45)

100 [90, 100]

(0/35)

100 [90, 100]

(0/35)

BCG vaccinated

% Specificity [95% CI]

(n/N)

100 [84, 100]

(0/20)

30 [11, 60]f

(7/10)

0 [0, 28]g

(10/10)

  1. aResponse considered positive if Δ skin thickness for DST-F ≥ 2 mm.
  2. bResponse considered positive if Δ skin thickness for PPDB—PPDA > 4 mm (standard OIE and UK interpretation).
  3. cResponse considered positive if Δ skin thickness for PPDB ≥ 4 mm.
  4. dn, number positive; N, total number tested.
  5. ep < 0.05 (compared to SIT), McNemar’s test.
  6. fp < 0.05 (compared to DST-F), McNemar’s test.
  7. gp < 0.01 (compared to DST-F), McNemar’s test.
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