Centro VISAVET, Universidad Complutense de Madid, 28040 Madrid, Spain.
Res Vet Sci. 2012 Oct;93(2):636-40. doi: 10.1016/j.rvsc.2011.10.009. Epub 2011 Nov 9.
The aim of this study was to evaluate the specificity of the most widely used tuberculosis (TB) diagnostic tests, single intradermal tuberculin (SIT) and single comparative intradermal tuberculin (SCIT) tests and interferon-gamma (IFN-γ) assay in 937 animals from eight TB-free caprine flocks under different epidemiological situations. Maximum specificity was found using SCIT test (99.4-100% depending on the interpretation criteria) while SIT test and IFN-γ assay showed a slightly lower overall specificity (97.6-99.2% and 96.4-98.4% respectively). Specificity of the SIT test in a Corynebacterium pseudotuberculosis infected flock was significantly (P<0.05) lower if a severe interpretation criterion was applied. Similarly, specificity values of SIT test and particularly IFN-γ assay in a paratuberculosis (PTB)-vaccinated flock were lower than those observed in non-vaccinated flocks. Higher proportion of false positive reactors to TB tests (SIT and IFN-γ assay) were observed among animals positive in the PTB-ELISA in PTB vaccinated flock. These results demonstrate that TB diagnostic tests show an adequate specificity when performed in goats from TB-free flocks in most situations. However, certain factors such as C. pseudotuberculosis infection and paratuberculosis vaccination can have a negative impact in the most sensitive tests.
本研究旨在评估最广泛使用的结核病（TB）诊断测试，即单一皮内结核菌素（SIT）和单一比较皮内结核菌素（SCIT）测试以及干扰素-γ（IFN-γ）检测在 8 个无 TB 山羊群的 937 只动物中的特异性。根据不同的解释标准，SCIT 测试的特异性最高（99.4-100%），而 SIT 测试和 IFN-γ 检测的总体特异性略低（97.6-99.2%和 96.4-98.4%）。如果应用严格的解释标准，SIT 测试在感染了棒状杆菌的羊群中的特异性显著降低（P<0.05）。同样，在感染副结核病（PTB）的羊群中，SIT 测试和 IFN-γ 检测的特异性值均低于未接种疫苗的羊群。在接种 PTB 的羊群中，PTB-ELISA 检测呈阳性的动物中，对 TB 检测（SIT 和 IFN-γ 检测）的假阳性反应比例更高。这些结果表明，在大多数情况下，在来自无 TB 羊群的山羊中进行 TB 诊断测试具有足够的特异性。然而，某些因素，如棒状杆菌感染和副结核病疫苗接种，可能会对最敏感的测试产生负面影响。
