Aranaz Alicia, De Juan Lucía, Bezos Javier, Alvarez Julio, Romero Beatriz, Lozano Francisco, Paramio José L, López-Sánchez Jesús, Mateos Ana, Domínguez Lucas
Departamento de Sanidad Animal I, Facultad de Veterinaria, Universidad Complutense de Madrid, Av. Puerta de Hierro s/n, 28040 Madrid, Spain.
Vet Res. 2006 Jul-Aug;37(4):593-606. doi: 10.1051/vetres:2006021. Epub 2006 May 16.
The intradermal tuberculin (IDTB) test and the interferon-gamma (IFN-gamma) assay are used worldwide for detection of bovine tuberculosis in cattle, but little is known about the effect of co-infecting agents on the performance of these diagnostic tests. This report describes a field trial conducted in a cattle herd with dual infection (bovine tuberculosis and paratuberculosis) during 3.5 years. It has been based on a strategic approach encompassing serial parallel testing (comparative IDTB test, the IFN-gamma assay and serology of paratuberculosis) that was repeated 8 times over the period, and segregation of animals into two herds. The IDTB test detected 65.2% and the IFN-gamma test detected 69.6% of the Mycobacterium bovis culture-positive cattle. However, the IDTB test performed better during the first part of the trial, while the IFN-gamma test was the only method that detected infected animals during the following three samplings. The number of false positive reactors with the IDTB and/or the IFN-gamma tests was remarkably high compared to other reports, and could be caused by cross-reactivity with M. avium subsp. paratuberculosis. Also, the M. bovis isolates from cattle and wildlife from the same property were characterised using molecular techniques to disclose an epidemiological link. The IDTB test may not be appropriate to eradicate bovine tuberculosis in herds with dual mycobacterial infections. This report highlights the need to use several diagnostic techniques for the accurate detection of M. bovis infected animals in these herds.
皮内结核菌素（IDTB）试验和干扰素-γ（IFN-γ）检测在全球范围内用于检测牛群中的牛结核病，但对于合并感染因子对这些诊断试验性能的影响知之甚少。本报告描述了在一个牛群中进行的为期3.5年的双感染（牛结核病和副结核病）现场试验。该试验基于一种战略方法，包括连续平行检测（比较IDTB试验、IFN-γ检测和副结核病血清学检测），在此期间重复进行了8次，并将动物分为两个牛群。IDTB试验检测出65.2%的牛分枝杆菌培养阳性牛，IFN-γ检测检测出69.6%的此类牛。然而，IDTB试验在试验的第一阶段表现更好，而IFN-γ检测是在随后三次采样中唯一检测出感染动物的方法。与其他报告相比，IDTB和/或IFN-γ检测的假阳性反应动物数量非常高，可能是由与鸟分枝杆菌副结核亚种的交叉反应引起的。此外，还使用分子技术对来自同一养殖场的牛和野生动物的牛分枝杆菌分离株进行了鉴定，以揭示流行病学联系。在存在双重分枝杆菌感染的牛群中，IDTB试验可能不适用于根除牛结核病。本报告强调了需要使用多种诊断技术来准确检测这些牛群中感染牛分枝杆菌的动物。
