Centro de Vigilancia Sanitaria Veterinaria (VISAVET), Universidad Complutense, Avda. Puerta de Hierro s/n, 28040 Madrid, Spain.
Prev Vet Med. 2013 Sep 1;111(3-4):304-13. doi: 10.1016/j.prevetmed.2013.05.013. Epub 2013 Jun 25.
Tuberculosis (TB) in llamas and alpacas has gained importance in recent years since they are imported into the European Union mainly for serving as pets and for production of natural fibre. The intradermal tuberculin test has been widely used for diagnosis of TB in these species showing lack of sensitivity (Se) although little information has been previously reported evaluating the effect on its performance of different PPD inoculation sites and time of readings. Moreover, different cost-effective serological assays have been developed in the recent years for TB diagnosis in camelids obtaining a variety of results and, for this reason, new assays still being developed. The main objectives of this study were: (1) to evaluate the performance of the intradermal tuberculin test using different inoculation sites (axillary, prescapular and cervical) and times of reading (72 and 120 h) and (2) to test a novel serological assay based on MPB83 antigen in a Mycobacterium bovis naturally infected alpaca herd in Spain. In regards to skin test, single intradermal tuberculin (SIT) test at the prescapular site and reading at 72 h showed the highest proportion of test-positive-culture positive animals among all culture positive animals (T+/C+), ranging from 53.8% (95% CI, 37.2-69.9) to 80% (95% CI, 44.4-97.5) using a more stringent interpretation than typically prescribed although, in general, low T+/C+ was achieved using both SIT and single comparative intradermal tuberculin (SCIT) tests alone. T+/C+ of the serological assay increased using samples collected 15-30 days after PPD injection [76.9% (95% CI, 60.7-88.9) - 100% (95% CI, 69.2-100)]. The best results of T+/C+ were obtained applying in parallel the most sensitive SIT test and serology using samples collected 15-30 days after PPD inoculation [90% (95% CI, 55.5-99.7)-100% (95% CI, 69.2-100)]. Therefore implementation of serology in parallel with the most sensitive skin test could maximize the detection of infected animals.
近年来，由于美洲驼和羊驼被进口到欧盟主要作为宠物和生产天然纤维，它们的结核病（TB）受到了重视。皮内结核菌素试验已广泛用于这些物种的 TB 诊断，尽管以前有报道称不同的 PPD 接种部位和读数时间对其性能有影响，但该试验的敏感性（Se）较低。此外，近年来为骆驼科动物的 TB 诊断开发了不同的具有成本效益的血清学检测方法，获得了各种结果，因此仍在开发新的检测方法。本研究的主要目的是：（1）评估使用不同接种部位（腋窝、颈前和颈后）和读数时间（72 和 120 小时）的皮内结核菌素试验的性能；（2）在西班牙一个自然感染牛分枝杆菌的羊驼群中测试一种基于 MPB83 抗原的新型血清学检测方法。关于皮肤测试，在颈前部位进行单次皮内结核菌素（SIT）测试，并在 72 小时读数，在所有培养阳性动物中，检测阳性-培养阳性动物（T+/C+）的比例最高，范围从 53.8%（95%CI，37.2-69.9）到 80%（95%CI，44.4-97.5），使用比通常规定更严格的解释，尽管一般来说，单独使用 SIT 和单次比较皮内结核菌素（SCIT）测试，T+/C+的结果都较低。使用在 PPD 注射后 15-30 天采集的样本进行血清学检测时，T+/C+增加[76.9%（95%CI，60.7-88.9）-100%（95%CI，69.2-100%）]。通过在 PPD 接种后 15-30 天采集样本，同时平行应用最敏感的 SIT 测试和血清学检测，获得了最佳的 T+/C+结果[90%（95%CI，55.5-99.7）-100%（95%CI，69.2-100%）]。因此，在最敏感的皮内试验的基础上，并行实施血清学检测，可以最大限度地发现感染动物。
