Wichert Annika, Kasbohm Elisa, Einax Esra, Wehrend Axel, Donat Karsten
Animal Health Service, Thuringian Animal Diseases Fund, Victor-Goerttler-Straße 4, 07745 Jena, Germany.
Clinic for Obstetrics, Gynaecology and Andrology for Large and Small Animals with Veterinary Ambulance, Justus-Liebig-University Gießen, Frankfurter Straße 106, 35392 Gießen, Germany.
Animals (Basel). 2022 May 25;12(11):1343. doi: 10.3390/ani12111343.
An easy-to-use and affordable surveillance system is crucial for paratuberculosis control. The use of environmental samples and milk pools has been proven to be effective for the detection of subsp. (MAP)-infected herds, but not for monitoring dairy herds certified as MAP non-suspect. We aimed to evaluate methods for the repeated testing of large dairy herds with a very low prevalence of MAP shedders, using different sets of environmental samples or pooled milk samples, collected monthly over a period of one year in 36 herds with known MAP shedder prevalence. Environmental samples were analyzed by bacterial culture and fecal PCR, and pools of 25 and 50 individual milk samples were analyzed by ELISA for MAP-specific antibodies. We estimated the cumulative sensitivity and specificity for up to twelve sampling events by adapting a Bayesian latent class model and taking into account the between- and within-test correlation. Our study revealed that at least seven repeated samplings of feces from the barn environment are necessary to achieve a sensitivity of 95% in herds with a within-herd shedder prevalence of at least 2%. The detection of herds with a prevalence of less than 2% is more challenging and, in addition to numerous repetitions, requires a combination of different samples.
一个易于使用且价格合理的监测系统对于副结核病防控至关重要。使用环境样本和混合乳样已被证明对检测感染分枝杆菌亚种（MAP）的牛群有效，但不适用于监测被认证为非疑似感染MAP的奶牛群。我们旨在评估对MAP排菌率极低的大型奶牛群进行重复检测的方法，使用不同组的环境样本或混合乳样，在一年时间内每月从36个已知MAP排菌率的牛群中采集样本。环境样本通过细菌培养和粪便PCR进行分析，25份和50份个体乳样的混合样本通过ELISA检测MAP特异性抗体。我们通过采用贝叶斯潜在类别模型并考虑测试间和测试内的相关性，估计了多达12次采样事件的累积敏感性和特异性。我们的研究表明，对于牛群内排菌率至少为2%的牛群，要达到95%的敏感性，至少需要对牛舍环境中的粪便进行7次重复采样。检测排菌率低于2%的牛群更具挑战性，除了大量重复采样外，还需要结合不同的样本。
