Department of Large Animal Sciences, Faculty of Life Sciences, University of Copenhagen, Grønnegårdsvej 8, DK-1870 Frederiksberg C, Denmark.
Prev Vet Med. 2010 May 1;94(3-4):185-90. doi: 10.1016/j.prevetmed.2010.01.014. Epub 2010 Feb 12.
A voluntary, risk-based control program for paratuberculosis in dairy herds was started in 2006 in Denmark. The program does not include non-dairy herds, and the occurrence of Mycobacterium avium subsp. paratuberculosis (MAP) in these herds is unknown. The objective of this study was to establish the prevalence of MAP infected adult non-dairy cattle in Denmark. Serum samples were collected between October, 2008 and January, 2009 from every 6th animal over 24 months of age, sent to slaughter to Danish slaughterhouses from non-dairy herds. The final sample included 2345 cattle of 13 different breeds, with the largest breed group being crossbreds (of unknown breeds) (30%) and three dairy breeds (Danish Holstein, Danish Jersey and Danish Red Cattle) comprising 27% of the samples. The serum samples were tested using a MAP specific antibody ELISA (IDScreen) and positives were defined as the sample-to-positive ratio greater than 0.60. Estimation of the breed-specific apparent prevalences, true prevalences (TP), and true prevalences with a random effect of breed was done in a Bayesian analysis. Information about test sensitivity and specificity were based on literature data and expert information. Regardless of the method of analysis, the estimated prevalences showed similar differences between breeds. The dairy breeds Danish Jersey, Danish Holstein and Danish Red Cattle were ranked highest (i.e. with highest prevalence) (TP medians: 13, 10, and 6, respectively). Combined, the dairy breeds had a significantly higher prevalence than the other breeds, median TP (dairy)=15.7% vs. median TP (non-dairy)=0.8%. For the individual non-dairy breeds, the median estimates were generally higher, illustrating the problems of ranking groups based on relatively small sample sizes.
2006 年，丹麦启动了一项针对奶牛群副结核病的自愿、基于风险的控制计划。该计划不包括非奶牛群，这些牛群中是否存在禽分枝杆菌副结核亚种（MAP）尚不清楚。本研究的目的是确定丹麦非奶牛群成年 MAP 感染牛的流行率。2008 年 10 月至 2009 年 1 月，从丹麦屠宰场送往屠宰的非奶牛群中，每 6 头 24 月龄以上的动物采集血清样本。最终样本包括 13 个不同品种的 2345 头牛，最大的品种组为杂交牛（品种不详）（30%）和三个奶牛品种（丹麦荷斯坦牛、丹麦泽西牛和丹麦红牛），占样本的 27%。使用 MAP 特异性抗体 ELISA（IDScreen）检测血清样本，阳性定义为样品与阳性的比值大于 0.60。在贝叶斯分析中，对品种特异性表观流行率、真实流行率（TP）和具有品种随机效应的真实流行率进行了估计。关于测试灵敏度和特异性的信息基于文献数据和专家信息。无论分析方法如何，估计的流行率在品种之间显示出相似的差异。奶牛品种丹麦泽西牛、丹麦荷斯坦牛和丹麦红牛的排名最高（即流行率最高）（TP 中位数：分别为 13、10 和 6）。这三种奶牛品种的流行率明显高于其他品种，奶牛品种的 TP 中位数（15.7%）与非奶牛品种的 TP 中位数（0.8%）相比差异显著。对于单个非奶牛品种，中位数估计值普遍较高，这说明了基于相对较小的样本量对群体进行排名存在问题。
