Specificity of the comparative skin test for bovine tuberculosis in Great Britain.
Specificity of the comparative skin test for bovine tuberculosis in Great Britain.
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DOI：
10.1136/vr.102961
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发表时间：
2015-09-12
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影响因子：
--
通讯作者：
de la Rua-Domenech R
中科院分区：
文献类型：
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作者：
Goodchild AV;Downs SH;Upton P;Wood JL;de la Rua-Domenech R
本文报道了一种利用牛结核病（bTB）监测试验结果评价单次皮内比较宫颈结核菌素（SICCT）试验特异性的新方法。根据2002年至2008年期间在英国（GB）官方无结核病（OTF）牛群中进行的所有常规检测的日期、位置和皮褶测量值，根据其与已知感染（OTF退出）牛群的分离（按距离和时间），估计了三个临界值下SICCT检测的特异性。当受试牛群与最近的感染牛群之间的距离超过8 km时，检测阳性动物的比例不变（P>0.20）。 对于标准临界值，计算的特异性为99.98%（95%置信区间± 0.004%），相当于每5000只未感染动物检测一个假阳性结果。对于严重临界值，其为99.91%（± 0.013%），对于超严重临界值（选择所有反应器和不确定反应器），其为99.87%（± 0.017%）。该测试的阳性预测值估计平均为91%，并因地区流行率而异。本研究进一步证明了在GB条件下SICCT试验的高度特异性，表明目前在GB中使用该试验扑杀的牛中有90%以上被感染，并支持屠宰至少这些牛用于bTB控制。
A novel method for estimating specificity of the Single Intradermal Comparative Cervical Tuberculin (SICCT) test for bovine tuberculosis (bTB) using surveillance tests results is reported. The specificity of the SICCT test at three cut-offs was estimated from the dates, locations and skinfold measurements of all routine tests carried out in Officially TB Free (OTF) cattle herds in Great Britain (GB) between 2002 and 2008, according to their separation (by distance and time) from known infected (OTF-withdrawn) herds. The proportion of animals that tested positive was constant (P>0.20) when the distance between tested herds and nearest infected herd exceeded 8 km. For standard cut-off, calculated specificity was 99.98 per cent (95 per cent confidence interval ±0.004 per cent), equating to one false positive result per 5000 uninfected animals tested. For severe cut-off it was 99.91 per cent (±0.013 per cent) and for ultrasevere cut-off (selecting all reactors and inconclusive reactors) it was 99.87 per cent (±0.017 per cent). The estimated positive predictive value of the test averaged 91 per cent and varied by regional prevalence. This study provides further evidence of the high specificity of the SICCT test under GB conditions, suggests that over 90 per cent of cattle currently culled using this test in GB were infected, and endorses slaughter of at least these cattle for bTB control.