Woolcock Peter R, Cardona Carol J
California Animal Health and Food Safety Laboratory System-Fresno Branch, University of California, Davis, USA.
Avian Dis. 2005 Dec;49(4):477-81. doi: 10.1637/7357-031605R.1.
Five antigen capture immunoassay test kits, Directigen Flu A (Becton Dickinson), QuickVue Influenza test kit (Quidel), FLU OIA (ThermoBiostar), Zstat Flu (ZymeTx, Inc.) and NOW FLU A Test (Binax) were used to detect avian influenza virus (AIV) in clinical specimens as per manufacturers' protocols. Each kit was shown to be specific for AIV propagated in embryonating chicken eggs (ECE); other respiratory viruses of poultry tested gave negative results. The Directigen Flu A kit proved to be 10-fold more sensitive than the other kits, capable of detecting 10(4.7) mean embryo lethal dose (ELD50)/ml in allantoic fluid; this is more sensitive than the hemagglutination test using chicken erythrocytes. None of the kits proved to be sufficiently sensitive to reliably detect AIV in oropharyngeal and cloacal swabs collected from chickens experimentally infected with AIV subtype H6N2. In two different experiments, individual swabs and pools of five or six swabs were tested. By virus isolation, 39 individual oropharyngeal swabs tested positive for AIV, but Directigen and Flu OIA only detected 2/39 and NOW FLU A 1/39. Zstat and QuickVue did not detect any. Five individual cloacal swabs positive by virus isolation were negative with all five kits. In a second experiment using pools of five swabs, 26 swab pools were positive by virus isolation and 5/26 were positive by Directigen, the only kit to provide any positive results. Five cloacal swab pools were also positive by virus isolation and 1/5 was positive by Directigen; all other test kits were negative. All of these experiments were performed using the H6N2 subtype of AIV. The results are disappointing, as the kits have proven to be insensitive for detecting AIV when compared with the gold standard, virus isolation. This limits their use in diagnostic field investigations. Individual or groups of chickens could be assumed to be positive for AIV if positive by any of the kits, but a negative result with any of the kits would not prove that birds were AIV free.
按照制造商的方案，使用了五种抗原捕获免疫测定试剂盒，即Directigen Flu A（贝克顿·迪金森公司）、QuickVue流感检测试剂盒（奎德公司）、FLU OIA（ThermoBiostar公司）、Zstat Flu（ZymeTx公司）和NOW FLU A检测试剂盒（Binax公司）来检测临床标本中的禽流感病毒（AIV）。每个试剂盒都显示对在鸡胚中增殖的AIV具有特异性；所检测的其他家禽呼吸道病毒均呈阴性结果。Directigen Flu A试剂盒的灵敏度比其他试剂盒高10倍，能够检测尿囊液中10(4.7)平均胚胎致死剂量（ELD50）/毫升；这比使用鸡红细胞的血凝试验更灵敏。没有一种试剂盒被证明足够灵敏，能够可靠地检测从实验感染AIV H6N2亚型的鸡采集的口咽拭子和泄殖腔拭子中的AIV。在两个不同的实验中，对单个拭子以及五或六个拭子的混合样本进行了检测。通过病毒分离，39个单个口咽拭子检测出AIV呈阳性，但Directigen和Flu OIA仅检测出2/39，NOW FLU A检测出1/39。Zstat和QuickVue未检测到任何阳性。通过病毒分离呈阳性的五个单个泄殖腔拭子，使用所有五种试剂盒检测均为阴性。在第二个实验中，使用五个拭子的混合样本，26个拭子混合样本通过病毒分离呈阳性，Directigen是唯一给出任何阳性结果的试剂盒，5/26呈阳性。五个泄殖腔拭子混合样本通过病毒分离也呈阳性，Directigen检测出1/5呈阳性；所有其他检测试剂盒均为阴性。所有这些实验均使用AIV H6N2亚型进行。结果令人失望，因为与金标准病毒分离相比，这些试剂盒已被证明在检测AIV时不灵敏。这限制了它们在诊断现场调查中的应用。如果任何一种试剂盒检测呈阳性，则可假定单个或一组鸡感染了AIV，但任何一种试剂盒检测呈阴性并不能证明鸡未感染AIV。
