Landry Marie L, Cohen Sandra, Ferguson David
Department of Laboratory Medicine, Yale University School of Medicine, P.O. Box 208035, New Haven, CT, United States.
J Clin Virol. 2008 Oct;43(2):148-51. doi: 10.1016/j.jcv.2008.06.006. Epub 2008 Jul 18.
Rapid tests have had a significant impact on influenza diagnosis, but more accurate tests are needed for hospitalized patients who test negative by rapid methods.
We sought to determine the increased yield obtained from influenza RT-PCR in hospitalized patients compared to two rapid methods.
Binax NOW, cytospin-enhanced direct immunofluoroescence (DFA), and influenza A and B multiplex TaqMan RT-PCR were performed on 237 clinical samples.
Binax NOW detected 70 (53.0%), cytospin-DFA detected 127 (96.2%), and TaqMan RT-PCR detected 132 (100%) influenza-positive samples. The difference in sensitivity was significant between RT-PCR and Binax NOW (p<0.0001), but not between RT-PCR and cytospin-DFA (p=0.0736). Two samples testing positive for influenza B by all three methods, tested falsely positive for influenza A by Binax. Eight true positive samples did not become reactive by Binax until 30 min, and thus were counted as negative.
The accuracy of real-time RT-PCR should greatly improve the diagnosis of influenza in hospitals using simple rapid flu tests, but may have a more modest impact in hospitals with expertise in cytospin-DFA. Further studies are needed to determine the effect of influenza RT-PCR on patient management and costs in hospitalized patients.
快速检测对流感诊断产生了重大影响，但对于快速检测方法结果为阴性的住院患者，需要更准确的检测方法。
我们试图确定与两种快速检测方法相比，住院患者中流感逆转录聚合酶链反应（RT-PCR）检测阳性率的增加情况。
对237份临床样本进行了Binax NOW检测、细胞离心涂片增强直接免疫荧光法（DFA）检测以及甲型和乙型流感多重TaqMan RT-PCR检测。
Binax NOW检测出70份（53.0%）流感阳性样本，细胞离心涂片-DFA检测出127份（96.2%），TaqMan RT-PCR检测出132份（100%）。RT-PCR与Binax NOW之间的敏感性差异具有统计学意义（p<0.0001），但RT-PCR与细胞离心涂片-DFA之间无显著差异（p=0.0736）。有两份样本经所有三种方法检测均为乙型流感阳性，但Binax检测为甲型流感假阳性。有八份真阳性样本直到30分钟后Binax检测才呈阳性反应，因此被计为阴性。
实时RT-PCR的准确性应能大大提高采用简单快速流感检测方法的医院对流感的诊断，但在具备细胞离心涂片-DFA专业技术的医院可能影响较小。需要进一步研究以确定流感RT-PCR对住院患者治疗管理及费用的影响。
