Enzootic bovine leucosis (EBL) is a neoplastic disease of cattle caused by Bovine leukaemia virus (BLV). EBL causes great economic losses, so a fast and reliable diagnostic method is critical for understanding the status of BLV. This will allow us to control BLV infections efficiently and mitigate economic losses. In this study, we established a direct diagnostic test for BLV using dried blood‐spotted filter papers without sample pre‐treatment. The study was based on 159 clinical blood specimens collected in EDTA from one farm in Kyushu, Japan. The blood‐spotted filter papers were used as the template for direct filter PCR. When an ELISA was used as the diagnostic gold standard, the sensitivity and specificity of the direct filter PCR were 90.1% and 97.5%, respectively. The kappa value for the direct filter PCR and real‐time PCR methods was 0.97. The dried blood samples spotted onto filter papers were stable for at least 10 days at room temperature, even when the samples were from cattle with a low BLV proviral load. Direct filter PCR is a rapid, easy, reliable and cost‐effective diagnostic test that directly detects the BLV proviral genome in clinical blood specimens without DNA extraction. Moreover, it simplifies the collection, transportation and storage procedures for clinical blood specimens.

中文翻译：

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使用直接过滤器PCR建立牛白血病病毒感染的新型诊断测试。

牛源性牛白血病（EBL）是由牛白血病病毒引起的牛的肿瘤性疾病（BLV）。EBL造成巨大的经济损失，因此快速可靠的诊断方法对于了解BLV的状态至关重要。这将使我们能够有效控制BLV感染并减轻经济损失。在这项研究中，我们建立了使用干血斑滤纸而不进行样品预处理的BLV直接诊断测试。该研究基于从日本九州一个农场的EDTA中收集的159种临床血液标本。血样滤纸用作直接过滤PCR的模板。使用ELISA作为诊断金标准品时，直接过滤PCR的灵敏度和特异性分别为90.1％和97.5％。直接过滤PCR和实时PCR方法的kappa值为0.97。点样在滤纸上的干血样本在室温下至少可稳定10天，即使样本来自具有低BLV前病毒载量的牛也是如此。直接过滤器PCR是一种快速，简便，可靠且具有成本效益的诊断测试，无需DNA提取即可直接检测临床血液样本中的BLV前病毒基因组。此外，它简化了临床血液标本的收集，运输和存储程序。