Faculty of Veterinary Medicine, Rajamangala University of Technology Tawan-Ok, Chonburi, Thailand.
Department of Veterinary Microbiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand.
Avian Pathol. 2021 Feb;50(1):78-84. doi: 10.1080/03079457.2020.1837343. Epub 2020 Nov 23.
General diagnosis of poultry viruses primarily relies on detection of viruses in samples, but many farms are located in remote areas requiring logistic transportation. Filter paper cards are a useful technology that offer an alternative for collecting and preserving samples without hazardous exposure. The goal of this study was to compare three filter papers: the Flinders Technology Associates filter (FTA®) card, dried blood spot (DBS) card and qualitative filter paper (FP) grade 2 to collect poultry samples. In particular, we have used Newcastle disease virus (NDV) to evaluate safety and a Marek's disease virus (MDV) attenuated vaccine (CVI988) to evaluate stability of viral DNA. This experiment was divided into two parts. The first part was to determine the DNA stability and detection limit of CVI988 in samples collected in different paper supports after four storage times (3, 7, 14 and 30 days post spot). The second part was to determine the safety of papers by evaluating the viral inactivation efficacy using NDV as a representative virus. Results showed that all papers could preserve CVI988 DNA at all times, with a detection limit of 0.5 PFU/5 µl for FTA® and DBS cards, and 5 PFU/5 µl for FP. Our results showed that the NDV remained viable and infectious on the DBS card and FP, while no viable virus was detected on the FTA® card, suggesting that the FTA® card was safest to use. Therefore, the use of the DBS card and FP for infectious sample collection should be discouraged and reconsidered. The detection limits of the FTA® card, DBS card and FP for CVI988 detection were 0.5, 0.5 and 5PFU/5µl, respectively. All three filter papers could preserve viral DNA for at least 30 days of post spot. The DBS card and FP are not suitable for collecting NDV samples, which is one of the major economical threats for the poultry industry worldwide.
家禽病毒的一般诊断主要依赖于对样本中病毒的检测，但许多农场位于偏远地区，需要进行物流运输。滤纸条是一种有用的技术，它提供了一种无需危险接触即可收集和保存样本的替代方法。本研究的目的是比较三种滤纸条：Flinders Technology Associates 滤纸条（FTA®）、干血斑（DBS）卡和定性滤纸条（FP）第 2 级，以收集家禽样本。特别是，我们使用新城疫病毒（NDV）来评估安全性，使用马立克氏病病毒（MDV）减毒疫苗（CVI988）来评估病毒 DNA 的稳定性。本实验分为两部分。第一部分是确定在 3、7、14 和 30 天斑点后，在不同的纸支持下收集的样品中 CVI988 的 DNA 稳定性和检测极限。第二部分是通过评估以 NDV 为代表的病毒的病毒失活效果来确定纸张的安全性。结果表明，所有纸张都可以在所有时间保存 CVI988 DNA，FTA®和 DBS 卡的检测极限为 0.5 PFU/5µl，FP 为 5 PFU/5µl。我们的结果表明，NDV 在 DBS 卡和 FP 上仍然具有活力和感染力，而在 FTA®卡上则未检测到有活力的病毒，这表明 FTA®卡使用最安全。因此，应不鼓励并重新考虑使用 DBS 卡和 FP 收集传染性样本。FTA®卡、DBS 卡和 FP 对 CVI988 检测的检测限分别为 0.5、0.5 和 5PFU/5µl。三种滤纸条都可以至少保存 30 天的病毒 DNA。DBS 卡和 FP 不适合收集 NDV 样本，这是全球家禽业的主要经济威胁之一。
