The continued search for intermediate hosts and potential reservoirs for SARS-CoV2 makes it clear that animal surveillance is critical in outbreak response and prevention. Real-time RT-PCR assays for SARS-CoV2 detection can easily be adapted to different host species. U.S. veterinary diagnostic laboratories have used the CDC assays or other national reference laboratory methods to test animal samples. However, these methods have only been evaluated using internal validation protocols. To help the laboratories evaluate their SARS-CoV2 test methods, an interlaboratory comparison (ILC) was performed in collaboration with multiple organizations. Forty-four sets of 19 blind-coded RNA samples in Tris-EDTA (TE) buffer or PrimeStore transport medium were shipped to 42 laboratories. Results were analyzed according to the principles of the International Organization for Standardization (ISO) 16140-2:2016 standard. Qualitative assessment of PrimeStore samples revealed that, in approximately two-thirds of the laboratories, the limit of detection with a probability of 0.95 (LOD95) for detecting the RNA was ≤20 copies per PCR reaction, close to the theoretical LOD of 3 copies per reaction. This level of sensitivity is not expected in clinical samples because of additional factors, such as sample collection, transport, and extraction of RNA from the clinical matrix. Quantitative assessment of Ct values indicated that reproducibility standard deviations for testing the RNA with assays reported as N1 were slightly lower than those for N2, and they were higher for the RNA in PrimeStore medium than those in TE buffer. Analyst experience and the use of either a singleplex or multiplex PCR also affected the quantitative ILC test results.

对 SARS-CoV2 中间宿主和潜在宿主的持续探索表明，动物监测对于疫情应对和预防至关重要。用于 SARS-CoV2 检测的实时 RT-PCR 检测可以轻松适应不同的宿主物种。美国兽医诊断实验室已使用 CDC 检测或其他国家参考实验室方法来测试动物样本。但是，这些方法仅使用内部验证协议进行了评估。为了帮助实验室评估其 SARS-CoV2 测试方法，与多个组织合作进行了实验室间比较 (ILC)。将在 Tris-EDTA (TE) 缓冲液或 PrimeStore 转运培养基中的 44 组 19 个盲编码 RNA 样品运送到 42 个实验室。结果根据国际标准化组织 (ISO) 16140-2:2016 标准的原则进行分析。PrimeStore 样本的定性评估显示，在大约三分之二的实验室中，检测 RNA 的概率为 0.95 (LOD95) 的检测限为每次 PCR 反应≤20 个拷贝，接近每个 3 个拷贝的理论 LOD。反应。由于其他因素，例如样品收集、运输和从临床基质中提取 RNA，临床样品中不会出现这种灵敏度水平。Ct 值的定量评估表明，报告为 N1 的检测 RNA 的重现性标准偏差略低于 N2，并且 PrimeStore 培养基中的 RNA 的重现性标准偏差高于 TE 缓冲液中的 RNA。