Anhui Center for Disease Control and Prevention, Hefei, Anhui, 230601, China; Key Laboratory for Medical and Health of the 13th Five-Year Plan, 12560, Fanhua Avenue, Hefei, Anhui, China.
First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, 230001, China.
J Virol Methods. 2021 Sep;295:114185. doi: 10.1016/j.jviromet.2021.114185. Epub 2021 May 26.
Viral nucleic acid detection by real-time reverse transcription polymerase chain reaction (qPCR) is the current standard method for diagnosis of SARS-CoV-2 infection. However, due to low viral load in some COVID-19 patients, false negative results from this method have been repeatedly reported.
In this study, we compared the sensitivity and specificity of digital PCR (dPCR) in simulated samples and clinical samples with qPCR assay through a series of vigorous tests.
The results showed that dPCR was more sensitive than qPCR especially for samples with low viral load (≤3 copies). In addition, dPCR had similar specificity as qPCR and could effectively distinguish other human coronaviruses and influenza virus from SARS-CoV-2. More importantly, dPCR was more sensitive than qPCR in detecting the virus in the "negative" samples from recurrent COVID-19 patients.
In summary, dPCR could serve as a powerful complement to the current qPCR method for SARS-CoV-2 detection, especially for the samples with extremely low viral load, such as recurrent COVID-19 patients.
实时逆转录聚合酶链反应（qPCR）的病毒核酸检测是目前诊断 SARS-CoV-2 感染的标准方法。然而，由于一些 COVID-19 患者的病毒载量较低，该方法的假阴性结果已被反复报道。
在这项研究中，我们通过一系列严格的测试，比较了数字 PCR（dPCR）在模拟样本和临床样本中的灵敏度和特异性与 qPCR 检测。
结果表明，dPCR 比 qPCR 更敏感，尤其是对于病毒载量较低（≤3 拷贝）的样本。此外，dPCR 与 qPCR 具有相似的特异性，可以有效区分 SARS-CoV-2 与其他人类冠状病毒和流感病毒。更重要的是，dPCR 在检测复发性 COVID-19 患者的“阴性”样本中的病毒时比 qPCR 更敏感。
总之，dPCR 可以作为当前 qPCR 方法检测 SARS-CoV-2 的有力补充，特别是对于病毒载量极低的样本，如复发性 COVID-19 患者。
