Department of Population Medicine and Diagnostic Sciences, Animal Health Diagnostic Center, Cornell COVID-19 Testing Laboratory, College of Veterinary Medicine, Cornell Universitygrid.5386.8, Ithaca, New York, USA.
Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell Universitygrid.5386.8, Ithaca, New York, USA.
Microbiol Spectr. 2022 Jun 29;10(3):e0226421. doi: 10.1128/spectrum.02264-21. Epub 2022 May 16.
In the present study, we assessed the diagnostic sensitivity and determined the viral RNA load and infectivity of SARS-CoV-2 in paired respiratory (nasopharyngeal and anterior nares) and oral samples (saliva and sublingual swab). Samples were collected from 77 individuals of which 75 were diagnosed with COVID-19 and classified as symptomatic ( = 29), asymptomatic ( = 31), or postsymptomatic ( = 15). Specimens were collected at one time point from each individual, between day 1 and 23 after the initial COVID-19 diagnosis, and included self-collected saliva (S), or sublingual (SL) swab, and bilateral anterior nares (AN) swab, followed by health care provider collected nasopharyngeal (NP) swab. Sixty-three specimen sets were tested using five assay/platforms. The diagnostic sensitivity of each assay/platform and specimen type was determined. Of the 63 specimen sets, SARS-CoV-2 was detected in 62 NP specimens, 52 AN specimens, 59 saliva specimens, and 31 SL specimens by at least one platform. Infectious SARS-CoV-2 was isolated from 21 NP, 13 AN, 12 saliva, and one SL specimen out of 50 specimen sets. SARS-CoV-2 isolation was most successful up to 5 days after initial COVID-19 diagnosis using NP specimens from symptomatic patients (16 of 24 positives, 66.67%), followed by specimens from asymptomatic patients (5 of 17 positives, 29.41%), while it was not very successful with specimens from postsymptomatic patients. Benefits of self-collected saliva and AN specimens balance the loss of sensitivity relative to NP specimens. Therefore, saliva and AN specimens are acceptable alternatives for symptomatic SARS-CoV-2 diagnostic testing or surveillance with increased sampling frequency of asymptomatic individuals. The dynamics of infection with SARS-CoV-2 have a significant impact on virus infectivity and in the diagnostic sensitivity of molecular and classic virus detection tests. In the present study we determined the diagnostic sensitivity of paired respiratory (nasopharyngeal and anterior nares swabs) and oral secretions (saliva and sublingual swab) and assessed infectious virus shedding patterns by symptomatic, asymptomatic, or postsymptomatic individuals. Understanding the diagnostic performance of these specimens and the patterns of infectious virus shedding in these bodily secretions provides critical information to control COVID-19, and may help to refine guidelines on isolation and quarantine of positive individuals and their close contacts identified through epidemiological investigations.
在本研究中，我们评估了 SARS-CoV-2 的诊断灵敏度，并确定了呼吸道（鼻咽和前鼻腔）和口腔样本（唾液和舌下拭子）中病毒 RNA 载量和感染力。样本取自 77 名个体，其中 75 名被诊断为 COVID-19，分为有症状（ = 29）、无症状（ = 31）或症状后（ = 15）。每个个体在 COVID-19 诊断后第 1 至 23 天采集一次样本，包括自我采集的唾液（S）或舌下拭子（SL），以及双侧前鼻腔（AN）拭子，随后由医疗保健提供者采集鼻咽（NP）拭子。使用 5 种检测平台对 63 个样本进行了检测。确定了每种检测平台和样本类型的诊断灵敏度。在 63 个样本中，至少有一个平台在 62 个 NP 样本、52 个 AN 样本、59 个唾液样本和 31 个 SL 样本中检测到 SARS-CoV-2。在 50 个样本中，有 21 个 NP 样本、13 个 AN 样本、12 个唾液样本和 1 个 SL 样本分离出传染性 SARS-CoV-2。从有症状患者的 NP 样本中，SARS-CoV-2 分离最为成功，在 COVID-19 诊断后 5 天内，24 个阳性样本中有 16 个阳性（66.67%），其次是无症状患者的样本（17 个阳性中有 5 个阳性，29.41%），而症状后患者的样本则不太成功。自我采集的唾液和 AN 样本的优势弥补了相对于 NP 样本的灵敏度损失。因此，唾液和 AN 样本是用于有症状 SARS-CoV-2 诊断检测或监测的可接受替代方法，增加了对无症状个体的采样频率。SARS-CoV-2 的感染动力学对病毒感染力和分子及经典病毒检测试验的诊断灵敏度有重大影响。在本研究中，我们确定了呼吸道（鼻咽和前鼻腔拭子）和口腔分泌物（唾液和舌下拭子）的诊断灵敏度，并评估了有症状、无症状或症状后个体的感染性病毒脱落模式。了解这些样本的诊断性能以及这些体液中传染性病毒脱落的模式，为控制 COVID-19 提供了关键信息，并可能有助于完善对通过流行病学调查确定的阳性个体及其密切接触者的隔离和检疫指南。
