Temporal profiles of viral load in posterior oropharyngeal saliva samples and serum antibody responses during infection by SARS-CoV-2: an observational cohort study
Temporal profiles of viral load in posterior oropharyngeal saliva samples and serum antibody responses during infection by SARS-CoV-2: an observational cohort study
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DOI：
10.1016/s1473-3099(20)30196-1
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发表时间：
2020-05-01
影响因子：
56.3
通讯作者：
Yuen, Kwok-Yung
中科院分区：
文献类型：
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作者：
To, Kelvin Kai-Wang;Tsang, Owen Tak-Yin;Yuen, Kwok-Yung
背景2019冠状病毒病（COVID-19）导致严重的社区和医院暴发。严重急性呼吸道综合征冠状病毒2型（SARS-CoV-2）感染患者的系列呼吸道病毒载量和血清抗体反应的综合数据尚未获得。鼻咽和咽喉拭子通常用于呼吸道感染的连续病毒载量监测，但收集这些标本可能会导致患者不适，并使卫生保健工作者处于危险之中。我们旨在确定COVID-19患者后口咽（深喉咙）唾液样本中SARS-CoV-2的系列呼吸道病毒载量和血清抗体应答。方法我们在香港两家医院进行了队列研究。我们纳入了实验室确诊的COVID-19患者。我们采集了血液、尿液、后口咽唾液和直肠拭子样本。通过逆转录酶定量PCR（RT-qPCR）确定系列病毒载量。采用EIA法检测SARS-CoV-2内部核蛋白（NP）和表面刺突蛋白受体结合域（RBD）的抗体水平。结果2020年1月22日至2020年2月12日期间，筛选了30例患者纳入研究，其中23例入选（中位年龄62岁[范围37-75]）。就诊时后口咽唾液或其他呼吸道标本中的中位病毒载量为5.2 log 10拷贝/mL（IQR 4.1-7.0）。唾液病毒载量在症状发作后第一周最高，随后随时间下降（斜率-0.15，95%CI-0.19至-0.11; R-2=0.71）。在一名患者中，在症状发作后25天检测到病毒RNA。年龄越大病毒载量越高（斯皮尔曼p= 0.48，95%CI 0.074-0.75; p=0.020）。对于16例在症状发作后14天或更长时间获得血清样本的患者，抗NP IgG的血清阳性率为94%（n=15），抗NP IgM的血清阳性率为88%（n=14），抗RBD IgG的血清阳性率为100%（n=16），抗RBD IgM的血清阳性率为94%（n=15）。抗SARS-CoV-2-NP或抗SARS-CoV-2-RBD IgG水平与病毒中和滴度相关（R-2 >0.9）。在连续样本中未检测到基因组突变。解释后口咽唾液样本是一种更容易被患者和医护人员接受的非侵入性标本。与严重急性呼吸系统综合征不同，COVID-19患者在发病前的病毒载量最高，这可能是这种流行病快速传播的原因。这一发现强调了严格的感染控制和早期使用有效的抗病毒药物的重要性，单独或联合使用，对高危人群。血清学检测可作为RT-qPCR诊断的补充。版权所有（C）2020爱思唯尔有限公司保留所有权利。
Background Coronavirus disease 2019 (COVID-19) causes severe community and nosocomial outbreaks. Comprehensive data for serial respiratory viral load and serum antibody responses from patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are not yet available. Nasopharyngeal and throat swabs are usually obtained for serial viral load monitoring of respiratory infections but gathering these specimens can cause discomfort for patients and put health-care workers at risk. We aimed to ascertain the serial respiratory viral load of SARS-CoV-2 in posterior oropharyngeal (deep throat) saliva samples from patients with COVID-19, and serum antibody responses.Methods We did a cohort study at two hospitals in Hong Kong. We included patients with laboratory-confirmed COVID-19. We obtained samples of blood, urine, posterior oropharyngeal saliva, and rectal swabs. Serial viral load was ascertained by reverse transcriptase quantitative PCR (RT-qPCR). Antibody levels against the SARS-CoV-2 internal nucleoprotein (NP) and surface spike protein receptor binding domain (RBD) were measured using EIA. Whole-genome sequencing was done to identify possible mutations arising during infection.Findings Between Jan 22,2020, and Feb 12,2020,30 patients were screened for inclusion, of whom 23 were included (median age 62 years [range 37-75]). The median viral load in posterior oropharyngeal saliva or other respiratory specimens at presentation was 5.2 log 10 copies per mL (IQR 4.1-7.0). Salivary viral load was highest during the first week after symptom onset and subsequently declined with time (slope -0.15, 95% CI -0.19 to -0.11; R-2=0.71). In one patient, viral RNA was detected 25 days after symptom onset. Older age was correlated with higher viral load (Spearman's p=0.48,95% CI 0.074-0.75; p=0.020). For 16 patients with serum samples available 14 days or longer after symptom onset, rates of seropositivity were 94% for anti-NP IgG (n=15), 88% for anti-NP IgM (n=14), 100% for anti-RBD IgG (n=16), and 94% for anti-RBD IgM (n=15). Anti-SARS-CoV-2-NP or anti-SARS-CoV-2-RBD IgG levels correlated with virus neutralisation titre (R-2 >0.9). No genome mutations were detected on serial samples.Interpretation Posterior oropharyngeal saliva samples are a non-invasive specimen more acceptable to patients and health-care workers. Unlike severe acute respiratory syndrome, patients with COVID-19 had the highest viral load near presentation, which could account for the fast-spreading nature of this epidemic. This finding emphasises the importance of stringent infection control and early use of potent antiviral agents, alone or in combination, for high-risk individuals. Serological assay can complement RT-qPCR for diagnosis. Copyright (C) 2020 Elsevier Ltd. All rights reserved.