ABSTRACT

Background: The gold standard for COVID-19 diagnosis relies on quantitative reverse-transcriptase polymerase-chain reaction (RT-qPCR) from nasopharyngeal swab (NPS) specimens, but NPSs present several limitations. The simplicity, low invasive and possibility of self-collection of saliva imposed these specimens as a relevant alternative for SARS-CoV-2 detection. However, the discrepancy of saliva test results compared to NPSs made of its use controversial. Here, we assessed Salivettes®, as a standardized saliva collection device, and compared SARS-CoV-2 positivity on paired NPS and saliva specimens.

Methods: A total of 303 individuals randomly selected among those investigated for SARS-CoV-2 were enrolled, including 30 (9.9%) patients previously positively tested using NPS (follow-up group), 90 (29.7%) mildly symptomatic and 183 (60.4%) asymptomatic.

Results: The RT-qPCR revealed a positive rate of 11.6% (n = 35) and 17.2% (n = 52) for NPSs and saliva samples, respectively. The sensitivity and specificity of saliva samples were 82.9% and 91.4%, respectively, using NPS as reference. The highest proportion of discordant results concerned the follow-up group (33.3%). Although the agreement exceeded 90.0% in the symptomatic and asymptomatic groups, 17 individuals were detected positive only in saliva samples, with consistent medical arguments.

Conclusion Saliva collected with Salivette® was more sensitive for detecting symptomatic and pre-symptomatic infections.

摘要

背景： COVID-19 诊断的黄金标准依赖于鼻咽拭子 (NPS) 标本的定量逆转录酶聚合酶链反应 (RT-qPCR)，但 NPS 存在一些局限性。这些样本简单、侵入性低且可以自行采集唾液，因此可以作为 SARS-CoV-2 检测的相关替代方案。然而，唾液测试结果与 NPS 的差异使其使用引起争议。在这里，我们评估了 Salivettes® 作为一种标准化唾液收集装置，并比较了配对 NPS 和唾液样本的 SARS-CoV-2 阳性率。

方法：从 SARS-CoV-2 调查对象中随机选出 303 名个体，其中 30 名（9.9%）名先前使用 NPS 检测呈阳性的患者（随访组）、90 名（29.7%）名轻度症状患者和 183 名（29.7%）名轻度症状患者60.4%）无症状。

结果： RT-qPCR 显示 NPS 和唾液样本的阳性率分别为 11.6% (n = 35) 和 17.2% (n = 52)。以 NPS 为参考，唾液样本的敏感性和特异性分别为 82.9% 和 91.4%。不一致结果的比例最高的是随访组（33.3%）。尽管有症状组和无症状组的一致性超过90.0%，但仅在唾液样本中检测出17人呈阳性，这与医学观点一致。

结论使用 Salivette® 采集的唾液对于检测有症状和症状前感染更敏感。