Bidkar Vijay, Mishra Meena, Gade Neeta, Selvaraj Kalaiselvi
Department of Otorhinolaryngology-Head and Neck Surgery, All India Institute of Medical Sciences, Nagpur, Maharashtra India.
Department of Microbiology, All India Institute of Medical Sciences, Nagpur, Maharashtra India.
Indian J Otolaryngol Head Neck Surg. 2022 Oct;74(Suppl 2):2923-2929. doi: 10.1007/s12070-021-02571-3. Epub 2021 Apr 26.
Comparing the diagnostic utility of salivary specimen samples with conventional nasopharynx-oropharynx (NP-OP) specimen samples to identify COVID-19 cases by reverse transcription-polymerase chain reaction (RT-PCR). Eighty COVID-19 suspects enrolled for the paired sampling. In addition to conventional sampling, suspects were asked to follow stepwise pictorial instructions for self salivary sampling. Separate nylon swab stick was used for taking the samples from NP-OP and the floor of the oral cavity. The data were analyzed for sensitivity, specificity, concordance of COVID-19 status, and limits of agreement for cycle threshold (ct) values by either method. Forty-nine suspects (61.3%) were males, the mean age was 36.4 years. To determine the diagnostic test performance of the saliva, RT-PCR results of the NP-OP samples were used as the reference standard. Out of 80 suspects, 41 showed positivity by NP-OP swabs and 12 by salivary samples. The salivary samples showed significantly lesser positivity rate. The sensitivity and specificity of salivary samples against conventional reference standards are 24.4%, 94.9% respectively. Concordance of these two types of samples in terms of agreement kappa statistics is estimated as K = 0.252 (0.09-0.42). Median ct values of both the E and ORF1ab gene for the salivary samples were higher compared to the corresponding NP-OP sample. This study showed lesser sensitivity with salivary swab samples as compared to conventional NP-OP sampling for RT-PCR, COVID-19 detection. Hence, we are of opinion that more studies are required to establish the utility of salivary sampling in COVID-19 diagnostics.
比较唾液标本样本与传统鼻咽-口咽（NP-OP）标本样本通过逆转录-聚合酶链反应（RT-PCR）识别新冠病毒病（COVID-19）病例的诊断效用。80名COVID-19疑似患者参与配对采样。除了传统采样外，还要求疑似患者按照逐步的图片说明进行自我唾液采样。使用单独的尼龙拭子棒从NP-OP和口腔底部采集样本。通过两种方法分析数据的敏感性、特异性、COVID-19状态的一致性以及循环阈值（ct）值的一致性界限。49名疑似患者（61.3%）为男性，平均年龄为36.4岁。为了确定唾液的诊断测试性能，将NP-OP样本的RT-PCR结果用作参考标准。在80名疑似患者中，41名通过NP-OP拭子呈阳性，12名通过唾液样本呈阳性。唾液样本的阳性率明显较低。唾液样本相对于传统参考标准的敏感性和特异性分别为24.4%、94.9%。根据一致性kappa统计，这两种样本类型的一致性估计为K = 0.252（0.09 - 0.42）。唾液样本中E基因和ORF1ab基因的中位ct值均高于相应的NP-OP样本。这项研究表明，与传统的NP-OP采样用于RT-PCR检测COVID-19相比，唾液拭子样本的敏感性较低。因此，我们认为需要更多研究来确定唾液采样在COVID-19诊断中的效用。
