Department of pathology, Imam Hospital Complex, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
Department of Radiation Oncology, Cancer Institute, Imam Khomeini Hospital Complex, Tehran, Iran.
J Infect Dev Ctries. 2022 Jan 31;16(1):5-9. doi: 10.3855/jidc.15239.
The introduction of a self-collection sampling method with less discomfort would be of great benefit in reducing the risk of medical provider's contamination and patient's acceptance. The aim of the present study was to investigate saliva samples' diagnostic performance for the COVID-19 RT-PCR test compared to pharyngeal swabs.
From individuals referred to a medical center with presentations compatible with COVID-19 who were eligible for molecular diagnostic tests, 80 cases were selected. Nasopharyngeal and oropharyngeal swabs (placed into the same transport tube) along with self-collected saliva sample were taken from each participant for COVID-19 RT-PCR assay. The results of pharyngeal swabs and saliva sample were compared.
Sixty-two (78%) infected cases were detected, of whom 31 (39%) cases tested positive for both pharyngeal swab and saliva samples. 24 (30%) and 7 (9%) cases tested positive only for pharyngeal or saliva samples, respectively. The overall percentage of agreement between pharyngeal swab and saliva sample was 61%, with a kappa value of 0.24 (p-value = 0.019, 95% CI: 0.04-0.44), showing a fair level of agreement. The diagnostic sensitivity of pharyngeal swabs was 88.71% (95% CI: 78.11-95.34), and the diagnostic sensitivity of saliva samples was 61.29% (95% CI: 48.07-73.40). Compared to pharyngeal swabs (oropharyngeal and nasopharyngeal swabs in the same collection tube), an important observation was that seven more positive cases were detected among saliva samples.
The findings of the present study indicated that self-collected saliva samples cannot replace pharyngeal swabs. Still, saliva samples significantly increased the case detection rate and can be used along with pharyngeal swabs.
引入一种不适感较低的自我采集样本方法，对于降低医疗提供者污染和患者接受度的风险将大有裨益。本研究旨在调查唾液样本与咽拭子相比对 COVID-19 RT-PCR 检测的诊断性能。
从符合 COVID-19 表现并符合分子诊断检测条件的个体中，选择了 80 例个体。从每位参与者中采集鼻咽和口咽拭子（置于同一运输管中）以及自我采集的唾液样本，用于 COVID-19 RT-PCR 检测。比较咽拭子和唾液样本的结果。
检测到 62 例（78%）感染病例，其中 31 例（39%）咽拭子和唾液样本均为阳性。24 例（30%）和 7 例（9%）仅咽拭子或唾液样本为阳性。咽拭子和唾液样本之间的总体一致性百分比为 61%，kappa 值为 0.24（p 值=0.019，95%CI：0.04-0.44），表明一致性为中等水平。咽拭子的诊断敏感性为 88.71%（95%CI：78.11-95.34），唾液样本的诊断敏感性为 61.29%（95%CI：48.07-73.40）。与咽拭子（同一采集管中的口咽拭子和鼻咽拭子）相比，一个重要的观察结果是，在唾液样本中多发现了 7 例阳性病例。
本研究结果表明，自我采集的唾液样本不能替代咽拭子。不过，唾液样本显著提高了病例检出率，可与咽拭子一起使用。
