The gold standard method in the diagnosis of SARS-CoV-2 infection is the detection of viral RNA in the nasopharyngeal sample by RT-PCR. Recently, saliva samples have been suggested as an alternative sample. In the present study, we aimed to compare RT-PCR results in nasopharyngeal, oro-nasopharyngeal and saliva samples of COVID-19 patients. 98 of 200 patients were positive in RT-PCR analysis performed before the hospitalization. On day 0, at least one sample was positive in 67 % of 98 patients. The positivity rate was 83 % for both oro-nasopharyngeal and nasopharyngeal samples, while it was 63 % for saliva samples (p < 0.001). On day 5, RT-PCR was performed in 59 patients, 34 % had at least one positive result. The positivity rate was 55 % for both saliva and nasopharyngeal samples, while it was 60 % for oro-nasopharyngeal samples. Our study shows that the sampling saliva does not increase the sensitivity of RT-PCR tests at the early stages of infection. However, on the 5th day, viral RNA detection rates in saliva were similar to nasopharyngeal and oro-nasopharyngeal samples. In conclusion, we suggest that, in patients receiving treatment, RT-PCR in saliva, in addition to the standard samples, is important to determine the isolation period and control transmission.

诊断SARS-CoV-2感染的金标准方法是通过RT-PCR检测鼻咽样品中的病毒RNA。最近，有人建议将唾液样本作为替代样本。在本研究中，我们旨在比较COVID-19患者鼻咽，口鼻咽和唾液样本中的RT-PCR结果。200例患者中有98例在住院前进行的RT-PCR分析为阳性。在第0天，98名患者中有67％至少有一个样本为阳性。鼻-鼻咽和鼻咽样品的阳性率为83％，而唾液样品的阳性率为63％（p <0.001）。在第5天，对59例患者进行了RT-PCR，其中34％的患者至少有一项阳性结果。唾液和鼻咽样品的阳性率为55％，而口鼻咽样品的阳性率为60％。我们的研究表明，在感染初期，唾液采样不会增加RT-PCR检测的敏感性。但是，在第5天，唾液中病毒RNA的检出率与鼻咽和口鼻咽样品相似。总之，我们建议，在接受治疗的患者中，除了标准样品外，唾液中的RT-PCR对于确定隔离期和控制传播也很重要。