Does sampling saliva increase detection of SARS-CoV-2 by RT-PCR? Comparing saliva with oro-nasopharyngeal swabs

Dogan O. A., Kose B., Agaoglu N. B., Yildiz J., Alkurt G., Demirkol Y. K., ...More

JOURNAL OF VIROLOGICAL METHODS, vol.290, 2021 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 290
  • Publication Date: 2021
  • Doi Number: 10.1016/j.jviromet.2020.114049
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, BIOSIS, Biotechnology Research Abstracts, CAB Abstracts, Chemical Abstracts Core, EMBASE, MEDLINE, Veterinary Science Database
  • Istanbul Technical University Affiliated: No


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 oronasopharyngeal and nasopharyngeal samples, while it was 63 % for saliva samples (p < 0.001). On day 5, RTPCR 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.