Infection and Drug Resistance (Jul 2021)

Saliva Testing is a Robust Non-Invasive Method for SARS-CoV-2 RNA Detection

  • Palikša S,
  • Lopeta M,
  • Belevičius J,
  • Kurmauskaitė V,
  • Ašmenavičiūtė I,
  • Pereckaitė L,
  • Vitkauskienė A,
  • Baliūtytė I,
  • Valentaitė M,
  • Mickienė A,
  • Gagilas J

Journal volume & issue
Vol. Volume 14
pp. 2943 – 2951

Abstract

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Sigitas Palikša,1 Mantvydas Lopeta,1 Jonas Belevičius,1 Vaida Kurmauskaitė,1 Ieva Ašmenavičiūtė,1 Laura Pereckaitė,2 Astra Vitkauskienė,2 Ieva Baliūtytė,3 Monika Valentaitė,3 Auksė Mickienė,3 Julius Gagilas1 1JSC Diagnolita, Vilnius, 10257, Lithuania; 2Department of Laboratory Medicine, Lithuanian University of Health Sciences, Kaunas, 50161, Lithuania; 3Department of Infectious Diseases, Lithuanian University of Health Sciences, Kaunas Hospital, Kaunas, 47116, LithuaniaCorrespondence: Sigitas PalikšaJSC Diagnolita, Saulėtekio al. 7C, Vilnius, 10257, LithuaniaTel +370 688 12972Email [email protected]: The precise diagnostic testing is of high importance in fighting the coronavirus pandemic. While nasopharyngeal (NP) swab testing is currently the gold standard, the SARS-CoV-2 virus could be also detected in some other body fluids. In this study, we aimed to compare the SARS-CoV-2 RNA detection results, obtained using saliva samples and NP swab samples, collected from infected patients and healthy volunteers.Patients and Methods: A total of 111 individuals were enrolled in this study: 53 healthy volunteers, participating in routine testing and 58 COVID-19 patients. Diagnosis for both groups was confirmed using a set of diagnostic CE-IVD labeled RT-qPCR kits. Most of the saliva samples were collected within 48 hours after the NP swabs were taken. RNA was purified from saliva samples and analyzed using a laboratory-developed kit (Diagnolita). Detection results for both sample types were compared and analyzed in terms of result agreement, Ct variation, and quantity of internal control, as well as population analysis.Results: We found a good concordance between the NP swab and saliva samples. The positive percent agreement was 98.28% (CI 90.76– 99.96%) and negative percent agreement was 98.11% (CI 89.93– 99.95%). Additionally, we observed a statistically significant (p< 0.05) and moderately strong (R = 0.53) correlation between Ct values in saliva and NP swab samples. The saliva collection method is more robust since the Ct variation of internal control ribonuclease P mRNA detection is lower in saliva samples.Conclusion: Saliva sample testing is a robust and reliable non-invasive alternative to the NP swab method for SARS-CoV-2 RNA detection, as well as a promising tool for COVID-19 screening.Keywords: COVID-19, coronavirus, infection, RT-qPCR

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