Evaluation of a new molecular test for the detection of SARS-CoV-2 Nucleic Acid in salivary samples

A new molecular test for SARS-CoV-2 in salivary samples

  • Ilaria Talli University of Padova, Padova, Italy
  • Andrea Padoan University of Padova, Padova, Italy
  • Stefania Moz University-Hospital of Padova, Padova, Italy
  • Filippo Navaglia University-Hospital of Padova, Padova, Italy
  • Mario Plebani University of Padova, Padova, Italy
  • Daniela Basso University of Padova, Padova, Italy
Keywords: COVID-19; molecular testing; nucleic acid amplification; salivary samples; SARS-CoV-2

Abstract


Background: Molecular testing is considered the gold standard for the detection of SARS-CoV-2. This study aimed to compare the performance of the P742H SARS-CoV-2 Nucleic Acid Multiplex Detection Kit in salivary samples, with respect to the 732HF Novel Coronavirus (2019-nCoV) Nucleic Acid Detection Kit and the TaqPath COVID-19 CE-IVD RT-PCR Kit, used at University-Hospital of Padova, Italy.

Methods: One hundred twenty-four salivary samples self-collected by healthcare workers (HCW) during the screening program at University-Hospital of Padova, Italy, from Oct to Nov 2022, were included in the study. RNA extraction was performed by Viral DNA and RNA Extraction Kit (Technogenetics, Lodi, Italy) and amplification by P742H and 732HF (Technogenetics, Lodi, Italy). RNA was extracted using MagNa Pure 96 DNA and Viral NA Small Volume Kit (Roche, Switzerland) for TaqPath analysis (Thermo Fisher Scientific, USA).

Results: 94 samples were positive at P742H, while 30 were negative; for 732HF, 96 samples were positive, while 28 were negative, with an overall agreement of 97.5% (Cohen’s κ = 0.930, p < 0.001). TaqPath gave 95 positive samples, and 29 negative results, with an overall agreement of 100% (Cohen’s κ = 1.0, p < 0.001) with respect to P742H, and 97.5% (Cohen’s κ = 0.931, p < 0.001) with respect to 732HF. Comparing cycle threshold (Ct) between the P742H and 732HF, no statistically significant differences were found (p = n.s.).

Conclusions: The P742H method proved better performances than 732HF for salivary samples, both presenting the same amplification time. In addition, P742H results were comparable to those obtained through the high-throughput method TaqPath.

Author Biographies

Ilaria Talli, University of Padova, Padova, Italy

1 Laboratory Medicine Unit, University-Hospital of Padova, Padova, Italy

2 QI.Lab.Med, Spinoff of University of Padova, Padova, Italy

Andrea Padoan, University of Padova, Padova, Italy

1 Laboratory Medicine Unit, University-Hospital of Padova, Padova, Italy

2 QI.Lab.Med, Spinoff of University of Padova, Padova, Italy

3 Department of Medicine-DIMED, University of Padova, Padova, Italy

Stefania Moz, University-Hospital of Padova, Padova, Italy

1 Laboratory Medicine Unit, University-Hospital of Padova, Padova, Italy

Filippo Navaglia, University-Hospital of Padova, Padova, Italy

1 Laboratory Medicine Unit, University-Hospital of Padova, Padova, Italy

Mario Plebani, University of Padova, Padova, Italy

1 Laboratory Medicine Unit, University-Hospital of Padova, Padova, Italy

2 QI.Lab.Med, Spinoff of University of Padova, Padova, Italy

3 Department of Medicine-DIMED, University of Padova, Padova, Italy

Daniela Basso, University of Padova, Padova, Italy

1 Laboratory Medicine Unit, University-Hospital of Padova, Padova, Italy

2 QI.Lab.Med, Spinoff of University of Padova, Padova, Italy

3 Department of Medicine-DIMED, University of Padova, Padova, Italy

References

[1] Statement on the fourteenth meeting of the International Health Regulations (2005) Emergency Committee regarding the coronavirus disease (COVID-19) pandemic. Available at https://www.who.int/news/item/30-01-2023-statement-on-the-fourteenth-meeting-of-the-international-health-regulations-(2005)-emergency-committee-regarding-the-coronavirus-disease-(covid-19)-pandemic.


[2] Thomas Craig KJ, Rizvi R, Willis VC, Kassler WJ, Jackson GP. Effectiveness of Contact Tracing for Viral Disease Mitigation and Suppression: Evidence-Based Review. JMIR Public Health Surveill 2021; 7: e32468.


[3] Çitak N, Pekçolaklar A. COVID-19 Screening Program Should be Performed in Healthcare Workers. Turk Thorac J 2021; 22: 169-174.


[4] Udani R, Schilter KF, Hillmer RE, Petersen RA, Srinivasan S, Marchant JS, et al. Implementation of an Active Screening Program for SARS-CoV2 - Experience at an Academic Medical Center. WMJ 2022; 121: 235-238. 


[5] Wilhelm A, Pallas C, Marschalek R, Widera M. Detection and Quantification of SARS-CoV-2 by Real-Time RT-PCR Assay. Methods Mol Biol 2022; 2452: 75-98. 


[6] WHO Coronavirus Disease (COVID-19) Technical Guidance: Laboratory Testing for 2019-nCoV in Humans. 2020. Available at: https://www.who.int/emergencies/diseases/novelcoronavirus-2019/technical-guidance/laboratory-guidance. Accessed July 27, 2020.


[7] World Health Organization. Laboratory testing for coronavirus disease 2019 (COVID-19) in suspected human cases: interim guidance, 2 March 2020. https://apps.who.int/iris/handle/10665/331329. Accessed: 6 May 2020.


[8] Basso D, Aita A, Padoan A, Cosma C, Navaglia F, Moz S, et al. Salivary SARS-CoV-2 antigen rapid detection: A prospective cohort study. Clin Chim Acta 2021; 517: 54-59.


[9] Dinnes J, Sharma P, Berhane S, van Wyk SS, Nyaaba N, Domen J, et al. Rapid, point-of-care antigen tests for diagnosis of SARS-CoV-2 infection. Cochrane Database Syst Rev 2022; 7: CD013705.


[10] Lippi G, Henry BM, Plebani M. An overview of the most important preanalytical factors influencing the clinical performance of SARS-CoV-2 antigen rapid diagnostic tests (Ag-RDTs). Clin Chem Lab Med 2022; 61: 196-204.


[11] Bastos ML, Perlman-Arrow S, Menzies D, Campbell JR. The Sensitivity and Costs of Testing for SARS-CoV-2 Infection With Saliva Versus Nasopharyngeal Swabs: A Systematic Review and Meta-analysis. Ann Intern Med 2021; 174: 501-510.


[12] Aita A, Basso D, Cattelan AM, Fioretto P, Navaglia F, Barbaro F, et al. SARS-CoV-2 identification and IgA antibodies in saliva: One sample two tests approach for diagnosis. Clin Chim Acta 2020; 510: 717-722.


[13] Basso D, Aita A, Navaglia F, Mason P, Moz S, Pinato A, et al. The University of Padova salivary-based SARS-CoV-2 surveillance program minimized viral transmission during the second and third pandemic wave. BMC Med 2022; 20: 96.


[14] Butler-Laporte G, Lawandi A, Schiller I, Yao M, Dendukuri N, McDonald EG, Lee TC. Comparison of Saliva and Nasopharyngeal Swab Nucleic Acid Amplification Testing for Detection of SARS-CoV-2: A Systematic Review and Meta-analysis. JAMA Intern Med 2021; 181: 353-360. Erratum in: JAMA Intern Med 2021; 181: 409.


[15] Schuit E, Venekamp RP, Veldhuijzen IK, van den Bijllaardt W, Pas SD, Stohr JJJM, et al. Head-to-head comparison of the accuracy of saliva and nasal rapid antigen SARS-CoV-2 self-testing: cross-sectional study. BMC Med 2022; 20: 406.


[16] Rhoads DD, Pinsky BA. The Truth about SARS-CoV-2 Cycle Threshold Values Is Rarely Pure and Never Simple. Clin Chem 2021; 68: 16-18.


[17] Lippi G, Henry BM. Possible drawbacks of relying only on molecular testing for diagnosing SARS-CoV-2 infections. Public Health 2022; 205: e2.


[18] Bohn MK, Lippi G, Horvath A, Sethi S, Koch D, Ferrari M, et al. Molecular, serological, and biochemical diagnosis and monitoring of COVID-19: IFCC taskforce evaluation of the latest evidence. Clin Chem Lab Med 2020; 58: 1037-1052.


[19] Yokota I, Shane PY, Okada K, Unoki Y, Yang Y, Inao T, et al. Mass Screening of Asymptomatic Persons for Severe Acute Respiratory Syndrome Coronavirus 2 Using Saliva. Clin Infect Dis 2021; 73: e559-e565.


[20] Rao M, Rashid FA, Sabri FSAH, Jamil NN, Zain R, Hashim R, et al. Comparing Nasopharyngeal Swab and Early Morning Saliva for the Identification of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Clin Infect Dis 2021; 72: e352-e356.


[21] Rai P, Kumar BK, Deekshit VK, Karunasagar I, Karunasagar I. Detection technologies and recent developments in the diagnosis of COVID-19 infection. Appl Microbiol Biotechnol 2021; 105: 441-455.


[22] Pighi L, Henry BM, Mattiuzzi C, De Nitto S, Salvagno GL, Lippi G. Cost-effectiveness analysis of different COVID-19 screening strategies based on rapid or laboratory-based SARS-CoV-2 antigen testing. Clin Chem Lab Med 2023. [ahead of print].


[23] You HL, Lin MC, Lee CH. Comparison of the Roche cobas 6800 SARS-CoV-2 test and the Taiwan CDC protocol for the molecular diagnosis of COVID-19. Biomed J 2021; 44: 101-104.


[24] Fomenko A, Weibel S, Moezi H, Menger K, Schmucker C, Metzendorf MI, et al. Assessing severe acute respiratory syndrome coronavirus 2 infectivity by reverse-transcription polymerase chain reaction: A systematic review and meta-analysis. Rev Med Virol 2022; 32: e2342.


[25] Banko A, Petrovic G, Miljanovic D, Loncar A, Vukcevic M, Despot D, et al. Comparison and Sensitivity Evaluation of Three Different Commercial Real-Time Quantitative PCR Kits for SARS-CoV-2 Detection. Viruses 2021; 13: 1321.

Published
2023/05/28
Section
Original paper