Automated molecular testing of saliva for SARS-CoV-2 detection

Nancy Matic; Tanya Lawson; Gordon Ritchie; Aleksandra Stefanovic; Victor Leung; Sylvie Champagne; Marc G Romney; Christopher F Lowe

doi:10.1016/j.diagmicrobio.2021.115324

Automated molecular testing of saliva for SARS-CoV-2 detection

Diagn Microbiol Infect Dis. 2021 May;100(1):115324. doi: 10.1016/j.diagmicrobio.2021.115324. Epub 2021 Jan 23.

Authors

Nancy Matic¹, Tanya Lawson², Gordon Ritchie³, Aleksandra Stefanovic³, Victor Leung³, Sylvie Champagne³, Marc G Romney³, Christopher F Lowe³

Affiliations

¹ Division of Medical Microbiology and Virology, St. Paul's Hospital, Vancouver, Canada; Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, Canada. Electronic address: nmatic@providencehealth.bc.ca.
² Division of Medical Microbiology and Virology, St. Paul's Hospital, Vancouver, Canada.
³ Division of Medical Microbiology and Virology, St. Paul's Hospital, Vancouver, Canada; Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, Canada.

Abstract

With surging global demand for SARS-CoV-2 testing capacity, laboratories seek automated, high-throughput molecular solutions, particularly for specimens not requiring specialized collection devices or viral transport media. Saliva specimens submitted from patients under investigation for COVID-19 from March to July 2020 were processed in the laboratory with sterile phosphate-buffered saline in a 1:2 dilution and tested using manual extraction and a commercial assay for detection of the SARS-CoV-2 E gene (LightMix®) in comparison to the Roche cobas® SARS-CoV-2 Test on the cobas® 6800 instrument. 34.4% (22/64) of saliva samples were positive for SARS-CoV-2. Positive and negative concordance between the LightMix® and cobas® assays were 100%. The overall invalid rate for saliva on the cobas® 6800 (1/128, 0.78%) was similar to the baseline invalid rate observed for nasopharyngeal swabs/viral transport media. Saliva is a feasible specimen type for SARS-CoV-2 testing on the cobas® 6800 platform, with potential to improve turnaround time and enhance testing capacity.

Keywords: COVID-19; SARS-Cov-2; automated; cobas 6800; saliva.

MeSH terms

Automation, Laboratory
COVID-19 Testing / methods*
Humans
Molecular Diagnostic Techniques
Saliva / virology*
Specimen Handling / methods