Investigation of discordant SARS-CoV-2 RT-PCR results using minimally processed saliva

Dawn White; Jimmy Gu; Catherine-Jean Steinberg; Deborah Yamamura; Bruno J Salena; Cynthia Balion; Carlos D M Filipe; Alfredo Capretta; Yingfu Li; John D Brennan

doi:10.1038/s41598-022-06642-5

Investigation of discordant SARS-CoV-2 RT-PCR results using minimally processed saliva

Sci Rep. 2022 Feb 18;12(1):2806. doi: 10.1038/s41598-022-06642-5.

Authors

Dawn White¹, Jimmy Gu², Catherine-Jean Steinberg³, Deborah Yamamura^{4

5}, Bruno J Salena³, Cynthia Balion⁵, Carlos D M Filipe⁶, Alfredo Capretta¹, Yingfu Li^{7

8

9

10}, John D Brennan¹¹

Affiliations

¹ Biointerfaces Institute, McMaster University, Hamilton, ON, L8S 4L8, Canada.
² Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, L8N 3Z5, Canada.
³ Department of Medicine, McMaster University, Hamilton, ON, L8N 3Z5, Canada.
⁴ Michael DeGroote Institute of Infectious Disease Research, McMaster University, Hamilton, ON, L8N 3Z5, Canada.
⁵ Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, L8N 3Z5, Canada.
⁶ Department of Chemical Engineering, McMaster University, Hamilton, ON, L8S 4M1, Canada.
⁷ Biointerfaces Institute, McMaster University, Hamilton, ON, L8S 4L8, Canada. liying@mcmaster.ca.
⁸ Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, L8N 3Z5, Canada. liying@mcmaster.ca.
⁹ Michael DeGroote Institute of Infectious Disease Research, McMaster University, Hamilton, ON, L8N 3Z5, Canada. liying@mcmaster.ca.
¹⁰ School of Biomedical Engineering, McMaster University, Hamilton, ON, L8S 4K1, Canada. liying@mcmaster.ca.
¹¹ Biointerfaces Institute, McMaster University, Hamilton, ON, L8S 4L8, Canada. brennanj@mcmaster.ca.

Abstract

Saliva is an attractive sample for coronavirus disease 2019 testing due its ease of collection and amenability to detect viral RNA with minimal processing. Using a direct-to-RT-PCR method with saliva self-collected from confirmed COVID-19 positive volunteers, we observed 32% false negative results. Confirmed negative and healthy volunteer samples spiked with 10⁶ genome copies/mL of heat-inactivated severe acute respiratory syndrome coronavirus 2 showed false negative results of 10% and 13%, respectively. Additional sample heating or dilution of the false negative samples conferred only modest improvements. These results highlight the potential to significantly underdiagnose COVID-19 infections when testing directly from minimally processed heterogeneous saliva samples.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

COVID-19 Nucleic Acid Testing*
False Negative Reactions
Healthy Volunteers
Humans
Point-of-Care Testing
SARS-CoV-2 / isolation & purification*
Saliva / virology*

Abstract

Publication types

MeSH terms

Grants and funding