Clinical Validation of a Sensitive Test for Saliva Collected in Healthcare and Community Settings with Pooling Utility for Severe Acute Respiratory Syndrome Coronavirus 2 Mass Surveillance

Nikhil S Sahajpal; Ashis K Mondal; Sudha Ananth; Allan Njau; Pankaj Ahluwalia; Vamsi Kota; Kevin Caspary; Ted M Ross; Michael Farrell; Michael P Shannon; Sadanand Fulzele; Alka Chaubey; Madhuri Hegde; Amyn M Rojiani; Ravindra Kolhe

doi:10.1016/j.jmoldx.2021.04.005

Clinical Validation of a Sensitive Test for Saliva Collected in Healthcare and Community Settings with Pooling Utility for Severe Acute Respiratory Syndrome Coronavirus 2 Mass Surveillance

J Mol Diagn. 2021 Jul;23(7):788-795. doi: 10.1016/j.jmoldx.2021.04.005. Epub 2021 May 4.

Authors

Affiliations

¹ Department of Pathology, Medical College of Georgia, Augusta University, Augusta, Georgia.
² Department of Pathology, Aga Khan University Hospital, Nairobi, Kenya.
³ Department of Medicine, Medical College of Georgia, Augusta University, Augusta, Georgia.
⁴ 4th Weapons of Mass Destruction Civil Support Team, Georgia Army National Guard, Marietta, Georgia.
⁵ Center for Vaccines and Immunology, University of Georgia, Athens, Georgia.
⁶ Institute for Internet Security and Privacy, Georgia Institute of Technology, Atlanta, Georgia.
⁷ Advanced Warfighting Technologies Division, Georgia Tech Research Institute, Georgia Institute of Technology, Atlanta, Georgia.
⁸ Center for Healthy Aging, Medical College of Georgia, Augusta University, Augusta, Georgia.
⁹ Global Laboratory Services, PerkinElmer Inc., Waltham, Massachusetts.
¹⁰ Department of Pathology, Medical College of Georgia, Augusta University, Augusta, Georgia. Electronic address: [email protected].

Abstract

The clinical performance of saliva compared with nasopharyngeal swabs (NPSs) has shown conflicting results in healthcare and community settings. In the present study, a total of 429 matched NPS and saliva sample pairs, collected in either healthcare or community setting, were evaluated. Phase-1 (protocol U) tested 240 matched NPS and saliva sample pairs; phase 2 (SalivaAll protocol) tested 189 matched NPS and saliva sample pairs, with an additional sample homogenization step before RNA extraction. A total of 85 saliva samples were evaluated with both protocols. In phase-1, 28.3% (68/240) samples tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from saliva, NPS, or both. The detection rate from saliva was lower compared with that from NPS samples (50.0% versus 89.7%). In phase-2, 50.2% (95/189) samples tested positive for SARS-CoV-2 from saliva, NPS, or both. The detection rate from saliva was higher compared with that from NPS samples (97.8% versus 78.9%). Of the 85 saliva samples evaluated with both protocols, the detection rate was 100% for samples tested with SalivaAll, and 36.7% with protocol U. The limit of detection with SalivaAll protocol was 20 to 60 copies/mL. The pooled testing approach demonstrated a 95% positive and 100% negative percentage agreement. This protocol for saliva samples results in higher sensitivity compared with NPS samples and breaks the barrier to using pooled saliva for SARS-CoV-2 testing.

Publication types

Validation Study

MeSH terms

COVID-19 / diagnosis*
COVID-19 / epidemiology
COVID-19 / virology
COVID-19 Nucleic Acid Testing / methods*
Delivery of Health Care*
Diagnostic Tests, Routine / methods
Georgia / epidemiology
Humans
Limit of Detection
Mass Screening / methods*
Population Surveillance / methods*
RNA, Viral / genetics
RNA, Viral / isolation & purification
Real-Time Polymerase Chain Reaction
Residence Characteristics*
SARS-CoV-2 / genetics*
Saliva / virology*
Sensitivity and Specificity

Substances

RNA, Viral

Grants and funding

75N93019C00052/AI/NIAID NIH HHS/United States