BMC Infect Dis . Salivary testing of COVID-19: evaluation of serological testing following positive salivary results

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BMC Infect Dis


. 2021 May 4;21(1):410.
doi: 10.1186/s12879-021-06108-5.
Salivary testing of COVID-19: evaluation of serological testing following positive salivary results


Lisa Caulley ¹ , Julie Shaw ² , Martin Corsten ³ , Nadia Hua ¹ , Jonathan B Angel ^{4 5} , Guillaume Poliquin ^{6 7} , Jonathan Whelan ⁸ , Kym Antonation ⁶ , Stephanie Johnson-Obaseki ⁹



Affiliations

• PMID: 33947347
• DOI: 10.1186/s12879-021-06108-5

Abstract

Background: Salivary detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been proposed as an alternative to nasopharyngeal or oropharyngeal swab testing. Our group previously published a study demonstrating that both testing methods identified SARS-CoV-2 using polymerase chain reaction (PCR)-based detection methodology. We therefore conducted a follow-up study using antibody testing to evaluate the accuracy of saliva versus swabs for COVID-19 detection and the durability of antibody response.
Methods: Venous blood samples were collected from consenting participants and the presence of serum antibodies for SARS-CoV-2 was evaluated on a large, automated immunoassay platform by the Roche anti-SARS-CoV-2 qualitative assay (Roche Diagnostics, Laval Quebec). Individuals with a serum antibody cut-off index (COI) ? 1.0 were considered positive.
Results: In asymptomatic and mildly symptomatic patients with a previously positive standard swab and/or saliva SARS-CoV-2 PCR-test, 42 demonstrated antibodies with 13 patients positive by swab alone, and 8 patients positive by saliva alone.
Conclusions: Despite their status as 'current standard' for COVID-19 testing, these findings highlight limitations of PCR-based tests.

Keywords: Antibodies; COVID-19; Coronavirus; SARS-CoV-2; Saliva.