Evaluation of water gargle samples for SARS-CoV-2 detection using Abbott ID NOW COVID-19 assay

The Abbott ID NOWTM COVID-19 assay has been shown as a reliable and sensitive alternative to RT-PCR testing from nasopharyngeal or nasal samples in symptomatic patients. Water gargle is an acceptable non-invasive alternative specimen for SARS-CoV-2 detection by RT-PCR. The objective of this study was to evaluate the performance of water gargle samples for the detection of SARS-CoV-2 using the ID NOW. Residual gargle samples were randomly selected amongst positive standard of care (SOC)-nucleic acid amplification test (NAAT) samples. For testing on ID NOW, the manufacturer instructions were followed, except for the specimen addition step: 500 µl of the gargle specimen was added to the blue sample receiver with a pipette and gently mixed. Amongst the 202 positive samples by SOC-NAAT, 185 were positive by ID NOW [positive percent agreement (PPA)]=91.6% (95% CI: 86.9 to 95.0)]. For the 17 discordant samples, cycle threshold (Ct) values were all ≥31.0. The PPA was significantly lower amongst asymptomatic patients (84.4%; 95% CI: 73.2 to 92.3) vs symptomatic patients (95.2%; 95% CI: 89.8 to 98.2). The performance of the ID NOW for the detection of SARS-CoV-2 infection on gargle samples is excellent when Ct values are 31.0 and for patients that have COVID-19 compatible symptoms. This article is protected by copyright. All rights reserved.
Auteurs (Zotero)
Lévesque, Simon; Beauchemin, Stéphanie; Vallée, Maud; Longtin, Jean; Jacob-Wagner, Mariève; Dumaresq, Jeannot; Dulcey, Carlos; Labbé, Annie-Claude
Date de publication (Zotero)
mai, 2022