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. 2022 Nov;2(4):100108.
doi: 10.1016/j.jcvp.2022.100108. Epub 2022 Sep 13.

Clinical performance of SARS-CoV-2 detection on the cobas Liat using water gargle samples

Maxime Veillette  1 , Francine Tourangeau  2 , Judith Fafard  3   4 , Jeannot Dumaresq  5   6 , Annie-Claude Labbé  4   7   8 ; G-SPIT study group
Affiliations

Clinical performance of SARS-CoV-2 detection on the cobas Liat using water gargle samples

Maxime Veillette et al. J Clin Virol Plus. 2022 Nov.

Abstract

Spring water gargle (SWG) is a suitable, non-invasive, alternative specimen for SARS-CoV-2 detection by RT-PCR. This study sought to evaluate the performance of the cobas Liat point-of-care system for the detection of SARS-CoV-2 in SWG samples. SWG samples and standard oral and nasopharyngeal swab (ONPS) were collected simultaneously from participants in a COVID-19 screening clinic, in November and December 2020. Both sample types were analyzed in parallel on the cobas Liat platform and with the Seegene Allplex 2019-nCoV assay. Among the 110 participants, 53% had compatible symptoms and 71% had a contact with a confirmed COVID-19 case. Only two (1.8%) individuals had neither symptoms nor contact. Amongst 110 paired samples, 25 (23%) were positive for SARS-CoV-2 on the cobas Liat for a least one sample type, with a kappa coefficient of 0.92. Agreement between the cobas Liat platform and the Seegene assay was also excellent (kappa coefficient values of 0.94 and 0.95). Two SWG samples failed to provide a positive result when their ONPS pair was positive, but their cycle threshold (Ct) values were >35 on the Seegene assay, reflecting a low viral load. Overall, the performance of the cobas Liat platform is excellent for the detection of SARS-CoV-2 in SWG samples in a high pre-test probability population.

Keywords: COVID-19; Gargle; SARS-CoV-2; cobas Liat.

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Conflict of interest statement

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Figures

Fig. 1
Fig. 1
Seegene Allplex 2019‐nCoV assay cycle threshold values distribution, by sample type. Ct: Cycle threshold; SWG: spring water gargle; ONPS: oronasopharyngeal swab. Note: The two cross symbols for N gene (Ct values of 37 and 38) indicate ONPS samples paired with negative SWG samples on both platforms. The other two targets were not detected from the two ONPS samples that were negative.
See this image and copyright information in PMC

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