Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Comparative Study
. 2021 Feb;40(2):269-277.
doi: 10.1007/s10096-020-04025-0. Epub 2020 Sep 4.

Evaluation of three commercial assays for SARS-CoV-2 molecular detection in upper respiratory tract samples

Flora Marzia Liotti #  1   2 , Giulia Menchinelli #  1   2 , Simona Marchetti  2 , Grazia Angela Morandotti  2 , Maurizio Sanguinetti  3   4 , Brunella Posteraro #  1   5 , Paola Cattani #  1   2
Affiliations
Comparative Study

Evaluation of three commercial assays for SARS-CoV-2 molecular detection in upper respiratory tract samples

Flora Marzia Liotti et al. Eur J Clin Microbiol Infect Dis. 2021 Feb.

Abstract

The increasing COVID-19 widespread has created the necessity to assess the diagnostic accuracy of newly introduced (RT-PCR based) assays for SARS-CoV-2 RNA detection in respiratory tract samples. We compared the results of the Allplex™ 2019-nCoV assay with those of the Simplexa™ COVID-19 Direct assay and the Quanty COVID-19 assay, respectively, all performed on 125 nasal/oropharyngeal swab samples of patients with COVID-19 suspicion. Fifty-four samples were positive, and 71 were negative with the Allplex™ assay, whereas 47 of 54 samples were also positive with the Simplexa™ assay. The Quanty assay detected 55 positive samples, including the 54 positive samples with the Allplex™ assay and 1 sample that was Allplex™ negative but Simplexa™ positive. Using a consensus result criterion as the reference standard allowed to resolve the eight samples with discordant results (one Allplex™ negative and seven Simplexa™ negative) as truly false negative. Interestingly, a Spearman's negative association was found between the viral RNA loads quantified by the Quanty assay and the CT values of RT PCRs performed with either the Allplex™ assay or the Simplexa™ assay. However, the strength of this association was higher for the Allplex™ assay (N gene, ρ = - 0.92; RdRP gene, ρ = - 0.91) than for the Simplexa™ assay (ORF1ab gene, ρ = - 0.65; S gene, ρ = - 0.80). The Allplex™ 2019-nCoV, the Simplexa™ COVID-19 Direct, and the Quanty COVID-19 assays yielded comparable results. However, the role these assays might play in future clinical practice warrants larger comparison studies.

Keywords: COVID-19; Molecular assay; Respiratory samples; SARS-CoV-2; Viral RNA load.

PubMed Disclaimer

Conflict of interest statement

The authors declare that they have no conflict of interest.

Figures

Fig. 1
Fig. 1
Correlation between the viral load levels quantified by the Quanty COVID-19 assay and the CT values obtained with the Allplex™ 2019-nCoV assay. Values are shown for each SARS-CoV-2 gene (E, RdRP, or N) detected by the assay
Fig. 2
Fig. 2
Correlation between the viral load levels quantified by the Quanty COVID-19 assay and the CT values obtained with the Simplexa™ COVID-19 Direct assay. Values are shown for each SARS-CoV-2 gene (S or ORF1ab) detected by the assay
See this image and copyright information in PMC

References

    1. Zhu N, Zhang D, Wang W, Li X, Yang B, Song J, Zhao X, Huang B, Shi W, Lu R, Niu P, Zhan F, Ma X, Wang D, Xu W, Wu G, Gao GF, Tan W, China Novel Coronavirus Investigating and Research Team A novel coronavirus from patients with pneumonia in China, 2019. N Engl J Med. 2020;382:727–733. doi: 10.1056/NEJMoa2001017. - DOI - PMC - PubMed
    1. Li R, Pei S, Chen B, Song Y, Zhang T, Yang W, Shaman J. Substantial undocumented infection facilitates the rapid dissemination of novel coronavirus (SARS-CoV2) Science. 2020;368:489–493. doi: 10.1126/science.abb3221. - DOI - PMC - PubMed
    1. Patel R, Babady E, Theel ES, Storch GA, Pinsky BA, St George K, Smith TC, Bertuzzi S. Report from the American Society for Microbiology COVID-19 international summit, 23 March 2020: value of diagnostic testing for SARS–CoV-2/COVID-19. mBio. 2020;11:e00722–e00720. doi: 10.1128/mBio.00722-20. - DOI - PMC - PubMed
    1. Cheng MP, Papenburg J, Desjardins M, Kanjilal S, Quach C, Libman M, Dittrich S, Yansouni CP (2020) Diagnostic testing for severe acute respiratory syndrome–related coronavirus-2: a narrative review. Ann Intern Med 172:726–734. 10.7326/M20-1301 - PMC - PubMed
    1. Hong KH, Lee SW, Kim TS, Huh HJ, Lee J, Kim SY, Park JS, Kim GJ, Sung H, Roh KH, Kim JS, Kim HS, Lee ST, Seong MW, Ryoo N, Lee H, Kwon KC, Yoo CK. Guidelines for laboratory diagnosis of coronavirus disease 2019 (COVID-19) in Korea. Ann Lab Med. 2020;40:351–360. doi: 10.3343/alm.2020.40.5.351. - DOI - PMC - PubMed