Analytical performances of the point-of-care SIENNA™ COVID-19 Antigen Rapid Test for the detection of SARS-CoV-2 nucleocapsid protein in nasopharyngeal swabs: A prospective evaluation during the COVID-19 second wave in France. (May 2021)

• Record Type: Journal Article
• Authors: Mboumba Bouassa, Ralph-Sydney; Veyer, David; Péré, Hélène; Bélec, Laurent
• Is Part Of: International journal of infectious diseases. Volume 106(2021)
• Page Start: 8
• Page End: 12
• Publication Date: 2021-05
• Subjects: COVID-19 -- Rapid diagnostic test -- Antigen -- Protein N -- France; Communicable diseases -- Periodicals; Communicable Diseases -- Periodicals; Communicable diseases; Periodicals; Electronic journals; 616.9
• DOI: 10.1016/j.ijid.2021.03.051
• Languages: English
• ISSNs: 1201-9712

Abstract

Highlights: There is an urgent need for independent validation of available antigen-detecting rapid diagnostic tests designed for direct detection of SARS-CoV-2 viral proteins produced by replicating virus in respiratory secretions. The SIENNA™ COVID-19 Antigen test demonstrates excellent analytical performances for viral loads ≤33 Ct, corresponding to situations of symptomatic COVID-19 and/or proven contagiousness. The SIENNA™ COVID-19 Antigen test can be recommended for routine clinical use in most diagnostic indications of SARS-CoV-2 infection. Abstract: Objectives: We herein assessed the analytical performances of the antigen-rapid diagnostic test (Ag-RDT) SIENNA ™ COVID-19 Antigen Rapid Test Cassette (Nasopharyngeal Swab) (Salofa Oy, Salo, Finland), targeting the SARS-CoV-2 N nucleocapsid protein, for the diagnosis of COVID-19 in hospitalized patients with suspected SARS-CoV-2 infection, by reference to real-time RT-PCR (rRT-PCR). Methods: Nasopharyngeal swabs were collected from patients with COVID-19-like illness during the second epidemic wave in Paris, France, among which 100 and 50 were positive and negative for SARS-CoV-2 RNA, respectively. Results: Overall, the Ag-RDT showed high sensitivity, specificity, positive and negative predictive values of 90.0%, 100.0%, 100.0% and 98.1%, respectively, as well as high or almost perfect agreement (93.3%), reliability assessed by Cohen's κ coefficient (0.86), and accuracy assessed by Youden's J index (90%) to detect SARS-CoV-2. The analytical performances of the Ag-RDT remained high in the event of significant viral excretion ( i.e., N gene Ct values ≤33 by reference rtRT-PCR), while the sensitivity of the Ag-RDT dropped to 69.6% with low or very low viral shedding (Ct > 33). Conclusions: The SIENNA™ Ag-RDT presents excellent analytical performances for viral loads ≤33 Ct, classically corresponding to situations of symptomatic COVID-19 and/or proven contagiousness.