Clinical Epidemiology and Ageing

Performance of six rapid diagnostic tests for SARS-CoV-2 antigen detection and implications for practical use.

Fourati S, Langendorf C, Audureau E, Challine D, Michel J, Soulier A, Ahnou N, Désveaux I, Picard O, Ortonne V, Gourgeon A, Mills C, Hemery F, Rieux C, Pawlotsky J-M, Malou N, Chevaliez S J Clin Virol. 2021;142:104930.

BACKGROUND: Direct detection of SARS-CoV-2 viral proteins in nasopharyngeal swabs using lateral flow immunoassays is a simple, fast and cheap approach to diagnose the infection.

AIMS AND METHODS: The performance of 6 SARS-CoV-2 antigen rapid diagnostic tests has been assessed in 634 hospitalized patients or outpatients including 297 patients found to be positive for SARS-CoV-2 RNA by means of RT-PCR and 337 patients presumed to be SARS-CoV-2 RNA-negative.

RESULTS: The specificity of SARS-CoV-2 RDTs was generally high (398.5%). One assay had a lower specificity of 93.2%. The overall sensitivity of the 6 RDTs was variable, from 32.3% to 61.7%. Sensitivity correlated with the delay of sampling after the onset of symptoms and the viral load estimated by the Ct value in RT-PCR. Four out of 6 RDTs tested achieved sensitivities 380% when clinical specimens were collected during the first 3 days following symptom onset or with a Ct value ≤25.

CONCLUSIONS: The present study shows that SARS-CoV-2 antigen can be easily and reliably detected by RDTs. These tests are easy and rapid to perform. However, the specificity and sensitivity of COVID-19 antigen RDTs may widely vary across different tests and must therefore be carefully evaluated before releasing these assays for realworld applications.

MeSH terms: Antigens, Viral; COVID-19; Diagnostic Tests, Routine; Humans; RNA, Viral; SARS-CoV-2; Sensitivity and Specificity
DOI: 10.1016/j.jcv.2021.104930