Performance of six rapid diagnostic tests for SARS-CoV-2 antigen detection and implications for practical use.
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.
['Fourati|Slim|S|', 'Langendorf|Céline|C|', 'Audureau|Etienne|E|', 'Challine|Dominique|D|', 'Michel|Justine|J|', 'Soulier|Alexandre|A|', 'Ahnou|Nazim|N|', 'Désveaux|Isaac|I|', 'Picard|Oriane|O|', 'Ortonne|Valérie|V|', 'Gourgeon|Aurélie|A|', 'Mills|Clair|C|', 'Hémery|François|F|', 'Rieux|Claire|C|', 'Pawlotsky|Jean-Michel|JM|', 'Malou|Nada|N|', 'Chevaliez|Stéphane|S|']
D000956:Antigens, Viral D000086382:COVID-19 D003955:Diagnostic Tests, Routine D006801:Humans D012367:RNA, Viral D000086402:SARS-CoV-2 D012680:Sensitivity and Specificity
Rapid diagnostic test Diagnostic SARS-CoV-2 COVID-19 Antigen assay Screening