Are SARS-CoV-2 rapid antigen tests useful for the control of latest variants spreading?

Abstract

Reverse Transcription Polymerase Chain Reaction (RT-PCR) conducted on nasopharyngeal swabs is the gold standard in the diagnosis of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). In Italy, recent guidelines indicate that rapid antigen tests (RATs) can be used for the isolation of positive patients or for the interruption of quarantine, but they are often less sensitive to detect positive subjects. Indeed, the performance of these RATs depends on the timing and the population on which they are evaluated. Herein, we evaluated the performance of BIOCREDIT COVID-19 Ag and Fluorecare^® SARS-CoV-2 Spike Protein Test during a population screening in the Calabria Region, Southern Italy. We report that both antigen test shows low sensitivity in contrast to the high sensitivity declared by manufacturer (90% and 92%, respectively) and that the area under the curve (AUC) was good for Fluorecare^® SARS-CoV- 2 Spike Protein Test but very poor for BIOCREDIT COVID-19 Ag. We suggest that these RATs should be re-evaluated in the current pandemic era.