Performance Characteristics of BinaxNOW COVID-19 Antigen Card for Screening Asymptomatic Individuals in a University Setting.

We compared the performance of the Abbott BinaxNOW COVID-19 Antigen Card to a standard RT-PCR assay (ThermoFisher TaqPath COVID-19 Combo Kit) for the detection of SARS-CoV-2 in 2,645 asymptomatic students presenting for screening at the University of Utah. SARS-CoV-2 RNA was detected in 1.7% of the study participants by RT-PCR. BinaxNOW identified 24 infections but missed 21 infections that were detected by RT-PCR. The analytical sensitivity (positive agreement) and analytical specificity (negative agreement) for the BinaxNOW was 53.3% and 100%, respectively when compared against the RT-PCR assay. The median cycle threshold (Ct) value in the specimens that had concordant positive BinaxNOW antigen result was significantly lower compared to those that were discordant (Ct 17.6 vs. 29.6; p < 0.001). In individuals with presumably high viral loads (Ct < 23.0), a 95.8% positive agreement was observed between the RT-PCR assay and BinaxNOW. Due to the possibility of false negative results, caution must be taken when utilizing rapid antigen testing for screening asymptomatic individuals.