Evaluation of Multiplex Rapid Antigen Test for the Detection of SARS-CoV-2 and Influenza A/B in Respiratory Samples.

Background: There is little data about the performance of multiplex rapid antigen tests (RATs) on the detection of SARS-CoV-2, influenza A (Flu A), and influenza B (Flu B). This study is to evaluate the performance of Panbio COVID-19/Flu A&B rapid panel (Abbott Diagnostics, Korea) and analyze the factors influencing its sensitivity.

Methods: Nasopharyngeal swabs were collected and stored at the Korea University Anam hospital. In total, 400 residual samples from nasopharyngeal swabs were examined. The diagnostic accuracy of RAT was compared to that of RT-qPCR using the Allplex SARS-CoV-2/FluA/FluB/RSV Assay (Seegene, Seoul, South Korea).

Results: Panbio COVID-19/Flu A&B rapid panel showed the sensitivities of 88.0%, 92.0%, and 100% for SARS-CoV-2, Flu A, and Flu B, respectively, and specificities of 100% for all. The agreements with previously licensed single-plex RATs were shown to be high. In the analysis of variables affecting sensitivity, inappropriate sampling time after symptom onset (STASO) and high cycle threshold (Ct value) were shown to negatively affect the sensi-tivity.

Conclusions: In conclusion, the multiplex RAT is useful for diagnosing SARS-CoV-2 and Flu A/B, but more clinical studies are needed.