Comparison of Two Commercial Respiratory Multiplex Kits for the Management of Severe Acute Respiratory Infection

Molecular diagnosis of respiratory infections has made great progress following the advent of multiplex diagnostic methods allowing simultaneous detection of several targets at the same time.

In this prospective study, a comparison of two respiratory multiplex diagnostic kits used in our laboratory was performed on samples of patients hospitalized for severe acute respiratory infection during 2023 - 2024: FilmArray® Respiratory Panel 2.1 plus and Xpert® Xpress SARS-CoV-2/Flu/RSV.

The results showed excellent agreement between the two tests, with a coefficient of Cohen's kappa of 0.960. The discrepancies were only relevant for the influenza A research results, for which Cohan's Kappa was 0.879. These discrepancies involved samples with a low viral load (only one probe detected by Xpert® Xpress SARS-CoV-2/Flu/RSV (Flu A1) with a cycle threshold ˃ 35).

As a result, both techniques remain of interest and depend on the clinical context of patients and the period of diagnosis, which will allow clinicians to rationalize the prescription of the two techniques to better meet the expectations of patients.