A-252 Differentiation of SARS-CoV-2, Influenza A and B, and Respiratory Syncytial Virus Using a Single Swab: A Clinical Performance Evaluation of the BD MAX System Multiplex PCR Assay

Abstract Background Some shared clinical features of SARS-CoV-2, influenza (flu), and respiratory syncytial virus (RSV) infection often pose a diagnostic challenge for clinicians. In that context, the use of molecular diagnostic systems multiplex assays, using a nasopharyngeal or nasal swab, facilitates the detection of the causing virus by differentiating between the RNA of each disease. Our study evaluated the clinical accuracy of one such multiplex PCR assay, the BD Respiratory Viral Panel for BD MAX™ System (BD MAX RVP). Methods Symptomatic patients that had a nasopharyngeal and nasal specimen prospectively collected from 6 geographical locations in the US were enrolled in the study between January and April 2022 along with nasopharyngeal swabs retrospectively collected between December 2019 and January 2022. All specimen testing was performed using the BD MAX System. Hologic® Flu A/B/RSV assay on Panther Fusion™ System was the comparator for flu A, flu B, and RSV while a composite of two out of three assays authorized under FDA Emergency Use Authorization (Roche cobas® SARS-CoV-2 on cobas® 6800 System, Hologic® Aptima® SARS-CoV-2 on Panther® System, and Quidel Lyra® SARS-CoV-2 on Applied Biosystems® 7500 Fast Dx) was used as comparator for SARS-CoV-2. Positive and negative percentage agreements (PPA and NPA, respectively) were calculated to determine performance. Reproducibility and precision assessments were also performed as part of the study. Results Tested specimens included 252 nasopharyngeal and 254 nasal swabs, prospectively collected, and 240 retrospectively acquired nasopharyngeal specimens. For prospectively collected SARS-CoV-2 nasopharyngeal specimens, PPA of 98.8% (95% CI 93.6, 99.8) and NPA of 98.2% (95% CI 94.9, 99.4) were observed while for flu A, PPA was 100% (95% CI 61.0, 100) and NPA 99.6% (95% CI 97.7, 99.9). PPA and NPA for prospectively collected SARS-CoV-2 anterior nasal specimens were 98.8% (95% CI 93.3, 99.8) and 98.3 (95% CI 95.1, 99.4), respectively. For flu A, PPA of 100% (95% CI 61.0, 100) and NPA of 99.6% (95% CI 97.8, 99.9) were observed. Lack of enrolled positive patients with flu B or RSV precluded the PPA calculation for those viruses. However, NPA for both flu B and RSV was 100% for the two specimen types. In retrospectively obtained nasopharyngeal specimens, PPA was 100% (95% CI 93.7, 100) for flu A, 100% (95% CI 93.8, 100) for flu B, and 98.4% (95% CI 91.5, 99.7) for RSV while NPA was 98.9% (95% CI 96.1, 99.7) for flu A, 98.9% (95% CI 96.1, 99.7) for flu B, and 100% (95% CI 97.9, 100) for RSV. Conclusion The BD MAX RVP assay showed a strong clinical performance in detecting and differentiating between the RNA of SARS-CoV-2, flu A and B, and RSV.