LAUSR

Purpose To detect and differentiate co-infection with influenza and respiratory syncytial virus during the COVID pandemic, a rapid method that can detect multiple pathogens in a single test is a significant diagnostic advance to analyze the outcomes and clinical implications of co-infection. Therefore, we validated and evaluated the performance characteristics of TaqMan SARS-CoV-2, Flu A/B, RSV RT-PCR multiplex assay for the detection of SARS-CoV-2, Flu A/B, and RSV using nasopharyngeal and saliva samples. Materials and Methods The method validation was performed by using culture fluids of Influenza A virus (H3N2) (A/Wisconsin/67/2005), Influenza B virus (B/Virginia/ATCC4/2009), RSV A2 cpts-248, SARS-CoV-2 (USA-WA1/2020) and quantitative RNA controls of Influenza A virus (H1N1) strain A/PR/8/34 (VR-95DQ), RSV A2 (VR-1540DQ) and SARS-CoV-2 (MN908947.3 Wuhan-Hu-1) from ATCC and Zeptometrix, NY, USA. A total of 110 nasopharyngeal specimens and 70 saliva samples were used for the SARS-CoV-2 detection, and a total of 70 nasopharyngeal specimens were used for Influenza and RSV detection. Total RNA was extracted from all the samples and multiplex PCR was performed using TaqMan SARS-CoV-2, Flu A/B, RSV RT-PCR multiplex assay. The assay was used for SARS-CoV-2 variant (B.1.1.7_601443, B.1.617.1_1662307, P.1_792683, B.1.351_678597, B.1.1.529/BA.1). Results Validation controls showed accurate and precise results. The correlation study found the accuracy of 96.38 to 100% (95% CI) in nasopharyngeal and 94.87 to 100% (95% CI) in saliva for SARS-CoV-2 and 91.1 to 100% (95% CI) for both Influenza A/B and RSV. The diagnostic efficiency of this assay was not affected by SARS-CoV-2 variant, including Omicron. Conclusion The TaqMan SARS-CoV-2, Flu A/B, RSV RT-PCR multiplex assay is a rapid method to detect and differentiate SAR-CoV-2, Flu A and B, and RSV in nasopharyngeal and saliva samples. It has a significant role in the diagnosis and management of respiratory illnesses and the clinical implications of co-infection.