Comparison of the Cepheid Xpert Xpress Flu/RSV Assay to in-house Flu/RSV triplex real-time RT-PCR for rapid molecular detection of Influenza A, Influenza B and Respiratory Syncytial Virus in respiratory specimens.

ABSTRACT

This study compared the performance of the commercially available Xpert Xpress Flu/RSV assay to an in-house FluAB/RSV triplex real-time RT-PCR assay for the detection of influenza A/B viruses and respiratory syncitial virus (RSV) from both nasopharyngeal aspirate (NPA) and nasopharyngeal flocked swab (NPS). A total of 20 external quality assurance (EQA) samples and 172 clinical respiratory samples were tested prospectively using both the Xpert Xpress Flu/RSV assay and the in-house FluAB/RSV triplex assay. For the EQA samples, concordance rate was 100 % when tested with both assays. For clinical samples, there was 100 % agreement between the two assays for detection of influenza A and influenza B, 96.7 % agreement for detection of RSV and 99.7 % agreement for negative results. With a shortened turnaround time and good diagnostic performance, application of the Xpert Xpress Flu/RSV assay can facilitate patient triage for prompt implementation of infection control measures and management of high-risk patients during influenza epidemics.