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.

Evaluation on testing of deep throat saliva and lower respiratory tract specimens with Xpert Xpress SARS-CoV-2 assay

“…With the use of Xpert Xpress SARS-CoV-2 assay as a complementary test, it will allow rapid testing of ad-hoc samples received from AED & intensive care unit and provide round-the-clock service for samples received after batch testing cut-time. Similar testing algorithm has been adopted in our laboratory for testing of influenza [ 10 ].…”

Implementation of the cobas Liat influenza point-of-care test into an emergency department during a high-incidence season: a retrospective evaluation following real-world implementation

“…It is reasonable to use fPCR as the reference standard alongside rPCR because previous studies have demonstrated their comparable performance. For example, one study comparing fPCR against a real-time RT-PCR similar to rPCR found 100 % agreement between the two assays for detection of influenza A and influenza B, and 99.7 % agreement for negative results [11]. A subanalysis comparing Liat against either rPCR or rPCR alone is as follows: vs fPCR (40 samples), influenza A or B sensitivity was 8/8 (100%) (95% CI 63.1e100) and specificity was 30/32 (93.8%) (95% CI 79.2e99.2); vs rPCR (632 samples), influenza A or B sensitivity was 68/83 (81.9%) (95% CI 72.0e89.5) and specificity was 535/549 (97.5%) (95% CI 95.8e98.6).…”

Rapid adaptation and continuous performance evaluation of SARS‐CoV‐2 envelope gene (E‐gene) real‐time RT‐PCR assays to support the hospital surge in test demand

“…The availability of technically competent staff familiar with conventional workflows is a challenge. Our laboratory has experience with providing in‐house influenza A/B and respiratory syncytial virus real‐time/reverse transcription polymerase chain reaction (RT‐PCR) testing to cope with the increase in demand during winter surge 8 and a team of technically competent staff is available. Despite published protocols and pre‐mixed primers and probes are available commercially, the testing platform available in our laboratory was different.…”