ABSTRACT
Background: SARS-CoV-2 is taking a huge toll on society while influenza and RSV detection are also becoming more important. These viruses pose a high burden on health care. Rapid and accurate diagnostics for these pathogens are important for swift triage in the hospital. Fast molecular point of care test (mPOCT) assays for these pathogens can prove an alternative. Here a multi-center evaluation of the Xpert® Xpress SARS-CoV-2/Flu/RSV assay is reported. Study design: The Xpert® Xpress SARS-CoV-2/Flu/RSV assay was compared to three reference assays at three Dutch medical microbiology laboratories. An external quality assessment panel consisting of 16 specimens containing SARS-CoV-2, influenza viruses, RSV or human seasonal coronaviruses, or a combination thereof were used. Clinical specimens containing SARS-CoV-2 (n = 57), influenza viruses (n = 21) or RSV (n = 12), at a wide range of relevant concentrations were used. One laboratory also tested zoonotic avian and swine influenza viruses, and eight relevant SARS-CoV-2 variants. Results: The Xpert® Xpress SARS-CoV-2/Flu/RSV assay showed equal performance compared to the reference assays. All SARS-CoV-2 variants of interest and variants of concern were accurately detected. Human seasonal coronaviruses were not detected. All four circulating seasonal influenza virus subtypes/lineages and both RSV types were accurately detected as well as a set of recent zoonotic avian and swine influenza viruses. The clinical specimens showed 98.2% concordance using this assay. Conclusion: The Xpert® Xpress SARS-CoV-2/Flu/RSV assay is a good alternative for accurate detection for SARS-CoV-2, influenza type A virus, influenza type B virus and RSV types A and B detection in a short timeframe.
ABSTRACT
BACKGROUND: With the outbreak of SARS-CoV-2, rapid diagnostics are paramount to contain the current pandemic. The routinely used realtime RT-PCR is sensitive, specific and able to process large batches of samples. However, turnaround time is long and in cases where fast obtained results are critical, molecular point of care tests (POCT) can be an alternative. Here we report on a multicenter evaluation of the Cepheid Xpert Xpress SARS-CoV-2 point-of-care test. STUDY DESIGN: The Xpert Xpress SARS-CoV-2 assay was evaluated against the routine in-house real-time RT-PCR assays in three medical microbiology laboratories in The Netherlands. A sensitivity and specificity panel was tested consisting of a dilution series of SARS-CoV-2 and ten samples containing SARS-CoV-2 and a range of other seasonal respiratory viruses. Additionally, 58 samples of patients positive for SARS-CoV-2 with different viral loads and 30 tested negative samples in all three Dutch laboratories using an in-house RT-PCR, were evaluated using Cepheids Xpert Xpress SARS-CoV-2 cartridges. RESULTS: Xpert Xpress SARS-CoV-2 point of care test showed equal performance compared to routine in-house testing with a limit of detection (LOD) of 8.26 copies/mL. Other seasonal respiratory viruses were not detected. In clinical samples Xpert Xpress SARS-CoV-2 reaches an agreement of 100 % compared to all in-house RT-PCRs CONCLUSION: Cepheids GeneXpert Xpert Xpress SARS-CoV-2 is a valuable addition for laboratories in situations where rapid and accurate diagnostics are of the essence.