Comparative evaluation of the Thermo fisher TaqPath™ COVID-19 combo kit with the Cepheid Xpert® Xpress SARS-CoV-2 assay for detecting SARS-CoV-2 in nasopharyngeal specimens

Abstract

Purpose With over 50 SARS-CoV-2 gene amplification assays that have been EUA cleared with minimal experimental validation performed, it is likely that not all of these assays are comparable in their ability to detect SARS-CoV-2 in clinical specimens. Thermo Fisher Scientific is a relatively new company in the molecular diagnostics field and the purpose of this study was to compare the performance of the Thermo Fisher TaqPath™ Combo Kit with an established test, the Cepheid Xpert® Xpress SARS-CoV-2 assay, for its ability to detect SARS-CoV-2 in nasopharyngeal specimens. Methods A total of 300 randomly selected nasopharyngeal specimens were evaluated and tested by the TaqPath and GeneXpert assays. Discordant test specimens were arbitrated by performing an alternative PCR assay and Sanger sequencing. Results The TaqPath assay had a 96.7 and 99.6% positive and negative agreement respectively when compared to the Xpert Xpress test. However, after test arbitration, the three discordant specimens were arbitrated in favor of the TaqPath assay producing a positive and negative percent agreement of 100% for the TaqPath Combo Kit while the Xpress SARS-CoV-2 assay had a positive and negative percent agreement of 98.3 and 99.2% respectively. Conclusions The TaqPath Combo Kit is a high complexity assay that compares favorably with the Xpert Xpress test and can be reliably used for the detection of SARS-CoV-2 in nasopharyngeal specimens.

RT-PCR test for the detection of SARS-CoV-2 in nasopharyngeal swabs: results of the Cepheid Xpert® Xpress SARS-CoV-2 assay versus the Thermo fisher TaqPath™ COVID-19 CE IVD

“…In this study the agreement between the two platforms is almost perfect with the hight value (>81%) of the Kappa coefficient [9]. Similar results were reported by Jamai et al [10] and Granato et al [11] showing respectively 99.5% and 96.7% positive agreement between the results obtained with the Xpert Xpress SARS-CoV-2 and the TaqPath-COVID-19-CE IVD kit.…”

Evaluation of self‐collected nasal, urine, and saliva samples for molecular detection of SARS‐CoV‐2 using an EUA approved RT‐PCR assay and a laboratory developed LAMP SARS‐CoV‐2 test

“…The TaqPath RT‐PCR COVID‐19 Kit (Thermo Fisher Scientific) is one of the many diagnostic kits that have been granted Emergency Use Authorization (EUA) by the FDA. 21 , 25 , 26 The kit is designed to detect the RNA from SARS‐CoV‐2 in respiratory specimens from patients suspected of having COVID‐19. LAMP tests, on the other hand, are an alternative to RT‐PCR tests, and they have gained popularity due to their simplicity and faster turnaround time.…”

“…Among the most widely used testing methods are RT‐PCR and loop‐mediated isothermal amplification (LAMP) tests. The TaqPath RT‐PCR COVID‐19 Kit (Thermo Fisher Scientific) is one of the many diagnostic kits that have been granted Emergency Use Authorization (EUA) by the FDA 21 25,26 . The kit is designed to detect the RNA from SARS‐CoV‐2 in respiratory specimens from patients suspected of having COVID‐19.…”

SARS-CoV-2 Detection via RT-PCR in Matched Saliva and Nasopharyngeal Samples Reveals High Concordance in Different Commercial Assays

“…The real-time reverse transcriptase-polymerase chain reaction (RT-PCR)-based detection of SARS-CoV-2 is the "gold standard" for the diagnosis of COVID-19. Several RT-PCR kits have been developed based on the conserved regions of the SARS-CoV-2 genome [3][4][5]. Owing to their high sensitivity and specificity, both upper and lower respiratory tract samples have been considered as standard sampling materials.…”