Preprint Article Version 1 Preserved in Portico This version is not peer-reviewed

Rapid Evaluation of the Xpert ® Xpress CoV-2 Plus and Xpert® Xpress CoV-2/Flu/RSV Plus Tests

Lara Dominique Noble
* ORCID logo ,
Lesley Erica Scott
,
Riffat Munir
,
Mignon Du Plessis
,
Kim Steegen
,
Lucia Hans
,
Puleng Marokane
,
Pedro Da Silva
,
Wendy Susan Stevens
Version 1 : Received: 1 December 2022 / Approved: 5 December 2022 / Online: 5 December 2022 (10:17:58 CET)

A peer-reviewed article of this Preprint also exists.

Noble, L.D.; Scott, L.E.; Munir, R.; Du Plessis, M.; Steegen, K.; Hans, L.; Marokane, P.; Da Silva, P.; Stevens, W.S. Rapid Evaluation of the Xpert ® Xpress CoV-2 plus and Xpert® Xpress CoV-2/Flu/RSV plus Tests. Diagnostics 2023, 13, 34. Noble, L.D.; Scott, L.E.; Munir, R.; Du Plessis, M.; Steegen, K.; Hans, L.; Marokane, P.; Da Silva, P.; Stevens, W.S. Rapid Evaluation of the Xpert ® Xpress CoV-2 plus and Xpert® Xpress CoV-2/Flu/RSV plus Tests. Diagnostics 2023, 13, 34.

Abstract

The Xpert® Xpress SARS-CoV-2 and Xpert® Xpress SARS-CoV-2/Flu/RSV tests were rapidly developed and widely used during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. In response to emerging genetic variability, a new SARS-CoV-2 target (RNA-dependent RNA-polymerase) has been added to both tests: Xpert® Xpress CoV-2 plus and Xpert® Xpress CoV-2/Flu/RSV plus test. A rapid evaluation of both tests was performed in South Africa, using residual respiratory specimens. Residual respiratory specimens (n=125) were used to evaluate the Xpert® Xpress CoV-2 plus test and included 50 genotyped specimens. The Xpert® Xpress CoV-2/Flu/RSV plus test was assessed using 45 genotyped SARS-CoV-2 specimens, ten influenza A, ten Influenza B and twenty respiratory syncytial virus specimens. Results were com-pared to in-country standard of care tests. Genotyped specimens tested the performance of the test under pressure from circulating SARS-CoV-2 variants of concern. Reference material was included to assess the test limits and linearity. The Xpert® Xpress CoV-2 plus test performance compared to reference results across residual respiratory specimens was good (positive per-centage agreement (PPA)=95.2%, negative percentage agreement (NPA)=95.0%) The Xpert® Xpress CoV-2/Flu/RSV plus test showed good performance across all residual respiratory specimens (PPA=100%, NPA=98.3%). All genotyped variants of concern were detected by both tests. The Xpert® Xpress CoV-2 plus and Xpert® Xpress CoV-2/Flu/RSV plus tests can be used to diagnose SARS-CoV-2, and to diagnose and differentiate SARS-CoV-2, influenza A, influenza B and respiratory syncytial virus respectively. The NPA was lower than the recommended 99%, but was influenced by the low number of negative specimens tested. The variants of concern assessed did not affect test performance. It is recommended that sites perform their own assessments compared to in-country standard of care tests.

Keywords

SARS-COV-2; respiratory tests; Xpert® Xpress COV-2 plus; Xpert(2) Xpress COV-2/Flu/RSV plus; diagnostic evaluation; novel target

Subject

Medicine and Pharmacology, Pathology and Pathobiology

Copyright: This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Download PDF Download Supplementary

Comments (0)

We encourage comments and feedback from a broad range of readers. See criteria for comments and our Diversity statement.

Leave a public comment
Send a private comment to the author(s)
* All users must log in before leaving a comment
Views 0
Downloads 0
Comments 0
Metrics 0
Get PDF Supplementary Files Cite Share 0
Bookmark BibSonomy Mendeley Reddit Delicious
×
Alerts
Notify me about updates to this article or when a peer-reviewed version is published.
We use cookies on our website to ensure you get the best experience.
Read more about our cookies here.