Xpert Xpress CoV-2/Flu/RSV plus

The Xpert Xpress CoV-2/Flu/RSV plus is an automated multiplexed real-time RT-PCR test that simultaneously detects and differentiates SARS-CoV-2, influenza A, influenza B, and respiratory syncytial virus (RSV) RNA in nasopharyngeal and anterior nasal swab specimens from patients with respiratory infection symptoms. The test is performed on the GeneXpert Xpress System and aids in diagnosis when used with clinical and epidemiological information.

The subject device uses the same real-time reverse transcription polymerase chain reaction (RT-qPCR) technology as the predicate device, with identical assay targets (SARS-CoV-2, Flu A, Flu B, RSV), specimen types (NPS and NS in UTM/VTM/eNAT), and automated workflow. The key difference is the instrument platform: the subject device runs on the GeneXpert Xpress System, while the predicate ran on GeneXpert Dx and Infinity Systems. Both employ single-use self-contained cartridges with Sample Processing Control and Probe Check Control.

The document cites Clinical and Laboratory Standards Institute (CLSI) document EP17-A2 for limit of detection studies. Standard performance evaluation metrics include Positive Percent Agreement (PPA), Negative Percent Agreement (NPA), and confidence intervals. In silico analysis was conducted against GISAID gene database sequences.

Substantial equivalence is established because the subject device uses identical regulatory classification (21 CFR 866.3981, Class II), product code (QOF), assay technology (RT-qPCR), intended use (differential detection of four respiratory viruses), and assay design (same targets, controls, specimen types, and result interpretation) as the predicate. Analytical performance studies demonstrate equivalent sensitivity and specificity across diverse viral strains and specimen matrices. Clinical performance on 4,310+ prospective specimens shows PPA/NPA ≥96.6% across all targets. The only material change—the instrument platform—does not alter the test's fundamental analytical or clinical performance characteristics.