With similar symptoms across various illnesses such as the flu, respiratory syncytial virus (RSV) disease, and COVID-19, an accurate and fast diagnosis is critical to patient care.
Two recently identified mutations in the matrix genes of the human influenza A virus have been reported to cause matrix gene target failure for several commercial diagnostic tests.
According to Cepheid, its respiratory test design enables detection of these new variants.
Citing scientific literature, the Sunnyvale, CA-based firm noted that variants of the 2009 H1N1 pandemic [(H1N1)pdm09] virus and influenza A virus subtype H3N2 [A(H3N2)] virus containing matrix gene mutations are currently circulating. Recombination and other mutations of the viruses impact the performance of molecular diagnostic tests -- which may lead to an increase in false negative test results. The greatest impact occurs in tests that detect only one genetic target of the influenza genome.
"In developing our portfolio of respiratory tests, we include multiple conserved gene targets to account for genetic drift within the influenza genome," Dr. David Persing, chief scientific officer of Cepheid, said in a statement. "The resulting target redundancy mitigates the impact of mutational drift. Our three-gene target design for detection of influenza A reduces the risk of false-negative test results, even in the event of an MGTF."
Cepheid said its respiratory tests all utilize a multitarget approach for the detection of influenza, providing target redundancy to mitigate the potential impact of genetic shift and drift on strain detection. The tests are the Xpert Xpress Flu/RSV, Xpert Xpress SARS-CoV-2/Flu/RSV, and Xpert Xpress CoV-2/Flu/RSV plus.