“Viruses do not have one single conserved genetic sequence that you can target and detect all viruses, unlike bacteria, where we can detect ribosomal RNA sequences,” added the University of Texas Medical Branch’s Mike Loeffelholz, a pathologist and clinical microbiologist who also was not involved in the work. “In order to broadly detect viruses, you have to have these massively multiplexed pathogen-specific assays. So if you can detect—instead of the actual viral pathogens—a host response signature . . . it gives you a single test for many different kinds of viral infections.”
The present study builds on previous work from Zaas’s group showing that certain genes are more highly expressed in patients with respiratory viral infections, compared with those with non-viral infections or healthy individuals. For the current investigation, the researchers evaluated the performance of their reverse transcription PCR (RT-PCR)-based assay on two cohorts of individuals experimentally infected with influenza A H3N2 or the related H1N1. They then further validated the test on a set of 102 patients presenting to the emergency department with fever, plus 41 healthy volunteers.