Neuraminidase inhibitors are the only licensed antiviral medications available to treat avian influenza A(H7N9) virus infections in humans. According to a neuraminidase inhibition assay, an R292K substitution reduced antiviral efficacy of inhibitors, especially oseltamivir, and decreased viral fitness in cell culture. Monitoring emergence of R292K-carrying viruses using a pH-modified neuraminidase inhibition assay should be considered.
Keywords: H7N9; R292K; antimicrobial resistance; antiviral resistance; avian influenza; influenza; neuraminidase inhibitor; oseltamivir; recombinant neuraminidase; viruses; zanamivir.