This manuscript describes the identification of an oseltamivir-resistant influenza A (H3N2) virus in a respiratory specimen collected from an immunocompromised patient in Alberta, Canada, during the 2014-2015 influenza season. Following treatment with oseltamivir, neuraminidase (NA) gene sequencing indicated the presence of an R292K mutation. Phenotypic susceptibility testing by the NA-Star assay indicated a highly reduced inhibition by oseltamivir and normal inhibition by zanamivir. The use of zanamivir following identification of the oseltamivir-resistant strain, combined with a partial immune reconstitution, was followed by a suggested decrease in the nasopharyngeal viral load in the nasopharynx and clinical improvement of the patient.
Keywords: H3N2; influenza; neuraminidase inhibitors; reduced susceptibility; resistance; sequence analysis.
© 2016 The Authors. Influenza and Other Respiratory Viruses Published by John Wiley & Sons Ltd.