Prolonged shedding of amantadine- and oseltamivir-resistant influenza A(H3N2) virus with dual mutations in an immunocompromised infant.

In this study, we report a case of multidrug-resistant influenza A(H3N2) virus isolated from an immunosuppressed patient with prolonged viral shedding. We also describe the genetic characterization of the haemagglutinin, neuraminidase and M2 influenza genes. The virus contained the substitutions E119V in neuraminidase and V27A in M2, which produce resistance to oseltamivir and adamantanes, respectively. This is the first report of this dual mutation pattern in multidrug-resistant influenza A(H3N2) virus.