Different drug-resistant influenza A(H3N2) variants in two immunocompromised patients treated with oseltamivir during the 2011-2012 influenza season in Italy

Oseltamivir resistance is reported for the first time in A(H3N2) virus strains during the 2011-2012 influenza season. Different drug-resistant viruses emerged in hospitalized immunocompromised patients showing prolonged virus shedding.