Complications and associated bacterial coinfections among children hospitalized with seasonal or pandemic influenza, United States, 2003-2010.

Data on the range and severity of influenza-associated complications among children are limited. We describe the frequency and severity of complications in hospitalized children aged <18 years with seasonal influenza (during 2003-2009) and 2009 pandemic influenza A(H1N1) (during 2009-2010).