Comparison of the clinical features of children hospitalized with pandemic 2009 A:H1N1 and seasonal influenza.

INTRODUCTION: We compared the demographics, clinical presentation, course and outcome of children hospitalized with pandemic A:H1N1 and seasonal influenza. METHODS: Sixty seven patients hospitalized from April 1st through August 31st 2009 with pandemic A:H1N1 influenza were enrolled. Two seasonal influenza cohorts were identified: 38 inpatients from January 1st 2004 through March 31st 2009, diagnosed by viral culture or direct fluorescent antibody testing; and 42 inpatients from January 1st 2007 through December 31st 2008 diagnosed via a rapid test. The two seasonal cohorts were not significantly different and were combined. RESULTS: Patients with pandemic influenza were older (median age 6.5 years versus 1.3 years, P <.0001); were more often black (46% versus 23%, P <.0002); more frequently had an underlying condition (72% versus 49% P <.0049); and more often had wheezing (57% versus 16%, P <.0001). CONCLUSION: There was no significant difference between the groups in measures of severity during hospitalization.