Comparison of pandemic and seasonal influenza A infections in pediatric patients: were they different?

This retrospective cohort study revealed that the presence of pandemic H1N1 influenza resulted in a 77.7% increase of patient visits in the emergency department for influenza like illnesses and a 67.2% increase of hospital days in our hospital by comparing to a regular influenza season (2008-2009 season). However, median length of hospital stay was no different in either period (pandemic: 3 days versus seasonal: 4 days, P = 0.06). Except for the patients hospitalized for pandemic H1N1 influenza (n = 111) were older (median age: 4.7 years versus 1.6 years, P = 0.04) and tended to have pre-existing asthma (21.6% versus 9.0%, P = 0.07) than those hospitalized for seasonal influenza A infections (n = 44), this study found no significant difference between the two comparison groups with regards of other clinical and epidemiological features.