We aim to compare the clinical characteristics and outcomes of children with seasonal and pandemic influenza infection.
Cases were defined as children <18 years of age with laboratory-confirmed influenza infection who required hospitalization at Primary Children’s Medical Center from June 2002 through 2010. Cases from April 2009 to June 2010 were considered to be pandemic 2009 (H1N1). Demographic, clinical, and financial data were collected through a combination of electronic query and chart review.
Between 2002 and 2010 we identified 688 cases of laboratory-confirmed influenza A illness among children. Gender was not a significant factor between pandemic and seasonal cases. Pandemic influenza affected older children predominantly (P<0.001). Rates of underlying medical conditions were similar between children with seasonal and pandemic influenza infection. Patients with pandemic infection were more likely to receive antiviral medications (P<0.01). Rates of antibiotic administration were similar among the two groups. Focal pneumonia was more frequently associated with pandemic influenza infection (P<0.001). Rates of bacterial co-infection and hospital length of stay were similar.
Pandemic influenza affected older children. These patients were more likely to be treated with antiviral medications than those with seasonal influenza. Focal pneumonias developed more frequently in children who had pandemic influenza compared to seasonal.