Hospitalization for Influenza A Versus B

BACKGROUND: The extent to which influenza A and B infection differs remains uncertain. METHODS: Using active surveillance data from the Canadian Immunization Monitoring Program Active at 12 pediatric hospitals, we compared clinical characteristics and outcomes of children ≤16 years admitted with laboratory-confirmed influenza B or seasonal influenza A. We also examined factors associated with ICU admission in children hospitalized with influenza B. RESULTS: Over 8 nonpandemic influenza seasons (2004-2013), we identified 1510 influenza B and 2645 influenza A cases; median ages were 3.9 and 2.0 years, respectively ( P P CONCLUSIONS: Mortality associated with pediatric influenza B infection was greater than that of influenza A. Among healthy children hosptialized with influenza B, those 10 years and older had a significant risk of ICU admission.