The study shown that influenza associated pneumonia in children hospitalized with laboratory confirm from 2003 to 2008.
"Influenza causes considerable morbidity among children and pneumonia is one of the most common complications in children hospitalized with influenza. Pneumonia has been reported in 10% to 26% of children hospitalized with influenza and in a recent study of influenza-associated pediatric mortality, 35% of children who died had pneumonia."
When I saw this data, I was really surprise then.
Here is the link where you can download the case study for free.