This is an epidemiological, retrospective and observational study, by reviewing clinical histories, of children hospitalized for influenza virus infection, their comorbidities and the treatments that have been performed

A better knowledge in our environment of the characteristics of the Influenza virus infection in the pediatric age, the clinical aspects, risk factors, the evolutionary and prognostic aspects, of morbidity and the direct medical costs, can allow a better management of the disease and a greater awareness of the importance of vaccination against influenza in the healthy child

Inclusion Criteria:

• Boys and girls under 15 years of age.
• With a clinical diagnosis of influenza virus infection.
• With infection by influenza virus confirmed microbiologically.
• Hospitalized more than 24 hours

Exclusion Criteria:

• Age equal to or greater than 15 years.
• That the clinical diagnosis is not influenza virus infection.
• Influenza virus not confirmed by microbiological diagnosis.
• Not hospitalized or hospitalized for less than 24 hours.

the population under study is children under 15 years of age, hospitalized for infection with influenza virus confirmed microbiologically during two consecutive seasons (September 15, 2014 to June 30, 2015) (September 15, 2015 to June 30, 2015). 2016).