Influenza is a respiratory disease ocasionated by influenza virus A and B. Is a disease with high morbi-mortality world-wide. Influenza produces an acute febrile respiratory illness with cough, headache and myalgias for 3-4 days, with simptoms that may persist for as long as 2 weeks.

There are three types of influenza virsuses:

A, B and C, of whom the type a has a higher ability to originate pandemias and is subclassified according to their surface antigens: hemaglutinine (H) and neuraminidase (N). Of the capacity of mutation that has the influenza virus and the consequent expression of different proteins, can modify its virulence. The transmission route is through direct contact with secretetory repirations. The transmission route is through direct contact with secretetory repirations. The incubation period is scant, between 12-72 hs.

The aim of this study was to compare the clinical characteristics demographicals and evolutive of pediatric patients hospitalized because by Influenze A:

subtypes H1N1 (pdm2009) and H3N2. An observative study was performed, retrospective, using data of hospitalizations of children during the years 2016 and 2017 with influenza A confirmed by laboratory. The study also, aimed to evaluate if the viral subtype constitutes a factor of risk, independent for complicated hospitalization (admission to intensive care and/or development of complications) in hospitalized children. The results obtained in the study are detailed in the paper. In conclusion, both viral subtypes affected mainly to children with risk factors. The viral subtype H1N1 was related with higher severety in hospitalized children. is of most importance to perform preventive works, specially in vulnerable groups, offering a good cover of immunizations. The clinical parameters arae commented (AU)