During the epidemic period, an excess of 18% (+10486) of pediatric outpatients and emergency department visits was registered, as compared with the mean measured over the 3 previous years during the same months. Figure 1 represents the evolution of H1N1v 2009 pediatric hospitalized cases over time in the four hospitals, with peak of the epidemic observed between the end of October and the beginning of November 2009. 215 children were hospitalized with proven or probable influenza A/ H1N1v infection; representing 2% of the total hospitals' admissions registered during the whole study period but 6% (191/3144) of those during the four weeks of the peak of the epidemic. Additionally, the PICU occupation rate by influenza A/H1N1v infected children was 3.5% over the whole study period and reached 8% during the peak of the epidemic.