In Germany, only limited epidemiological data on hospitalisations and complications of seasonal influenza in children is available. In the population-based PRIDE study, conducted in 11 paediatric practices and 4 hospitals on children < 3 years of age from November 1999 to October 2001, annual incidence of influenza-associated hospitalisations was estimated as 120/100,000 [9] . In another population-based study conducted 1996-2001 in two paediatric hospitals, incidence was calculated as 123/100,000 children < 6 years of age, and 53/100,000 in children < 17 years of age [10] . However, both studies were too small to detect rare severe influenza-associated complications and fatalities resulting in PICU admittance.