In Germany, first cases of PIA were reported in April 2009; the first wave of the pandemic lasted from calendar week 42/2009 to 02/2010 [5] . The sentinel surveillance system for laboratory-confirmed PIA reported 226,137 cases and 253 fatalities for the total population until April 2010 [6] . A nationwide surveillance of critically ill children admitted to pediatric intensive care units (PICU) and fatalities associated with PIA estimated an incidence rate of 2.8 cases/100,000 children in infants * Correspondence: Liese_J@kinderklinik.uni-wuerzburg.de † Equal contributors 1 <1 year of age and 0.8 cases/100,000 in children <15 years of age [7] . Thus far, there is only limited data on clinical characteristics and outcome of PIAH in Germany [8] . In the current study, we therefore investigated clinical characteristics of all pediatric PIAH in a defined geographical region.