Of 442 cases of fatal infl uenza in children and young adults reported to CDC during the 1998-99 through 2007-08 infl uenza seasons, 105 (24%) cases had available autopsy specimens with suffi cient DNA for genotyping. Case-patient characteristics are summarized in Table 1 . Genotyped casepatients had a median age of 6.0 years (range 1 month-40 years) and 52% were female. Sixty-one percent of casepatients were white, and 17% were black. Seventy-four percent of cases occurred during 3 infl uenza seasons: 2003-04 (31%), 2006-07 (21%), and 2007-08 (22%). Eighty-one (77%) of 105 case-patients were infected with infl uenza A and 24 (23%) with infl uenza B. There were no signifi cant differences in the distribution of infl uenza types by season between cases and the national pattern of types found in the US viral surveillance system (data not shown).