To determine if a similar pattern of influenza-associated encephalopathy
cases is occurring in the United States, CDC is requesting information on
any case meeting certain criteria. The criteria include a person aged <18
years with altered mental status or personality change lasting >24 hours and
occurring within 5 days of the onset of an acute febrile respiratory illness,
laboratory or rapid diagnostic test evidence of acute influenza virus infection
associated with the respiratory illness, and diagnosis of the condition in
the United States.