Table 1. The ICD-9 codes used to describe ILI symptoms (NOS = Not otherwise specified).

ICD9	Code Description for ILI Symptoms
79.99	Viral infection, NOS
382.9	Unspecified otitis media
460	Acute nasopharyngitis (common cold)
461.9	Acute sinusitis unspecified
465.8	Acute upper respiratory infections of other multiple sites
465.9	Acute upper respiratory infections of unspecified sites
466	Acute bronchitis
486	Pneumonia organism unspecified
487	Influenza with pneumonia
487.1	Influenza with other respiratory manifestations
487.8	Influenza with other manifestations
488	Influenza due to identified agent
490	Bronchitis, NOS
780.6	Fever
786.2	Cough