Morbidity patterns reflected in a school health program during an influenza epidemic season.
D000041:Absenteeism; D000293:Adolescent; D002648:Child; D004196:Disease Outbreaks; D006801:Humans; D007087:Illinois; D007114:Immunization; D007251:Influenza, Human / Q000453:epidemiology*; D012572:School Health Services