Burden of influenza in children in the community.
BACKGROUND
Influenza vaccination of healthy children is encouraged because children are frequently hospitalized for influenza-attributable illnesses. However, most children with influenza are treated as outpatients, and scarce data are available on the burden of influenza in these children.


METHODS
We performed a prospective study of respiratory infections in preenrolled cohorts of children < or = 13 years old during 2 consecutive respiratory seasons (2231 child-seasons of follow-up). At any sign of respiratory infection, we examined the children and obtained a nasal swab for the detection of influenza. The parents filled out daily symptom diaries. Of all the enrollees, 94% remained active participants in the study.


RESULTS
The average annual rate of influenza was highest (179 cases/1000 children) among children < 3 years old. Acute otitis media developed as a complication of influenza in 39.7% of children < 3 years old. For every 100 influenza-infected children < 3 years old, there were 195 days of parental work loss (mean duration, 3.2 days).


CONCLUSIONS
Influenza causes a substantial burden of illness on outpatient children and their families. Vaccination of children < 3 years old might be beneficial for reducing the direct and indirect costs of influenza in children.
Heikkinen
Terho
T
Department of Pediatrics, Turku University Hospital, Turku, Finland. terho.heikkinen@utu.fi.
Silvennoinen
Heli
H
Peltola
Ville
V
Ziegler
Thedi
T
Vainionpaa
Raija
R
Vuorinen
Tytti
T
Kainulainen
Leena
L
Puhakka
Tuomo
T
Jartti
Tuomas
T
Toikka
Pia
P
Lehtinen
Pasi
P
Routi
Taina
T
Juven
Taina
T
D000208:Acute Disease; D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D017714:Community-Acquired Infections / Q000191:economics / Q000453:epidemiology*; D017281:Cost of Illness; D005260:Female; D005387:Finland / Q000453:epidemiology; D006801:Humans; D007223:Infant; D007251:Influenza, Human / Q000191:economics / Q000453:epidemiology*; D008297:Male; D010033:Otitis Media / Q000191:economics / Q000453:epidemiology; D011446:Prospective Studies; D012141:Respiratory Tract Infections / Q000191:economics / Q000453:epidemiology*