Influenza burden in children newborn to eleven months of age in a pediatric emergency department during the peak of an influenza epidemic.
BACKGROUND
The aim of this study was to determine the burden of influenza-related diseases in children 0 to 11 months of age during the peak of the 2001 to 2002 influenza epidemic.


METHODS
This was a prospective study at the Pediatric Emergency Department of Edouard Herriot tertiary teaching hospital in Lyon, France. The study included 304 infants 0 to 11 months of age. Consecutive patients were systematically enrolled during the 4 weeks of the influenza epidemic peak (Weeks 3 to 6, 2002). Influenza viruses were detected by antigen detection and virus culture from nasal swabs. Structured telephone interviews were conducted on Days 8 and 15 after virus detection. There was also a 6-month survey into the medicoadministrative database to detect late complications that required delayed hospitalization of influenza-positive children.


RESULTS
Influenza virus was detected in 99 (33%) of 304 patients (A/H3N2 in 30% and B in 3%). Nonrespiratory symptoms were the dominant clinical manifestations in 30% of influenza-positive children. One child with influenza presented with febrile seizures. Twenty (20%) children with influenza were hospitalized. Parents reported recovery from the illness in 63 and 94% of children on Days 8 and 15, respectively. The median length of an influenza episode was 8 days.


CONCLUSIONS
Our results confirm the high prevalence of influenza-related morbidity in infants during the epidemic peak. One child in three consulting to the pediatric emergency room had a virologically confirmed influenza infection regardless of the body temperature. Every fifth child with influenza was admitted to hospital, which corresponds to an admission rate of 237 per 100 000 children 0 to 11 months of age.
Ploin
Dominique
D
Départment d'Information Médicale des Hospices Civils de Lyon, Lyon, France. daniel.floret@chu-lyon.fr
Liberas
Sylviane
S
Thouvenot
Daniele
D
Fouilhoux
Alain
A
Gillet
Yves
Y
Denis
Angelique
A
Chapuis
Francois
F
Lina
Bruno
B
Floret
Daniel
D
D000367:Age Factors; D004196:Disease Outbreaks; D004636:Emergency Service, Hospital; D005260:Female; D005500:Follow-Up Studies; D005602:France / Q000453:epidemiology; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D007251:Influenza, Human / Q000175:diagnosis* / Q000453:epidemiology*; D008297:Male; D011446:Prospective Studies; D012494:Sampling Studies; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric