title: Pediatric hospitalizations associated with 2009 pandemic influenza A (H1N1) in Argentina.
abstract: BACKGROUND
  While the Northern Hemisphere experiences the effects of the 2009 pandemic influenza A (H1N1) virus, data from the recent influenza season in the Southern Hemisphere can provide important information on the burden of disease in children.
  
  
  METHODS
  We conducted a retrospective case series involving children with acute infection of the lower respiratory tract or fever in whom 2009 H1N1 influenza was diagnosed on reverse-transcriptase polymerase-chain-reaction assay and who were admitted to one of six pediatric hospitals serving a catchment area of 1.2 million children. We compared rates of admission and death with those among age-matched children who had been infected with seasonal influenza strains in previous years.
  
  
  RESULTS
  Between May and July 2009, a total of 251 children were hospitalized with 2009 H1N1 influenza. Rates of hospitalization were double those for seasonal influenza in 2008. Of the children who were hospitalized, 47 (19%) were admitted to an intensive care unit, 42 (17%) required mechanical ventilation, and 13 (5%) died. The overall rate of death was 1.1 per 100,000 children, as compared with 0.1 per 100,000 children for seasonal influenza in 2007. (No pediatric deaths associated with seasonal influenza were reported in 2008.) Most deaths were caused by refractory hypoxemia in infants under 1 year of age (death rate, 7.6 per 100,000).
  
  
  CONCLUSIONS
  Pandemic 2009 H1N1 influenza was associated with pediatric death rates that were 10 times the rates for seasonal influenza in previous years.
authors.affiliation: Fundación INFANT, Buenos Aires.
authors.forename: Romina
authors.initials: R
authors.lastname: Libster
authors.forename: Jimena
authors.initials: J
authors.lastname: Bugna
authors.forename: Silvina
authors.initials: S
authors.lastname: Coviello
authors.forename: Diego R
authors.initials: DR
authors.lastname: Hijano
authors.forename: Mariana
authors.initials: M
authors.lastname: Dunaiewsky
authors.forename: Natalia
authors.initials: N
authors.lastname: Reynoso
authors.forename: Maria L
authors.initials: ML
authors.lastname: Cavalieri
authors.forename: Maria C
authors.initials: MC
authors.lastname: Guglielmo
authors.forename: M Soledad
authors.initials: MS
authors.lastname: Areso
authors.forename: Tomas
authors.initials: T
authors.lastname: Gilligan
authors.forename: Fernanda
authors.initials: F
authors.lastname: Santucho
authors.forename: Graciela
authors.initials: G
authors.lastname: Cabral
authors.forename: Gabriela L
authors.initials: GL
authors.lastname: Gregorio
authors.forename: Rina
authors.initials: R
authors.lastname: Moreno
authors.forename: Maria I
authors.initials: MI
authors.lastname: Lutz
authors.forename: Alicia L
authors.initials: AL
authors.lastname: Panigasi
authors.forename: Liliana
authors.initials: L
authors.lastname: Saligari
authors.forename: Mauricio T
authors.initials: MT
authors.lastname: Caballero
authors.forename: Rodrigo M
authors.initials: RM
authors.lastname: Egües Almeida
authors.forename: Maria E
authors.initials: ME
authors.lastname: Gutierrez Meyer
authors.forename: Maria D
authors.initials: MD
authors.lastname: Neder
authors.forename: Maria C
authors.initials: MC
authors.lastname: Davenport
authors.forename: Maria P
authors.initials: MP
authors.lastname: Del Valle
authors.forename: Valeria S
authors.initials: VS
authors.lastname: Santidrian
authors.forename: Guillermina
authors.initials: G
authors.lastname: Mosca
authors.forename: Mercedes
authors.initials: M
authors.lastname: Garcia Domínguez
authors.forename: Liliana
authors.initials: L
authors.lastname: Alvarez
authors.forename: Patricia
authors.initials: P
authors.lastname: Landa
authors.forename: Ana
authors.initials: A
authors.lastname: Pota
authors.forename: Norma
authors.initials: N
authors.lastname: Boloñati
authors.forename: Ricardo
authors.initials: R
authors.lastname: Dalamon
authors.forename: Victoria I
authors.initials: VI
authors.lastname: Sanchez Mercol
authors.forename: Marco
authors.initials: M
authors.lastname: Espinoza
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Peuchot
authors.forename: Ariel
authors.initials: A
authors.lastname: Karolinski
authors.forename: Miriam
authors.initials: M
authors.lastname: Bruno
authors.forename: Ana
authors.initials: A
authors.lastname: Borsa
authors.forename: Fernando
authors.initials: F
authors.lastname: Ferrero
authors.forename: Angel
authors.initials: A
authors.lastname: Bonina
authors.forename: Margarita
authors.initials: M
authors.lastname: Ramonet
authors.forename: Lidia C
authors.initials: LC
authors.lastname: Albano
authors.forename: Nora
authors.initials: N
authors.lastname: Luedicke
authors.forename: Elias
authors.initials: E
authors.lastname: Alterman
authors.forename: Vilma
authors.initials: V
authors.lastname: Savy
authors.forename: Elsa
authors.initials: E
authors.lastname: Baumeister
authors.forename: James D
authors.initials: JD
authors.lastname: Chappell
authors.forename: Kathryn M
authors.initials: KM
authors.lastname: Edwards
authors.forename: Guillermina A
authors.initials: GA
authors.lastname: Melendi
authors.forename: Fernando P
authors.initials: FP
authors.lastname: Polack
mesh_terms: D000293:Adolescent; D017677:Age Distribution; D001118:Argentina / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D015897:Comorbidity; D004196:Disease Outbreaks; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D000860:Hypoxia / Q000209:etiology / Q000401:mortality; D007223:Infant; D007231:Infant, Newborn; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000145:classification / Q000150:complications / Q000453:epidemiology* / Q000401:mortality; D008297:Male; D018410:Pneumonia, Bacterial / Q000453:epidemiology / Q000209:etiology; D012720:Severity of Illness Index; D013210:Staphylococcus / Q000302:isolation & purification; D013296:Streptococcus pneumoniae / Q000302:isolation & purification