title: Risk factors for need of mechanical ventilation in children with influenza A(H1N1)pdm09.
abstract: OBJECTIVE
  The pandemic caused by influenza A(H1N1)pdm09 virus peaked between July and August of 2009 in southern Brazil, with the highest incidence in children and young adults. In the post-pandemic period, there was an increase in the incidence of cases during the winter months of 2011 and 2012 in Brazil, similar to seasonal influenza virus. Since infections due to pandemic influenza are still occurring, the present study aimed to investigate the risk factors for worse outcome in children.
  
  
  METHODS
  A retrospective cohort study was performed by reviewing the charts of hospitalized patients younger than 14 years with reverse transcription-polymerase chain reaction (RT-PCR) positive for influenza A(H1N1)pdm09 during the first pandemic wave in six Brazilian tertiary centers. Need for mechanical ventilation was defined as the severity of outcome; age, chronic diseases, bacterial and viral co-detection, chest radiograph findings, and use of oseltamivir were possible predictors.
  
  
  RESULTS
  In the present study, 120 patients were included. In a multivariate analysis, chronic diseases (prevalence ratio: 2.613, 95% CI: 1.267-5.386) and viral co-detection (prevalence ratio: 2.43, 95% CI: 1.203-4.905) were statistically associated with worse outcome (p<0.05).
  
  
  CONCLUSIONS
  The presence of chronic diseases as predictors reinforces previous finding. Furthermore, viral co-detection was found to be a risk factor. Further studies are necessary to confirm this association.
authors.affiliation: MSc Candidate in Child and Adolescent Health, Faculdade de Medicina, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil. Pediatric Infectious Disease's Specialist, Hospital da Criança Santo Antonio, Departamento de Pediatria, Porto Alegre, RS, Brazil. Electronic address: marcelo.scotta@ufrgs.br.
authors.forename: Marcelo C
authors.initials: MC
authors.lastname: Scotta
authors.forename: Rita
authors.initials: R
authors.lastname: Mattiello
authors.forename: Paulo J C
authors.initials: PJ
authors.lastname: Marostica
authors.forename: Marcus H
authors.initials: MH
authors.lastname: Jones
authors.forename: Letícia G
authors.initials: LG
authors.lastname: Martins
authors.forename: Gilberto B
authors.initials: GB
authors.lastname: Fischer
mesh_terms: D000293:Adolescent; D000367:Age Factors; D001938:Brazil / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D002908:Chronic Disease; D060085:Coinfection / Q000821:virology; D015897:Comorbidity; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D007223:Infant; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000401:mortality* / Q000628:therapy; D007902:Length of Stay; D008297:Male; D015999:Multivariate Analysis; D015995:Prevalence; D012121:Respiration, Artificial; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome
keywords: Child; Criança; Fatores de risco; Influenza A H1N1 subtype; Influenza A subtipo H1N1; Insuficiência respiratória; Respiratory insufficiency; Risk factors