title: [Clinical and epidemiological characteristics of influenza A virus infection in children aged less than 7 years old in primary care].
abstract: BACKGROUND
  The aim of this study was to describe the clinical and epidemiological features of confirmed influenza A virus infection in patients aged less than 7 years old.
  
  
  METHODS
  We performed a retrospective, descriptive study of the clinical and epidemiological features of influenza A virus infection in patients aged less than 7 years old attending three primary care centers during the 2003-2004 influenza season. Patients with influenza A infection confirmed by immunofluorescence, cell culture, or polymerase chain reaction were interviewed to obtain clinical and epidemiological data on their disease.
  
  
  RESULTS
  Influenza A virus was detected in 47 patients aged between 5 months and 7 years (mean: 37.3 +/- 5.7 months). Of these, 35 children (74.4 %) were aged between 0 and 4 years. The most frequent symptoms were fever (100 %), cough (95.7 %), and rhinorrhea (76.6 %). Gastrointestinal symptoms were present in 40.4 % of the patients. The mean duration of fever was 5.2 +/- 1.8 days (range 2-8). Complications occurred in nine patients (19.2 %). The frequency of influenza-like disease in parents was 9.1 % (8/88) at diagnosis of the index case and was 23.9 % (21/88) immediately after the episode in the child (p 5 0.01). The mean number of days of absence from school was 7.5 +/- 3.6 days.
  
  
  CONCLUSIONS
  The mean age of our patients confirms that influenza is a frequent disease in infancy and childhood. The results demonstrate that the infection is transmitted from children to parents in the household setting, since the frequency of influenza-like symptoms in adults increases after influenza episodes in children.
authors.affiliation: CAP Pare Claret. Institut Català de la Salut. Barcelona. España. dvanesso@menta.net
authors.forename: D L
authors.initials: DL
authors.lastname: van Esso Arbolave
authors.forename: A
authors.initials: A
authors.lastname: Estabanell Buxó
authors.forename: I
authors.initials: I
authors.lastname: Fernández García
authors.forename: M
authors.initials: M
authors.lastname: Pérez Cifuentes
authors.forename: R
authors.initials: R
authors.lastname: Besora Anglerill
authors.forename: J M
authors.initials: JM
authors.lastname: Casanovas Gordó
authors.forename: T
authors.initials: T
authors.lastname: Pumarola Suñé
authors.forename: M A
authors.initials: MA
authors.lastname: Marcos Maeso
authors.forename: A
authors.initials: A
authors.lastname: Martínez Mateo
authors.forename: A
authors.initials: A
authors.lastname: Domínguez García
mesh_terms: D002648:Child; D002675:Child, Preschool; D006801:Humans; D007223:Infant; D009980:Influenza A virus; D007251:Influenza, Human / Q000175:diagnosis* / Q000453:epidemiology*; D011320:Primary Health Care; D012189:Retrospective Studies