title: [Influence of respiratory viruses, cold weather and air pollution in the lower respiratory tract infections in infants children].
abstract: BACKGROUND
  All winters, there is an increase in the number of pediatric consultations, associated to three factors: cold weather, air pollution and respiratory virus epidemics.
  
  
  OBJECTIVE
  To study the influence of these three factors in the demand for pediatric consultations between March and September, in an area of Metropolitan Santiago.
  
  
  METHODS
  The number of consultations between March and September 1998 in the emergency room and the number of hospital discharges due to lower respiratory tract infections, were registered in a public pediatric hospital of Santiago. A respiratory virus surveillance (respiratory syncytial virus, adenovirus, influenza and parainfluenza virus) was done among children admitted for lower respiratory infections. Atmospheric temperature values and air pollution, measured as the number of particles of 10 microns or more per m3 (MP 10), were obtained from local health services.
  
  
  RESULTS
  Two elevation waves of outpatient consultations were detected at weeks 19 and 26, that coincided with the periods of maximal detection of influenza and syncytial respiratory virus, respectively. The epidemics of respiratory syncytial virus coincided with the maximal number of hospital admissions for lower respiratory tract infections at week 27. There was no correlation between air pollution and the number of pediatric consultations. The lower ambient temperatures coincided with the higher detection of respiratory syncytial virus at week 28, moment in which the demand for consultations or hospital admissions was descending.
  
  
  CONCLUSIONS
  There is a direct relationship between respiratory virus epidemics and the demand for pediatric consultations. There is also a minor influence of ambient temperature.
authors.affiliation: Programa de Virología, ICBM, Facultad de Medicina, Universidad de Chile. lavendan@machi.med.uchile.cl
authors.forename: L F
authors.initials: LF
authors.lastname: Avendaño
authors.forename: A
authors.initials: A
authors.lastname: Céspedes
authors.forename: X
authors.initials: X
authors.lastname: Stecher
authors.forename: M A
authors.initials: MA
authors.lastname: Palomino
mesh_terms: D000208:Acute Disease; D000397:Air Pollution / Q000009:adverse effects*; D002675:Child, Preschool; D002677:Chile / Q000453:epidemiology; D003080:Cold Temperature / Q000009:adverse effects*; D015981:Epidemiologic Factors; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D012136:Respiratory Syncytial Viruses; D012141:Respiratory Tract Infections / Q000453:epidemiology / Q000209:etiology*; D012621:Seasons; D014505:Urban Population