title: The causes of hospital-treated acute lower respiratory tract infection in children.
abstract: OBJECTIVE
  To determine the etiologic agents in children with acute lower respiratory infection.
  
  
  METHODS
  A survey of a series of patients.
  
  
  METHODS
  General pediatric hospital serving an urban population with and without referrals in Helsinki, Finland.
  
  
  METHODS
  135 Finnish children aged 2 months to 15 years (mean, 1.75 years), with clinically defined acute lower respiratory infection (with difficulty of breathing), or found to have fever and a pneumonic infiltrate on chest roentgenogram.
  
  
  METHODS
  Consecutive sample on voluntary basis.
  
  
  METHODS
  None.
  
  
  RESULTS
  Of 121 children with adequate samples, an etiologic diagnosis could be established in 84 (70%): 30 (25%) had bacterial, 30 (25%) viral, and 24 (20%) mixed infections. Antibody assays alone identified the agent in 91% of positive cases.
  
  
  CONCLUSIONS
  Bacterial infections are common but generally underestimated in acute lower respiratory infection; serologic methods add significantly to their detection.
authors.affiliation: National Public Health Institute, Helsinki, Finland.
authors.forename: H
authors.initials: H
authors.lastname: Nohynek
authors.forename: J
authors.initials: J
authors.lastname: Eskola
authors.forename: E
authors.initials: E
authors.lastname: Laine
authors.forename: P
authors.initials: P
authors.lastname: Halonen
authors.forename: P
authors.initials: P
authors.lastname: Ruutu
authors.forename: P
authors.initials: P
authors.lastname: Saikku
authors.forename: M
authors.initials: M
authors.lastname: Kleemola
authors.forename: M
authors.initials: M
authors.lastname: Leinonen
mesh_terms: D000208:Acute Disease; D000257:Adenoviridae Infections / Q000382:microbiology; D000293:Adolescent; D001424:Bacterial Infections / Q000382:microbiology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D005387:Finland; D006192:Haemophilus Infections / Q000382:microbiology; D006193:Haemophilus influenzae / Q000302:isolation & purification; D006760:Hospitalization; D006801:Humans; D007223:Infant; D007251:Influenza, Human / Q000382:microbiology; D008297:Male; D001936:Moraxella catarrhalis / Q000302:isolation & purification; D011008:Pneumococcal Infections / Q000382:microbiology; D012136:Respiratory Syncytial Viruses / Q000302:isolation & purification; D012141:Respiratory Tract Infections / Q000382:microbiology*; D010253:Respirovirus Infections / Q000382:microbiology; D014505:Urban Population; D014777:Virus Diseases / Q000382:microbiology*