title: Bacteriology of acute otitis media in a cohort of Finnish children followed for the first two years of life.
abstract: BACKGROUND
  Timely information on the bacteriology of primary, noncomplicated acute otitis media (AOM) may today be needed more than ever, because of the increasing antimicrobial resistance of its major bacterial causes and because of the potential of new pneumococcal and other bacterial vaccines for prevention of AOM.
  
  
  METHODS
  The study followed 329 children from 2 to 24 months of age at scheduled healthy visits and sick visits at the study clinic. Whenever AOM was diagnosed during the follow-up, myringotomy was performed and middle ear fluid was aspirated for bacterial culture.
  
  
  RESULTS
  At least one middle ear fluid sample was available from 772 AOM events; Streptococcus pneumoniae (Pnc) was isolated in 201 (26%), Moraxella catarrhalis (Mc) in 177 (23%) and Haemophilus influenzae (Hi) in 174 events (23%). The incidence of Pnc AOM peaked at 12 months of age, whereas the incidence of Mc AOM showed the first peak at 6 months and Hi AOM at 20 months. Pnc AOM showed less prominent seasonality in occurrence than Mc and Hi AOM. Hi was a rare cause of the first 2 AOM episodes (13%) but became increasingly common from the third episode on (32% on average).
  
  
  CONCLUSIONS
  Pnc, Mc and Hi were almost equally common findings in AOM. Pnc seems to be the most pathogenic of these three, the role of Mc is increasing and Hi is clearly associated with recurrent AOM.
authors.affiliation: National Public  Health Institute, Helsinki, Finland.
authors.forename: T
authors.initials: T
authors.lastname: Kilpi
authors.forename: E
authors.initials: E
authors.lastname: Herva
authors.forename: T
authors.initials: T
authors.lastname: Kaijalainen
authors.forename: R
authors.initials: R
authors.lastname: Syrjänen
authors.forename: A K
authors.initials: AK
authors.lastname: Takala
mesh_terms: D000208:Acute Disease; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D005387:Finland; D006192:Haemophilus Infections / Q000382:microbiology*; D006193:Haemophilus influenzae / Q000302:isolation & purification*; D006801:Humans; D007223:Infant; D008297:Male; D001936:Moraxella catarrhalis / Q000302:isolation & purification*; D016870:Neisseriaceae Infections / Q000382:microbiology*; D010033:Otitis Media / Q000188:drug therapy / Q000382:microbiology* / Q000517:prevention & control; D011008:Pneumococcal Infections / Q000382:microbiology*; D022242:Pneumococcal Vaccines / Q000627:therapeutic use; D012008:Recurrence; D012703:Serotyping; D013296:Streptococcus pneumoniae / Q000302:isolation & purification*; D013396:Suction / Q000379:methods
chemical_list: D000900:Anti-Bacterial Agents; D022242:Pneumococcal Vaccines