title: Association of clinical signs and symptoms with pneumococcal acute otitis media by serotype--implications for vaccine effect.
abstract: BACKGROUND
  Clinical symptoms and signs in acute otitis media (AOM) may differ depending on the various pneumococcal serotypes causing the disease. Alteration in clinical presentation of AOM could be expected after wide-scale pneumococcal vaccinations if there were considerable differences between vaccine serotypes and nonvaccine serotypes.
  
  
  METHODS
  In this study, data from 831 children in the control arm of the Finnish Otitis Media Vaccine Trial were used. The children were followed up prospectively in 8 study clinics from 2 to 24 months of age. If AOM was diagnosed, myringotomy was done, and middle ear fluid was aspirated for bacterial culture. Clinical symptoms and signs of AOM were routinely recorded on structured case report forms.
  
  
  RESULTS
  Consistent with previous studies, 60% of pneumococcal episodes were caused by vaccine serotypes. There were no major differences between the clinical presentations of AOM due to different serotypes or serotype categories. However, earache was more often associated with AOM caused by vaccine and cross-reactive serotypes, compared with AOM caused by non-vaccine-related serotypes (42% vs. 29%; odds ratio, 1.66; 95% confidence interval, 1.02-2.70).
  
  
  CONCLUSIONS
  Introduction of the currently available pneumococcal conjugate vaccine is unlikely to result in a remarkable alteration in the clinical presentation of pneumococcal AOM in infants.
authors.affiliation: National Public Health Institute, Helsinki, Finland. arto.palmu@ktl.fi
authors.forename: Arto A I
authors.initials: AA
authors.lastname: Palmu
authors.forename: Jukka T
authors.initials: JT
authors.lastname: Jokinen
authors.forename: Tarja
authors.initials: T
authors.lastname: Kaijalainen
authors.forename: Maija
authors.initials: M
authors.lastname: Leinonen
authors.forename: Pekka
authors.initials: P
authors.lastname: Karma
authors.forename: Terhi M
authors.initials: TM
authors.lastname: Kilpi
mesh_terms: D000208:Acute Disease; D002648:Child; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D010033:Otitis Media / Q000209:etiology / Q000382:microbiology* / Q000503:physiopathology; D022242:Pneumococcal Vaccines / Q000009:adverse effects*; D012703:Serotyping; D013296:Streptococcus pneumoniae / Q000145:classification* / Q000472:pathogenicity
chemical_list: D022242:Pneumococcal Vaccines