Nasopharyngeal carriage of Streptococcus pneumoniae in Finnish children younger than 2 years old

J Infect Dis. 2001 Aug 15;184(4):451-9. doi: 10.1086/322048. Epub 2001 Jul 6.


To describe the natural course of nasopharyngeal carriage of Streptococcus pneumoniae and its relationship to acute otitis media (AOM), 329 Finnish children were followed from ages 2 to 24 months. In total, 3024 nasopharyngeal (NP) swabs (obtained at 10 scheduled healthy visits) and 2007 NP aspirates (obtained during respiratory infections) were cultured. Carriage during health increased gradually (9%-43%) with age. Within 4 age intervals, carriage was lower during health (13%-43%) than during respiratory infection without AOM (22%-45%). Higher proportions of positive samples were found during AOM (45%-56%), in particular during pneumococcal AOM (97%-100%). Antimicrobial treatment reduced carriage only temporarily. The most frequent NP serotypes were 6B, 6A, 11, 19F, and 23F. Both age and health status were important determinants of NP carriage of S. pneumoniae and these features should be considered carefully during analysis of carriage rates.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carrier State / epidemiology*
  • Carrier State / microbiology
  • Child, Preschool
  • Female
  • Finland / epidemiology
  • Humans
  • Infant
  • Male
  • Nasopharynx / microbiology*
  • Otitis Media / epidemiology
  • Otitis Media / microbiology
  • Pneumococcal Infections / epidemiology*
  • Pneumococcal Infections / microbiology
  • Seasons
  • Streptococcus pneumoniae / classification
  • Streptococcus pneumoniae / isolation & purification*