title: Long-term effects of pneumococcal conjugate vaccine on nasopharyngeal carriage of S. pneumoniae, S. aureus, H. influenzae and M. catarrhalis.
abstract: BACKGROUND
  Shifts in pneumococcal serotypes following introduction of 7-valent pneumococcal conjugate vaccine (PCV-7) may alter the presence of other bacterial pathogens co-inhabiting the same nasopharyngeal niche.
  
  
  RESULTS
  Nasopharyngeal prevalence rates of S. pneumoniae, S. aureus, H. influenzae and M. catarrhalis were investigated before, 3 and 4.5 years after introduction of PCV-7 in the national immunisation program in children at 11 and 24 months of age, and parents of 24-month-old children (n≈330/group) using conventional culture methods. Despite a virtual disappearance of PCV-7 serotypes over time, similar overall pneumococcal rates were observed in all age groups, except for a significant reduction in the 11-month-old group (adjusted Odds Ratio after 4.5 years 0.48, 95% Confidence Interval 0.34-0.67). Before, 3 and 4.5 years after PCV-7 implementation, prevalence rates of S. aureus were 5%, 9% and 14% at 11 months of age (3.59, 1.90-6.79) and 20%, 32% and 34% in parents (1.96, 1.36-2.83), but remained similar at 24 months of age, respectively. Prevalence rates of H. influenzae were 46%, 65% and 65% at 11 months (2.22, 1.58-3.13), 52%, 73% and 76% at 24 months of age (2.68, 1.88-3.82) and 23%, 30% and 40% in parents (2.26, 1.58-3.33), respectively. No consistent changes in M. catarrhalis carriage rates were observed over time.
  
  
  CONCLUSIONS
  In addition to large shifts in pneumococcal serotypes, persistently higher nasopharyngeal prevalence rates of S. aureus and H. influenzae were observed among young children and their parents after PCV-7 implementation. These findings may have implications for disease incidence and antibiotic treatment in the post-PCV era.
authors: Department of Pediatric Immunology and Infectious Diseases, Wilhelmina Children's Hospital, University Medical Center, Utrecht, The Netherlands.
authors: Judith
authors: J
authors: Spijkerman
authors: Sabine M P J
authors: SM
authors: Prevaes
authors: Elske J M
authors: EJ
authors: van Gils
authors: Reinier H
authors: RH
authors: Veenhoven
authors: Jacob P
authors: JP
authors: Bruin
authors: Debby
authors: D
authors: Bogaert
authors: Alienke J
authors: AJ
authors: Wijmenga-Monsuur
authors: Germie P J M
authors: GP
authors: van den Dobbelsteen
authors: Elisabeth A M
authors: EA
authors: Sanders
mesh_terms: D002353:Carrier State; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006193:Haemophilus influenzae / Q000302:isolation & purification*; D006801:Humans; D007223:Infant; D008297:Male; D001936:Moraxella catarrhalis / Q000302:isolation & purification*; D009305:Nasopharynx / Q000382:microbiology*; D022242:Pneumococcal Vaccines / Q000627:therapeutic use*; D013211:Staphylococcus aureus / Q000302:isolation & purification*; D013296:Streptococcus pneumoniae / Q000302:isolation & purification*
chemical_list: D022242:Pneumococcal Vaccines