Serotypes 1, 7F and 19A Became the Leading Causes of Pediatric Invasive Pneumococcal Infections in Portugal After 7 Years of Heptavalent Conjugate Vaccine Use

Vaccine. 2010 Jul 19;28(32):5167-73. doi: 10.1016/j.vaccine.2010.06.008. Epub 2010 Jun 15.

Abstract

We characterized 353 isolates responsible for pediatric invasive pneumococcal infections (IPD) in Portugal between 2006 and 2008. Serotypes included in the seven-valent conjugate vaccine (PCV7) accounted for 17% of IPD. Serotypes 1, 7F and 19A were the most frequent causes of IPD and the later consolidated as the most frequent serotype among erythromycin and penicillin non-susceptible isolates. Serotype 1 was associated with older children and empyemas, while serotype 19A was associated with IPD in younger (<2 years) children. The higher valency vaccines PCV10 and PCV13 have a potentially superior coverage, 55% and 83% respectively, but non-vaccine serotypes are emerging as important causes of IPD. A decline of resistance with patient age was noted. Comparing with previous data from Portugal, this study showed a continued decline of PCV7 serotypes and that overall resistance has stabilized following the initial decline of the first post-PCV7 years.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Child
  • Child, Preschool
  • Drug Resistance, Bacterial
  • Heptavalent Pneumococcal Conjugate Vaccine
  • Humans
  • Microbial Sensitivity Tests
  • Pneumococcal Infections / epidemiology*
  • Pneumococcal Infections / immunology
  • Pneumococcal Infections / prevention & control
  • Pneumococcal Vaccines / administration & dosage*
  • Portugal / epidemiology
  • Serotyping
  • Streptococcus pneumoniae / classification*
  • Streptococcus pneumoniae / drug effects
  • Vaccines, Conjugate / administration & dosage

Substances

  • Heptavalent Pneumococcal Conjugate Vaccine
  • Pneumococcal Vaccines
  • Vaccines, Conjugate