Baseline Epidemiology of Streptococcus Pneumoniae Serotypes in Canada Prior to the Introduction of the 13-valent Pneumococcal Vaccine

Microb Drug Resist. 2012 Apr;18(2):176-82. doi: 10.1089/mdr.2011.0197. Epub 2011 Dec 28.


Changes in the epidemiology of Streptococcus pneumoniae were reported worldwide after the introduction of the 7-valent pneumococcal vaccine, particularly an increase in multi-drug resistant (MDR) 19A strains. Subsequently, a 13-valent pneumococcal vaccine (PCV-13) has been introduced. This study assessed the incidence of S. pneumoniae serotypes in all age groups prior to the introduction of PCV-13 in Canada (2007-2009). Eight hundred S. pneumoniae isolates from respiratory specimens and blood cultures were collected as part of a Canadian surveillance study (CANWARD) from patients in 15 tertiary-care centers. Serotyping was performed by the Quellung method and antimicrobial susceptibility testing was performed by broth microdilution in accordance with the Clinical and Laboratory Standards Institute guidelines. The most common serotypes were 19A (8.6%), 3 (7.3%), 22F (6.0%), 4 (4.6%), 5 (4.4%), and 11A (4.4%); and the first serotype 6D isolate in Canada was identified. Serotypes 5, 7F, and 19A were significantly (p<0.001) more frequently isolated from bloodstream infections. Considerable serotype variability was noted for different age groups: 15B (p<0.01) and 19A (p<0.001) were more frequently isolated from children ≤2 years old. Overall, 46.4% of currently circulating S. pneumoniae serotypes in Canada are included in PCV-13. Notably, 87.5% of MDR-S. pneumoniae were covered by PCV-13. Accordingly, PCV-13 will provide coverage against a significant proportion of circulating S. pneumoniae strains in Canada, including the critical antimicrobial-resistant strains.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Anti-Bacterial Agents
  • Canada / epidemiology
  • Child
  • Child, Preschool
  • Female
  • Humans
  • Infant
  • Male
  • Microbial Sensitivity Tests
  • Middle Aged
  • Pneumococcal Infections / epidemiology*
  • Pneumococcal Infections / microbiology
  • Pneumococcal Infections / prevention & control
  • Pneumococcal Vaccines / therapeutic use*
  • Population Surveillance / methods*
  • Serotyping
  • Streptococcus pneumoniae / classification*
  • Streptococcus pneumoniae / drug effects
  • Streptococcus pneumoniae / immunology
  • Streptococcus pneumoniae / isolation & purification*
  • Young Adult


  • 13-valent pneumococcal vaccine
  • Anti-Bacterial Agents
  • Pneumococcal Vaccines