Serotypes and antimicrobial susceptibilities of invasive Streptococcus pneumoniae pre- and post-seven valent pneumococcal conjugate vaccine introduction in Alberta, Canada, 2000-2006

Abstract

Alberta, Canada introduced the Streptococcus pneumoniae seven valent conjugate vaccine (PCV7) program for children less than 2 years of age in September 2002. We determined the rates of invasive pneumococcal disease in Alberta, Canada 2 years pre- and 4 years post-PCV7 introduction (2000-2006) as well as the rates of antibiotic resistance and serotype distribution in this same time period. Overall, PCV7 serotypes decreased 61% from 2000 to 2006. The greatest decrease in incidence of invasive pneumococcal disease occurred in children less than 2 years of age declining from a high of 96.7/100,000 (2000) to 25.8/100,000 (2006) (P<0.0001). Non-susceptibility of S. pneumoniae isolates to penicillin dropped significantly from 14% in 2000 to 4.6% in 2006 (P<0.0001). Non-susceptible erythromycin isolates also decreased from 8.8% (2000) to 5.8% (2006) (P=0.13). The introduction of PCV7 in Alberta, Canada has decreased the incidence of invasive pneumococcal disease in Alberta as well as resulting in a decrease in antibiotic resistance over this same time frame, principally for penicillin resistance.