Epidemiology of Streptococcus pneumoniae in France before introduction of the PCV-13 vaccine.

The purpose of this article was to describe the serotype incidence and antibiotic susceptibility of Streptococcus pneumoniae strains isolated from adults and children with invasive disease (IPD) or acute otitis media (AOM) before introduction of the 13-valent pneumococcal vaccine. During 2009, 494 strains of S. pneumoniae isolated were collected. Complete serotyping by latex antisera and molecular methods was performed. The most frequent serotypes isolated from children with IPD were 1 (26.2%), 19A (25%) and 7F (14.3%). Serotype 19A was predominant (42.1%) in children ≤ 2 years, whereas serotype 1 was predominant (63.3%) after the age of 5. Serotype 19A was the most frequently isolated serotype from AOM (62.3%). In adults, serotypes responsible for IPD were 7F (19.4%), 19A (13.7%), 1 (8.4%) and 3 (7.5%). The serotype 19A was predominant in adults older than 65 years (19.1%). The emergence of serotype 12F was observed in adults. Between 2007 and 2009, the introduction of PCV-7 has resulted in a significant decrease of IPD caused by serotypes included in the vaccine, in children as well as in adults, confirming the herd effect. Serotype coverage of PCV-13 was 70% and 80.9% for adult and children's IPD, respectively. PCV-13 will be more efficient in preventing invasive diseases among children and adults.