Epidemiology of Acute Otitis Media Caused by Streptococcus pneumoniae Before and After Licensure of the 7-Valent Pneumococcal Protein Conjugate Vaccine

Abstract

We studied, by pulsed-field gel electrophoresis, multilocus sequence typing and penicillin-binding protein 2b amplicon-restriction profiles, pneumococcal isolates recovered from children with acute otitis media during 1 January-31 December 1999 and 2001. The proportion of nonvaccine serogroups increased from 14.8% (13/ 88) to 36.5% (23/63) from 1999 to 2001 (P