Objective To describe the serotype distribution of S. pneumoniae associated with invasive pneumococcal disease in children in the Valencia Community (5.9 million inhabitants), Spain, after introduction of a 7 valent (7V) pneumococcal conjugate vaccine.
Methods We serotyped all S. pneumoniae isolated from blood, spinal fluid (CSF) and sterile liquid cultures collected during the year 2007 from children (aged <15 year) who were diagnosed with invasive pneumococcal disease in any of the 10 participating hospitals. Serotyping was performed by antiserum agglutination (Denka Seiken, Japan). In cases of serotypes 19 and 23, subtypes were done by use of the capsular reaction test (Neufeld test)
Results We serotyped 72 isolates of S. pneumoniae from 61 patients (53 blood cultures, 13 CSF and 6 sterile fluids). The serotypes in order of frequency were: 7 (26%), 1 (25%), 14 (15%), 19A (12%), 18 (5%), 8 (3%), 6(3%), 4 (2%), 16 (2%), 19F (2%), 22(2%), 23A (2%), 23F (2%), 24 (2%).
Conclusions Of the serotypes isolated in this study, only 28% are included in the 7V-vaccine. Serotypes 1 and 7, which were most frequently isolated (51% of total) are not included in the 7 V-vaccine. Continued surveillance is needed to guide development of future formulations of conjugate vaccines and to monitor the effects of continued vaccine use.
Note: Data used from the Surveillance Network of the Valencian Community. Public Health Department. Conselleria de Sanitat