title: Changes in serotypes causing invasive pneumococcal disease (2005-2007 vs. 1997-1999) in children under 2 years of age in a population with intermediate coverage of the 7-valent pneumococcal conjugated vaccine.
abstract: Serotypes causing invasive pneumococcal disease (IPD) in children aged <2 years in Catalonia (Spain) before and after licensing of the 7-valent pneumococcal conjugated vaccine (7vPCV) were assessed, using samples taken during 1997-1999 and 2005-2007 respectively. The distribution of serotypes causing IPD within these groups was obtained by serotyping strains sent by 22 Catalan hospitals to the Carlos III Health Institute, Madrid. Between 1997-99 and 2005-2007, the proportion of vaccine serotypes causing IPD in Catalonia fell from 70.54% to 31.67% (p <0.0001). The proportion of vaccine-related serotypes, mainly serotype 19A, increased from 9.82% to 32.50% (p <0.0001). The proportion of non-vaccine, non-related serotypes (serotypes not related to vaccine serotypes) rose from 19.64% to 35.83% (p <0.05). Within this group, the proportions of serotype 24F increased significantly. There has been a change in the distribution of serotypes isolated from cases of IPD in children <2 years old in Catalonia, comprising a reduction in the proportion of 7-valent vaccine serotypes, a rise in vaccine-related serotypes, especially 19A, and a smaller rise in non-vaccine, non-related serotypes, especially serotype 24F. A new 13-valent vaccine will cover 77.91% of the serotypes causing IPD in children <2 years old in Catalonia from 2005 to 2007.
authors.affiliation: Department of Public Health, School of Medicine, University of Barcelona, Barcelona, Spain. salleras@ub.edu
authors.forename: L
authors.initials: L
authors.lastname: Salleras
authors.forename: A
authors.initials: A
authors.lastname: Domínguez
authors.forename: P
authors.initials: P
authors.lastname: Ciruela
authors.forename: C
authors.initials: C
authors.lastname: Izquierdo
authors.forename: E
authors.initials: E
authors.lastname: Navas
authors.forename: N
authors.initials: N
authors.lastname: Torner
authors.forename: E
authors.initials: E
authors.lastname: Borras
mesh_terms: D015373:Bacterial Typing Techniques; D005260:Female; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011008:Pneumococcal Infections / Q000453:epidemiology* / Q000382:microbiology* / Q000517:prevention & control; D022242:Pneumococcal Vaccines / Q000276:immunology*; D015995:Prevalence; D012703:Serotyping; D013030:Spain / Q000453:epidemiology; D013296:Streptococcus pneumoniae / Q000145:classification* / Q000302:isolation & purification*
chemical_list: D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D022242:Pneumococcal Vaccines