title: Serotypes 1, 7F and 19A became the leading causes of pediatric invasive pneumococcal infections in Portugal after 7 years of heptavalent conjugate vaccine use.
abstract: We characterized 353 isolates responsible for pediatric invasive pneumococcal infections (IPD) in Portugal between 2006 and 2008. Serotypes included in the seven-valent conjugate vaccine (PCV7) accounted for 17% of IPD. Serotypes 1, 7F and 19A were the most frequent causes of IPD and the later consolidated as the most frequent serotype among erythromycin and penicillin non-susceptible isolates. Serotype 1 was associated with older children and empyemas, while serotype 19A was associated with IPD in younger (<2 years) children. The higher valency vaccines PCV10 and PCV13 have a potentially superior coverage, 55% and 83% respectively, but non-vaccine serotypes are emerging as important causes of IPD. A decline of resistance with patient age was noted. Comparing with previous data from Portugal, this study showed a continued decline of PCV7 serotypes and that overall resistance has stabilized following the initial decline of the first post-PCV7 years.
authors.affiliation: Instituto de Microbiologia, Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, PT 1649-028 Lisboa, Portugal.
authors.forename: Sandra I
authors.initials: SI
authors.lastname: Aguiar
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Brito
authors.forename: José
authors.initials: J
authors.lastname: Gonçalo-Marques
authors.forename: José
authors.initials: J
authors.lastname: Melo-Cristino
authors.forename: Mário
authors.initials: M
authors.lastname: Ramirez
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D024881:Drug Resistance, Bacterial; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D006801:Humans; D008826:Microbial Sensitivity Tests; D011008:Pneumococcal Infections / Q000453:epidemiology* / Q000276:immunology / Q000517:prevention & control; D022242:Pneumococcal Vaccines / Q000008:administration & dosage*; D011174:Portugal / Q000453:epidemiology; D012703:Serotyping; D013296:Streptococcus pneumoniae / Q000145:classification* / Q000187:drug effects; D018074:Vaccines, Conjugate / Q000008:administration & dosage
chemical_list: D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D022242:Pneumococcal Vaccines; D018074:Vaccines, Conjugate