title: Epidemiological analysis of pneumococcal serotype 19A in healthy children following PCV7 vaccination.
abstract: After the introduction of conjugate vaccines, a strong rearrangement of pneumococcal serotypes was observed globally. Probably most concerning was the emergence of serotype 19A, which has not only high invasive disease potential, but also high antibiotic resistance. In the current study we focused on the increased prevalence of serotype 19A after the PCV vaccination rate became widely used in Hungary. A total of 2262 children aged 3-6 years were screened for pneumococcus carriage using nasal swabs. Children were divided into two groups according to the vaccination rates, low level (group 1) vs. high level (group 2). While the carriage rate did not change over time (average 32·9%), the serotype distribution differed greatly in the two groups. The prevalence of serotype 19A increased >eightfold. Almost all 19A isolates had high-level macrolide resistance and elevated penicillin minimum inhibitory concentrations. Genotyping methods revealed that these new 19A isolates are different from the previously frequent Hungary19A-6 PMEN clone. Both the carriage rate and the overall penicillin and macrolide resistance remained stable over time, but while several serotypes were represented in group 1, serotype 19A alone was clearly dominant in group 2.
authors.affiliation: Institute of Medical Microbiology,Semmelweis University,Budapest,Hungary.
authors.forename: A
authors.identifier: 0000-0002-5204-9450
authors.initials: A
authors.lastname: Tóthpál
authors.affiliation: Institute of Medical Microbiology,Semmelweis University,Budapest,Hungary.
authors.forename: K
authors.initials: K
authors.lastname: Laub
authors.affiliation: Institute of Medical Microbiology,Semmelweis University,Budapest,Hungary.
authors.forename: S
authors.initials: S
authors.lastname: Kardos
authors.affiliation: Pneumococcal Reference Laboratory,National Center for Epidemiology,Budapest,Hungary.
authors.forename: T
authors.initials: T
authors.lastname: Tirczka
authors.affiliation: CellCall Ltd,Budapest,Hungary.
authors.forename: A
authors.initials: A
authors.lastname: Kocsis
authors.affiliation: German National Reference Center for Streptococci; Department of Medical Microbiology,University Hospital RWTH Aachen,Aachen,Germany.
authors.forename: M
authors.initials: M
authors.lastname: VAN DER Linden
authors.affiliation: Institute of Medical Microbiology,Semmelweis University,Budapest,Hungary.
authors.forename: O
authors.identifier: 0000-0001-7094-2288
authors.initials: O
authors.lastname: Dobay
mesh_terms: D002353:Carrier State / Q000453:epidemiology / Q000382:microbiology / Q000517:prevention & control; D002648:Child; D002675:Child, Preschool; D005260:Female; D000069443:Heptavalent Pneumococcal Conjugate Vaccine / Q000008:administration & dosage*; D006801:Humans; D006814:Hungary / Q000453:epidemiology; D008297:Male; D011008:Pneumococcal Infections / Q000453:epidemiology* / Q000382:microbiology / Q000517:prevention & control*; D065288:Serogroup; D013296:Streptococcus pneumoniae / Q000145:classification / Q000235:genetics / Q000276:immunology*; D018074:Vaccines, Conjugate / Q000008:administration & dosage
chemical_list: D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D018074:Vaccines, Conjugate
keywords: Pneumococcus; resistance; serotypes; vaccination