title: Increase in the nasopharyngeal carriage of non-vaccine serogroup 15 Streptococcus pneumoniae after introduction of children pneumococcal conjugate vaccination in Hong Kong.
abstract: This study assessed pneumococcal carriage in the early periods after routine use of 13-valent pneumococcal conjugate vaccine (PCV13) in Hong Kong. Nasopharyngeal swabs were obtained from 1110 children (<5 years) admitted with acute illness during September 2010-August 2013. Pneumococcal carriage rate was 13.5% in unvaccinated children, 14.1% in children who had ≥1 PCV dose and 15.3% in children who had ≥3 PCV doses. Nonv-PCV13 serotypes comprised 56.4% of all isolates. The most common serogroup/types were 15 (15A, 5.1%; 15B, 10.3%; 15C, 9.6%; 15F, 0.6%), 19F (17.9%), 6A (7.1%) and 6C (7.1%). Carriage of serogroup 15 was more common among vaccinated children (4.1% versus 0.6%, P = 0.033). Molecular typing revealed that expansion of several clones (clonal complex, CC63, CC199, CC1262, CC3397) was responsible for the increase in serogroup 15. Almost all CC63 and CC3397 isolates were nonsusceptible to both penicillin and erythromycin. The finding highlights the emergence of serogroup 15 following PCV13 use.
authors.affiliation: Department of Microbiology, The University of Hong Kong, Pokfulam Road, Hong Kong Special Administrative Region, China. Electronic address: plho@hkucc.hku.hk.
authors.forename: Pak-Leung
authors.initials: PL
authors.lastname: Ho
authors.affiliation: Department of Paediatrics and Adolescent Medicine, The University of Hong Kong, Pokfulam Road, Hong Kong Special Administrative Region, China.
authors.forename: Susan S
authors.initials: SS
authors.lastname: Chiu
authors.affiliation: Department of Microbiology, The University of Hong Kong, Pokfulam Road, Hong Kong Special Administrative Region, China.
authors.forename: Pierra Y
authors.initials: PY
authors.lastname: Law
authors.affiliation: Department of Paediatrics and Adolescent Medicine, The University of Hong Kong, Pokfulam Road, Hong Kong Special Administrative Region, China.
authors.forename: Eunice L
authors.initials: EL
authors.lastname: Chan
authors.affiliation: Department of Microbiology, The University of Hong Kong, Pokfulam Road, Hong Kong Special Administrative Region, China.
authors.forename: Eileen L
authors.initials: EL
authors.lastname: Lai
authors.affiliation: Department of Microbiology, The University of Hong Kong, Pokfulam Road, Hong Kong Special Administrative Region, China.
authors.forename: Kin-Hung
authors.initials: KH
authors.lastname: Chow
mesh_terms: D002353:Carrier State / Q000453:epidemiology* / Q000382:microbiology / Q000517:prevention & control*; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D005838:Genotype; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D007223:Infant; D008297:Male; D017720:Molecular Epidemiology; D058889:Molecular Typing; D009305:Nasopharynx / Q000382:microbiology; D011008:Pneumococcal Infections / Q000453:epidemiology* / Q000382:microbiology / Q000517:prevention & control*; D022242:Pneumococcal Vaccines / Q000008:administration & dosage*; D065288:Serogroup; D013296:Streptococcus pneumoniae / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D014611:Vaccination / Q000706:statistics & numerical data
chemical_list: C538862:13-valent pneumococcal vaccine; D022242:Pneumococcal Vaccines
keywords: Drug resistance; Prevalence; Serotype; Streptococcus pneumoniae