title: Impact of the pneumococcal conjugate vaccine on serotype distribution and susceptibility trends of pediatric non-invasive Streptococcus pneumoniae isolates in Tokai, Japan over a 5-year period.
abstract: Introduction of the 7-valent pneumococcal conjugate vaccine (PCV7) in February 2010 markedly reduced the burden of invasive pneumococcal disease (IPD) and changed serotype distribution in Japan. We investigated the serotype distribution and susceptibility trends of non-invasive Streptococcus pneumoniae isolates collected from pediatric patients. A total of 564 pneumococcal isolates were collected over a 5-year period between 2008 and 2012. The coverage of PCV7 significantly decreased throughout the study period, from 49.3% in period 1 (between June 2008 and April 2009) to 23.4% in period 4 (between October 2011 and March 2012). This change was mainly due to a large decrease in the frequency of 19F (from 20.6% to 9.9%) and 6B (from 10.3% to 2.7%) and an increase in serotype 3 (from 5.1% to 13.5%) and serogroup 15 (from 4.4% to 9.0%). According to serotype replacement, the susceptible ratios of S. pneumoniae to β-lactams increased slightly while macrolide resistance remained high. The high frequency of macrolide-resistant pneumococcal isolates may continue because of the high frequency of erm(B) in replace serotypes such as serotype 3 and serogroup 15. The continuous surveillance study is essential following the introduction of a second generation 13-valent pneumococcal conjugate vaccine (PCV13).
authors.affiliation: Department of Clinical Infectious Diseases, Aichi Medical University Graduate School of Medicine, 1-1 Yazakokarimata, Nagakute, Aichi 480-1195, Japan; Research Laboratories, Toyama Chemical Co., Ltd., 2-4-1 Shimookui, Toyama 930-8508, Japan. Electronic address: hayato_okade@toyama-chemical.co.jp.
authors.forename: Hayato
authors.initials: H
authors.lastname: Okade
authors.affiliation: Research Laboratories, Toyama Chemical Co., Ltd., 2-4-1 Shimookui, Toyama 930-8508, Japan.
authors.forename: Tori
authors.initials: T
authors.lastname: Funatsu
authors.affiliation: Research Laboratories, Toyama Chemical Co., Ltd., 2-4-1 Shimookui, Toyama 930-8508, Japan.
authors.forename: Maki
authors.initials: M
authors.lastname: Eto
authors.affiliation: Department of Clinical Infectious Diseases, Aichi Medical University Graduate School of Medicine, 1-1 Yazakokarimata, Nagakute, Aichi 480-1195, Japan; Research Laboratories, Toyama Chemical Co., Ltd., 2-4-1 Shimookui, Toyama 930-8508, Japan.
authors.forename: Yuri
authors.initials: Y
authors.lastname: Furuya
authors.affiliation: Research Laboratories, Toyama Chemical Co., Ltd., 2-4-1 Shimookui, Toyama 930-8508, Japan.
authors.forename: Shingo
authors.initials: S
authors.lastname: Mizunaga
authors.affiliation: Research Laboratories, Toyama Chemical Co., Ltd., 2-4-1 Shimookui, Toyama 930-8508, Japan.
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Nomura
authors.affiliation: Development Division, Toyama Chemical Co., Ltd., 3-2-5 Nishishinjyuku, Shinjyuku-ku, Tokyo 160-0023, Japan.
authors.forename: Junichi
authors.initials: J
authors.lastname: Mitsuyama
authors.affiliation: Department of Clinical Infectious Diseases, Aichi Medical University Hospital, 1-1 Yazakokarimata, Nagakute, Aichi 480-1195, Japan.
authors.forename: Yuka
authors.initials: Y
authors.lastname: Yamagishi
authors.affiliation: Department of Clinical Infectious Diseases, Aichi Medical University Graduate School of Medicine, 1-1 Yazakokarimata, Nagakute, Aichi 480-1195, Japan; Department of Clinical Infectious Diseases, Aichi Medical University Hospital, 1-1 Yazakokarimata, Nagakute, Aichi 480-1195, Japan.
authors.forename: Hiroshige
authors.initials: H
authors.lastname: Mikamo
mesh_terms: D000293:Adolescent; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D024881:Drug Resistance, Bacterial; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007564:Japan; D018942:Macrolides / Q000627:therapeutic use; D011008:Pneumococcal Infections / Q000188:drug therapy / Q000276:immunology* / Q000517:prevention & control*; D022242:Pneumococcal Vaccines / Q000008:administration & dosage* / Q000276:immunology; D065288:Serogroup; D012703:Serotyping / Q000379:methods; D013296:Streptococcus pneumoniae / Q000145:classification* / Q000187:drug effects* / Q000276:immunology / Q000302:isolation & purification; D018074:Vaccines, Conjugate / Q000008:administration & dosage / Q000276:immunology
chemical_list: D000900:Anti-Bacterial Agents; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D018942:Macrolides; D022242:Pneumococcal Vaccines; D018074:Vaccines, Conjugate
keywords: Non-invasive pneumococcal disease; PCV7; Streptococcus pneumoniae