Analysis of Streptococcus pneumoniae and Haemophilus influenzae isolated from middle ear fluid before and after the introduction of government subsidies for pneumococcal and H. influenzae type b vaccines in Japan

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• 作者：Tadashi Hoshino^a ; ^{t.hshn12@pref.chiba.lg.jp} ; Noriko Takeuchi^b ; Chie Fukasawa^a ; Shoko Hirose^a ; Hideyuki Okui^a ; Hiroko Sato^c ; Mari Sato^c ; Yukiko Arimoto^d ; Atsuko Nakano^d ; Naruhiko Ishiwada^b
• 关键词：Streptococcus pneumoniae ; Haemophilus influenzae ; Middle ear fluid ; Serotypes ; Japan
• 刊名：Journal of Infection and Chemotherapy
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：23
• 期：2
• 页码：85-89
• 全文大小：413 K
• 卷排序：23

文摘

This study aimed to identify trends in frequency, serotype, and antimicrobial susceptibility of Streptococcus pneumoniae and Haemophilus influenzae isolated from middle ear fluid specimens of children aged≤15 years (mean, 2 years), before and after the introduction of the 7-valent pneumococcal conjugate vaccine (PCV7) and the H. influenzae type b vaccine, at a pediatric facility in Japan.Sixty-six S. pneumoniae and 88 H. influenzae strains were isolated from 820 middle ear fluid samples. Serotyping and antimicrobial susceptibility testing were performed. The study time-frame was divided into period 1 (2007–2010) and period 2 (2011–2014), according to the availability of vaccine public funding.The S. pneumoniae detection rate decreased from 9.6% in period 1–6.1% in period 2 (p = 0.042). PCV7 serotypes decreased from 56.8% to 9.1% (p = 0.0002). No significant change was observed for the 13-valent pneumococcal conjugate vaccine (PCV13) serotypes: 72.7% in period 1 and 59.1% in period 2. Penicillin-resistant strains (penicillin G-MIC ≥2 μg/mL) decreased from 25% to 4.5% (p = 0.038). Detection rates for H. influenzae did not change significantly: 10.3% in period 1 and 11.3% in period 2. Serotypes were mostly non-typeable: 97.9% in period 1 and 90.2% in period 2, and only one serotype b strain was isolated in each period. The frequency of ampicillin-resistant strains (MIC ≥4 μg/mL) did not change.These results show a preventative effect of PCV7 on otitis media due to S. pneumoniae. PCV7 was replaced with PCV13 in 2013 in Japan; therefore, a further decrease in pneumococcal otitis media is anticipated in the future.