Otsuka Taketo, Okazaki Minoru
Department of Pediatrics, Sado General Hospital.
Kansenshogaku Zasshi. 2012 Mar;86(2):103-8. doi: 10.11150/kansenshogakuzasshi.86.103.
Haemophilus influenzae type b (Hib) remains the leading cause of invasive bacterial infection in Japanese children. More than 110 countries that have included Hib conjugate vaccines in their routine vaccination programs have seen dramatical decrease in the incidence of Hib infections. In Japan, the vaccine has been introduced for voluntary immunization since December 2008 and has been provided free of charge only since January 2011. This review reports the prevalence of Hib and its clones among healthy children and pediatric patients diagnosed with invasive or non-invasive Hib infections in Sado Island, Japan. Of 25 Hib isolates collected in this surveillance, 4 genotypic patterns (ST54-gBLPACR-III, ST54-gBLNAR-I/II, ST190-gBLNAS, and ST95-gBLPACR-I/II) were detected. These STs were double or triple-locus variants of each other. Under the same antimicrobial selective pressure, high prevalence of gBLPACR strain (76.0%) was confirmed in Hib isolates, while gBLPACR prevalence in nontypeable H. influenzae was very low (5.2%). These data suggested that each ST strain may be brought into Sado Island by different routes. We note that surveillance of healthy subjects to identify Hib carriers is important to understand their role in transmission of Hib.
b型流感嗜血杆菌（Hib）仍是日本儿童侵袭性细菌感染的主要原因。超过110个将Hib结合疫苗纳入其常规疫苗接种计划的国家，Hib感染的发病率已大幅下降。在日本，该疫苗自2008年12月起开始用于自愿免疫，自2011年1月起才免费提供。本综述报告了在日本佐渡岛健康儿童以及被诊断为侵袭性或非侵袭性Hib感染的儿科患者中Hib及其克隆株的流行情况。在本次监测收集的25株Hib分离株中，检测到4种基因型模式（ST54 - gBLPACR - III、ST54 - gBLNAR - I/II、ST190 - gBLNAS和ST95 - gBLPACR - I/II）。这些序列型（ST）相互之间为双位点或三位点变异体。在相同的抗菌选择压力下，在Hib分离株中确认了gBLPACR菌株的高流行率（76.0%），而在不可分型流感嗜血杆菌中gBLPACR的流行率非常低（5.2%）。这些数据表明，每种ST菌株可能通过不同途径传入佐渡岛。我们注意到，对健康受试者进行监测以识别Hib携带者对于了解他们在Hib传播中的作用很重要。
