2006～2010年湖北省流行性脑脊髓膜炎病原学和血清学监测分析

目的分析湖北省2006～2010年流行性脑脊髓膜炎(流脑)病原学和血清学监测结果,掌握湖北省流脑的变迁规律。方法对2006～2010年分离的脑膜炎奈瑟菌(Nm)菌株进行生化鉴定、血清学分型和药物敏感性检测,并采用多位点序列分型(MLST)和脉冲场凝胶电泳(PFGE)方法进行分子分型;对所有的脑脊液和血液标本进行Nm种属特异性荧光PCR检测;对健康人群血清,运用血清杀菌试验(SBA)进行C群杀菌力抗体水平测定。结果 2007年湖北省Nm以B群为主,2008～2010年以来C群为优势菌群;对青霉素等6种抗生素均敏感,但对环丙沙星、米诺环素、萘啶酸、复方新诺明4种抗生素出现多重耐药;分子分型结果显示,湖北省B群Nm菌株具有高度的遗传多样性,未发现明显优势的克隆群,C群优势病原株为ST-4821型。RT-PCR检测(988份脑脊液)确诊29例流脑病例,其中C群22例,A群2例、B群5例。C群杀菌力总保护率(抗体滴度≥1︰8)为38.10%。结论湖北省流脑菌株发生了从B群散发到C群流行的变迁,人群对C群Nm的免疫力不足。

Analysis of the results on surveillance of epidemic cerebrospinal meningitis in Hubei,2006-2010

Objective To ascertain the changing epidemiological features of epidemic cerebrospinal meningitis(ECM) by analyzing results of etiological and serological surveillance of ECM.Methods Biochemical testing,serotyping,and antimicrobial susceptibility testing were performed on Neisseria meningitides strains isolated between 2006 and 2010.Multilocus sequence typing(MLST) and pulsed-field gel electrophoresis(PFGE) were used to subtype the strains.Real-time PCR was used to detect N.meningitidis-specific genes from cerebrospinal fluid specimens.Bactericidal antibodies against serogroup C N.meningitidis in healthy serum samples were measured with serum bactericidal assays(SBA).Results Serogroup B N.meningitidis predominated in 2007 and serogroup C predominated from 2008 to 2010.All of the tested strains were susceptible to six antibiotics including penicillin.Multiple drug resistance(Ciprofloxacin,Minocycline,Nalidixic acid & Cotrimoxazole) was observed in some isolates.Molecular typing indicated that N.meningitidis serogroup B strains were genetically diverse and no clearly predominant clonal group was found.The main subtype of serogroup C strains was ST-4821.Based on culturing and real-time PCR,29 of 988 suspected cases were diagnosed as N.meningitidis infection(serogroup C,22;serogroup A,2;serogroup B,5).Targeted protection(bactericidal antibody titer ≥ 1:8) against serogroup C strains was 38.1% among the population studied.Conclusion N.meningitidis is transitioning from serogroup B to C in Hubei Province.The population has inadequate immunity to N.meningitidis serogroup C.