Djibo S, Nicolas P, Alonso J-M, Djibo A, Couret D, Riou J-Y, Chippaux J-P
CERMES, Niamey, Niger.
Trop Med Int Health. 2003 Dec;8(12):1118-23. doi: 10.1046/j.1360-2276.2003.01126.x.
In the African meningitis belt, the recurrent meningococcal meningitis epidemics are generally caused by serogroup A. In the past 20 years, other serogroups have been detected, such as X or W135, which have caused sporadic cases or clusters. We report here 134 meningitis cases caused by Neisseria meningitidis serogroup X that occurred in Niamey between 1995 and 2000. They represented 3.91% of the meningococcal isolates from all CSF samples, whereas 94.4% were of serogroup A. Meningococcal meningitis cases were detected using the framework of the routine surveillance system for reportable diseases organized by the Ministry of Public Health of Niger. The strains were isolated and determined by the reference laboratory for meningitis in Niamey (CERMES) and further typed at the WHO collaborating center of the Pharo in Marseille and at the National Reference Center for the Meningococci at the Institut Pasteur. Reference laboratories in Marseille and Paris characterized 47 isolates having the antigenic formula (serogroup:serotype:sero-subtype) X:NT:P1.5. Meningitis cases due to meningococcus serogroup X did not present any clinical or epidemiological differences to those due to serogroup A. The seasonal incidence was classical; 93.3% of the cases were recorded during the dry season. The mean age of patients was 9.2 years (+/- 6 years). The sex ratio M/F was 1.3. Case fatality rate was 11.9% without any difference related to age or sex. The increasing incidence of the serogroup X was not related to the decrease of serogroup A, but seemed cyclic, and evolved independently of the recurrence of both serogroups A and C.
在非洲脑膜炎带，复发性脑膜炎球菌性脑膜炎流行通常由A群引起。在过去20年中，已检测到其他血清群，如X群或W135群，它们引起了散发病例或聚集性病例。我们在此报告1995年至2000年期间在尼亚美发生的134例由脑膜炎奈瑟菌X群引起的脑膜炎病例。它们占所有脑脊液样本中脑膜炎球菌分离株的3.91%，而94.4%为A群。脑膜炎球菌性脑膜炎病例是在尼日尔公共卫生部组织的法定传染病常规监测系统框架内检测到的。菌株由尼亚美的脑膜炎参考实验室（CERMES）分离和鉴定，并在马赛法罗的世界卫生组织合作中心以及巴斯德研究所的脑膜炎球菌国家参考中心进一步分型。马赛和巴黎的参考实验室对47株具有抗原公式（血清群：血清型：血清亚型）X:NT:P1.5的分离株进行了鉴定。X群脑膜炎球菌引起的脑膜炎病例与A群引起的病例在临床或流行病学上没有任何差异。季节性发病率呈典型特征；93.3%的病例在旱季记录。患者的平均年龄为9.2岁（±6岁）。男女比例为1.3。病死率为11.9%，与年龄或性别无关。X群发病率的增加与A群的减少无关，而是似乎呈周期性，并且独立于A群和C群的复发而演变。
