广西壮族自治区儿童A群和C群流行性脑脊髓膜炎抗体水平调查

Investigation on antibody levels against groups A and C meningococcal meningitis in children in Guangxi Zhuang Autonomous Region

目的了解儿童体内流行性脑脊髓膜炎(简称流脑)自然抗体水平。方法采用血清体外杀菌试验(serum bactericidal antibody,SBA)检测广西壮族自治区3 822份未接种流脑疫苗0~6岁儿童血清样本的A群和C群流脑抗体滴度,计算抗体几何平均滴度(GMT)和易感人群比例,并按不同组别(0~2月龄、3~5月龄、6~23月龄和2~6岁)进行统计分析。结果 6岁以下不同年龄组受试者的A群和C群流脑血清杀菌抗体GMT均小于1∶2;绝大多数受试者的A群和C群流脑血清杀菌抗体滴度低于1∶8,为流脑易感人群。不同年龄组之间A群流脑杀菌抗体滴度≥1∶8人群比例差异程度不同。而在2~6岁人群组中C群流脑杀菌抗体滴度≥1∶8的受试者比例显著高于其他年龄组(P<0.05)。结论 6岁以下儿童体内整体A群和C群流脑血清杀菌抗体水平低,为流脑易感人群,应接受流脑疫苗接种,并持续观察人群中流脑杀菌抗体动态变化。

Objective To investigate the natural antibody level against meningococcal meningitis in children. Methods A total of 3 822 serum samples were collected from children unvaccinated with meningococcal meningitis vaccine in Guangxi Zhuang Autonomous Region,China,at ages of 0 ~ 6 years,and determined for antibody levels against groups A and C meningococcal meningitis by serum bactericidal antibody（SBA） assay,based on which the geometric mean titer（GMT） of antibody and proportion of susceptible population were calculated and analyzed statistically according to the ages（0 ~ 2 months,3 ~ 5 months,6 ~ 23 months and 2 ~ 6 years）. Results All the GMTs of antibodies against groups A and C meningococcal meningitis in sera of children in various age groups were less than 1 ∶ 2. The serum bactericidal antibody titers of most of the subjects were less than 1 ∶ 8,suggesting that the children were susceptible to meningococcal meningitis. There were differences at various levels in the proportions of subjects with serum antibody titers against group A meningococcal meningitis of not less than 1 ∶ 8 in various age groups. However,the proportion of subjects with serum bactericidal antibody titers against group C meningococcal meningitis of not less than 1 ∶ 8 in the children at ages of 2 ~ 6 years was significantly lower than those in other age groups（P 〈0. 05）. Conclusion In general,the serum bactericidal antibody levels against groups A and C meningococcal meningitis in children at ages of less than 6 years were low,indicating that the children were susceptible to meningococcal meningitis. These populations should be inoculated with meningococcal meningitis vaccine and observed for the dynamic changes of bactericidal antibody against meningococcal meningitis.