免疫接种人群在麻疹疫情发生时体内特异性抗体水平的变化规律

Change rule of specific antibody level in immunization population in measles outbreak

目的分析计划免疫人群在麻疹疫情发生时体内抗体水平,探讨麻疹疫苗在麻疹高发季补种的必要性。方法采集涉及疫情的152例患者/密接者的血清标本,运用酶联免疫法(ELISA)检测样本的血清中麻疹特异性IgM、IgG抗体,根据抗体分布水平情况,分析计划免疫人群在麻疹疫情发生时体内抗体水平变化的规律。结果 (1)在152例样本中,25例为IgM抗体阳性,阳性率16.45%,且IgM阳性率随监测时间推移而出现明显下降。血清IgG抗体检测147例阳性,阳性率为97.25%。(2)按照IgG水平进行分层分析,结果 IgM阳性例数随IgG水平的增高而增多,人群分布集中在IgG低水平组和高水平组,提示在没有受到病原体刺激时人体内麻疹IgG处于低水平,受到刺激时表现为IgM和/或IgG水平增高,表现出个体差异。(3)根据IgM结果将人群分为IgM阳性组和IgM阴性组,采用秩和检验比较两组的IgG抗体水平,两组IgG水平差异有统计学意义(P=0.012,P<0.05)。结论麻疹高发季节,及时对医护人员进行免疫强化接种,使其免疫功能得到强化十分必要的。

Objective To analyze the antibody levels of immunization crowd in measles outbreaks, and discuss the necessity of second measles vaccination in high incidence period of measles. Methods Serum specimens were collected from 152 patients / close contacts in the measles outbreak to detect the measles specific IgM and IgG antibodies using enzyme - linked immunosor- bent assay （ELISA）. Then the change rule of specific antibodies in planed immunization population in measles outbreak was an- alyzed according to the antibody distribution situation. Results In the 152 serum samples, 25 cases were IgM antibody positive （16.45%）, 147 cases were IgG antibody positive （97.25%）, and IgM positive rate significantly declined over monitoring time. Stratification analysis of IgG levels showed IgM positive cases were positively with IgG level, mainly in low - IgG level group and high -IgG level group, indicating measles IgG was at a low level in human body without pathogen stimulation, but IgG and/or IgM levels increased after pathogen stimulation, exhibiting individual differences. According to IgM detection re- sults, rank sum test showed the IgG level had significant difference between IgM positive group and IgM negative group （P = 0.012, P 〈 0.05）. Conclusion Therefore, immunization should be timely strengthened in medical staff in measles epidemic