2013—2015年大理州人群麻疹抗体水平监测

Population based measles antibody level surveillance in Dali prefecture,Yunnan,2013-2015

目的了解大理州人群麻疹抗体水平,为消除麻疹提供科学决策依据。方法采用分层整群抽样,于2013—2015年采集14 119人血清,应用ELISA法测定血清中麻疹Ig G抗体。结果麻疹抗体阳性率为94.51%,保护率为61.87%,抗体几何平均浓度(GMC)为1 143.78 mIU/ml,不同地区GMC差异有统计学意义(P=0.001);各年龄组的GMC差异有统计学意义(P=0.001),以18~23月龄组最高,2~3岁组次之,含麻疹成分疫苗(MCV)接种率与抗体阳性率、保护率均呈正相关(P<0.05);接种MCV 2剂次的人群,GMC可达到1 242.31 mIU/ml,与接种1剂次相比,差异有统计学意义(P=0.001)。结论大理州基本形成预防麻疹的免疫屏障,发生暴发或流行的可能性较小,但麻疹抗体保护率偏低,且存在一定的地区差异;加强麻疹抗体水平监测,及时发现免疫薄弱地区和空白人群是消除麻疹的关键。

Objective To understand the level of measles antibody in population in Dali prefecture of Yunnan province and provide scientific evidence for the elimination of measles. Methods A total of 14 119 persons selected through stratified cluster sampling were surveyed, their blood samples were collected for the detection of measles IgG with enzyme linked immunosorbent assay （ELISA）. Results The positive rate of measles antibody and the protective rate were 94. 51% and 61.87%. The geometric mean concentration （GMC） was 1 143.78 mlU/ml, and the difference in GMC among different counties were significant （P = 0. 001 ）. The differences in GMC among difference age groups were also significant （P=0.001） . The highest GMC were observed in age group 18 -23 months, followed by age group 2 -3 years, the immunization coverage rate of measles containing vaccine （MCV） was positively correlated with antibody positive rate and protection rate （ P 〈 0. 05 ）. In population with 2 doses of MCV vaccination, GMC could reach 1 242. 31 mlU/ml, compared with those receiving 1 dose vaccination, the difference was significant （ P = 0. 001 ）. Conclusion The herd immunity has been basically formed, so the possibility of measles outbreak or epidemic was lower, but the protection rate was low and varied with county. It is essential to eliminate measles by strengthening the surveillance for measles antibody level in healthy population and finding the weak areas and blank population in immunization.