2010—2011年北京市四次甲型H1N1流感病毒抗体水平动态变化分析

Four surveys on the serological epidemiology of pandemic （H1N1） 2009 in Beijing during 2010 -2011

目的了解和掌握北京市不同人群对甲型H1N1流感的免疫水平。方法在2010年1月-2011年4月期间，四次采用多阶段分层随机抽样方法，在北京市六个区分年龄组随机选取调查对象进行问卷调查，并采集血清标本进行甲型H1N1流感病毒抗体检测。结果共选取调查对象18264名。5456名（28．9％）调查对象体内甲型H1N1流感病毒抗体为阳性。总体人群甲型H1N1流感抗体滴度主要集中在1：40—1：320，其中抗体滴度为1：40的人数占总体阳性数的比例达41．61％。同一时间点不同年龄组问、同一年龄组的不同时间点间，血凝抑制（HI）保护性抗体阳性率、抗体GMT水平比较的差异均有统计学意义（P〈0．05）。HI保护性抗体阳性率和抗体GMT存在地区差异（P〈0．05）。不同职业人群间HI保护性抗体阳性率和抗体GMT水平比较差异存在统计学意义（P〈0．05）。结论目前北京市人群中已有超过25％的人群具有甲型H1N1流感病毒保护性抗体，甲型H1N1流感疫苗接种与HI抗体阳性存在相关性，普通人群中已经建立了一定的免疫屏障，但抗体滴度水平较低。

Objective To investigate the immunological level against pandemic （H1N1） 2009 in Beijing. Methods Subjects were randomly selected from natural populations at four different periods in Beijing from Jan 2010 to Apr 2011, and samples were tested by hemagglutination-inhibition （HI） assays. Positive rate of protective antibody against 2009 H1N1 and Geometric mean titers （GMTs） were estimated. Results 18264 subjects participated in this survey, and 5456 were positive of HI antibody against pandemic virus. The antibody level in the population is low; the antibody titer of 41.61% positive cases was 1：40.. Significant difference on rates of protective antibody and GMTs among various age groups were observed in the same period （ P 〈 0.05 ）, and similar results were observed among different periods in the same age group （ P 〈 0.05 ）. There were significant differences on rates of protective antibody and GMTs among different areas and different occupational groups. Conclusion Above 25% of the population in Beijing has protective antibody against pandemic （H1N1） 2009 virus, and the immunological barrier has been constituted to some extent. However, the antibody level is low.