淄博市甲型H1N1流感感染状况的调查

目的了解淄博市不同人群甲型H1N1流感实际感染水平和动态变化趋势,为应对流感大流行,完善防控措施提供可靠依据。方法 2010年1月～9月期间,采取多阶段随机抽样方法抽取4500名调查对象,进行问卷调查,并采集血清利用血凝抑制方法检测甲型H1N1流感抗体水平。结果该市甲型H1N1流感病毒抗体阳性率为25.60%,自然感染率为21.09%,显性感染和隐性感染比例为1.97︰1;抗体阳性率以16～24和6～15岁年龄组最高,60岁以上年龄组最低;教师和学生阳性率最高,医务人员阳性率相对较低;第1次调查抗体阳性率最高,第3次调查最低,接种甲型H1N1流感疫苗半年后抗体阳性率为11.36%。结论甲型H1N1流感大流行期间,该市实际感染人数远远超过确诊病例数,学龄人群和年轻人是最大的感染群体,人群中存在无症状感染者,自然感染或接种疫苗后抗体水平随时间推移逐步下降。

Investigation of influenza A(H1N1)virus infection in Zibo City

OBJECTIVE To explore the status of influenza A(H1N1)infection and dynamic trends of different people in Zibo,and to set up scientific bases for prevention and control for an influenza pandemic.METHODS 4 500 subjects were chosen by multi-stage stratified random sampling from January to September,2010.They were investigated by an uniform questionnaire and their blood samples were tested influenza A(H1N1)antibody by serum agglutination test.RESULTS The positive rate of antibody in Zibo was 25.60%,the natural infection rate was 21.09%,ratio of apparent infection and silent infection was 1.97︰1;the highest positive rates of antibody were in the 16 to 24 and 6 to 15 age groups,the lowest in the age group that more than sixty;the positive rate of antibody in teachers and students was the highest,in medical staff relatively was the lowest;positive rate of antibody in the first investigation was highest,the third was lowest,that of vaccine infection of influenza A(H1N1)after half past year was 11.36%.CONCLUSION Influenza A(H1N1)spread widely in Zibo,students and young people are the highest infection groups,asymptomatic cases exist in people,antibody level decrease with the passage of time after natural infection or vaccine inoculation.