福建省甲型H1N1流感血清流行病学调查

目的了解甲型H1N1流感(甲流)大流行前后福建省人群甲流血清流行病学特征。方法采集2008年甲流流行前血清标本800例和2010年1-4月甲流流行后不同地区血清标本1250例，以血凝抑制试验方法(HI)检测血清HI抗体。结果甲流流行后人群HI抗体≥1∶10和≥1∶40的阳性率分别从流行前的6.5%和0.63%上升为52.72%和36.24%（P<0.01），HI抗体几何平均滴度（GMT）从5.39上升为18.26（P<0.01）。流行后各年龄组人群HI抗体都显著高于流行前，以6-17岁为最高，HI抗体≥1∶10和≥1∶40的阳性率及GMT分别达到74.02%、57.22%和38.15，显著高于其他年龄组（P<0.01）。男女性之间HI抗体差异无统计学意义（P>0.05）。福州市人群HI抗体水平显著高于其他设区市。在接种甲流疫苗的人群中，HI抗体≥1∶10和≥1∶40的阳性率分别为83.84%和64.62%，GMT为46.62,分别显著高于未接种疫苗人群的32.72%, 18%和7.48（P<0.01）。结论甲流流行后福建省人群HI抗体显著提高，已形成一定的免疫屏障，但应加强重点年龄组人群疫苗接种，防控甲流流行出现反弹。

Serologic survey on 2009 pandemic influenza A (H1N1) in Fujian Province

This study was aimed at investigating the serologic responses to 2009 pandemic influenza A（H1N1） virus in Fujian Province before and after the H1N1 pandemic.Before the occurrence of the H1N1 pandemic,800 serum specimen were obtained in 2008,whereas 1250 specimen were taken from different districts from January to April,after the pandemic in 2010.Antibody titres were measured by using haemagglutination inhibition（HI） assay.The results showed that the positive rates of HI≥10 and HI≥40 after the pandemic were increased to 52.72% and 36.24% from 6.5% and 0.63% respectively before the pandemic（P0.01）,and geometric mean titer（GMT） was increased to 18.26 from 5.39（P0.01）.The levels of HI antibody after the pandemic was significantly higher than those before the pandemic in each age group（P0.01）.The positive rates of HI≥10,HI≥40 and GMT in the subjects of 6-17 years old were 74.02%,57.22% and 38.15 respectively,which were the highest among various age groups.There were no significant difference in the levels of HI antibody between males and females（P0.05）.The levels of HI antibody in the subjects from Fuzhou were the highest among 9 prefectures.The positive of HI≥10,HI≥40 and GMT in the subjects received H1N1 vaccination were 83.84%,64.62% and 46.62 respectively,which were significantly higher than those in the subjects without vaccination.Our data revealed that the levels of HI antibody had been significantly increased and the development of immunological barrier to 2009 pandemic influenza A（H1N1） virus had been formed,to some extent after the pandemic in Fujian Province.However,mass vaccination campaigns targeting the key age groups should be strengthened to prevent the rebound of pandemic.