云南省2004年流感流行情况分析

目的了解2004年云南省流感流行情况及病毒的变异情况。方法定期采集流感样病人标本以及从暴发疫情中采集标本,利用MDCK细胞从标本中分离病毒,对分离病毒利用血清学方法进行抗原性分析;对病毒的HA1基因进行序列测定,用DNAstat软件进行基因种系发生树分析病毒的遗传变异情况。结果2004年云南省共分离到甲3亚型流感病毒50株,乙型流感病毒56株,没有分离到甲1亚型流感病毒。62%的甲3亚型流感病毒与A/福建/411/2002(H3N2)的血凝效价有4倍或以上差别;2004年4月份以后分离的甲3亚型流感病毒HA1区氨基酸序列上与A/福建/411/2002(H3N2)相比第145位K>N,159位Y>F,189位S>N,226位V>I发生氨基酸替换。5.8%的Yamagata系毒株与B/上海/361/2002血凝效价有4倍或以上的差别,HA1区氨基酸序列与B/上海/361/2002比较,第36、40、129、131、179、232、255位发生了氨基酸替换。10.8%的Victoria系毒株与B/浙江/2/2002有4倍或以上的差别。与B/浙江/2/2001比较第121,126,197位发生了替换。结论2004年云南省流行甲3亚型流感毒株和乙型流感毒株,并且它们的抗原性和基因特性发生了变异。

Analysis on the Prevalence of Influenza in Yunnan Province in 2004

Objective To study the antigenic and genetic characteristics of influenza virus circulated in Yunnan province in 2004.(Methods )Specimen was collected from ILI patients and patients during influenza outbreak, Virus was isolated by MDCK cell isolation method.HI test was used to test the antigenic characteristics of viruses.HA1 of selected virus isolates was sequenced by using automatic sequencer. The sequence data was analysed by DNAstar software.(Results) Totally 111 influenza virus strains were isolated in 2004,in which 50 isolates were H3 virus and 56 isolates were B virus, no H1 virus was isolated in 2004. 62% H3 virus showed 4 folds HI titer as compared with A/Fujian/411/2002(H3N2), and amino acid data showed that four important mutant positions appeared , they were 159 Y>F,189 S>N,145 K>N,226 V>I respectively. 5.8% Yamaga lineage virus showed 4 folds HI titer as compared with B/Shanghai/361/2002, and amino acid data showed that 36,40,129,131,179,232,255 amino acids mutated. 10.8% Victoria lineage virus showed 4 folds HI titer as compared with B/zhejiang/2/2001, and amino acid data showed that 121,126,197 amino acids mutated.Conclusion H3 and B virus were circulated in Yunnan province in 2004, and the antigenic and genetic characteristics have been changed during 2004.