甲型H1N1流行性感冒病毒血凝素蛋白基因进化研究

Objective To determine the evolutionary rate and divergence time of influenza A virus HA gene isolated recently worldwide pandemic and explore the origin and its transmission. Methods A total of 344 HI sequences available in the GenBank (including 248 isolated from human, 84 from swine, 11 from avian, and 1 from ferret) and 7 isolated in Shanghai were collected. The nucleotide substitution rate and time to most recent common ancestor (tMRCA) was calculated using molecular clock theory and Bayesian Skyline Plot (BSP) based on Markov chain Monte Carlo. Then genetic phylogeny was constructed referring to posterior distribution. Results It was found that H1 sequences in the US from human, swine and avian were clustered significantly with swine H1 ones from Asia phylogenetieally (Cluster US). The second cluster (Cluster Eurasian Human) nearly consisted of human H1 sequences isolated in other regions. The third cluster (Cluster Eurasian Animal) consisted of swine and avian H1 sequences from China and Italy respectively. As for all the H1 sequences, the evolutionary rate was of 2.57×10-3substitutions/site per year averagely (95% Highest Posterior Density: 1.96×10-3-3.03×10-3/site per year). The estimated dates for tMRCA of human H1 in Europe and swine H1 in the mainland of China were the earliest, with the corresponding rates of 6.46×10-3/site per year and 0.97×10-3/site per year respectively. The tMRCAs of human and swine H1 sequences from the US were similar, with the rates of 5.86×10-3/site per year and 5.02×10-3/site per year. Conclusion The present flu outbreak was possibly induced by long-term circulation of influenza A virus (H1 N1) in human population and swine herds in America. There was no evidence proving that influenza virus in China involved in the present outbreak.     

甲型流感病毒血凝素基因的进化与分型研究

 目的 分析甲型流感病毒各亚型血凝素基因的系统发育特征,探讨甲型流感病毒血凝素基因的起源与演化规律。 方法 从互联网获取甲型流感16个亚型的基因序列资料,运用DNAStar、Clustal X1.83、MEGA 4及PHYLIP 3.67等生物信息学软件对其进行系统发育关系研究。结果 16个亚型的甲型流感病毒的血凝素基因能够按照各自的血清亚型实现聚类,亚型内各基因的遗传距离在0.10231～0.22516厘摩(centimorgan,cM,SE为0.006～0.011)之间不等,按照系统发育关系,16个血清亚型可以分为5个大的进化簇：亚型H1、H2、H5与H6 构成A簇,H8、H9与H12构成B簇,H11、H13与H16构成C簇,H7、H10与H15构成D簇,H3、H4与H14构成E簇,其中A簇、B簇与C簇可进一步聚类为一个进化群,而D簇与E簇也可以进一步聚类为另一进化群。结论 按血凝素基因的序列信息可将甲型流感病毒分为5个进化簇并进而分为两个进化群。     

上海市人群H1、H3、H5、H9亚型流感病毒抗体血清学监测

为了解上海市人群既往感染流感病毒A/H3N2、A/H1N1的免疫保护以及接触禽类人群中禽流感病毒H5、H9亚型既往感染状况,进行了H1、H3、H5、H9亚型流感病毒抗体的血清学监测.     

2008年上海及周边地区婴幼儿手足口病病原学研究

目的 了解2008年上海及周边地区婴幼儿手足IZl病病原体分布情况及其基因特征.方法 采集2008年5月至6月手足口病流行期间复旦大学附属儿科医院及浙江省德清市住院患儿咽拭标本,部分患儿同时采集脑脊液标本,分别接种于Vem、MRC-5及RD细胞进行病原体分离,RTPCR检测肠道病毒属、柯萨奇病毒A组16型(CoxA16)、肠道病毒71型(EV71),并对扩增产物测序鉴定.结果 100例患儿的107份咽拭和22份脑脊液标本中,共计50例患儿的咽拭标本致细胞病变,经鉴定肠道病毒感染37例,占74.0%,其中EV71为26例,占52.0%(26/50例),CoxAl6为10例,占20.0%(10/50例),其他肠道病毒(CoxB3)1例,占2.O%(1/50例);肠道病毒属外的其他病原体13例,占26.0%,且其中1例患儿的脑脊液标本致Vero细胞病变.所有26例EV71病毒株与2008年中国浙江省及安徽省阜阳市EV71病毒株相似,同属于C基因型;10例CoxA16病毒株均属于C遗传世系.结论 手足口病病原复杂,2008年上海及周边地区婴幼儿手足口病的主要病原体仍是EV71和CoxA16,但尚存在一定比例的其他未知病原体.     

70对母婴麻疹野病毒中和抗体检测结果分析

[目的]了解母婴的麻疹野病毒中和抗体水平及其相关性。[方法]采用中和试验的方法直接检测孕妇及新生儿的麻疹野病毒中和抗体水平并进行相关分析。[结果]孕妇及新生儿的麻疹野病毒中和抗体阳性率分别为91．52％和88．57％,平均几何滴度（GMT）分别为61．32和58．17;配对母婴的麻疹野病毒中和抗体水平呈高度正相关（r=0．899,P〈O．01）。当母体的抗体滴度≥l：16时,其子代抗体的阳性率可达100．00％。[结论]母婴的麻疹抗体水平密切相关,提高母源麻疹抗体水平应是控制低月龄小儿麻疹发病的重要措施之一。     

多重PCR和单重PCR在流感病毒快速检测中的比较与应用

[目的]建立快速检测H1、H3亚型和乙型流感病毒的多重PCR技术,并与单熏PCR技术进行比较与应用. [方法]根据H1、H3亚型和乙型流感病毒设计引物,进行多重PCR扩增及电泳检测,在快速检测中与单重PCR进行比较与应用. [结果]该多重PCR技术能在4 h内同时检测3种型别的流感病毒,时间短于单重PCR技术,特异性和灵敏度相似.[结论]本研究建立多重PCR技术可以准确检测流感病毒,不仅灵敏度高、特异性好,而且可以得到快速的检测结果.     

上海地区人群甲型H1N1流感抗体水平监测分析

Objective To understand levels of antibody to swine-origin influenza A(H1 N1) virus (A/ H1N1) among different age groups in Shanghai, and to compare the levels between antibodies to A/H1N1 and to 2008-2009 seasonal influenza vaccine virus A/Brisbane/59/2007(H1N1). Methods The anti-A/HlN1 antibody levels were determined among 5 age groups (0-5 months, 6 months-4 years, 5-24 years, 25-59 years, and ≥60 years) with routine micro-hemagglutination inhibition test. The positive rates of the antibodies among different age groups were compared by Pearson's X2 test and Fisher' s exact probability test. Results The positive rate of antibody to A/H1N1 in the whole population in Shanghai was 9.2% (37/404). The highest rate was 25.0% (21/84) in the age group of ≥60 years, the next was 10. 0% (8/80) in the age group of 25-59 years, the positive rates in other groups were lower. The result of Pearson's X2 test showed that there were statistically significant differences in the positive rates of the antibodies among different age groups. Of 329 sera positive for antibody to 2008 -2009 seasonal influenza vaccine virus A/Brisbane/59/ 2007 (H1N1), 31 had anti-A/HlNl antibodies, and of 75 sera negative for antibody to A/Brisbane/59/ 2007(H1N1), 6 had anti-A/HlNl antibodies. The result of Pearson's X2 test showed that there were no significant differences in positive rates of antibody to A/H1N1 between the two types of population. Conclusions The anti-A/HlNl levels in Shanghai population are low, and people are generally susceptible to A/H1N1. The sera positive for antibody to A/Brisbane/59/2007(H1N1) can not provide cross-protection against A/H1N1.     

甲型流感病毒血凝素基因变异与抗原变异关系研究

目的 了解甲型流感病毒流行株的血凝素基因变异和抗原变异及两者间的关系,结合流行病学资料分析基因变异和抗原变异的吻合情况.方法 从2005-2007年上海市季节性流感样病例分离到的甲型流感病毒株中,选取H1N1、H3N2两个亚型中部分有代表性的病毒株,并同WHO北半球流感疫苗推荐株一起,进行血凝素全基因序列测定后做基因进化树分析.同时用灭活的全病毒抗原免疫金黄地鼠,通过血凝抑制试验测定病毒的血凝效价,对血凝抑制结果进行聚类分析,绘制病毒的抗原变异图.结果 H3N2分离株与WHO北半球疫苗推荐株A/Sydney/5/97、A/Fujian/411/2002处于不同的基因进化分枝上,时间间隔越久,进化距离越远,同样的结果也出现在抗原变异分析中.而H1N1分离株的基因变异情况和抗原变异情况则不一致,在基因变异中,与疫苗推荐株A/New Caledonia/20/1999的距离远近受到分离时间的影响,抗原变异还与病毒是否从散发病例或聚集性病例分离有关.结论 流感病毒血凝素的基因变异和抗原变异的结果基本吻合,采用流行株免疫血清的血凝抑制试验能更好地反映病毒的变异和进化情况.     

四起学校聚集性发热疫情流行病学调查分析

2009年1～2月份,上海市卢湾区发生了4起学校聚集性发热疫情,为了解其流行特征,探讨科学有效的防控措施,现对这4起疫情分析如下。1对象与方法1.1流行概况4起疫情发生在2所小学、一所初中和一所高中,以下简称A、B、C、D,其中,AB2起均发生在1月份,CD2起均发生在2月份。A起共发生聚集性发热病例16例,B起7例,C起5例,D起3例,共31例。1.2调查方法1.2.1调查项目聚集性发热学生的姓名、