禽流感病毒概述

禽流感(Avian Ifluenza，AI)是由禽流感病毒(Avian Influenza Virus，AIV)引起的一种烈性传染病，也是严重危害畜牧业和人类健康的一种传染性疾病．从禽流感病毒的分类、形态结构、核酸特点、抵抗力、毒力及其变异等角度对其进行综述，以便为防治禽流感提供一定的参考．     

禽流感疾病及预防

禽流感(Avian lnfuenza-AV)是由正黏病毒科、流感病毒属的A型流感病毒引起的一种禽类传染病，又称真性鸡瘟、欧洲鸡瘟。其病毒广泛存在于野生禽、鸟类和人工饲养的禽类中，是目前危害养禽业最严重的疫病之一，特别是1997年香港发生禽流感病毒感染人的事件，更突显其公共卫生意义，根据AIV的毒力将禽流感分为高致病性禽流感(HPAI)、低致病性禽流感(LPAI)和无致病性禽流感(NPAI)，     

禽流感防治35问

1什么是禽流感?什么是高致病性禽流感?禽流感是禽流行性感冒的简称。是由A型禽流行性感冒病毒引起的一种禽类(家禽和野禽)传染病。禽流感病毒感染后可以表现为轻度的呼吸道症状、消化道症状,死亡率较低;或表现为较严重的全身性、出血性、败血性症状,死亡率较高。这种症状上的不     

A型流感病毒H5N1

1.何谓禽流感? 禽流感是由正粘病毒科A型流感病毒引起的一种禽类感染综合症,主要感染家禽,也可感染人。根据病毒核蛋白(NP)和基质蛋白(MS)抗原性的不同,将流感病毒分成A、8、C三个型。A型流感病毒除感染禽类之外,还可感染猪、马和人类;B型和C     

禽流感与公共卫生

禽流感是A型流感病毒引起的禽类烈性传染病，被世界动物卫生组织(OIE)列为A类动物疫病，我国将其列为一类动物疫病。依据病毒表面的两种糖蛋白血凝素(HA)和神经氨酸酶(NA)不同，可将A型流感病毒分咸若干亚型，目前已有15种HA和9种NA，其中高致病性的亚型如H5N1和H7N7可造成毁灭性的流行爆发，并可直接感染人。由于禽流感病毒的核酸是分节段的，因此易发生交换和重排，从而发生变异，出现新的亚型。这就是流行了一个世纪的禽流感至今无有效的方法预防和控制的原因所在。1997香港、2003年3月荷兰、2004泰国和越南都出现禽流感直接感染人的事件，并引起人员死亡，因此禽流感引起全世界的关注和高度的重视。     

禽流感防控知识

一、禽流感病毒的H和N是什么意 思? H和N都是指病毒的糖蛋白(蛋白 质),一种糖蛋白叫血凝素(HA),另一种 叫神经氨酸酶(NA),由于这两种糖蛋白 容易发生变异,因此,根据糖蛋白变异的 情况,HA分为H1-H15十五个不同的型 别,NA分为N1-N9九个不同的型别。其 中H5与H7为高致病亚型。 二、禽流感有哪些常见症状? 禽流感的症状依感染禽类的品种、年 龄、性别、并发感染程度、病毒毒力和环境 因素等而有所不同,主要表现为呼吸道、 消化道、生殖系统或神经系统的异常。     

认识预防禽流感

禽流感(Avian Influenza AI)是指由禽流感病毒引起的一种人、禽共患的急性传染病。主要发生在鸡、鸭、鹅、鸽子等禽类中，引起从呼吸系统到严重全身败血症等多种症状。按病原体的类型，禽流感可分为高致病性、低致病性和非致病性三大类。高致病性禽流感因其传播快、危害大，被世界动物卫生组织列为A类动物疫病，我国将其     

鸡六种病毒多重PCR检测方法的建立和应用

禽流感(Avian influenza,AI)、鸡新城疫(Newcastle disease,ND)、鸡传染性支气管炎(Infectious bronchitis,IB)、鸡传染性喉气管炎(Infectious laryngotracheitis,ILT)、鸡传染性法氏囊病(Infectious bursal disease,IBD)和鸡减蛋综合症(Egg drop syndrome 76,EDS-76)是6种常见的禽类病毒性传染病,给养鸡业造成重大经济损失。依据NCBI核酸数据库中禽流感病毒(Aiv)、新城疫病毒(Ndv)、鸡传染性支气管炎病毒(Ibv)、传染性法氏囊病(Ibdv)、鸡传染性喉气管炎病毒(Iltv)及减蛋综合征病毒(Edsv)基因序列,设计了6对特异性引物,建立并优化针对鸡Aiv、Ndv、Ibv、Ibdv、Iltv和Edsv的多重PCR鉴别诊断方法,同时进行现场检测应用。结果显示该多重PCR体系检测限为100fg,与其他常见病原体无交叉反应。研究表明鸡六种病毒多重PCR方法具有较高敏感性与特异性,在禽类常见病毒现场诊断方面具有广阔的应用前景。     

2005年8月国内外科技要闻

●7月28日,光明日报报道,北京协和医院在一位艾滋病患者眼部前房水中检测出HIV-1病毒。这是我国科学家首次在房水中发现HIV(艾滋病病毒)。这一发现提示,当艾滋病患者血浆中HIV检测呈阴性时,患者房水中仍可有HIV存在,抗HIV治疗仍然不能中断。●7月29日,新华网报道,新加坡VEREDUS生物技术公司成功开发出一种能快速、有效检验H5N1禽流感病毒的检测装置。该装置能在4小时内检测出H5N1病毒中的一种特殊基因,可在病发后两天内对禽流感病毒进行诊断,从而将诊断时间提前了数日。这是世界上首次推出的商用禽流感病毒检测装置。●7月30日,…     

刊中报

世界卫生组织西太平洋地区主任尾身茂说,与非典相比,禽流感潜在的危害更令人担忧。如果不采取有力的措施,禽流感很有可能出现全球大流行。尾身茂在世卫组织西太区委员会第55届会议新闻发布会上说,目前看来,禽流感的传播范围远远超出原先的预测。一旦人体病毒和禽流感病毒重新组合成一种新的病毒,还没有人对它有免疫     

Special features of the 2009 pandemic swine-origin influenza A H1N1 hemagglutinin and neuraminidase

Since the 2009 pandemic H1N1 swine-origin influenza A virus (09 S-OIV) has reminded the world about the global threat of the ever changing influenza virus,many questions regarding the detailed re-assortment of influenza viruses yet remain unanswered.Influenza A virus is the causative agent of the pandemic flu and contains 2 major antigenic glycoproteins on its surface:(i) hemagglutinin (HA);and (ii) neuraminidase (NA).The structures of the 09 S-OIV HA and NA proteins (09H1 and 09N1) have recently been resolved in our laboratory and provide some clues as to why the 09 S-OIV re-assortment virus is highly infectious with severe consequences in humans.For example,the 09H1 is highly similar to the HA of the 1918 influenza A pandemic virus in overall structure and especially in regards to its 5 defined antibody binding epitopes.For 09N1,its most distinctive feature is the lack of a 150-loop active site cavity,which was previously predicted to be present in all N1 NAs,and we hypothesize that the 150-loop may play a important role in the substrate specificity (α2,3 or α2,6 linked sialic acid receptors) and enzymatic mechanism of influenza NA.Combination of the HA and NA with special characteristics for the 09 S-OIV might contribute to its high increased transmissibility in humans.     

Subtyping of type A influenza by sequencing the variable regions of HA gene specifically amplified with RT-PCR

The outbreak of a novel influenza A （H1N1） virus across the globe poses a threat to human health. It is of paramount importance to develop a rapid, reliable and inexpensive diagnostic procedure. Based on the bioinformatic information from public database, primers specific for influenza A virus surface protein haemagglutinin （HA） of several subtypes （including H1, H2, H3, H5, H7 and H9） were designed. Primer-specific PCR products were subiected to sequencing for accurately distinguishing H1 and H3 subtypes from others. This sequencing-based detection method will not only be applied to rapid detection and simultaneous subtype identification of new influenza A virus H1N1, but also provide the strategies to monitor other new types of influenza virus with explosive potential.     

The genomic and epidemiological dynamics of human influenza A virus

The evolutionary interaction between influenza A virus and the human immune system, manifest as 'antigenic drift' of the viral haemagglutinin, is one of the best described patterns in molecular evolution. However, little is known about the genome-scale evolutionary dynamics of this pathogen. Similarly, how genomic processes relate to global influenza epidemiology, in which the A/H3N2 and A/H1N1 subtypes co-circulate, is poorly understood. Here through an analysis of 1,302 complete viral genomes sampled from temperate populations in both hemispheres, we show that the genomic evolution of influenza A virus is characterized by a complex interplay between frequent reassortment and periodic selective sweeps. The A/H3N2 and A/H1N1 subtypes exhibit different evolutionary dynamics, with diverse lineages circulating in A/H1N1, indicative of weaker antigenic drift. These results suggest a sink-source model of viral ecology in which new lineages are seeded from a persistent influenza reservoir, which we hypothesize to be located in the tropics, to sink populations in temperate regions.     

Genome evolution of novel influenza A （H1N1 ） viruses in humans

The epidemic situation of A H1N1 flu arose in North America in April 2009, which rapidly expanded to three continents of Europe, Asia and Africa, with the risk ranking up to 5. Until May 13th, the flu virus of A H1N1 had spread into 33 countries and regions, with a laboratory confirmed case number of 5728, including 61 deaths. Based on IRV and EpiFluDB database, 425 parts of A H1N1 flu virus sequence were achieved, followed by sequenced comparison and evolution analysis. The results showed that the current predominant A H1N1 flu virus was a kind of triple reassortment A flu virus： （i） HA, NA, MP, NP and NS originated from swine influenza virus; PB2 and PA originated from bird influenza virus; PB1 originated from human influenza virus. （ii） The origin of swine influenza virus could be subdivided as follows： HA, NP and NS originated from classic swine influenza virus of H1N1 subtype; NA and MP originated from bird origin swine influenza virus of H1N1 subtype. （iii） A H1N1 flu virus experienced no significant mutation during the epidemic spread, accompanied with no reassortment of the virus genome. In the paper, the region of the representative strains for sequence analysis （A/California/04/2009 （H1N1） and A/Mexico/4486/2009 （H1N1）） included USA and Mexico and was relatively wide, which suggested that the analysis results were convincing.     

猪流感病毒及其人类公共卫生意义

猪流感是目前危害全世界养猪业的重要呼吸道疾病之一.目前猪流感的致病毒株主要有经典性H1N1,类人型流感病毒,类禽型流感病毒,H1N2亚型流感病毒,H5N1和H9N2亚型流感病毒.特别是从猪体分离H5N1和H9N2亚型流感病毒对禽流感的控制及人类公共卫生方面有重要意义.     

玉溪市2009～2012年流感哨点监测流行病学和病原学分析

目的：分析玉溪市2009~2012年流感哨点医院ILI（流感样病例）监测结果,探索流感流行特征及规律,为制定预防和控制策略提供依据;方法对2009-2012年国家流感监测哨点医院发热门诊流感样病例（ILI）进行流行病学分布研究,通过实验室分离培养流感病毒,并对流感病毒型别检测和分析;结果2009~2012年,ILI占门诊总数百分率平均为4.25%,年平均采样数为762,标本占ILI百分率平均为6.56%,每年1~3月、10~12月呈现两个发病高峰,ILl主要集中青壮年人群,职业分布以农民和学生为主,流感病毒型别流行特点：2009~2010年以新型甲型H1N1流行为主,2010~2011年以B型流感Victory系列流行为主,2012年以季节流感H3N2l流行为主;结论对玉溪市2009~2012年流感病毒的监测,发现具有时间、人群和不同型别的流行特点,结合实验室结果科学合理地使用疫苗,积极预防和控制流感病毒的流行。     

动物源性流感病毒与人流感流行

2009年4月.北美地区发生了人感染H1N1"猪流感"疫情,并且疫情呈现暴发漫延的态势.全世界关注的目光继1997年H5N1禽流感病毒感染人事件首次在中国香港发生,以及2003年以来包括15个国家和地区多起H5N1禽流感病毒感染人事件之后,再次聚焦到动物源性流感病毒上.是否动物流感病毒已经具备了引起人类疫情暴发的能力?是否新的一场大的人流感疫情就要暴发?为什么世界卫生组织又于4月30日为本次"猪流感"更名为"甲型H1N1流感"?对于流感暴发脚步的逼近我们是否做好了准备?本文对历史上人流感疫情暴发情况,动物流感病毒感染人事件的发生情况和流行病学特点,以及人流感疫情发生与动物流感病毒之间的关系等进行了总结与分析,以期更好地了解流感病毒在不同宿主之间的传播,为更加从容地面对这场突如其来的疫情,以及为疫情的预防和控制提供理论指导.为了能够准确反映这次流感的情况和国际对流感及流感病毒的统一命名法则,以及更加清晰并易于理解地表述清楚.我们建议将这次流感称作"北美流感"或"墨西哥流感".     

Subtyping of type A influenza by sequencing the variable regions of HA gene specifically amplified with RT-PCR

The outbreak of a novel influenza A(H1N1) virus across the globe poses a threat to human health.It is of paramount importance to develop a rapid,reliable and inexpensive diagnostic procedure.Based on the bioinformatic information from public database,primers specific for influenza A virus surface protein haemagglutinin(HA) of several subtypes(including H1,H2,H3,H5,H7 and H9) were designed.Primer-specific PCR products were subjected to sequencing for accurately distinguishing H1 and H3 subtypes from others.T...     

KMB17细胞培养流感病毒的实验研究

 探讨了流感病毒在KMB₁₇细胞上培养的可行性.将3株不同型别的流感病毒(A/Wisconsin/67/2005H3N2,A/New Caledonia/20/1999 H1N1和B/Malaysia/2506/2004)分别接种于KMB₁₇细胞上,在无血清的条件下于不同pH值和不同胰酶浓度的维持液中35℃培养72 h后收获病毒,测定血凝效价.实验结果表明,所用的3个毒株中的H3N2亚型毒株(A/Wisconsin/67/2005 H3N2)血凝效价明显高于另外的H1N1亚型(A/NewCaledonia/20/1999 H1N1)和B型(B/Malaysia/2506/2004)毒株.因此认为KMB₁₇细胞可作为培养流感病毒的备选培养基质.