H5亚型高致病性禽流感病毒的暴发、传播与进化研究

发布时间：2018-07-10 02:55

本文选题：禽流感病毒 + 传播网络　；参考：《清华大学》2016年博士论文

【摘要】：自1996年后H5亚型高致病性禽流感病毒迅速在全球范围内广泛传播,并不断进化,世界各地的家禽产业遭受了巨大的损失,野生鸟类、哺乳动物的生命也受到了严重威胁。因此,研究H5亚型高致病性禽流感病毒的暴发、传播和进化模式,对疫情的防控具有重要意义。本研究目的是研究H5亚型高致病性禽流感病毒的暴发、传播及进化规律,探索不同宿主、宿主行为、地理环境等因素对疾病传播与进化的影响,以期为该疾病未来预防与控制提供建议和理论支持。具体研究及发现如下:(1)对2004年至2015年H5亚型高致病性禽流感疫情出现的时间、地点等信息进行空间化展示,发现该病毒在2004至2008年出现集中暴发及大面积扩散后,于2011年至2015年出现第二次大面积暴发,同时伴随多种禽流感亚型;此外,对不同地区病毒的遗传差异进行分析,发现地理隔离会造成病毒在区域内鲜有进化或暴发;而病毒在一个地区持续性存在并感染不同宿主,导致病毒的进化及遗传的多样性。这是造成有些地区如南亚、北美洲,病毒遗传差异较小,而有些地区如东北亚、中国等病毒的遗传差异显著的原因。(2)结合2005年至2013年H5亚型高致病性禽流感病毒暴发事件和基因序列信息,利用生物信息学方法研究不同宿主体内病毒的进化模式,重建了黑海—地中海迁徙带不同宿主源病毒的传播网络:野鸟源病毒传播网络以长距离传播为主;而家禽源病毒由于家禽养殖过程中与野鸟的接触以及地区间贸易过程中家禽间的相互接触,同时出现相邻区域间短距离和长距离病毒传播模式。(3)利用斑头雁和赤麻鸭的卫星跟踪数据,结合其生态环境信息(如湿地、NDVI等),利用广义线性混合模型,研究不同鸟类对生态环境的特定选择。研究发现不同鸟类的迁徙行为存在差异,这种差异会影响其在迁徙过程中对生态环境的选择—如停歇地的选择从而影响禽流感病毒扩散方式:斑头雁在迁徙过程中停歇地成聚集性分布,容易造成病毒在种群内传播;赤麻鸭在迁徙过程中停歇地成相对离散型分布,容易造成病毒在种群间的大面积传播。
[Abstract]:Since 1996, the highly pathogenic avian influenza virus of H5 subtype has been widely spread and evolved in the world. The poultry industry in the world has suffered great losses, and the life of wild birds and mammals has also been seriously threatened. Therefore, it is of great significance to study the outbreak, transmission and evolution of H5 subtype highly pathogenic avian influenza virus. The purpose of this study was to study the outbreak, transmission and evolution of H5 subtype highly pathogenic avian influenza virus, and to explore the effects of different hosts, host behavior and geographical environment on disease transmission and evolution. In order to provide advice and theoretical support for the prevention and control of the disease in the future. The specific studies and findings are as follows: (1) the time and location of the outbreak of H5 subtype highly pathogenic avian influenza from 2004 to 2015 were spatially displayed, and it was found that the virus occurred in a concentrated outbreak and spread in a large area from 2004 to 2008. The second outbreak occurred from 2011 to 2015, accompanied by a variety of avian influenza subtypes. In addition, the genetic differences of viruses in different regions were analyzed, and it was found that geographic isolation would result in little evolution or outbreak of the virus in the region. Viruses persist in a region and infect different hosts, leading to the evolution and genetic diversity of the virus. This is the result of relatively small genetic differences in some areas, such as South Asia and North America, while in some regions, such as North-East Asia, The causes of the significant genetic differences among Chinese and other viruses. (2) based on the outbreak events and gene sequence information of H5 subtype H5 virus from 2005 to 2013, the evolutionary patterns of viruses in different hosts were studied by bioinformatics. The transmission network of virus from different hosts in the Black Sea Mediterranean migration belt was reconstructed: the transmission network of wild bird origin virus was mainly long-distance transmission; Because of the contact with wild birds during poultry breeding and the contact between poultry in the process of inter-regional trade, At the same time, there are short and long distance virus transmission modes between adjacent regions. (3) based on satellite tracking data of wild goose and red duck, combined with ecological environment information (such as NDVI), a generalized linear hybrid model is used. To study the specific selection of different birds to the ecological environment. The study found that the migration behavior of different birds is different. This kind of difference will affect the ecological environment selection in the course of migration, such as the choice of resting place, so as to influence the way of avian influenza virus spreading. During the migration of red duck, it is easy to spread the virus in a large area.
【学位授予单位】：清华大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S852.65

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