【作者】 张妙红；

【导师】 曾德年； 邓治邦；

【作者基本信息】 湖南农业大学 ， 预防兽医学， 2008， 硕士

【摘要】 2006年夏秋之季,我国部分地区发生以高热为特征的猪病。最初许多人称之为“高热病”。受害猪群包括生长、肥育猪、保育猪和部分母猪。大部分患病猪场发病率在50%以上,死淘率高达50%～100%,母猪死淘率达到15%～30%。一些猪场因此病而倒闭。农业部及时组织中国动物疫病预防控制中心、中国兽医药品监察所、中国动物卫生与流行病学中心、中国农科院哈尔滨兽医研究所等单位及有关专家,对“高热病”开展了流行病学调查、病原分离鉴定、动物试验等科技攻关。分离到猪繁殖与呼吸综合症(猪蓝耳病)病毒变异株。2007年1月,农业部最终确定“高热病”即“猪高致病性蓝耳病”。对湖南省各地区感染高致病性猪蓝耳病猪场的420头病死猪和实验室人工感染病死猪进行了一系列病理学研究。组织学观察可见肺脏间质性支气管肺炎,脾脏出血性梗死,淋巴结出血、坏死等;用透射电镜方法观察了心、肝、肾、肺等组织亚显微结构的变化;免疫荧光检测到淋巴结、脾脏中抗原的主要存在位置为淋巴小结的中心区、扁桃体中的抗原主要分布在隐窝及其周边;比较了临床自然病例与人工感染病例病变及临床表现的差异;描述了单核巨噬细胞系统的改变及免疫损害等。提出了高致病性猪蓝耳病发生机理与其它病原的关系。更多还原

【Abstract】 Porcine reproductive and respiratory syndrome (PRRS) is a severe viral disease in pigs, causing great economic losses worldwide each year. The causative agent of the disease, PRRS virus (PRRSV), is a member of the family Arteriviridae. It has been reported that the unparalleled large-scale outbreaks of an originally unknown, but so-called "high fever" disease in China in 2006 with the essence of PRRS, which spread to more than 10 provinces (autonomous cities or regions) and affected over 2,000,000 pigs with about 400,000 fatal cases. Different from the typical PRRS, numerous adult sows were also infected by the "high fever" disease. This atypical PRRS pandemic was initially identified as a hog cholera-like disease manifesting neurological symptoms (e.g., shivering), high fever (40～42℃), erythematous blanching rash, etc.The aim of this work was to characterize the lesions and agents present in clinically affected pigs in hogpens of Hunan during an outbreak of atypical PRRS, and to establish the indirect immunofluorescence(IIF) techniques for detecting fatal PRRSV variants. Autopsies combined with immunological analyses clearly showed that multiple organs were infected by highly pathogenic PRRSVs with severe pathological changes observed. The lung showed interstitial pneumonia change, spleen infarct and bladder dilatation filled with reddish brown urine, obvious haemorrhagic spots in lymph node. IIF revealed that PRRSV were mostly present in the center of lymphatic nodule in spleen and lymph node, and present in cryptae tonsillares or around it. In a word , the fatal PRRSV variants could be make disoperation of monocaryon- macrophage system, so the power of resistance was decreasing which made more sensibility to catch other diseases. Measures must be taken to control the outblreak of Fatal PRRS.更多还原