Avian encephamyelitis ( ae ) , which is also called epidemic tremor , characterized by nonsuppurative encephamyelitis , is caused by avian encephalomyelitis virus and has a sign of decreasing egg production . in adult chickens and decreasing hatching rate in fertilized eggs and has 40 % - 60 % of incidence and 25 % of mortality 该病发病率为40 60 ，死亡率为25左右。成年鸡感染后出现产蛋率下降，种蛋出雏率降低。但雏鸡感染aev的早期血清中的igm ， igg系统的变化规律尚未见报道。
Biogen - tab is an effective and invaluable medicine for many poultry diseases , particularly chronic respiratory disease , infectious coryza , salmonelloses fowl typhoid and paratyphoid infection , blue comb disease , fowl cholera , coccidiosis , and leucocytozoon disease . the diseases infected by virus , such as newcastl disease , avian encephalomyelitis are found not to be effected by biogen - tab treatment 爱禽美对许多家禽疾病是相当有效的药品，特别是慢性呼吸器病，通称crd ，传染性可利查，沙士杆菌病如家禽伤寒，副伤寒，蓝冠病，家禽霍乱，球虫病，及白冠病等但有些疾病，由病毒感染者无效如新城鸡瘟，传染性喉头气管炎
The research consist of four parts . the first part is multiplication , purification and electron microscope examination of the avian encephalomyelitis virus . a 1 : 5 dilution of isolate - nh937 of aev and control group of pbs were inoculated to susceptible 6 - day - old chickens embryos . respectively . after incubation for 10 days , the urinay vesicle liquid was collected . making a comparison the size of the chickens embryos between the test group and the control group , the results showed that the size of the control group is bigger than that of the test group . purified virions were examined under the electron microscope , the result revealed that there are a lot of virions and the aev - nh937 was multiplicated in embryos . the second part was seguence analysis of the genome of the aev - nh937 . nine pairs of primers were designed according to published calnek vaccine strain of aev 本研究共分四个部分：第一部分为aev的增殖，纯化和电镜观察，用1 : 5倍稀释的aev - nh937株和阴性对照pbs分别经卵黄囊接种于6dspf鸡胚，继续孵化10d后，收集尿囊液。比较接种组和健康对照组鸡胚的大小，结果显示，健康对照组鸡胚明显大于接种组。分离、提纯aev ，把纯化的病毒在电镜下观察，证明确有大量aev病毒粒子存在，说明aev在鸡胚中成功扩增；第二部分是aev - nh937基因组的序列测定工作。
Avian encephalomyelitis virus ( aev ) is a picornavirus with a predilection for the central nervous system and other parenchymous organs of chickens that is transmited by the oral - faecal route . the virus may be spread by the vertical and horizontalroutes , and because of its great stability , contaminated areas may remain infectious for long periods . the egg - adapted van roekel strain is highly neurotropic and does not grow efficiently in the enteric tract of the chicken , and the field isolates of aev is usually enterotropic . despite this . the virion polypeptides of both naturally - occurring strains and the van roekel strain are antigenically identical 侵害鸡的中枢神经系统和其它实质性器官，该病毒通过口-粪途径传播，具有水平和垂直传播的能力。由于它极大的稳定性，被污染的区域可能长期保持传染性。鸡胚适应株vanroekel是高度嗜神经的，并且在鸡的肠道内不能有效的生长，而野毒株却是嗜肠道型的。
