A study of the epidemiology of infectious bursal disease in poultry in Queensland, 1976–1979

The epidemiology of infectious bursal disease (IBD) was studied by serology and sometimes by visual examination of the bursa of Fabricius in poultry flocks in Queensland during 1976–1979.
Ten flocks, each of approximately 30,000 meat breeding chickens, were surveyed. All chickens had maternally-derived antibody against IBD virus (IBDV) at hatching and active antibody was not detected while the chickens were brooded on rearing farms. When distributed to breeding farms, 7 of the flocks developed antibody when 11 to 25 weeks of age. The remaining 3 flocks were vaccinated by infection of 10% of the birds and within 4 weeks more than 80% of the chickens had developed precipitating antibody to IBDV.
Blood samples of 20 to 30 broiler chickens were collected at slaughter (7 to 9 weeks of age) from each of 312 broiler flocks raised on 37 contract farms. While the samples from 21 flocks were without detectable antibody to IBDV, all serum samples for 263 flocks contained antibody. The ratio of bursal weight to bodyweight was significantly lower in birds from 144 flocks having antibody to IBDV than in birds from 10 flocks that were without detectable antibody. In sequential studies, IBDV antibody became demonstrable in 27 of 30 flocks when the chickens were one to 6 weeks of age and was accompanied by bursal atrophy.
Serological investigation of 4 flocks of layer breeding chickens on a multi-age farm at approximately monthly intervals resulted in antibody to IBDV being detected at every examination.
Serological tests and bursal examinations were carried out weekly in 2 flocks each of 4000 layer chickens between one and 20 weeks of age. Serum antibody developed in one flock at 4 weeks of age and in the other at 17 weeks of age. In both flocks, bursal atrophy occurred concurrently with the development of antibody.     

鹌鹑法氏囊病的应对措施

近年来在生产中鹌鹑的法氏囊病时有发生。笔者于2008年3B初确诊了一起鹌鹑患传染性法氏囊病的病例,由于及时采取了防治措施病情得到有效控制,避免了更大的损失。     

谨防非典型传染性法氏囊病

传染性法氏囊病(IBD)是雏鸡和育成鸡的一种急性、接触性、免疫抑制性传染病。我国刘福致等于1979年在北京郊区一些鸡场发现该病并分离到病毒。1981～1989年全国患IBD的病鸡达2000万只,死亡240万只,死亡率11.8%。病鸡主要表现为精神不振、厌食、间歇性腹泻、震颤和高度虚脱,剖检以脱水、肌肉出血、肾小管尿酸盐沉积和法氏囊肿大、出血为特征,呈典型的IBD症状。近几年来,随着IBD弱毒疫苗的广泛使用,特别是使用了中等毒力的疫苗,基本上控制了典型IBD的发生,但是非典型IBD却常发不断,给养鸡业,特别是肉鸡饲养业带来严重的经济损失。1非…     

对某鸡场传染性法氏囊病的诊治体会

传染性法氏囊病是养鸡场常发的一种急性传染病，其发病率高、病程短、死亡率高，雏鸡感染后还可导致免疫抑制，并可诱发多种疫病或使多种疫苗免疫失败。最常见的是导致鸡新城疫、鸡传染性支气管炎的免疫失败，给养鸡业带来巨大的经济损失。我县某养鸡场今年年初暴发该病，现将其诊断及治疗过程报告如下。     

鸡传染性法氏囊病的诊治报告

自2005年春季以来,法库县频繁发生鸡传染性法氏囊病,其发病日龄逐渐拓宽,最早7日龄,最迟120日龄。临床表现及病理变化逐渐趋向非典型性,尖峰式零星死亡,现将诊治情况报告如下。     

Studies on a vaccine against infectious bursal disease

An infectious bursal disease vaccine, registered for use in breeder flocks, was studied for efficacy on the day-old offspring of vaccinated hens and for virulence in susceptible day-old and 6-week-old chickens. When given to susceptible day-old chicks and 6-week-old cockerels, the vaccine was found to induce atrophy and pathology of the bursa of Fabricius similar to that observed in field infections. Chicks vaccinated at day-old had markedly lowered titres in the haemagglutination inhibition test to Newcastle disease virus, when this was given 2 weeks later, but the response of the 6-week-old cockerel was similar to that of control birds. Maternal antibody induced by the vaccine protected chicks against infection at day-old.     

鸡传染性法氏囊病的诊断

鸡传染性法氏囊炎病是一种主要危害鸡的体液免疫中枢器官——法氏囊的病毒性传染病。牡丹江市某大型养鸡场2006年10月,购自某种鸡场海     

鸡传染性法氏囊病病毒的快速检测

随着 IBDV变异株的出现 ,发病鸡常不产生法氏囊的肉眼病变 ,由于传染性和非传染性因素亦可引起淋巴细胞减少和法氏囊坏死 ,所以 ,采取组织病理学方法诊断 IBDV感染并不完全可靠。由于主动性抗体应答需要一定的时间及大多数雏鸡都带有母源抗体 ,因此血清学早期诊断也不完全可靠。该试验采用本所研究的 IBD快速试纸与经典的琼扩试验 ,在对 IBDV的检测效果上进行了详细的比较 ,介绍如下。1　材料与方法1 .1　 IBD快速检测试纸　由河南省农业科学院生物技术研究所制备提供。1 .2　试验鸡　 1日龄试验鸡 30 0只由河南农业大学试验鸡场提…     

传染性法氏囊病病毒抗原表位分析--单克隆抗体的制备与鉴定

将传染性法氏囊病病毒(IBDV)分离毒株ZB和TA3的细胞培养物采用不连续蔗糖密度梯度离心的方法浓缩纯化病毒,免疫BALB/c小鼠,运用淋巴细胞杂交瘤技术将免疫鼠脾细胞与SP2/0骨髓瘤细胞融合,建立了6株分泌抗IBDV单克隆抗体(McAb)的杂交瘤细胞系1C1、1E6、2B2、2G8、3A2、3E2。间接ELISA测定,杂交瘤细胞培养上清液的抗体效价为102,诱生腹水的抗体效价为106～107。相加ELISA分析,这6株单克隆抗体对应不同的病毒抗原表位。中和试验结果表明,2G8对病毒有较强的中和能力,腹水的中和效价为105。用2B1和3E2配对建立的夹心ELISA可特异地检测IB DV。     

由法氏囊病毒引起鸡的免疫抑制

1法氏囊 禽类法氏囊是雏鸡免疫系统的中枢免疫器官.它是鸟类特有的免疫器官,所以值得特别关注.许多研究已搞清了其生理学作用.雏鸡前3周是法氏囊快速发展时期,在这个时期法氏囊迅速增殖,3周龄后法氏囊就逐渐退化,研究表明,大约在12周龄,法氏囊就完全退化.     

Baculovirus virions displaying infectious bursal disease virus VP2 protein protect chickens against infectious bursal disease virus infection

Infectious bursal disease (IBD) is an acute and contagious viral infection of young chickens caused by IBD virus (IBDV). The VP2 protein of IBDV is the only antigen for inducing neutralizing antibodies and protective immunity in the natural host. In the current study, we have succeeded in construction of one recombinant baculovirus BacSC-VP2 expressing His6-tagged VP2 with the baculovirus envelope protein gp64 transmembrane domain (TM) and cytoplasmic domain (CTD). The His6-tagged recombinant VP2 was expressed and anchored on the plasma membrane of Sf-9 cells, as examined by western blot and confocal microscopy. Immunogold electron microscopy demonstrated that the VP2 protein of IBDV was successfully displayed on the viral surface. Vaccination of chickens with the VP2-pseudotyped baculovirus vaccine (BacSC-VP2) elicited significantly higher levels of VP2-specific enzyme-linked immunosorbent assay antibodies and neutralizing antibodies than the control groups. IBDV-specific proliferation of lymphocytes was observed in chickens immunized with the recombinant BacSC-VP2. An in vivo challenge study of the recombinant baculovirus BacSC-VP2 showed effective protection against a very virulent (vv) IBDV infection in chickens. In addition, mortality and gross and histopathological findings in the bursa demonstrated the efficacy of the vaccine in reducing virulence of the disease. These results indicate that the recombinant baculovirus BacSC-VP2 can be a potential vaccine against IBDV infections.     

世界各国控制法氏囊病的几种措施

传染性法氏囊病(IBD)是一种全球范围的疾病,不仅可导致家禽发病,还可造成严重的免疫抑制。许多国家对该病做了大量研究,尤其是病毒基因和发病机理方面的研究。疫苗制造商也在不断地改进疫苗的安全性和疗效,生产出不同病原型的疫苗,大多数都能有效地控制该病的流行。针对IBD病,不同的国家尚需采取不同的措施。西班牙制药公司HIPRA实验室负责禽病诊治的技术服务人员对IBD的控制措施进行了调查。下面阐述的是全球家禽企业中成功控制IBD病的4位专家的经验。1东南亚AlmasdiPogor,印尼共和国人,国家食品公司的一名兽医。因地区的重要性使…     

鸡传染性喉气管炎的防治

传染性喉气管炎(ILT)是由A型疱疹病毒引起的鸡的一种急性呼吸道传染病。1936年由Beaudette首次证明其病原是一种滤过性病毒。目前此病在许多国家广泛流行,是危害养鸡业的重要疾病,近几年来,在我国一些养鸡集中的地区,ILT引起产蛋鸡产蛋下降和鸡群的高死亡率,产蛋率一般下降10%～50%,死亡率一般在5%～70%之间,给养鸡业带来巨大经济损失,现将实践中对该病的诊断、治疗经验及防制要点总结如下。1流行特点鸡是ILT感染的主要自然宿主,各种日龄的鸡均可感染,以4～10月龄的成年鸡最为严重,对产蛋高峰期的鸡特别易感且危害大;从鸡品种来看,以褐…     

Immunogenicity of infectious bursal disease viruses in chickens.

Cross-protective properties of infectious bursal disease viruses (IBDVs) were studied. Viruses represented different subtypes of serotype 1, including recently isolated viruses (variants), and a serotype 2 virus. Chickens were vaccinated at 3 weeks of age with inactivated vaccines containing 10(5), 10(6), 10(7), or 10(8) mean tissue-culture infectious dose of a given virus and challenged 2 weeks later using either 10(2) or 10(3.5) mean embryo infectious dose (EID50) of either a standard virus or a variant serotype 1 virus. Protection was evaluated at 5 and 10 days post-challenge, based on gross and microscopic lesions, body weight, and bursa/body-weight ratios. The serotype 2 virus did not confer protection on birds challenged with the serotype 1 viruses. Vaccines made of variant viruses at the low doses protected chickens challenged with the high or low doses of either the standard or the variant viruses. Vaccines made of the standard or variant strains at low doses protected against high or low challenge doses of the standard strain. Vaccines made of the high dose of any of the standard strains protected chickens against the variant virus when the low challenge dose (10(2) EID50) was used, but not when the high challenge dose (10(3.5) EID50) was used. The lowest dose of the standard viruses vaccines required to confer protection against the variant virus varied depending on the strain. Results indicated that protection depended on the strain and dose of both the vaccine and challenge viruses and that the variant strains and standard strains share a common protective antigen(s).     

Investigations on live vaccines against infectious bursal disease of chicks

Summary

Four live virus vaccines against Infectious Bursal Disease (IBD) were studied with regard to their safety, immune response and applicability. None of the vaccines caused clinical symptoms or had an adverse impact on bodyweight. Differences between these vaccins were observed in their effect on the Bursa/ Bodyweight Ratio and the severity of the microscopical lesions of the bursa Fabricii. The immunosuppressive effect of IBD vaccination at one day of age on the response to Newcastle disease vaccine applied was rather low.

Three of the four vaccines induced antibodies associated with protection against challenge. Vaccination of SPF rearing chickens by drinking water at an age of 15 weeks produced an antibody response (Agar Gel Precipitin Test) whereas at an age of 23, 32 and 60 weeks it did not. Chickens of all age groups responded serologically to an intramusculair vaccination.

A correlation was found between the immunological response and the effect of the vaccines on the bursa Fabricii.     

鸡传染性法氏囊病毒反转录环媒恒温检测方法的初步建立

本研究利用Primer Explorer V4软件设计了针对鸡传染性法氏囊病毒（IBDV）VP1基因保守区6个特异性部位的4条引物,建立了IBDV的反转录环媒恒温检测方法。该方法反应体系在恒温水浴锅中作用1 h即可得到其特有的阶梯状条带,加入荧光素后肉眼可直接观察结果。本方法特异性高,对IBDV的最低检出量为10-6稀释倍数,敏感性是普通RT-PCR的100倍。反转录环媒恒温检测方法和普通RT-PCR方法检测临床样品的符合率为93.8%。因此该方法可以作为IBDV的综合防治和疾病诊断的实用方法。     

A comparison of three different regimens of infectious bursal disease vaccination in chickens

Five days old progeny chicks from breeders which have received primary and booster doses of live infectious bursal disease vaccine, demonstrated precipitating antibodies unlike progenies from single dose vaccinated breeders. All chicks from the two different groups of breeders were however seronegative at 22 days of age, despite vaccination at 7 or 14 days of age. Post vaccination seroconversion was first noticeable at 32 days in the group of chicks vaccinated at 7 days. Post challenge mortalities was significantly lower (P less than 0.05) and organ lesions very significantly minimized (P less than 0.01) in 7 day old vaccinated group than in 14 or 28 days old vaccinated chicks. These results showed that early (7 days) IBD Vaccination was superior to vaccination at 14 or 28 days, in terms of antibody response and protectivity against mortalities and bursal lesions.     

Thermostability of the vaccination strain of infectious bursal disease virus

The vaccination strain of infectious bursal disease virus, multiplied in cultures of chick embryo cells, was very resistant to heat. At a temperature of 56 degrees C the infection titre of the virus (TCID50) decreased by 0.9 log10 within two hours and by 1.2 log10 within five hours, but the virus remained infective still after 24 hours. At a temperature of 37 degrees C, a slight decrease in infection titre was recorded only after two days and a decrease by 1.2 log10 was recorded within ten days. After the 21st day the virus was almost inactivated. At a temperature of about 20 degrees C the infection titre of the virus decreased linearly from the third to the twelfth weeks. The control samples kept at +4 degrees C retained their infectivity for three months and at -20 degrees C even for six months. The discussion deals with the effect of the concentration of protein and magnesium chloride in the medium on the thermostability of infectious bursal disease virus.     

传染性法氏囊病病毒主要结构蛋白研究进展

传染性法氏囊病病毒(Infectious bursal disease virus,IBDV)引起禽类的传染性法氏囊病(Infectious bursal disease,IBD),主要侵害免疫器官,直接引起感染鸡的发病或死亡,更重要的是能引起鸡的免疫抑制,导致对其他病原因子的易感性增强及对疫苗的免疫应答能力下降。近年来随着反向遗传等新技术的应用,对该病毒的基因组及编码蛋白研究有了长足的进步,本文对该病毒主要结构蛋白方面的研究进展进行了综述。