边界病的研究进展

边界病（border disease,BD）是由边界病病毒（border disease virus,BDV）引起绵羊和山羊感染的一种传染性疾病,在世界范围内给畜牧业生产造成巨大的经济损失。该病临床表现为母羊生殖障碍,羔羊畸形、震颤、多毛等。BDV在绵羊、牛和猪的种间传播经常发生,给该病的诊断带来困难。目前,尚无有效的疫苗用于边界病的防控,因此,了解不同区域的边界病流行情况有助于防止其传播并优化控制措施。结合国内外近期研究报道,从病原学、流行病学、诊断措施等方面对边界病进行综述,以期为该病的防控工作提供参考。     

边界病

边界病段宏安（中国连云港动植物检疫局，江苏２２２０４２边界病（ＢｏｒｄｅｒＢｉｓｅａｓｅ，ＢＤ）是由边界病病毒引起的，主要侵害绵羊的一种传染病，以新生羔羊体表出现茸毛状胎毛（ｈａｉｒｙｂｉｒｔｈｃｏａｔ）、持续节律性震颤以及中枢神经髓鞘缺失或异常为特...     

羊流行性肝炎的诊断与预防

羊流行性肝炎是绵羊病毒性传染病，牛也可感染发病。本病潜伏期短，绵羊最易感，山羊最钝感。绵羊、牛、山羊和骆驼发病后，常引起孕畜流产，仔畜死亡。自然感染是由多种蚊传播的，猴、家鼠和牛是自然疫源，候鸟参与其传播。健康羊，特别是羔羊与患病羊一同饲养时，可能发生感染，子宫内感染也已被证明，流产胎儿体内含有大量病毒。人类流行性肝炎常因接触病畜或病料而发生感染，传播途径主要是呼吸道，蚊虫叮咬在人类感染中占次要地位。     

引起羊黄疸的几种传染病的临床鉴别

1传染性地方流行性肝炎 本病病毒为核糖核酸病毒,有很广的脊椎动物寄生谱,绵羊发病最严重,其次是山羊。多种蚊子可传播该病毒,所有年龄的绵羊均可感染,羔羊最严重。发病率在羊群中高达100%,1周龄以内的羔羊死亡率高达95%。最急性病例突然倒地死亡。急性病例潜伏期非常短,发热,脉搏加快,步态不稳,呕吐,流粘液性鼻液,出血性腹泻和可视黏膜有血斑或血点,在24-72小时内死亡。亚急性病例发生在成年绵羊,病羊发热并伴随厌食和虚弱,黄疸是主要症状,还有一些羊出现呕吐和腹痛的症状。孕羊流产为绵羊患病的唯一特征,山羊与绵羊症状相似,没有绵羊严重。可用酶联免疫吸附测定试验和反向被动凝集试验快速检查血样中的病毒抗原。     

羔羊传染性脓疱病的诊治

羔羊传染性脓疱病俗称“羊口疮” ,是绵羊和山羊的一种病毒引起的传染病 ,在羔羊多为群发。其特征为口唇等处皮肤和黏膜形成丘疹、脓疱、溃疡和形成疣状厚痂。近几年来 ,由于香加乡出生的羔羊感染传染性脓疱病比较普遍。笔者对该病的预防和治疗积累了一些经验 ,现介绍如下。1　发病情况该病多发于出生 1～ 3月龄的羔羊 ,以山羊为多数 ,多以群体发病为主 ,而且传染速度极快。病初表现为不愿吃母乳 ,若一群羔羊中发现一例呈现该病症状后 ,则大多数羔羊已经感染。发病率为 15 1%(489 32 41) ,死亡率为 7 2 5 %(2 35 32 41)。2　临床症状病初…     

羊传染性脓疱皮炎的综合防治

正(一)流行病学本病可感染绵羊及山羊等,主要是羔羊,黄羊羔也可感染。病羊和带毒羊是主要的传染源。由于本病毒在痂皮中存活时间较长,所以病羊的痂皮是为主要的病毒源。本病主要通过直接和间接接触感染。存在于污染的圈舍、垫草、饲草等环境中的病毒可以通过受损伤皮肤、     

小反刍兽疫的诊治

正小反刍兽疫是一种急性传染病。它是由小反刍兽疫病毒引起的病毒病。其主要症状为体温增高、眼和鼻有分泌物、腹泻、口腔炎和肺炎。1流行特征本病主要感染小反刍动物,山羊最易感染。直接和间接接触、吸入染病动物呼吸道飞沫是本病主要传播途径。传染源是染病和隐性感染动物。2临床症状潜伏期多为3~6 d,个别长达20 d左右。山羊和绵羊发病最为常见,临床绵羊症状较轻微,而山羊则症状严重、典型。     

羊口疮病的预防治疗

羊口疮,又称为羊传染性脓疱性皮炎,主要感染小型反刍兽如绵羊和山羊,以口唇、舌、鼻、乳房等部位形成丘疹、水疱、脓疱和结成疣状结痂为特征。1易感动物和传播途径本病主要感染小型反刍兽如绵羊和山羊,偶尔感染其它野生反刍动物如鹿等,人也可被感染。临床上以羔羊和母羊最为易感,波尔山羊更易发生持续感染并表现症状较为严重。主要通过病羊或带病羊的皮肤和黏膜擦伤的方式感染流行。     

谨防以羊、牛为侵害对象的“杀手”——蓝舌病流行病学及防控技术研究进展

2007年9月,在英国的多个牧场发现了BTV8型毒株感染病例。此次致病的BTV8型毒株与以往发现的病毒有所不同,病畜的发病症状非常严重。通常情况下,蓝舌病对绵羊的危害最大,病牛的症状相对较少,也较轻。但此次发病病牛的症状却非常严重,除高热和舌头变蓝外,鼻黏膜和口腔黏膜严重充血,这是非常少见的。分子流行病学分析结果显示,该毒株的基因序列最接近于1982年在尼日利亚分离出的一株病毒,这意味着该毒株很可能来自于非洲。专家指出,全球化趋势使外来动物疫病传入我国的风险在加大,蓝舌病为非接触性传染病,通过嗜血媒介昆虫(如库蠓等)吸吮带毒血液后,病毒在昆虫体内增殖并在叮咬易感动物过程中进行传播。绵羊、山羊和牛是本病的主要易感动物,蓝舌病病毒可经胎盘感染胎儿,引起流产、死胎或胎儿先天性异常,严重时甚至可使整个羊群丧失一个产羔期的全部羔羊。一般情况下绵羊感染后急性发病率约30%,死亡率高达35%;山羊和牛呈隐性感染,症状不明显,但有资料显示,当前国际上的一些流行毒株可导致牛发生明显临床症状。     

浅析羊口疮病的防治技术

<正>近年来,我国养殖业快速发展,饲养条件不断改变,羊口疮发病率也逐年提高,对养殖户的经济效益造成了严重影响。羊口疮病是一种接触性传染疾病,由传染性脓疮病病毒(ORFV)所致,人畜共患,主要发生在山羊与绵羊群体,特别是幼羊及羔羊极易患病,羔羊发病率可达100%,成年羊发病较少。羊口疮病无明显的季节性,羊群一旦被感染便会快速传播,对养殖业造成了严重危害。     

羊病毒性关节炎-脑炎诊断与防治

羊病毒性关节炎-脑炎是由反转录病毒科慢病毒属山羊关节脑炎病毒引发的一种病毒性传染性疾病。临床上患病羊所出现的持续性的病症是急性脑脊髓炎,成年羊表现为关节炎、乳腺炎、慢性进行性肺炎和脑炎。病毒危害的羊群终身携带病毒,成为养殖场的主要传染源。由于该类疾病没有特效药物,再加上传染源的存在,经常会造成羊群反复流行该类疾病,最终引发死亡,对整个群体造成的威胁极大。为缩小经济损失、提高牲畜生产性能,该文探讨羊病毒性关节炎-脑炎的诊断与防治过程。     

A serological survey of Akabane virus infection in cattle and sheep in northwest China

Purpose

Akabane disease characterized mainly by fetal damage is a ruminant disease caused by insect-transmitted Akabane virus infection.

Methods

We investigated Akabane disease using serum neutralization tests in 446 blood samples collected from 187 cattle and 259 sheep of Xinjiang province, northwest China.

Results

(1) The overall prevalence rate of neutralizing antibody was 19.06?% (85/446), (2) the prevalence rates of Akabane disease in cattle and sheep were 20.32?% (38/187) and 18.15?% (47/259), respectively, (3) the disease prevalence rates were not significantly different between cattle and sheep, but significantly different among samples collected from different sampling months, (4) the disease was most prevalent in July when mosquitoes and culicoides were most active, and (5) the disease prevalence rates were significantly different between individuals with abortion experience and without abortion experience (P?<?0.05), suggesting that Akabane virus infection may significantly increase abortion risk in cattle and sheep.

Conclusions

To our knowledge, this is the first report confirming that Akabane virus infection is common in cattle and sheep of Xinjiang province, northwest China and providing useful epidemiological information for cattle and sheep abortion prevention and control.     

Border disease of sheep: the disease in the newborn, adolescent and adult.

Border disease (BD) is a condition of newborn sheep that results from congenital infection by a non-cytopathic pestivirus occurring during the first half of gestation. The expression of the virus is largely determined by the age of the fetus at the time of infection, producing four distinct disease syndromes: (1) early embryonic death, (2) abortion and stillbirth, (3) birth of lambs with malformations, and (4) birth of small, weak lambs, lacking characteristic clinical signs, but bearing features of immunosuppression. The effects of the virus infection during the developmental stages of the fetus are most apparent as distinctive clinical signs at the time of birth but a state of specific immuno-tolerance with associated virus persistence remains for the lifetime of the sheep. Although the clinical signs disappear with time, some effects of virus persistence may continue into adolescence and often into adulthood. Characteristic lesions are found in the nervous, endocrine, skeletal and integumentary, and immune systems.     

绵羊种布鲁菌致病机制与防控研究进展

布鲁菌病(Brucellosis)是一种高度流行的人畜共患传染病,可造成巨大的经济损失,严重制约了当今畜牧业的发展并对人类健康构成了严重威胁。绵羊种布鲁菌病是由绵羊种布鲁菌(Brucella ovis,B.ovis)引起的一种以绵羊生殖系统功能障碍和怀孕绵羊流产为特征的慢性传染性疾病。目前,对于绵羊种布鲁菌的胞内寄生机制和感染机制尚不清楚,现将从病原学、流行病学、致病机制和疾病防控等方面对绵羊种布鲁菌病的研究进展进行概述,为后期挖掘绵羊种布鲁菌的致病机理和与其相关的研究奠定一定的理论基础。     

羊口疮病预防与专业治疗方案

羊口疮病又被称为羊传染性脓疱病,是由羊口疮病毒感染引发的一种高度接触性急性传染性疾病。该病具有传播速度、传播范围广、发病率高的特点,虽然造成的死亡率降低,但是会严重影响羊的正常产生、正常休息,使羊群生长发育不良,身体逐渐消瘦,如果继发感染多种细菌性疾病、病毒性疾病,会加重病情,表现出复杂的临床症状,给疾病的诊断工作带来很大难度。养殖户在发展羊养殖中如果没有做好科学管理,饲料中存在杂质或者饲料坚硬,造成羊口腔出现损伤,给传染性脓疱病的发生流行提供条件。发生流行后如果不能做好针对有效的诊断,易造成病原的扩散蔓延,带来严重损失。该文主要论述羊口疮病的预防和治疗。     

Age-specific seroprevalence of Border disease virus and presence of persistently infected sheep in Basque dairy-sheep flocks

Using p125/p80 antibody and antigen-ELISA tests, age-specific seroprevalence and presence of persistently infected (PI) sheep were investigated in six commercial latxa dairy-flocks, housed for variable periods. The flocks all had a recent history of Border disease (BD). Every flock included seropositive sheep and seven 0.5-3-year-old PI sheep were detected in two of four flocks tested. Age-specific antibody patterns differed according to the presence or absence of PI sheep in the flock. In flocks free of PI sheep, seroprevalence was 6-13% in 1-year-old sheep and 42-93% in older sheep. In contrast, seroprevalence was 67-99% in sheep raised with PI sheep for at least 1 year and 29-33% in replacement 0.5-0.6-year-old sheep (including a PI sheep) indicating that Border disease virus (BDV) transmission in Basque dairy-flocks can be relatively slow. Moderate seroprevalence in young replacement sheep should not discourage further testing to detect PI sheep, and our results highlight the risk of failing to achieve "natural vaccination" prior to pregnancy by mixing PI sheep with BDV-unexposed ewes.     

Persistence of FDMV and its effects on disease control strategies

It is well-known that foot-and-mouth disease virus (FMDV) causes a persistent infection, lasting for more than 28 days, in cattle, sheep, goat as well as some other ruminant species, but not in pigs. Although convincing evidence for virus transmission is missing, these carrier animals have to be considered as a potential risk of infection. Some aspects of FMDV persistence are presented and discussed with regard to disease control strategies.     

Diagnosis of ovine chlamydial abortions by PCR-RFLP performed on vaginal swabs

Ovine enzootic abortion is an infectious and contagious disease clinically characterized by abortion and weak neonates, affecting sheep and goats. The etiological agent is Chlamydophila (C.) abortus, which is considered one of the most common animal pathogens of small ruminants; it has important economic implications and represents a significant zoonotic risk. Clinical diagnosis is often difficult because the clinical signs and the pathological lesions are not specific for C. abortus infection, in fact they can also be observed as a result of infections with other abortifacient agents. Moreover, the involvement of the laboratory is necessary to perform the definitive diagnosis. One hundred and seventeen vaginal swabs from sheep with clinical signs related to chlamydial infection were examined by a PCR-RFLP assay that demonstrated high specifity and sensitivity. Six samples were positive for C. abortus. Vaginal swabs are easy to handle and allow to deal with biohazardous material in safety conditions.     

影响持续感染的因素研究进展

持续感染是指病原体在宿主体内持续存在而不被清除的状态,其潜伏期长达数月至数年甚至终生,但不引起症状,病原体不一定持续增殖。不同病原体所致持续感染的定义不同,如口蹄疫病毒(FMDV)引起的持续感染被定义为动物感染28d后仍然携带活的病毒。持续感染是造成免疫失败、肿瘤形成或药物敏感性下降的重要原因。存在持续感染的宿主是重要的传染源,还是病原体发生变异的来源,但因无症状常被忽视。充分了解持续感染的形成机理及持续感染状态中宿主与病原体之间的相互作用,有助于寻找诊断、治疗和预防感染性疾病的最佳方法。论文从病原体和宿主因素两个方面阐述了持续感染的形成机理。