鸡传染性喉气管炎

1、鸡传染性喉气管炎Dr. KarstenAugustinskiLAH,CuxhavenChina, March 2009罗曼动物保健，库克汉文中国. 2009年3月Infectious LaryngotracheitisDefinition定义Infectious Laryngotracheitis (ILT) is a viral infection of the respiratory tract of chickens鸡传染性喉气管炎（鸡传染性喉气管炎（ILT）是鸡呼吸道的一种病毒感染。是鸡呼吸道的一种病毒感染。 pheasants and peafowl can be affected

2、through contact with chickens雉鸡和孔雀雉鸡和孔雀可以通过与鸡接触感染孔雀可以通过与鸡接触感染ILT is recognized worldwideILT被认为在全球广泛存在 serious outbreaks occur when ILT virus spreads from persistentlyinfected flocks to non-vaccinated animals在ILT病毒从持续感染鸡群传播给非免疫鸡群时，病毒从持续感染鸡群传播给非免疫鸡群时，严重爆发才发生 severe forms are of economic importance sin

3、ce they may result insevere production losses due to mortality and/or decreased egg production由于严重爆发的形式，由于严重爆发的形式，引起鸡死亡和/或产蛋减少，或产蛋减少，会导致严重的生产损失，致严重的生产损失，有经济重要性Jones, 2001Etiology病因学ILT is caused by a herpesvirusILT由疱疹病毒引起Family:Herpesviridae疱疹病毒科Subfamily:Alphaherpesvirinae-疱疹病毒亚科Species:Gallidherpe

4、svirus1禽疱疹病毒1型(syn.: Infectious LaryngotracheitisVirus)（命名为：命名为：传染性喉气管炎病毒）传染性喉气管炎病毒）herpesvirusesare enveloped DNA-viruses 疱疹病毒是有囊膜的DNA病毒 replicate in the nucleus of the host cell 在宿主细胞核内复制 there is one serotypeand strains appear to be antigenicallyhomogeneous 只存在1个血清型，个血清型，不同毒株的抗原性一致。不同毒株的抗原性一致。疱疹病

5、毒导致 herpesvirusleads to formation of type A intranuclearinclusion bodies during first days of infection in tracheal epithelial cells and occasionally in conjunctivalepithelium (diagnostically important)A型核内包含体 herpesviruseslead to persistantinfection of the host宿主的持续感染 naturally occuringILT virus st

6、rains vary in virulence from highly virulent strains to strains of low virulence自然存在的ILT病毒株，病毒株，有高毒力到低毒力的不同。有高毒力到低毒力的不同。ILT: Herpesvirus传染性喉气管炎：传染性喉气管炎：疱疹病毒Epidemiology流行病学all ages of fowl are susceptible, most characteristic signs are seen in adult birds所有年龄的鸡都易感，所有年龄的鸡都易感，最为特征性的症状见于成年鸡 males and h

7、eavier breeds are more susceptible公鸡和较重型品种更易感usually well controlled in layers by vaccination通过接种疫苗，通过接种疫苗，通常能够在蛋鸡进行很好的控制within developed countries ILT virus has tended to persist as endemic infection in backyard and fancier chicken flocks在发达国家，在发达国家，ILT病毒已经趣向于以庭院和观赏鸡群地方流行性感染的形式而持续存在Pathogenesis I致病

8、机理Isources of infection感染来源acutely infected birds急性感染鸡carrier birds携带病毒的鸡contaminated equipment, animals, personnel, feed, water污染的设备、污染的设备、动物、动物、人员、人员、饲料、饲料、水exsudates from nares, trachea conjunctiva are spread by air来自鼻孔、来自鼻孔、气管和结膜的排出物，气管和结膜的排出物，通过空气传播Pathogenesis II 致病机理II 致病机理 The virus kills th

9、e cells lining the airways, resulting in variable degrees of inflammation and breathing difficulties Dies quickly in the environment 病毒破坏呼吸道细胞，导致不同程 病毒破坏呼吸道细胞， 度的感染和呼吸困难 Transmission through the egg is not known 在环境中很快死亡 Birds that recover from ILT may be carriers of the virus for a prolonged period

10、 of up to two years ILT 经蛋传递未知 发病康复鸡可以携带病 毒长达2年 Can survive up to 100 days if protected by organic material Newly hatched chicks are free from infection! 若有有机物的保护， 若有有机物的保护， 有机物的保护 病毒可存活达100天 新出壳小 鸡无感染 Pathogenesis III致病机理IIISpread of the disease疾病的传播natural route of infection is by way of the respi

11、ratory tract and ocular route (eyes). 自然感染途径是经呼吸道和眼the latent carrier usually defined as recovered birds or vaccinated chickens become carriers and can shed the virus for long periods of time.潜伏携带者通常被限制，潜伏携带者通常被限制，因为康复鸡或疫苗接种鸡会成为携带者并长时间地排毒re-excretion of ILT virus from latently infected chicks follow

12、ing the stress of re-housing and the onset of reproduction. 潜伏感染鸡在转群和开产应激后再次排毒usually associated with a break down in bio-security; movement of personnel, dead bird disposal, manure disposal, exchanging farm equipment etc. 通常与生物安全漏洞有关；通常与生物安全漏洞有关；人员移动、人员移动、死鸡处理、死鸡处理、粪便处理、处理、鸡场设备交换等incubation time is

13、 from 6 spreads rather slowly within a few days.12 days, within a flock ILT潜伏期为6-12天，在群内，在群内，ILT的传播要慢几天ImmunityI免疫力Ihumoralimmune response体液免疫应答virus-neutralizing antibodies are detectable 5 -7 days after infection, peak around 21 days p.i., may persist for a year 感染后5-7天，可检测到病毒中和抗体，可检测到病毒中和抗体，大约感染后

14、21天达到高峰，天达到高峰，可以持续1年能够粘附ILT病毒的粘膜抗体（病毒的粘膜抗体（IgA，IgG），感染后），感染后7天即可检测到mucosalantibodies (IgA, IgG) which are capable of binding ILTV become detectable from 7 days p.i. they are notthe primary mechanisms of protection 它们不是主要的保护机制there is generally a poor correlation between serum antibody titers and imm

15、une status of the flock 通常鸡群的血清抗体和免疫状态之间的相关性差mucosalantibodies are not essential in preventing replication in the trachea粘膜抗体在防止病毒在气管中复制方面不是必要的Immunity II免疫力IIcell mediated immune response细胞免疫应答principal mediator of ILT resistanceILT抵抗力的主要调节者 maternal antibodies母源抗体不产生抗感染的保护，不产生抗感染的保护，也不干扰疫苗接种do not

16、 confer protection against infection or interfere with vaccinationClinical findings临床所见severity of the disease varies with virulence of the virus field strain and the resistance of the bird疾病的严重性，疾病的严重性，随着感染毒株的毒力和感染鸡只的抵抗性而变化mild form温和型in ILT virus infections of low pathogenic strains conjunctivitis

17、, watery eyes, nasal discharge, swollen infraorbitalsinuses, lowered egg productionILT病毒低致病性毒株感染，病毒低致病性毒株感染，可见：可见：结膜炎、结膜炎、眼流泪、眼流泪、鼻有分泌物、鼻有分泌物、眶下窦肿胀、眶下窦肿胀、产蛋下降Clinical findings临床所见acute severe form 急性严重型marked dyspnea(loud gasping, coughing)明显呼吸困难（明显呼吸困难（大声喘息、大声喘息、咳嗽）咳嗽）severe affected chickens often

18、 raise and extend their head and neck during inspiration and make wheezing sounds严重感染鸡经常在吸气期间抬伸头和颈expectoration of bloody mucus (may be seen on beaks, faces, or feathers) 带血粘液的痰(可见于喙、可见于喙、粪便或羽毛)high morbidity (50 70%), considerable mortality (normally 10 20 %)发病率高(50-70%)，死亡多(通常10-20%)disease lasts

19、for 2 6 weeks in a flock在一群内，在一群内，疾病持续达2-6周Clinical signs临床症状Clinicalsigns临床症状Clinical signs临床症状Pathology病理学gross lesions are in most cases restricted to the upper respiratory tract and vary with the severity of the disease大体病变，大体病变，在大多数病例中限于上呼吸道，多数病例中限于上呼吸道，并随疾病的严重程度而变化changes in tracheal and laryn

20、geal tissues may vary from mucus in the trachea, mild conjunctivitis and sinusitis up to hemorrhage and/or diphtheritic changes气管和喉部组织的变化，气管和喉部组织的变化，可以从气管有粘液、从气管有粘液、轻度结膜炎和窦炎到出血性和/或白喉性变化 inflammation may extend to bronchi and air sacks炎症可以延伸到支气管和气囊bloody or caseousexudates occurring in trachea cause

21、frequently obstructive plugs in the trachea气管中产生的带血的或干酪样的渗出物，气管中产生的带血的或干酪样的渗出物，常常引起气管阻塞 hemorrhagic inflammation of the cloacae泄殖腔出血性炎症histologically intranuclear inclusion bodies can be seen in epithelial cells组织学检查，组织学检查，可在上皮细胞中见到核内包含体Lesions病变病变Lesions病变Lesions病变LesionsLesions病变Lesions病变病变Lesions

22、Diagnosis诊断in the more severe forms gasping respiration and hemorrhages in trachea and cloaca are diagnostic of ILT在较为严重的病型中，在较为严重的病型中，喘气性呼吸以及气管和泄殖腔的出血具有ILT的诊断意义mild form cannot be differentiated from other mild respiratory diseases温和型，温和型，不能与其它温和型呼吸道疾病histologically demonstration of eosinophilic in

23、tranuclear inclusions bodies in the respiratory and conjunctival epithelium during early stages of the disease is pathognomonic发病早期，发病早期，组织学证实上呼吸道和结膜上皮的嗜酸性核内包含体，呼吸道和结膜上皮的嗜酸性核内包含体，有特殊诊病意义demonstration of viral antigen in tracheal epithelium with fluorescent antibodies用荧光抗体证实气管上皮中的病毒isolation of ILT v

24、irus on CAM of embryonated chicken eggs (typical plaques) or in chicken embryo liver cultures鸡胚绒毛尿囊膜上ILT病毒的分离（病毒的分离（典型噬斑典型噬斑）噬斑）或鸡胚肝细胞中ILT病毒的分离ILT: Plaques on CAM绒毛尿囊膜上的噬斑Serology血清学is of limited use in confirming infection 确认感染，确认感染，作用有限but may be useful in monitoring the spread of the infection or

25、 for vaccination control但可用于监测感染的传播或疫苗接种控制 detection methods of ILTV antibodies in serum血清中ILTV抗体的检测方法agar-gel immunodiffusion琼脂凝胶沉淀virus neutralisation病毒中和ELISA酶联免疫吸附试验cave: serum antibodies are of no value for protection against ILTV infection注意：注意：血清抗体对于ILTV感染的预防没有价值there is no relationship betwe

26、en the route of application ofvaccine and the mean ELISA titer (Fulton et al., 2000)疫苗使用途径与ELISA抗体滴度之间，抗体滴度之间，没有相关性(Fulton等, 2000)Differential diagnosis鉴别诊断all diseases affecting the respiratory tract diphtheritic form of avian poxvirus infections caused byNDVAIVIBVFowl adenovirusAspergillus spp.Pne

27、umovirus (ART)Avibacterium paragallinarum Mycoplasma gallisepticum所有侵袭呼吸道的疾病禽痘病毒的白喉形式由以下病原引起的感染鸡新城疫病毒禽流感病毒传染性支气管病毒禽腺病毒曲霉菌肺病毒（肺病毒副鸡嗜血杆菌（ART）鸡毒支原体Control I控制Ipremises contaminated with ILTV should be depopulated, cleaned, disinfected, and left empty for 4 6 weeks before re-stockingILTV感染场，感染场，应将鸡群淘汰、应

28、将鸡群淘汰、清洁、清洁、消毒，消毒，并在重新进鸡前空舍4-6周virus destruction is enhanced by heating up contaminated poultry houses (38 40C for 72 hours)通过热处理（通过热处理（38-40 C，72h）污染鸡舍，污染鸡舍，可促进病毒灭活 Effective control requires the full co-operation of all segments of the industry.No secrets!进行有效控制，进行有效控制，需要行业所有部门的通力合作Farm bio-securi

29、ty is a MUST.Re-evaluate your farm bio-security, but more importantly it has to be implemented鸡场生物安全是必需的。鸡场生物安全是必需的。再次评估你鸡场的生物安全，再次评估你鸡场的生物安全，但更为重要的是必须严格执行Control II控制IIpoultry workers must not have contact to other poultry家禽工作者一定不要接触其它家禽staff working on more than one farm need to change cloth compl

30、etely and shower before entering在超过1个鸡场工作的员工，个鸡场工作的员工，需要彻底更换衣服，需要彻底更换衣服，并在进场前淋浴control traffic between farms: Do not use same equipment or same vehicles in affected and non-affected farms控制鸡场之间的交通：控制鸡场之间的交通：在感染和非感染鸡场中，在感染和非感染鸡场中，不使用相同的设备和车辆schedule farm visits from uninfected to infected and younger

31、 to older flocks安排农场来访人员从非感染场到感染场并从较小鸡群到较大鸡群Control III控制IIIvaccination in the face of an outbreak limits virus spread and shortens duration of disease在疾病爆发时接种疫苗，在疾病爆发时接种疫苗，可限制病毒传播并缩短病程 in endemic areas attenuated vaccines should be administered在疫区，在疫区，应该使用弱毒疫苗when vaccinating all birds on one farm

32、or even in one integration / region have to vaccinated to avoid spread to susceptible birds接种疫苗时一个农场乃至一个一条龙企业/地区的所有鸡，有鸡，都必须进行疫苗接种，都必须进行疫苗接种，以避免蔓延到易感鸡avoid adding vaccinated or recovered (latently infected carrier birds) with susceptible chickens避免增加免疫鸡或康复鸡到易感鸡群中Vaccines疫苗live vaccines活疫苗field strain

33、s of ILTV have been attenuated by sequential passage in embryonatedchicken eggs or cell cultures 已经通过鸡胚或细胞培养的系列传代，已经通过鸡胚或细胞培养的系列传代，将ILTV野毒株致弱 attention must be given to procedures of vaccine administration to ensure adequate immunisation:致弱，致弱，必须适宜于疫苗接种程序，必须适宜于疫苗接种程序，确保免疫力 this includes concentratio

34、n of infective virus 这包括感染性病毒的浓缩and route of administration和接种途径 inactivated vaccines灭活疫苗 showed varying degrees of protection显示不同程度的保护Routes of administration接种途径premise for successful immunisation: it is required that the vaccine virus has contact to the nasal epithelium as a result of aspirating

35、the virus through naresor choanae成功免疫的前提：成功免疫的前提：由于病毒通过鼻孔和后鼻孔吸入，由于病毒通过鼻孔和后鼻孔吸入，疫苗病毒接触到鼻上皮是必需的vaccinated birds closer to the water source were better protected 饮水免疫的鸡，饮水免疫的鸡，接近水源的要比水线末段的得到更好的保护 some vaccines did not provide protection at all when applied by (but: a small droplet size may result in de

36、ep penetration of therespiratory tract)当进行喷雾免疫时，当进行喷雾免疫时，某些疫苗根本不提供保护（某些疫苗根本不提供保护（但是：但是：小雾滴可以引起穿透呼吸道深部application by was shown to provide more uniform protection经Fulton et al., 2000Incorrect use of vaccines疫苗的非正确使用spread from vaccine virus to non-vaccinates疫苗病毒传播给非免疫鸡production of latently infected c

37、arriers产生潜伏感染携带者increased virulence as a result of in vivo(bird-to-bird) passage由于体内(鸡-鸡)传代，传代，导致毒力增强Does virulence of vaccine virusincrease after sequential in vivopassage?体内连续传代后，体内连续传代后，疫苗病毒的毒力增强吗？疫苗病毒的毒力增强吗？two live vaccines两种活疫苗chicken embryo-origin virus 鸡胚来源病毒tissue culture-origin virus组织培养来源

38、病毒sequential passage in SPF chicken用SPF鸡连续传代 result: after 10 passages in chickens the embryo-origin virus possessed increased virulence comparable to that of a highly virulent reference strain结果：结果：经鸡传10代后，代后，鸡胚源病毒增加的毒力相当于强毒参考毒株的毒力improper application of vaccines allow uncontrolled spread of vaccin

39、e virus to non-vaccinated, and sequential in vivopassage of vaccine viruses may occur疫苗使用不当，疫苗使用不当，可导致疫苗病毒不可控地传播到非免疫鸡，疫苗病毒的体内连续传代可以发生。疫苗病毒的体内连续传代可以发生。Guy et al., 1991AviPro ILT (Eye-drop) 鸡传染性喉气管炎活疫苗（点眼） 鸡传染性喉气管炎活疫苗（点眼） single application round about the 7th. Week 大约7周时单剂量使用 little loss of vaccine 几乎没有疫苗损失 save deliverance (important for vaccines with low titers ） 释放剂量不足（疫苗效价低） diluent is necessary 必须用稀释液 labor consuming 耗费劳力 protecti