雞傳染性喉氣管炎

1、雞傳染性喉氣管炎Dr. KarstenAugustinskiLAH,CuxhavenChina, March 2009羅曼動物保健，庫克漢文中國. 2009年3月Infectious LaryngotracheitisDefinition定義Infectious Laryngotracheitis (ILT) is a viral infection of the respiratory tract of chickens雞傳染性喉氣管炎（雞傳染性喉氣管炎（ILT）是雞呼吸道的一種病毒感染。是雞呼吸道的一種病毒感染。 pheasants and peafowl can be affected

2、through contact with chickens雉雞和孔雀雉雞和孔雀可以通過與雞接觸感染孔雀可以通過與雞接觸感染ILT is recognized worldwideILT被認為在全球廣泛存在 serious outbreaks occur when ILT virus spreads from persistentlyinfected flocks to non-vaccinated animals在ILT病毒從持續(xù)感染雞群傳播給非免疫雞群時，病毒從持續(xù)感染雞群傳播給非免疫雞群時，嚴重爆發(fā)才發(fā)生 severe forms are of economic importance sin

3、ce they may result insevere production losses due to mortality and/or decreased egg production由于嚴重爆發(fā)的形式，由于嚴重爆發(fā)的形式，引起雞死亡和/或產(chǎn)蛋減少，或產(chǎn)蛋減少，會導致嚴重的生產(chǎn)損失，致嚴重的生產(chǎn)損失，有經(jīng)濟重要性Jones, 2001Etiology病因學ILT is caused by a herpesvirusILT由皰疹病毒引起Family:Herpesviridae皰疹病毒科Subfamily:Alphaherpesvirinae-皰疹病毒亞科Species:Gallidherpe

4、svirus1禽皰疹病毒1型(syn.: Infectious LaryngotracheitisVirus)（命名為：命名為：傳染性喉氣管炎病毒）傳染性喉氣管炎病毒）herpesvirusesare enveloped DNA-viruses 皰疹病毒是有囊膜的DNA病毒 replicate in the nucleus of the host cell 在宿主細胞核內復制 there is one serotypeand strains appear to be antigenicallyhomogeneous 只存在1個血清型，個血清型，不同毒株的抗原性一致。不同毒株的抗原性一致。皰疹病

5、毒導致 herpesvirusleads to formation of type A intranuclearinclusion bodies during first days of infection in tracheal epithelial cells and occasionally in conjunctivalepithelium (diagnostically important)A型核內包含體 herpesviruseslead to persistantinfection of the host宿主的持續(xù)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傳染性喉氣管炎：傳染性喉氣管炎：皰疹病毒Epidemiology流行病學all ages of fowl are susceptible, most characteristic signs are seen in adult birds所有年齡的雞都易感，所有年齡的雞都易感，最為特征性的癥狀見于成年雞 males and h

7、eavier breeds are more susceptible公雞和較重型品種更易感usually well controlled in layers by vaccination通過接種疫苗，通過接種疫苗，通常能夠在蛋雞進行很好的控制within developed countries ILT virus has tended to persist as endemic infection in backyard and fancier chicken flocks在發(fā)達國家，在發(fā)達國家，ILT病毒已經(jīng)趣向于以庭院和觀賞雞群地方流行性感染的形式而持續(xù)存在Pathogenesis I致病

8、機理Isources of infection感染來源acutely infected birds急性感染雞carrier birds攜帶病毒的雞contaminated equipment, animals, personnel, feed, water污染的設備、污染的設備、動物、動物、人員、人員、飼料、飼料、水exsudates from nares, trachea conjunctiva are spread by air來自鼻孔、來自鼻孔、氣管和結膜的排出物，氣管和結膜的排出物，通過空氣傳播Pathogenesis II 致病機理II 致病機理 The virus kills th

9、e cells lining the airways, resulting in variable degrees of inflammation and breathing difficulties Dies quickly in the environment 病毒破壞呼吸道細胞，導致不同程 病毒破壞呼吸道細胞， 度的感染和呼吸困難 Transmission through the egg is not known 在環(huán)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 經(jīng)蛋傳遞未知 發(fā)病康復雞可以攜帶病 毒長達2年 Can survive up to 100 days if protected by organic material Newly hatched chicks are free from infection! 若有有機物的保護， 若有有機物的保護， 有機物的保護 病毒可存活達100天 新出殼小 雞無感染 Pathogenesis III致病機理IIISpread of the disease疾病的傳播natural route of infection is by way of the respi

11、ratory tract and ocular route (eyes). 自然感染途徑是經(jīng)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.潛伏攜帶者通常被限制，潛伏攜帶者通常被限制，因為康復雞或疫苗接種雞會成為攜帶者并長時間地排毒re-excretion of ILT virus from latently infected chicks follow

12、ing the stress of re-housing and the onset of reproduction. 潛伏感染雞在轉群和開產(chǎn)應激后再次排毒usually associated with a break down in bio-security; movement of personnel, dead bird disposal, manure disposal, exchanging farm equipment etc. 通常與生物安全漏洞有關；通常與生物安全漏洞有關；人員移動、人員移動、死雞處理、死雞處理、糞便處理、處理、雞場設備交換等incubation time is

13、 from 6 spreads rather slowly within a few days.12 days, within a flock ILT潛伏期為6-12天，在群內，在群內，ILT的傳播要慢幾天ImmunityI免疫力Ihumoralimmune response體液免疫應答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，可檢測到病毒中和抗體，可檢測到病毒中和抗體，大約感染后

14、21天達到高峰，天達到高峰，可以持續(xù)1年能夠粘附ILT病毒的粘膜抗體（病毒的粘膜抗體（IgA，IgG），感染后），感染后7天即可檢測到mucosalantibodies (IgA, IgG) which are capable of binding ILTV become detectable from 7 days p.i. they are notthe primary mechanisms of protection 它們不是主要的保護機制there is generally a poor correlation between serum antibody titers and imm

15、une status of the flock 通常雞群的血清抗體和免疫狀態(tài)之間的相關性差mucosalantibodies are not essential in preventing replication in the trachea粘膜抗體在防止病毒在氣管中復制方面不是必要的Immunity II免疫力IIcell mediated immune response細胞免疫應答principal mediator of ILT resistanceILT抵抗力的主要調節(jié)者 maternal antibodies母源抗體不產(chǎn)生抗感染的保護，不產(chǎn)生抗感染的保護，也不干擾疫苗接種do not

16、 confer protection against infection or interfere with vaccinationClinical findings臨床所見severity of the disease varies with virulence of the virus field strain and the resistance of the bird疾病的嚴重性，疾病的嚴重性，隨著感染毒株的毒力和感染雞只的抵抗性而變化mild form溫和型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，可見：可見：結膜炎、結膜炎、眼流淚、眼流淚、鼻有分泌物、鼻有分泌物、眶下竇腫脹、眶下竇腫脹、產(chǎn)蛋下降Clinical findings臨床所見acute severe form 急性嚴重型marked dyspnea(loud gasping, coughing)明顯呼吸困難（明顯呼吸困難（大聲喘息、大聲喘息、咳嗽）咳嗽）severe affected chickens often

18、 raise and extend their head and neck during inspiration and make wheezing sounds嚴重感染雞經(jīng)常在吸氣期間抬伸頭和頸expectoration of bloody mucus (may be seen on beaks, faces, or feathers) 帶血粘液的痰(可見于喙、可見于喙、糞便或羽毛)high morbidity (50 70%), considerable mortality (normally 10 20 %)發(fā)病率高(50-70%)，死亡多(通常10-20%)disease lasts

19、for 2 6 weeks in a flock在一群內，在一群內，疾病持續(xù)達2-6周Clinical signs臨床癥狀Clinicalsigns臨床癥狀Clinical signs臨床癥狀Pathology病理學gross lesions are in most cases restricted to the upper respiratory tract and vary with the severity of the disease大體病變，大體病變，在大多數(shù)病例中限于上呼吸道，多數(shù)病例中限于上呼吸道，并隨疾病的嚴重程度而變化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氣管和喉部組織的變化，氣管和喉部組織的變化，可以從氣管有粘液、從氣管有粘液、輕度結膜炎和竇炎到出血性和/或白喉性變化 inflammation may extend to bronchi and air sacks炎癥可以延伸到支氣管和氣囊bloody or caseousexudates occurring in trachea cause

21、frequently obstructive plugs in the trachea氣管中產(chǎn)生的帶血的或干酪樣的滲出物，氣管中產(chǎn)生的帶血的或干酪樣的滲出物，常常引起氣管阻塞 hemorrhagic inflammation of the cloacae泄殖腔出血性炎癥histologically intranuclear inclusion bodies can be seen in epithelial cells組織學檢查，組織學檢查，可在上皮細胞中見到核內包含體Lesions病變病變Lesions病變Lesions病變LesionsLesions病變Lesions病變病變Lesions

22、Diagnosis診斷in the more severe forms gasping respiration and hemorrhages in trachea and cloaca are diagnostic of ILT在較為嚴重的病型中，在較為嚴重的病型中，喘氣性呼吸以及氣管和泄殖腔的出血具有ILT的診斷意義mild form cannot be differentiated from other mild respiratory diseases溫和型，溫和型，不能與其它溫和型呼吸道疾病histologically demonstration of eosinophilic in

23、tranuclear inclusions bodies in the respiratory and conjunctival epithelium during early stages of the disease is pathognomonic發(fā)病早期，發(fā)病早期，組織學證實上呼吸道和結膜上皮的嗜酸性核內包含體，呼吸道和結膜上皮的嗜酸性核內包含體，有特殊診病意義demonstration of viral antigen in tracheal epithelium with fluorescent antibodies用熒光抗體證實氣管上皮中的病毒isolation of ILT v

24、irus on CAM of embryonated chicken eggs (typical plaques) or in chicken embryo liver cultures雞胚絨毛尿囊膜上ILT病毒的分離（病毒的分離（典型噬斑典型噬斑）噬斑）或雞胚肝細胞中ILT病毒的分離ILT: Plaques on CAM絨毛尿囊膜上的噬斑Serology血清學is of limited use in confirming infection 確認感染，確認感染，作用有限but may be useful in monitoring the spread of the infection or

25、 for vaccination control但可用于監(jiān)測感染的傳播或疫苗接種控制 detection methods of ILTV antibodies in serum血清中ILTV抗體的檢測方法agar-gel immunodiffusion瓊脂凝膠沉淀virus neutralisation病毒中和ELISA酶聯(lián)免疫吸附試驗cave: serum antibodies are of no value for protection against ILTV infection注意：注意：血清抗體對于ILTV感染的預防沒有價值there is no relationship betwe

26、en the route of application ofvaccine and the mean ELISA titer (Fulton et al., 2000)疫苗使用途徑與ELISA抗體滴度之間，抗體滴度之間，沒有相關性(Fulton等, 2000)Differential diagnosis鑒別診斷all diseases affecting the respiratory tract diphtheritic form of avian poxvirus infections caused byNDVAIVIBVFowl adenovirusAspergillus spp.Pne

27、umovirus (ART)Avibacterium paragallinarum Mycoplasma gallisepticum所有侵襲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雞新城疫病毒禽流感病毒傳染性支氣管病毒禽腺病毒曲霉菌肺病毒（肺病毒副雞嗜血桿菌（ART）雞毒支原體Control I控制Ipremises contaminated with ILTV should be depopulated, cleaned, disinfected, and left empty for 4 6 weeks before re-stockingILTV感染場，感染場，應將雞群淘汰、應

28、將雞群淘汰、清潔、清潔、消毒，消毒，并在重新進雞前空舍4-6周virus destruction is enhanced by heating up contaminated poultry houses (38 40C for 72 hours)通過熱處理（通過熱處理（38-40 C，72h）污染雞舍，污染雞舍，可促進病毒滅活 Effective control requires the full co-operation of all segments of the industry.No secrets!進行有效控制，進行有效控制，需要行業(yè)所有部門的通力合作Farm bio-securi

29、ty is a MUST.Re-evaluate your farm bio-security, but more importantly it has to be implemented雞場生物安全是必需的。雞場生物安全是必需的。再次評估你雞場的生物安全，再次評估你雞場的生物安全，但更為重要的是必須嚴格執(zhí)行Control II控制IIpoultry workers must not have contact to other poultry家禽工作者一定不要接觸其它家禽staff working on more than one farm need to change cloth compl

30、etely and shower before entering在超過1個雞場工作的員工，個雞場工作的員工，需要徹底更換衣服，需要徹底更換衣服，并在進場前淋浴control traffic between farms: Do not use same equipment or same vehicles in affected and non-affected farms控制雞場之間的交通：控制雞場之間的交通：在感染和非感染雞場中，在感染和非感染雞場中，不使用相同的設備和車輛schedule farm visits from uninfected to infected and younger

31、 to older flocks安排農(nóng)場來訪人員從非感染場到感染場并從較小雞群到較大雞群Control III控制IIIvaccination in the face of an outbreak limits virus spread and shortens duration of disease在疾病爆發(fā)時接種疫苗，在疾病爆發(fā)時接種疫苗，可限制病毒傳播并縮短病程 in endemic areas attenuated vaccines should be administered在疫區(qū)，在疫區(qū)，應該使用弱毒疫苗when vaccinating all birds on one farm

32、or even in one integration / region have to vaccinated to avoid spread to susceptible birds接種疫苗時一個農(nóng)場乃至一個一條龍企業(yè)/地區(qū)的所有雞，有雞，都必須進行疫苗接種，都必須進行疫苗接種，以避免蔓延到易感雞avoid adding vaccinated or recovered (latently infected carrier birds) with susceptible chickens避免增加免疫雞或康復雞到易感雞群中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 已經(jīng)通過雞胚或細胞培養(yǎng)的系列傳代，已經(jīng)通過雞胚或細胞培養(yǎng)的系列傳代，將ILTV野毒株致弱 attention must be given to procedures of vaccine administration to ensure adequate immunisation:致弱，致弱，必須適宜于疫苗接種程序，必須適宜于疫苗接種程序，確保免疫力 this includes concentratio

34、n of infective virus 這包括感染性病毒的濃縮and route of administration和接種途徑 inactivated vaccines滅活疫苗 showed varying degrees of protection顯示不同程度的保護Routes of administration接種途徑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：由于病毒通過鼻孔和后鼻孔吸入，由于病毒通過鼻孔和后鼻孔吸入，疫苗病毒接觸到鼻上皮是必需的vaccinated birds closer to the water source were better protected 飲水免疫的雞，飲水免疫的雞，接近水源的要比水線末段的得到更好的保護 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)當進行噴霧免疫時，當進行噴霧免疫時，某些疫苗根本不提供保護（某些疫苗根本不提供保護（但是：但是：小霧滴可以引起穿透呼吸道深部application by was shown to provide more uniform protection經(jīng)Fulton et al., 2000Incorrect use of vaccines疫苗的非正確使用spread from vaccine virus to non-vaccinates疫苗病毒傳播給非免疫雞production of latently infected c

37、arriers產(chǎn)生潛伏感染攜帶者increased virulence as a result of in vivo(bird-to-bird) passage由于體內(雞-雞)傳代，傳代，導致毒力增強Does virulence of vaccine virusincrease after sequential in vivopassage?體內連續(xù)傳代后，體內連續(xù)傳代后，疫苗病毒的毒力增強嗎？疫苗病毒的毒力增強嗎？two live vaccines兩種活疫苗chicken embryo-origin virus 雞胚來源病毒tissue culture-origin virus組織培養(yǎng)來源

38、病毒sequential passage in SPF chicken用SPF雞連續(xù)傳代 result: after 10 passages in chickens the embryo-origin virus possessed increased virulence comparable to that of a highly virulent reference strain結果：結果：經(jīng)雞傳10代后，代后，雞胚源病毒增加的毒力相當于強毒參考毒株的毒力improper application of vaccines allow uncontrolled spread of vaccin

39、e virus to non-vaccinated, and sequential in vivopassage of vaccine viruses may occur疫苗使用不當，疫苗使用不當，可導致疫苗病毒不可控地傳播到非免疫雞，疫苗病毒的體內連續(xù)傳代可以發(fā)生。疫苗病毒的體內連續(xù)傳代可以發(fā)生。Guy et al., 1991AviPro ILT (Eye-drop) 雞傳染性喉氣管炎活疫苗（點眼） 雞傳染性喉氣管炎活疫苗（點眼） single application round about the 7th. Week 大約7周時單劑量使用 little loss of vaccine 幾乎沒有疫苗損失 save deliverance (important for vaccines with low titers ） 釋放劑量不足（疫苗效價低） diluent is necessary 必須用稀釋液 labor consuming 耗費勞力 protecti