Immunoperoxidase study of canine distemper virus pneumonia

Forty-two cases of canine pneumonia were examined for the presence of canine distemper virus. For that purpose canine distemper virus inclusion bodies were located. The histopathological lesions were related to the presence of canine distemper antigen, as demonstrated with an immunoperoxidase technique. This technique was more sensitive for detecting canine distemper infection in lung tissue than was the study of inclusion bodies. Attention was also paid to combined infection with canine adenovirus and Bordetella bronchiseptica.     

Cell-mediated immunity and age at vaccination associated with measles inoculation and protection of dogs against canine distemper.

The antibody-mediated immune response (AMIR) of dogs to measles and canine distemper viruses has been described. However, there is little information on the cell-mediated immune response (CMIR). The AMIR and the CMIR of dogs to canine distemper and to measles were examined. The CMIR was determined for 6 weeks by measuring the 3H-thymidine uptake by immune lymphocytes in the lymphocyte transformation test. Concurrently, canine distemper and measles virus serum-neutralization antibodies were measured by a microtitration serum-neutralization test. Dogs vaccinated with canine distemper virus had a CMIR and an AMIR to canine distemper. However, measles virus-vaccinated dogs had only a CMIR to canine distemper. A CMIR in the absence of an AMIR indicates that cell-mediated immunity is the most important immune mechanism in protecting measles virus-vaccinated dogs against canine distemper. Development of CMIR and AMIR to canine distemper and measles antigens depended on the age of the dog at the time of vaccination. Adult and juvenile dogs had immune responses to both canine distemper and measles. Neither virus, however, elicited an immune response in neonates.     

RT-PCR方法检测犬瘟热的流行情况

犬瘟热是由犬瘟热病毒引起的犬科烈性传染病,给患病动物带来重大危害。本研究基于犬瘟热病毒的NP蛋白基因设计特异性引物,利用RT-PCR获得287 bp目的片段,经TA克隆并测序。结果表明,该片段与NCBI上公布的犬瘟热病毒NP序列(登录号:EU716322)同源性达到98%。利用该特异性的RT-PCR方法,检测杭州市及周边部分地区犬瘟热的流行情况,结果表明,整个杭州及周边地区犬瘟热病毒总阳性检出率为6.7%,杭州城区阳性个体数最多,阳性率最高达到18.8%,其他地方(临安、台州、舟山)阳性率较低。该研究为犬瘟热的综合防制提供基础数据。     

Magnetic resonance imaging findings in acute canine distemper virus infection

Demyelination is the prominent histopathological hallmark in the acute stage of canine distemper virus infection. Magnetic resonance imaging is an important diagnostic tool in human beings to determine demyelination in the brain, for example in multiple sclerosis. Five young dogs with clinically suspected canine distemper virus infection were subjected to magnetic resonance imaging of the brain and histopathological and immunohistochemical examinations. Hyperintense lesions and loss of contrast between grey and white matter were detected in T2-weighted images in the cerebellum and/or in the brainstem of three dogs, which correlated with demyelination demonstrated in histopathological examination. Furthermore, increased signal intensities in T2-weighted images were seen in the temporal lobe of four dogs with no evidence of demyelination. Magnetic resonance imaging seems to be a sensitive tool for the visualisation of in vivo myelination defects in dogs with acute canine distemper virus infection. Postictal oedema and accumulation of antigen positive cells have to be considered an important differential diagnosis.     

Thrombocytopenia associated with vaccination of a dog with a modified-live paramyxovirus vaccine

Thrombocytopenia (10,000/mm3), with hematochezia and melena, appeared in a dog 8 days after it was given modified-live canine distemper, virus vaccine and persisted for approximately 5 days. Clinical investigation discounted other possible causes of thrombocytopenia; the condition was considered to be associated with vaccination. The problem spontaneously resolved. The appearance of thrombocytopenia after modified-live canine distemper virus vaccination is not unknown and may assume a severe form. This condition may be mistaken for idiopathic thrombocytopenia of immune origin, and in other instances, it may contribute significantly to surgical risk if concurrent coagulation disorders are present. Administration of levamisole HCl may alleviate the decrease in platelet count in affected animals.     

水貂犬瘟热流行病学调查

为了调查山东省水貂犬瘟热的流行病学情况,对2010年8月－2012年8月期间由诸城、文登等地养貂场送诊的996份水貂病例进行了临床诊断和病原学检查。结果显示,共检出犬瘟热病毒阳性病料223份,阳性率为22.39%。其中,犬瘟热病毒与其他病原混合感染136例,占阳性病例的60.99%;阳性样本中未免疫病例116个;诸城检出阳性病例数最多,为147例;3月龄水貂发病率最高,占阳性病例的43.0%;水貂感染犬瘟热病毒主要症状为眼、鼻黏液性分泌物增多、脚垫增厚、呼吸困难;主要病理变化为肠、脑部出血。结果表明,犬瘟热依然是危害水貂养殖的重要疫病,且犬瘟热病毒易与其他病原混合感染;免疫接种能有效预防水貂犬瘟热,且宜在3月龄以前进行。     

Effects of vaccines on the canine immune system.

The effects of several commercially available polyvalent canine vaccines on the immune system of the dog were examined. The results demonstrated that the polyvalent vaccines used in this study significantly suppressed the absolute lymphocyte count and that most of the polyvalent vaccines significantly suppressed lymphocyte response to mitogen, but had no effect on natural effector cell activity, neutrophil chemiluminescence, nor antibody response to canine distemper virus. The individual vaccine components from the polyvalent vaccines when inoculated alone did not significantly suppress the lymphocyte response to mitogen. However, when canine distemper virus was combined with canine adenovirus type 1 or canine adenovirus type 2, significant suppression in lymphocyte responsiveness to mitogen occurred. The results indicate that interactions between canine distemper virus and canine adenovirus type 1 or canine adenovirus type 2 are responsible for the polyvalent vaccine induced suppression of lymphocyte responsiveness.     

犬瘟热的诊治

犬瘟热是一种由犬瘟热病毒引起的犬科动物急性传染病,病犬以双相热、鼻炎、严重的消化障碍和呼吸道炎症为特征。主要对该病的病原、流行病学、临床症状及病理变化等作一阐述,并以一例犬瘟热典型病例的诊治为例,介绍了治疗该病的有效措施,以期为有效防治犬瘟热提供参考。     

Simultaneous Growth of Rabies and Canine Distemper Viruses in Chick Embryos

Rabies virus and canine distemper virus were grown simultaneously, and possibly symbiotically, in the same chick embryos. There seemed to be no adverse effect on either virus when cultured in such manner.

Bivalent vaccines for rabies and canine distemper were produced. The potencies and the virus titers of such vaccines were comparable to those of rabies vaccine and canine distemper vaccine produced separately.

     

犬瘟热病毒感染机制及其诊断方法研究进展

本综述介绍了犬瘟热病毒的6种结构蛋白N、P、L、F、H和M蛋白在病毒入侵宿主和宿主细胞内繁殖的功能;简要描述了犬瘟热病毒入侵动物机体感染传播的机制,其中细胞受体SLAM和PVRL4解释病毒的趋向性;介绍了临床诊断、试验动物法、血清学方法和核酸诊断等鉴别诊断犬瘟热的方法及其优缺点.通过系统了解犬瘟热病毒的感染途径及其诊断方法,有助于发现控制犬瘟热病毒传播的新方法.     

Post-vaccinal distemper encephalitis in two Border Collie cross littermates

Abstract

CASE HISTORY: One 4.5-month-old male Border Collie cross presented with aggression and seizures in October 2006. A 16-month-old, female, spayed Border Collie cross presented with hypersalivation and a dropped jaw and rapidly became stuporous in September 2007. The dogs were littermates and developed acute neurological signs 5 and 27 days, respectively, after vaccination with different modified live vaccines containing canine distemper virus.

HISTOPATHOLOGICAL FINDINGS: Sections of brain in both dogs showed evidence of encephalitis mainly centred on the grey matter of brainstem nuclei, where there was extensive and intense parenchymal and perivascular infiltration of histiocytes and lymphocytes. Intra-nuclear and intra-cytoplasmic inclusions typical of distemper were plentiful and there was abundant labelling for canine distemper virus using immunohistochemistry.

DIAGNOSIS: Post-vaccinal canine distemper.

CLINCIAL RELEVANCE: Post-vaccinal canine distemper has mainly been attributed to virulent vaccine virus, but it may also occur in dogs whose immunologic nature makes them susceptible to disease induced by a modified-live vaccine virus that is safe and protective for most dogs.     

Absence of rabies encephalitis in a raccoon with concurrent rabies and canine distemper infections

Concurrent infection of a raccoon by rabies and canine distemper viruses is described. Fluorescent antibody (FA) test demonstrated rabies antigen in the brain of this animal, however, histologically only lesions characteristic of canine distemper infection were seen. We recommend testing tissues for rabies of animals that histologically are positive for canine distemper.     

小熊猫源犬瘟热病毒全基因序列的克隆及序列分析

本研究对军事兽医研究所病毒二室分离驯化后的小熊猫源犬瘟热病毒(canine distemper virus,CDV)基因组进行全序列测定,并对其基因组特征及H基因遗传稳定性进行比较分析。根据GenBank公布的犬瘟热病毒全长基因组序列设计合成17对特异性引物,以小熊猫源犬瘟热病毒总RNA为模板,RT-PCR进行分段扩增,并克隆到pEASY-Blunt Simple载体中,经测序、拼接获得全长cDNA序列。结果显示,小熊猫源犬瘟热病毒全基因序列与GenBank登录号分别为AF014953、AY445077、AY542312、AY466011、AY386316、AF164967、EU716337、EU726268、AY443350、AB474397、GU138403和AY649446的12个不同毒株全基因序列的同源性分别为86.6%、92.4%、92.5%、92.5%、94.3%、96.3%、95.9%、87.1%、94.5%、92.3%、87.4%和94.6%,与标准强毒株A75/17株(AF164967)的亲缘关系最近,全基因同源性达96.3%,但与疫苗株Onderstepoort(AF014953)亲缘关系相对较远,同源性为86.6%。小熊猫源犬瘟热病毒H基因与其他不同地区具有代表性的30株CDV进化树分析显示,小熊猫源犬瘟热病毒属于Asia Ⅰ型,H蛋白中309－311位氨基酸残基所形成的潜在糖基化位点,为疫苗株没有而野毒株所共有的,并且可能与病毒的免疫原性有关。因此,致弱的小熊猫源CDV在预防免疫的针对性上可能强于已有的疫苗株。     

Comparison of tissue and fluid samples for the early detection of canine distemper virus in experimentally infected dogs

The clinical utility of various specimens was examined for the early diagnosis of canine distemper (CD). Seven healthy dogs at 17 weeks of age were experimentally infected with a field isolate of canine distemper virus. The RT-PCR was carried out to detect CDV NP gene. Dogs showed mild fever and leukopenia, however, typical clinical signs of CD were not seen through the experimental period. CDV amplicons were detected more, earlier and for longer period in the conjunctival swabs than in the other samples employed. These results suggested that conjunctival swab samples, which are easy to obtain and non-invasive, would be the most suitable and practical specimen for the early antemortem diagnosis of CDV infection.     

Canine distemper viral antigens and antibodies in dogs with rheumatoid arthritis

Dogs with canine rheumatoid arthritis had significantly elevated levels of antibodies to canine distemper virus. This increase was particularly seen in the synovial fluids, compared with paired sera, and was not found in dogs with infective arthropathies, osteoarthritis or in osteoarthritis secondary to rupture of the cranial cruciate ligament. Analysis of the immune complexes precipitated from synovial fluids showed immunoglobulins in all types of arthropathy. Western blotting analyses showed reactivity with anti-distemper antisera in immune complexes from dogs with rheumatoid arthritis, but not in immune complexes from dogs with other joint diseases. These results suggest that there are increased immune responses to distemper in canine arthritis and that these may be due to the presence of this paramyxovirus in affected joints. The implications for the role of a possible infectious agent in rheumatoid arthritis in the dog are considerable.     

Dog lymphocyte cultures facilitate the isolation and growth of virulent canine distemper virus.

Optimal conditions for the isolation and growth of virulent canine distemper virus (CDV) in canine thymic and peripheral blood lymphocyte cultures were determined. Peak virus titers were seen from 3 to 6 days postinoculation of lymphocytes and depended on the multiplicity of infection. Dog lymphocytes were at least as susceptible as canine macrophages to infection with virulent CDV. Virus replication in lymphocytes resulted in higher virus titers than in dog lung macrophages. Peripheral blood lymphocytes (PBL) from CDV-immune dogs were as susceptible to CDV as were PBL from susceptible dogs.     

急性犬瘟热感染组织脏器的研究

临床中犬瘟热多分为急性和亚急性,3月龄犬多发本病,急性病例和亚急性病例的临床症状和病毒复制的脏器与慢性病例有很大区别。临床上急性病例的病变主要集中在肺脏和淋巴组织,组织病理学可观察到淋巴结炎和多核巨细胞性肺炎。根据免疫组织化学染色结果发现,在犬瘟热急性病例的淋巴结皮质中犬瘟热抗原呈强阳性,且密度很高。而病犬虽然表现出严重的肺炎症状,但在犬的肺脏中犬瘟热病毒抗原阳性反应弱,仅在支气管上皮和少量的巨噬细胞胞浆中观察到。犬瘟热病毒首先在犬的淋巴组织中进行复制、增殖,破坏被膜下淋巴窦和淋巴小节中的T淋巴细胞和B淋巴细胞,影响淋巴组织输出到外周血液循环中的淋巴细胞数量。本研究结果表明,犬瘟热虽然临床上以肺脏病变最严重,但在急性和亚急性病例,犬瘟热病毒主要在淋巴组织的T淋巴细胞、B淋巴细胞和巨噬细胞中增殖,故应以淋巴组织作为犬瘟热病毒的主要分离脏器。