Recent information on tick-borne diseases (II)

Tick-borne encephalitis (central european encephalitis) and Lyme disease (erythema chronicum migrans) are diseases mainly transmitted by ticks of the ixodus ricinus species. The tick-borne encephalitis, a virus infection, can produce severe encephalitic symptoms. There is no specific treatment but the infection can be prevented by active or passive immunization. Lyme disease is caused by a spirochete (borrelia burgdorferi). Due to the variety of often uncharacteristic symptoms this infection is not easily recognized. However, early diagnosis and antibiotic treatment are necessary to prevent chronic damage to skin, joints, heart or nervous system.     

Ten years of clinical experiences with canine parvovirus infection CPV-2 infection)]

Clinical and laboratory data of 205 dogs with acute canine parvovirus infection were collected. Seventy-six of these dogs underwent 179 clinical reexaminations. Parvovirus infection can be clinically diagnosed if there are typical gastrointestinal symptoms (vomiting, diarrhoea) in combination with a leucopenia of under 4000 cells/microliters and/or a rise in antibody titer of two degrees or more. In typical parvovirus infection a distinct hyperthermia often precedes vomiting and diarrhoea. The characteristic fall in leucocyte concentration is rapid and most marked between the 3rd and 5th day of the disease. In some cases virus-induced encephalitis and moderate coincident involvement of the cardiac muscle were seen. Secondary bacterial infections of subcutaneous tissue and lungs as well as invaginations are important complications. Surviving dogs will not necessarily have digestive problems later. Therapeutical considerations are discussed.     

鳖鳃腺炎的病原和病理学研究现状和问题

介绍了鳖鳃腺炎的一般临床症状、病原学和病理学研究现状以及实际生产中的防治办法。对病毒感染,细菌感染,环境因素和其他因素的研究进行了阐述,总结了目前生产中预防和治疗的方法,提出对"鳃腺炎"病名的质疑,疾病模型的研究是急需解决的问题。     

The effectiveness of the paramunity inducer Baypamun (PIND-ORF) for the prevention and metaphylaxis of an experimental infection with the infectious bovine rhinotracheitis virus in cattle

Efficacy of the paramunity inducer Baypamun (PIND-ORF) was evaluated by an IBR challenge trial in cattle, as one model for infectious diseases in bovine. Prophylactic treatment with Baypamun protected cattle against manifestation of clinical symptoms after experimental IBR infection. The degree of protection depended on the time between paramunization and challenge infection. Even in metaphylactically paramunized cattle Baypamun reduced the IBR symptoms. In correlation to the reduction of clinical symptoms paramunization also reduced virus excretion by more than 99% in treated cattle compared to non paramunized animals. The induction of interferon following IBR infection was investigated in paramunized cattle. Application of Baypamun enabled treated animals to react faster with interferon synthesis following IBR infection than control animals did. The demonstration of the status of paramunity following Baypamun application in cattle provides a concept in the prevention of infectious disease in the practice.     

Immune intervention in Borna disease]

Borna disease is a naturally occurring meningoencephalomyelitis of sheep and horses. After experimental infection of rats with Borna disease virus a biphasic disease with initial gait disturbances and later paresis and paralysis can be observed. The disease symptoms in these experimental animals resemble those of the natural hosts. The disease is not caused by the infecting virus itself but rather by a CD4+ T cell-mediated immune response. After the pathogenesis had been elucidated new strategies for the therapy of Borna disease by interfering with the immune reaction have been developed. Treatment with immunosuppressive drugs, with monoclonal antibodies directed against certain immune cells and with mediators of the immune reaction resulted in an inhibition or significant reduction of Borna disease symptoms.     

Ocular manifestations of selected zoonoses in humans]

A report is given on the epidemiology and clinical signs of some selected zoonoses that may be of significance for ocular infections in man: brucellosis, leptospirosis, Lyme borreliosis, lymphocytic choriomeningitis, Newcastle Disease, ornithosis (chlamydiosis), rabies, Streptococcus suis infection, larva migrans ocularis by Toxocara canis or Baylisascaris procyonis, toxoplasmosis and tularemia.     

Borna virus infection (Borna disease) in naturally and experimentally infected animals: its significance for research and practice

In this survey article on Borna Disease-many years after the review of Zwick (1939)-again a modern comprehensive summary of "Borna Disease virus infection" is given. The infection occurs in horses and sheep, furthermore, in laboratory animal species inoculated experimentally; its clinical, virological and neuropathological features have been described in numerous presentations. Clinical symptoms in naturally and experimentally infected animals are characterized by initial alterations in the sensorium. The neurological symptomatology of the disease (disturbances in coordination, motor, sensory and vegetative symptoms) reflect the presumed localisation of the virus in various brain areas and the course of the disease supports the assumption of intraneural spread of the agent. In horses the incidence is highest during spring. Experimental infections show an exceptionally broad spectrum of infectible animals extending from higher mammals to birds. Our investigations make it clear that we have to differentiate between infections followed by disease (e.g. horse, rabbit, older rat) and persistent infections without overt clinical symptoms (mouse, chicken). Persistent infections are sometimes associated with fine alterations in behaviour (tree shrew) or decreased learning ability (mice). Borna Disease virus, which has not been characterized up to now, is known to grow without any cytopathic effect in tissue cultures. All tested cell lines (including those from man) could be infected. The investigations indicate that Borna Disease virus comprises an enveloped RNS-containing agent. The infection induces the production of specific antigens such as a complex known as the soluble antigen, and a 14500 dalton protein. Under natural conditions and in experimentally infected animals antibodies are produced against such soluble proteins and determinants involved in neutralization of the virus. In the central nervous system (CNS) a local immune response accompanied by the production of oligoclonal immunoglobulins is demonstrable. Besides the humoral reaction it was possible to study the influence of cellular defence mechanisms on the disease process in monkeys, rats and rabbits. Histopathologically, Borna Disease is characterized by a non-purulent inflammation of the brain and the spinal cord. Most alterations are found in the grey matter, mainly in the Ammon's horn, olfactory lobe, caudate nucleus, thalamus, lamina quadrigemina and in he cerebellar nuclei. The perivascular infiltrations, consisting of lymphocytes, histiocytes and plasma cells are most conspicuous. Occasionally, degenerative alterations are observed in ganglion cells.(ABSTRACT TRUNCATED AT 400 WORDS)     

青虾“红体病”组织病理学观察

用连续切片的方法对患有红体病的青虾进行组织病理学研究，结果表明患病青虾鳃部、肌肉组织和肝胰腺部位病症比较明显，不同患病阶段组织变形差异显著。鳃片细胞在患病初期表现为胞质收缩，后期则细胞膨胀破裂。细胞内物质外溢，细胞边缘界限不完整；肌肉组织在后期出现肌纤维束之间间隙，且部分肌纤维有断裂的现象；中期肝小叶间隔出现空隙和腺细胞变形，在后期则表现为小叶溃烂。造成青虾因红体病死亡的原因，初期主要是因为鳃片的组织病变导致呼吸困难，进而造成青虾生理异常；后期主要是因为肝胰脏的溃烂造成消化功能全面丧失。     

无乳链球菌不同途径感染吉富罗非鱼后病原菌在体内的分布规律研究

为探讨无乳链球菌(Streptococcus agalactiae)感染罗非鱼(Oreochromis spp)的致病途径。采用腹腔注射、灌胃和浸泡三种方式对吉富罗非鱼进行无乳链球菌(HN016菌株)胁迫感染,利用平板活菌计数法统计三种方式感染后病原菌在体内组织的分布。注射和灌胃两种方式感染后均出现典型的链球菌感染发病症状,其中注射组在感染24 h后出现死亡高峰,死亡率为92.5%;灌胃组感染48 h后出现死亡高峰,死亡率为90%;而浸泡组,感染后均没有出现明显的发病症状,也没有出现死鱼。注射组和灌胃组在感染后2 h,其脾脏、肝脏、前肾、胃、腮、皮肤和肌肉组织中均可分离出病原菌,5 h后在脑组织中均可分离出病原菌,8 h后各组织分离出的病原菌数达到峰值;而浸泡组在感染8 h后才从各组织中分离出病原菌,且它们的数量均低于同时期的注射组和灌胃组。注射和灌胃两种方式可使吉富罗非鱼快速感染无乳链球菌而发病,而浸泡方式感染后病原菌虽可以侵入机体,但不表现出症状。由此,我们推测在自然条件下养殖的罗非鱼是通过口腔采食携带无乳,链球菌的食物而被感染。     

Rabies in cattle

Diagnostic results of the post mortem examinations of the brains of 99 rabies-suspected--but actually not infected--cattle are reported. In 19 cases listeria encephalitis was stated. Furthermore non-purulent encephalitis 9 X, including 1 X malignant catarrhal fever of cattle and 2 X mucosal disease; purulent encephalitis 1 X; corticocerebral necrosis 1 X and arterial sclerosis 1 X were diagnosed. 68 cases proved to be no cerebral disease. By means of the presented diagnostic results and literature, peculiarities of rabies in cattle are discussed in view of differential diagnosis, and practical hints are given.     

Pathogenesis of acute and chronic diseases caused by cyprinid herpesvirus‐3

The pathogenesis of cyprinid herpesvirus‐3 (CyHV‐3) was studied using different lineages of carp/koi. After exposure to the virus, infected cells were first found in the skin by histopathology and by in situ hybridization. The epidermis of the skin was most severely damaged and often sloughed off in the fish sampled on days 5 through 8, and the fish that were highly sensitive to the virus died within 8 or 10 days after infection. Serum osmolality of the infected fish, particularly just before death, was significantly lower, suggesting that the osmotic shock consequent on the damage to the skin was the direct cause of the acute deaths. On the other hand, clinical and histopathological observations indicate that the carp of a less sensitive lineage most probably died of viral encephalitis around 3 weeks after infection. For these fish, the largest number of infected cells was found in the central nervous system (CNS) sampled on day 12. A substantial amount of viral genome was found in the CNS of carp surviving more than 1 year after the infection. Thus, the CNS is probably a major target for CyHV‐3, and the virus can persistently infect the CNS, presumably establishing latency.     

Yersinia ruckeri—A threat not only to rainbow trout

Yersinia ruckeri (Y. ruckeri) can cause mortalities that are contributing to substantial economic losses in the rainbow trout (Oncorhynchus mykiss) aquaculture sector. Because of its most characteristic clinical signs, the disease in rainbow trout caused by this pathogen is called enteric redmouth disease. Although it is considered to affect mainly salmonids, there are reports in the available literature of isolating this bacterium from other fish species, both clinically healthy and diseased. The aim of this study was to analyse the available data concerning yersiniosis in non‐salmonid fish. The analysed data indicate that Y. ruckeri is a threat not only to rainbow trout. Some of the affected species have high commercial importance and mortalities may contribute to high economic losses. The disease symptoms may not be specific and can be different from those characteristic for enteric redmouth in trout, which may lead to misdiagnosis. Collected information indicates that infection with Y. ruckeri should be taken into account in the diagnostic procedures not only in salmonids.     

Neonatal isoerythrolysis in newborn foals]

Aetiology, pathogenesis, clinical symptoms, diagnosis, prophylaxis and therapy of neonatal isoerythrolysis in foals are presented. Neonatal isoerythrolysis is caused by isoimmunisation of a brood mare to the Aa and Qa erythrocyte antigens of the foal. The disease can develop, when the mare does not possess Aa resp. Qa blood group antigens, is sensitized to the Aa or Qa erythrocyte antigens--i.e. through pregnancy, parturition, blood resp. plasma transfusions, etc.--and the foal suckles colostral antibodies to its own blood cells. Aa and Qa antibodies can cause haemagglutination and haemolysis in the foal, with a consequent decline in erythrocytes, PCV and haemoglobin resulting in several clinical symptoms. In most instances the first signs of the disease are noticed by day 2 and 3, ranging from 8 to 96 hours of life. Diagnosis is based upon clinical examination and determination of erythrocyte count, PCV and haemoglobin concentration and can be further confirmed by immunological tests. Several tests can be used to prevent the occurrence of neonatal isoerythrolysis in the newborn foal. Prior to parturition, brood mares can be typed for blood groups and tested for antibodies to Aa and Qa in order to identify mares at risk for causing neonatal isoerythrolysis in the foal. After birth, compatibility of the mare's colostrum and the foal's erythrocytes can be checked by the "jaundice foal agglutination" test. Some instructions for prophylaxis of neonatal isoerythrolysis and for the treatment by red blood cell resp. whole blood transfusions are given.     

养殖大菱鲆主要疾病及防治技术

在流行病学调查的基础上,对目前我国大菱鲆养殖中常见疾病进行了较全面的介绍,包括病毒性、细菌性和寄生虫性疾病。系统地描述了这些疾病的流行特征、发病症状、危害程度、感染率及致病原等。同时为各种疾病提供了具体的防治技术和措施,对大菱鲆养殖生产与疾病防治具有理论指导意义和重要的参考价值。本文系国内首次对养殖大菱鲆疾病进行的全面性报道。     

Experiences in the paraimmunization of cats in veterinary practice

The inducer PIND-AVI was used prophylactically and therapeutically to test the effects of paramunization in a SPF cat colony and in various small animal practices. Prophylactic paramunization significantly improved the breeding results in the SPF cat colony. Mortality declined from 44.6% to 3.4%. The corresponding placebo groups were also tested thereby demonstrating the significance of the results. In comparison, the treatment of acutely diseased cats (all of the same litter or the same colony) showed that paramunization can also be used as an additional measure to the conventional therapy of infectious diseases with different etiology. Furthermore, it is possible that this measure alone can limit the incidence of disease providing the dosage is high enough and treatment is long enough (at least 3-5 days). The course of disease is thereafter mild and complications can be hindered. Chronic and recurrent infections (e.g., dermatitis and gingivitis) can be controlled with repeated paramunization. Prophylactic paramunization decreases the danger of an acute infection and provides for the newborn's fast adaptation to a contaminated environment. It also reduces the consequences of an exogenous and endogenous immune suppression.     

Vaccination of rabbits and fur animals

Short survey of vaccination programmes for rabbits and fur animals and of vaccines, available in Western Germany. Rabbits: myxomatosis, pasteurella infection, dysenteria; mustelides (mink, polecat a.o.): distemper, virus enteritis, botulism, pseudomonas infection; fox: leptospirosis, distemper, fox encephalitis; ocelot: panleukopenia; chinchilla: pseudomonas infection, coli infection, yersinia infection.     

Equine viral arteritis

Equine viral arteritis (EVA) caused by the equine arteritis virus, member of the genus arterivirus within the family of Togaviridae was recently isolated from the seminal plasma of two stallions indicating that the virus infection is also prevalent in the Federal Republic of Germany despite the apparent lack of acute clinical symptoms in the horse population. These findings are further supported by data from serological screenings. Out of 739 horse sera, 28 (3.8%) were found to have EVA virus-specific antibodies with titers greater than or equal to 4. It is important to note that the percentage of sero-positive horses was found to be increased from 1.8% in 1987-1988 to 6.8% in 1989. A voluntary prophylactic programme based on virological and serological tests is proposed to prevent further spread of the EVA virus infection. The pathogenesis, clinical symptoms and diagnosis of EVA are also reviewed.     

IHHN Virus as an Etiological Factor in Runt-Deformity Syndrome (RDS) of Juvenile Penaeus vannamei Cultured in Hawaii

Runtdeformity syndrome (RDS) is an economically significant, frequent disease problem of cultured Penaeus vannamei . RDS is characterized by variable, often greatly reduced, growth rate of up to 30% of a cultured population and many shrimp with cuticle deformities of the rostrum, anterior appendages or other parts. The cause of RDS is undetermined.
Nursery trials comparing histologically IHHN-positive and histologically IHHN-negative Penaeus vannamei cultured under identical conditions were conducted at The Oceanic Institute. The IHHN-positive populations developed RDS symptoms including increased individual size variation, reduced population growth, and high prevalance of rostrum, antennae or cuticle deformity, while the IHHN-negative groups displayed none of these symptoms. No other diseases or parasites were identified in the IHHN-positive populations that would account for the RDS symptoms.
A single commercialele nursery was stocked with histologidly IHHN-positive P. vannamei and a high prevalence of RDS was observed. Shrimp growth was bimodal with a subpopulation growing normally and a subpopulation growing slowly. Significant relationships between shrimp harvest size and IHHN prevalance, selected individual organ IHHN severity grades and IHHN severity index (six organs evaluated) were found. Large, apparently normal shrimp were less severely infected with virus and did not display any cuticle deformities.
In sum, these data provide epidemiological and histopathological evidence for the hypothesis that infection by IHHN virus is the cause of RDS in cultured P. vannamei .     

Diagnosis of liver diseases in dogs, cats and horses

Clinical symptoms of hepatopathies are not specific and must be verified by further investigation. Laboratory diagnosis is a very useful method to decide if liver disease is present or not. In individual cases laboratory methods can give hints as to the aetiology of the illness. If necessary, biopsy, angiography or/and cholecystography can be carried out for further clarification of the diagnosis.     

Transmission dynamics of pancreas disease (PD) in a Norwegian fjord: aspects of water transport,contact networks and infection pressure among salmon farms

Pancreas disease (PD) in marine salmon farming is caused by salmon pancreas disease virus (SPDV). Virus survival, infection pressure and contact networks among farms influence the potential of PD to spread. The present study aims to explore contact networks and infection pressure and their ability to explain transmission dynamics of PD in a Norwegian fjord. In this study, we included all records of PD by subtype 3 (SPDV3) in the study population from the first reported in August 2006 to the last reported in November 2009. Using logistic regression analyses, we found that contact network by water transport explained better transmission of PD than contact networks defined by ownership or close distance to infected farms. Hydrodynamic modelling can be a valuable tool to forecast the spread of PD and thereby take actions to reduce the transmission. Knowing the risk of getting infected, it is important to avoid water transport from infected farms when new cohorts are transferred to sea water, and to have conscious control regarding management operations between farms.