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1.
L REDDACLIFF P KIRKLAND A PHILBEY R DAVIS L VOGELNEST F HULST D BLYDE A DEYKIN J SMITH P HOOPER A GOULD A HYATT 《Australian veterinary journal》1999,77(8):522-528
OBJECTIVE: To investigate whether preparations containing Wallal and/or Warrego viruses could cause disease when inoculated subcutaneously into captive kangaroos. DESIGN AND PROCEDURE: Four groups of two kangaroos, seronegative to both Wallal and Warrego virus, were each inoculated with wild Wallal virus, cultured Wallal virus, wild Warrego virus, or wild Warrego virus followed by wild Wallal virus after 3 weeks. A single uninoculated animal served as a control. Animals were monitored weekly under anaesthesia, examined ophthalmoscopically (including fundic photography), and samples collected for haematological and serum biochemical analysis, virus isolation, PCR and serological examination for antibodies against Wallal and Warrego viruses. Animals inoculated with cultured Wallal virus were killed at week 10, and remaining kangaroos were reinoculated with cultured Wallal virus at week 12. RESULTS: Virus was isolated from the blood of two kangaroos 2 weeks after inoculation with Wallal virus preparations, and from a third kangaroo 2 weeks after reinoculation. By 3 weeks after inoculation, all kangaroos given Wallal virus preparations had seroconverted to Wallal virus and one had seroconverted to Warrego virus. Fundic changes were detected in the three viraemic kangaroos 4 or more weeks after inoculation, and lesions were present in the eye and brain typical of those seen in field cases of chorioretinitis. No other kangaroos had lesions. Wallal virus was identified by PCR and immunohistochemical analysis in the retina of one affected animal and orbivirus-like particles were seen by electron microscopy in the remains of retinal cells. CONCLUSION: The condition of chorioretinitis was reproduced in three of eight kangaroos by inoculation with preparations containing Wallal virus. 相似文献
2.
P T Hooper G M Russell P W Selleck R A Lunt C J Morrissy M A Braun M M Williamson 《Veterinary microbiology》1999,68(1-2):89-93
Immunohistochemistry plays an important part in the diagnosis of some viral diseases. Demonstration of viral antigen in a lesion is an important contribution to diagnosis, either at the time of investigation or retrospectively. At the CSIRO Australian Animal Health Laboratory, the most frequent use of immunohistochemistry has been in the diagnosis of the important avian diseases, highly pathogenic avian influenza and Newcastle disease. The technology took key roles in the diagnoses of Hendra virus infections, and, later, an immunoperoxidase test gave the first indication of the existence of Australian bat lyssavirus. The test can often confirm that a virus isolated in an animal is the actual virus causing disease and not a coincidental isolation. Good examples of that in some more new diseases were the association of Wallal virus with blindness in kangaroos, and of the new porcine Menangle virus in natural and experimental cerebral disease in foetal piglets. 相似文献
3.
Epidemiology and control of Menangle virus in pigs 总被引：6，自引：0，他引：6
Kirkland PD Love RJ Philbey AW Ross AD Davis RJ Hart KG 《Australian veterinary journal》2001,79(3):199-206
OBJECTIVE: To describe the epidemiology and eradication of Menangle virus infection in pigs. DESIGN: Field observations and interventions, structured and unstructured serological surveys, prospective and cross-sectional serological studies and laboratory investigations. PROCEDURE: Serum samples were collected from pigs at a 2600-sow intensive piggery in New South Wales that experienced an outbreak of reproductive disease in 1997. Serum samples were also collected from piggeries that received pigs from or supplied pigs to the affected piggery and from other piggeries in Australia. Serum and tissue samples were collected from pigs at piggeries experiencing reproductive disease in New South Wales. Sera and faeces were collected from grey-headed flying foxes (Pteropus poliocephalus) in the region of the affected piggery. Serum samples were tested for neutralising antibodies against Menangle virus. Virus isolation was attempted from faeces. RESULTS: Following the outbreak of reproductive disease, sera from 96% of adult pigs at the affected piggery, including sows that produced affected litters, contained neutralising antibodies against Menangle virus. Neutralising antibodies were also detected in sera from 88% of finisher pigs at two piggeries receiving weaned pigs from the affected piggery. No evidence of Menangle virus infection was found in other piggeries in Australia. In cross-sectional studies at the affected piggery, colostral antibodies were undetectable in most pigs by 14 to 15 weeks of age. By slaughter age or entry to the breeding herd, 95% of pigs developed high antibody titres (> or = 128) against Menangle virus in the virus neutralisation test. Menangle virus was eradicated from the affected piggery following a program of serological testing and segregation. Neutralising antibodies against Menangle virus were also detected in P poliocephalus from two colonies in the vicinity of the affected piggery. Two piggery workers were infected with Menangle virus. There was no evidence of infection in cattle, sheep, birds, rodents, feral cats and a dog at the affected piggery. CONCLUSIONS: Serological evidence of infection with Menangle virus was detected in pigs at a piggery that had experienced reproductive disease, in pigs at two associated piggeries and in fruit bats in the region of the piggery. Two humans were infected. The mode of transmission between pigs is unknown, but spread by faecal or urinary excretion is postulated. This virus can be eradicated by the segregation of pigs into discrete age groups. 相似文献
4.
云南省乙型脑炎病毒宿主和媒介研究 总被引：18，自引：0，他引：18
于１９７８年至１９９７年,从云南猪血液和乳猪脑组织中分离到乙型脑炎（ＪＥ）病毒５株,从蝙蝠脑组织中分得ＪＥ病毒１０株,从鸟类脑组织中分得ＪＥ病毒５株,从１５种蚊虫体内分离到ＪＥ病毒６３株,从２种蠓类中分得ＪＥ病毒２株。分析认为,猪是ＪＥ病毒的主要扩散宿主,蝙蝠和鸟类在该病毒保存和传播中起重要作用;三带喙库蚊是该病毒的主要传播媒介,伪杂鳞库蚊、霜背库蚊、蚊腿库蚊、白蚊伊和刺扰伊蚊为重要媒介,蠓类亦可 相似文献
5.
Roman M Pogranichniy Bruce H Janke Thomas G Gillespie Kyoung-Jin Yoon 《Journal of veterinary diagnostic investigation》2003,15(2):191-194
A commercial swineherd in Indiana experienced high death loss of nursery pigs with neurologic disorders for a prolonged period. Polioencephalomyelitis was the consistent histopathological lesion in affected animals. A porcine enterovirus (PEV) classified to group I was isolated from spinal cords and brains collected from the affected animals. The isolate (ISUVDL 200103183) was determined to belong to either serogroup 5 or 6 at the National Veterinary Services Laboratories, Ames, IA. No other significant viral or bacterial agents were isolated from or detected in the animals. A prospective longitudinal serological monitoring of pigs in the index herd for the PEV isolate revealed that colostrum-derived neutralizing antibodies to the virus rapidly declined, and by the age of 21 days the majority of piglets had no or minimal neutralizing antibody against the virus. Seroconversion to the virus then coincided with increased mortality in the herd. Results of diagnostic and cohort observations supported a diagnosis of PEV infection as the cause of the prolonged outbreak of "polio." Investigation into factors that may be contributing to the prolonged problem is currently in progress. 相似文献
6.
Serodiagnosis of acute toxoplasmosis in macropods 总被引：1，自引：0，他引：1
The sera of 34 Australian macropods, the brains of which had been bioassayed for Toxoplasma gondii, were used to establish that a titre greater than 1/32 was significant for a direct agglutination test against toxoplasmosis. In addition, the concentration of 2-mercaptoethanol required to destroy the IgM fraction of macropod serum was confirmed in a modified direct agglutination test. To further validate the tests, the serological responses of three eastern grey kangaroos (Macropus giganteus) dosed orally with T. gondii oocysts and one M. giganteus injected with T. gondii cysts were studied. The tests were then used to investigate a diagnosis of acute toxoplasmosis in four Tasmanian pademelons (Thylogale billardierii) clinically suspected of acquiring toxoplasmosis naturally. One hundred and fifty-one Bennett's wallabies (Macropus rufogriseus rufogriseus) and 85 T. billardierii were also tested to determine the prevalence of acute toxoplasmosis of macropods in the wild. Four percent of M. r. rufogriseus and 1.2% of T. billardierii possessed T. gondii-specific IgM in their sera. 相似文献
7.
T.D. St.George 《Veterinary microbiology》1985,10(6):493-504
Twenty-two sentinel cattle were observed daily during an outbreak of ephemeral fever on a dairy farm in eastern Australia in the summer of 1981–192. Of the 22 cattle, 9 developed clinical ephemeral fever. None developed sub-clinical infection. The pattern of the epidemic was a single index case followed 10 days later by the main epidemic wave which lasted for 7 days. This wave stopped when there were still 14 uninfected susceptible animals remaining in the sentinel group, and when biting flies were very active. Ten isolations of bovine ephemeral fever virus were made in Aedes albopictus tissue cultures from the blood of 5 clinical cases. One hundred and twelve isolations of CSIRO Village virus and one each of Kimberley and Akabane viruses were also made from various members of the sentinel group. There was serological evidence that infections with Tibrogargan, Tinaroo and Aino viruses also occurred in 6 cattle in the observation period. The 13 cattle undergoing a sub-clinical viraemia with CSIRO Village virus, Tibrogargan, Kimberley, Akabane or Aino viruses at the time of the main outbreak, appeared to be temporarily protected against ephemeral fever. However, 9 of the 11 still remaining in the herd were susceptible in a subsequent outbreak of ephemeral fever 2 years later. Evidence is presented that subclinical infections with other arboviruses may limit an ephemeral fever epidemic by providing temporary protection by interference. 相似文献
8.
R A Crandell C W Livingston M J Shelton 《Journal of veterinary diagnostic investigation》1989,1(1):62-65
An epizootic of abortions, weak lambs, stillbirths, and congenital arthrogryposis-hydranencephaly occurred in a sheep flock in West Texas. The outbreak began during the first week of January 1987 and continued through the third week of February 1987. Lambs born after February 1987 were not affected. A high incidence of antibodies to Cache Valley virus (Texas 7856 isolate) was demonstrated in the ewes' serum and in precolostral serum from affected lambs. No virus was isolated from tissues and body fluids of the affected lambs. The clinical, pathological, and immunological features of the epizootic were similar to those reported in Akabane virus infection in sheep. Although serological findings strongly suggest Cache Valley virus as the etiological agent of this outbreak, transmission studies are needed. 相似文献
9.
Cave JG McLaren PJ Whittaker SJ Rast L Stephens A Parker EM 《Australian veterinary journal》2008,86(4):130-135
OBJECTIVE: To report an outbreak of congenital chondrodystrophy in calves in South East Australia. METHODS: District veterinarians investigated reported cases of calf deformities. Owners of affected herds were interviewed using a standard questionnaire to identify potential risk factors. Dams of several affected calves were serologically tested for Akabane virus, Aino virus, pestivirus and bluetongue, and affected calves were tested for pestivirus antigen and serum immunoglobulin concentrations. Gross and histopathological examinations of numerous calves were performed, concentrating on the musculoskeletal system. RESULTS: A case definition of distinctive skeletal deformities was established, and 89 property owners reported calves with chondrodystrophy in Spring 2003, 2004 or 2005. Some 14 property owners reported affected calves in more than one year. Prevalence and severity of deformity varied greatly between and within properties. None of breed, sex, age of dam, lineage, pasture type, supplementary feeding, fertiliser use or toxic plants was consistently associated with the disease. All dams experienced hot, dry conditions during the first trimester of pregnancy and were exposed to adverse conditions thereafter. Consistently dams were reported to have been grazing undulating to hilly terrain during early pregnancy. All serological tests were negative for Akabane virus, Aino virus, pestivirus and bluetongue. Histopathology of affected skeletal samples showed chondrodysplasia. CONCLUSION: The outbreak had similarities with previous outbreaks reported in the region. No specific aetiology could be determined. There is some evidence that the cause of the deformities could be a manganese deficiency during foetal development. Ongoing work to test this hypothesis is therefore warranted. 相似文献
10.
P. W. Physick-Sheard J. B. Hopkins R. D. O'Connor 《The Canadian veterinary journal. La revue veterinaire canadienne》1980,21(2):53-60
An outbreak of nervous disease and abnormally hairy fleece was observed among newborn lambs in a closed flock of sheep in southern Ontario. The outbreak was investigated and found to closely parallel syndromes described in the British Isles and Australia and variously referred to as border disease, hypomyelinogenesis congenita and hairy shaker syndrome. Clinically affected lambs represented only a portion of the animals affected, considerable losses being caused by reproductive failure in the ewes and suboptimal performance in subclinically affected lambs. Sheep from the affected flock showed a strong serological response to the causative agent of bovine virus diarrhea/mucosal disease. The episode appeared to be chronologically related to the introduction of beef heifers from a sales barn. The paper discusses the results of clinico-epidemiological investigation of the outbreak in the light of current knowledge of border disease-like syndromes. 相似文献
11.
Ross River Virus (RRV) was believed to be the cause of acute illness in four horses around the Bellarine peninsula in south-west Victoria, Australia. The horses presented with clinical signs including petechial haemorrhages, lymphadenopathy, distal limb swelling and reluctance to move. Fibrinogen was also elevated in three of the four horses. Whilst no virus was isolated, serological testing revealed elevated RRV IgM titres in all horses indicating acute infection. The outbreak occurred at a time when a known RRV vector, the mosquito Aedes camptorhynchus was recorded at very high levels in the region. This report is one of very few to attribute specific signs of disease to RRV in horses in conjunction with serological evidence of infection. Aust Vet J 2008;86:367-370. 相似文献
12.
Serum samples from pig herds in Great Britain have been examined for antibodies to influenza virus since 1968. Antibodies to H3N2 virus strains have been found since 1968 and the serological data presented here suggests that H3N2 virus strains continue to persist in the pig population. An outbreak of acute respiratory disease occurred in a 400-sow unit. The outbreak was characterised by coughing, anorexia, fever, inappetence and loss of condition. The gilts and weaners were affected and the morbidity approached 100 per cent. An influenza A virus designated A/Swine/Weybridge/117316/86 (H1N1) was isolated from the herd and 28 paired serum samples from the affected animals showed increases in the haemagglutination inhibition titres to this isolate. Haemagglutinin and neuraminidase characterisation indicated that the virus is similar to H1N1 viruses isolated recently from pigs in Europe. A total of 91 herds experiencing respiratory disease were investigated, of which 42 gave positive reactions in the haemagglutination inhibition test. Antibodies to A/Port Chalmers/1/73 (H3N2) were also detected in some of the herds but it is not known whether this strain plays any role in the current respiratory disease problems in pigs. 相似文献
13.
OBJECTIVE: To provide information on possible ecological determinants of infection with Echinococcus granulosus in a beef pastoral area of northern Queensland. PROCEDURE: An ecological study was carried out on the prevalence and viability of infection with Echinococcus granulosus in definitive and potential intermediate hosts, and their predator prey relationships. Seven adjacent extensive beef properties 100 km south of Townsville, that included areas of savannah, open woodland and dense closed scrub, were selected for the study. Infection with E granulosus in dingoes was determined at post mortem, and in domestic dogs by examining duodenal mucus after purging with arecoline hydrobromide. Cattle, wild pigs and macropods were examined at post mortem for viable hydatid cysts. The diet of dingoes was investigated by identifying the hair of prey species found in their stomach and colon, and that of domestic dogs by questioning their owners. RESULTS: Prevalence of hydatidosis in adult cattle ranged from 41% in animals from properties with large areas of dense closed scrub, to 3% on properties with little or no scrub. Hydatid cysts were found in 21.8% of black-striped wallabies (Macropus dorsalis), 9.4% of feral pigs, 1.5% of wallaroos (Macropus robustus), and 1.4% of eastern grey kangaroos (Macropus giganteus). No rufous rat kangaroos (Aepyprymnus rufescens) or swamp wallabies (Wallabia bicolor) were infected. Most cysts in macropods were viable, whereas in pigs about half were viable and in cattle only 0.7% contained viable protoscoleces. Infection with E granulosus was detected in 76% of dingoes, whereas no infection was detected in domestic dogs in the study area. CONCLUSIONS: It was concluded that the sylvatic cycle of E granulosus in the study area was maintained mainly through predation of black-striped wallabies by dingoes, and that the verges of dense scrub were the main nidus of infection. 相似文献
14.
OBJECTIVE: To determine the susceptibility of the agile wallaby (Macropus agilis) and the dusky pademelon (Thylogale brunil) to infection with Trypanosoma evansi. METHOD: Two agile wallabies and three dusky pademelons were experimentally infected with between 5 x 10(4) and 10 x 10(4) T evansi from a cryopreserved stabilate isolated from an indonesian buffalo. Animals were observed twice daily for clinical signs and blood was collected every 3 days to determine parasitaemia. Necropsy was conducted on animals that died or were euthanised when in extremis and representative tissue sections examined. RESULTS: All wallabies developed a high parasitaemia by 6 days after infection, which persisted until death or euthanasia in extremis, between days 8 and 61. Clinical signs included anorexia, weakness and ataxia. Anaemia occurred in one wallaby that survived for 61 days. Gross pathological changes varied between animals. They included pericarditis, serous atrophy of fat, splenomegaly, ulcerative gastritis and enteritis. Histological changes were characterised by a mononuclear cell infiltration of the connective tissue of most organs with little cellular destruction. Striking lesions were seen in the choroid, heart, stomach and small intestine. CONCLUSION: Agile wallabies and pademelons are highly susceptible to infection with T evansi. Wallabies, therefore, have the potential to spread T evansi within New Guinea and Australia if infection is introduced. Mortality is likely to be high thereby acting as an indicator of recent introduction. Histological changes seen in wallabies infected with T evansi are diagnostic for infections occurring in Australia and Papua New Guinea. 相似文献
15.
16.
Salem virus (SalV) is a recently identified equine virus belonging to the family Paramyxoviridae. The only known isolate was obtained from a horse that was involved in a disease outbreak of undetermined nature and the circumstances of its isolation suggested an etiologic role. However, the experimental infection of a colostrum-deprived foal failed to reproduce the disease; only mild neutropenia and temperature elevation were recorded. An additional attempt to establish an etiological relationship with the disease was made by conducting a retrospective evaluation of the serological profiles of animals involved in the outbreak. Animals reported as being affected by the disease according to a comprehensive United States Department of Agriculture (USDA) database were found to be 48% (n=27) positive for antibodies to SalV, but the percent positive for all horses, affected and unaffected, was actually higher at 56% (n=62). For 15 affected horses for which paired acute and convalescent serum specimens were available, no unequivocal seroconversions to SalV were identified. Furthermore, the horse from which SalV was isolated was not listed as one of the animals affected by the disease. In total, the evidence suggests that SalV was not the etiological agent of the disease and that its isolation was fortuitous. 相似文献
17.
The lesions and etiologic agents associated with 13 outbreaks of respiratory disease in commercial chickens were investigated. Adenoviruses were isolated from tracheal and lung tissues of affected chickens in all 13 outbreaks. Escherichia coli was isolated from the lung of an occasional bird. The tracheal specimens were consistently negative for Bordetella avium, but E. coli and occasionally Staphylococcus aureus were isolated. There was also serological evidence in one outbreak, and pathological evidence in another, of a concurrent infectious bursal disease virus (IBDV) infection of chickens affected with the disease. Gross and microscopic alterations in the tracheas and lungs of affected chickens were similar in all outbreaks and consisted of catarrhal tracheitis and occasionally multifocal pneumonia with mononuclear cell infiltrates. Hepatitis and splenitis with heterophil infiltrates occasionally were seen in birds with coliform septicemia. The tracheal and lung lesions in the present investigation were considered primarily of adenovirus etiology, complicated by secondary bacterial infection. 相似文献
18.
KA Rose PD Kirkland RJ Davis D Blumstein LI Pritchard KM Newberry RA Lunt 《Australian veterinary journal》2012,90(12)
Epizootics of sudden death in tammar wallabies (Macropus eugenii) occurred at six research facilities and zoological gardens in New South Wales, Australia, in late 1998 and at one Queensland research facility in March 1999. There were 120 confirmed tammar wallaby deaths during this period; however, population censuses indicated that up to 230 tammar wallabies may have died. The majority of animals died without premonitory signs. A small proportion of wallabies exhibited increased respiratory rate, sat with a lowered head shortly before death or were discovered in lateral recumbency, moribund and with muscle fasciculations. Gross postmortem findings consistently included massive pulmonary congestion, mottled hepatic parenchyma and subcutaneous oedema throughout the hindlimbs and inguinal region. Approximately 30% of the animals examined also had extensive haemorrhage within the fascial planes and skeletal muscle of the hindlimb adductors, inguinal region, ventral thorax, dorsal cervical region and perirenal retroperitoneal area. The tissues of affected animals became autolytic within a short period after death. Bacteriological examination of tissues from 14 animals did not provide any significant findings. Toxicological examination of the gastric and colonic contents of four animals did not reveal evidence of brodifacoume or other rodenticides. Viruses from the Eubenangee serogroup of the Orbivirus genus were isolated from the cerebral cortex of nine, and the myocardium of two, tammar wallabies and the liver and intestine of another tammar wallaby. A similar orbivirus was also isolated from the cerebrospinal fluid of another tammar wallaby that died suddenly. The disease agent appears to be a previously unrecognised orbivirus in the Eubenangee serogroup. This is the first report of epizootics of sudden deaths in tammar wallabies apparently associated with an orbivirus infection. 相似文献
19.
ABSTRACT: African horse sickness is an economically highly important non-contagious but infectious Orbivirus disease that is transmitted by various species of Culicoides midges. The equids most severely affected by the virus are horses, ponies, and European donkeys; mules are somewhat less susceptible, and African donkeys and zebra are refractory to the devastating consequences of infection. In recent years, Bluetongue virus, an Orbivirus similar to African horse sickness, which also utilises Culicoides spp. as its vector, has drastically increased its range into previously unaffected regions in northern Europe, utilising indigenous vector species, and causing widespread economic damage to the agricultural sector. Considering these events, the current review outlines the history of African horse sickness, including information concerning virus structure, transmission, viraemia, overwintering ability, and the potential implications that an outbreak would have for Ireland. While the current risk for the introduction of African horse sickness to Ireland is considered at worst 'very low', it is important to note that prior to the 2006 outbreak of Bluetongue in northern Europe, both diseases were considered to be of equal risk to the United Kingdom ('medium-risk'). It is therefore likely that any outbreak of this disease would have serious socio-economic consequences for Ireland due to the high density of vulnerable equids and the prevalence of Culicoides species, potentially capable of vectoring the virus. 相似文献
20.
CSIRO 132 virus, which is new to science in Australia, and probably the world, has been isolated from Culicoides brevitarsis. Electron micrographs show that it resembles a rhabdovirus. Antibodies to the new virus have been detected in water buffaloes and cattle, but not in 58 human beings, 14 camels, 21 dogs, 67 goats, 15 horses, 43 pigs, 154 sheep, 98 wallabies or 38 possums. The distribution of antibodies in cattle lies within the distribution range of C. brevitarsis. It has not so far been associated with disease. The name Tibrogargan is proposed for the new virus. 相似文献