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1.
Ovine scrapie was first recorded in Cyprus in 1985. Subsequently four dairy goats kept in two mixed flocks with affected sheep developed characteristic clinical signs similar to those seen in sheep. Fifteen goats from the two flocks were examined histologically and neurological lesions consistent with a diagnosis of scrapie were found in the four animals and in three others which had subsequently developed early neurological signs. These lesions were similar to those of naturally-affected sheep although neuronal degeneration and vacuolation were more severe in some cases.  相似文献   

2.
The first cases of scrapie were detected in Greece in a flock of sheep in October 1986. All the animals of the affected flock and all sheep in two flocks that were in contact were killed and buried. A systematic investigation of all available cases with signs indicating a neurological disease started in sheep and goats in late 1986, as well as in cattle in 1989. The investigation was based on clinical examination, necropsy or macroscopical examination of the brain and viscera, and histological examination of the brain in all animals except those with coenurosis. Histological examinations of specimens from the spinal cord and other tissues, and if considered necessary bacteriological, toxicological and serological examinations were also carried out. In October 1997, scrapie was diagnosed in sheep of a second flock (a mixed flock of sheep and goats), grazing in a pasture close to the place where scrapie was initially detected. All animals of the second flock were also killed and buried. Diagnosis in the first flock was based on clinical signs and histological lesions, and in the second immunoblotting was also used. Distinctive lesions of scrapie were found in the brain and/or the spinal cord of eight sheep with clinical signs from the two flocks. The lesions were revealed in the brain stem and/or in the cervical spinal cord, and tended to be symmetrical. In one sheep, severe lesions in the cortex of cerebral hemispheres and of the cerebellum were also found. In the brain of two sheep from the second flock the pathological isoform of PrP protein was detected. Despite the eradication scheme applied, scrapie in sheep reappeared after 11 years in a place close to where it occurred initially. This may indicate that the effectiveness of the eradication scheme implemented was not adequate and additional approaches may be needed.  相似文献   

3.
Scrapie was first recorded in Cyprus in 1985 in two flocks of sheep and subsequently the disease was diagnosed in dairy goats kept in mixed flocks with affected sheep. By 1989 scrapie had been diagnosed in 23 flocks. Epidemiological data presented in the present study are essentially from clinicopathological investigations between 1985 and 1989. A total of 356 out of 957 sheep and 10 out of 30 goats examined from flocks in Nicosia, Larnaca and Limassol districts showed histopathological lesions consistent with a diagnosis of scrapie.  相似文献   

4.
This article reports the clinical signs of scrapie occurring in sheep-goat flocks in Italy. The research, carried out on over 500 goats and 550 sheep, yielded an interesting clinical picture, especially of goat scrapie. The affected animals, aged between 2 and 8 years, showed neurological signs that could be classified into three categories: changes in mental status, abnormalities of movement and changes in sensation. Some general clinical signs were also observed. The clinical suspicion was confirmed by histopathological and biochemical investigations.  相似文献   

5.
Six cases of scrapie were confirmed in two separately maintained flocks of moufflon, in both of which the disease appeared to be endemic. The clinical signs and histopathology were indistinguishable from those observed in scrapie-affected domesticated sheep. The pathology included lesions in the cerebral cortex which, although commonly present in scrapie-affected sheep, have not previously been described in the natural disease.  相似文献   

6.
The case histories of the 20 goats affected with natural scrapie which have been examined since 1975 at the Central Veterinary Laboratory, Weybridge, are reviewed. Their ages ranged from two to seven years (median three years, four months) and 85 per cent of them were between two and four years old. The most common clinical signs were hyperaesthesia, ataxia and pruritus. The histories indicated that scrapie can occur in goats which have not been in contact with sheep.  相似文献   

7.
ABSTRACT: One hundred and four scrapie positive and 77 negative goats from 34 Greek mixed flocks were analysed by prion protein gene sequencing and 17 caprine scrapie isolates from 11 flocks were submitted to molecular isolate typing. For the first time, the protective S146 variant was reported in Greece, while the protective K222 variant was detected in negative but also in five scrapie positive goats from heavily infected flocks. By immunoblotting six isolates, including two goat flockmates carrying the K222 variant, showed molecular features slightly different from all other Greek and Italian isolates co-analysed, possibly suggesting the presence of different scrapie strains in Greece.  相似文献   

8.
Programmes based on the identification and treatment of cases and the culling of animals refractory to treatment had failed to eradicate virulent footrot from two districts in the western region of Nepal. From 1993 to 1996 vaccination against two endemic virulent strains of Dichelobacter nodosus was tested for its potential to contribute to the eradication of footrot from the region. Only sheep and goats which had been free of signs of footrot at three inspections at monthly intervals before their annual migration to alpine pastures were eligible for inclusion. From November 1992, the treatment of cases identified during inspections included the injection of specific vaccine. Successfully treated cases migrated with their flocks but were excluded from the vaccine trial. Non-responding cases were culled. Forty combined flocks of sheep and goats (approximately 9500 animals) were used initially to compare three vaccination regimens. Eleven flocks (sheep and goats) were treated with two doses of specific vaccine (group A), nine (sheep and goats) were treated with commercial vaccine followed by specific vaccine (group B) and 10 (sheep and goats) were treated with two doses of commercial vaccine (group C) in March to April 1993 before the annual migration; 10 flocks (sheep and goats) remained unvaccinated (group D). Only sheep and goats free of signs of footrot were allowed to migrate. Nevertheless, virulent footrot recurred in many flocks three months later. However, its prevalence was significantly lower in group A than in the other three groups combined. Groups A, B and C then received the specific vaccine before their migrations in 1994 to 1996; group D remained unvaccinated. The annual programme of inspection and identification and treatment of cases continued for seven years, but the vaccinations ceased after four years. There was no recurrence of virulent footrot after November 1993. After the first season the virulent strains of D nodosus used in the specific vaccine could no longer be isolated, although antigenically distinct, benign strains of the organism persisted in cases of benign footrot.  相似文献   

9.
Scrapie is a transmissible spongiform encephalopathy of sheep and goats, which leads to neurological signs and ends with the death of the infected animal. In Switzerland only a few cases were reported since 1982. In 1999, a questionnaire survey was conducted to increase information about neurological diseases in sheep and goat breeding farms. The aim was to estimate the frequency of neurological disorders including Scrapie and to increase the disease awareness of sheep and goat breeders. The main goal of the study was to increase the reporting of suspect cases of Scrapie and its differential diagnoses. Out of a database of all registered farms with at least five breeding sheep or breeding goats a random sample of 4711 was drawn to which anonymous questionnaires were sent. The return rate was 36%. In a parallel study, 150 voluntarily participants were interviewed using the same questionnaire. The results of both parts of the survey coincided. For the years 1997 and 1998, on average 1.0% of the breeding sheep and breeding goats showed neurological signs. 7.7% of the breeders indicated to have observed animals with neurological symptoms in their flock. At the population level, a total of 1954-2336 animals with neurological signs are observed in 691-929 flocks. The minority is reported to the veterinary authorities.  相似文献   

10.
OBJECTIVE: To compare incubation time and clinical signs of scrapie in codon 136/171 alanine-valine/glutamine-glutamine (AVQQ) experimentally inoculated sheep with that in sheep with the more common 136/171 AAQQ genotype. ANIMALS: 60 Suffolk sheep. PROCEDURE: Twenty-seven 171 QQ ewes purchased from 2 private flocks were bred with a 171 QQ Suffolk ram before being inoculated with a 20% solution of scrapie-positive brain homogenate (5 mL, PO) from sheep containing genotypes 136/154/171 AA/arginine-arginine (RR)/QQ, AVRRQQ, and VVRRQQ that had died of scrapie. Ewes had 33 lambs, which were inoculated in the same manner on the day of birth. RESULTS: All 16 genotype 136/154/171 AVRRQQ sheep that died of scrapie were 9 to 11 months of age; clinical signs lasted 1 day to 3 weeks with no wasting and only mild pruritus. The first AARRQQ sheep died with typical clinical signs of scrapie 27 months after inoculation, and 14 were still alive 37 to 42 months after inoculation. The 136/171 AVQQ sheep had minimal accumulation of modified cellular protein (PrP(SC)) as determined by immunohistochemical (IHC) staining within affected cells; thus the severity of clinical signs and time of death were not associated with brain lesions or the amount of PrP(SC) in brain TISSUE OF 136/154/171 AVRRQQ sheep as determined by IHC staining. CONCLUSIONS AND CLINICAL RELEVANCE: The rapid incubation time may have been influenced by the codon 136 genotype, a new unreported valine (V)-dependent strain of scrapie similar to strain SSBP/1, or the inoculum may have contained a traditional strain and a V-dependent or SSBP/1-like strain of scrapie.  相似文献   

11.
Different types of transmissible spongiform encephalopathies (TSEs) affect sheep and goats. In addition to the classical form of scrapie, both species are susceptible to experimental infections with the bovine spongiform encephalopathy (BSE) agent, and in recent years atypical scrapie cases have been reported in sheep from different European countries. Atypical scrapie in sheep is characterized by distinct histopathologic lesions and molecular characteristics of the abnormal scrapie prion protein (PrP(sc)). Characteristics of atypical scrapie have not yet been described in detail in goats. A goat presenting features of atypical scrapie was identified in Switzerland. Although there was no difference between the molecular characteristics of PrP(sc) in this animal and those of atypical scrapie in sheep, differences in the distribution of histopathologic lesions and PrP(sc) deposition were observed. In particular the cerebellar cortex, a major site of PrP(sc) deposition in atypical scrapie in sheep, was found to be virtually unaffected in this goat. In contrast, severe lesions and PrP(sc) deposition were detected in more rostral brain structures, such as thalamus and midbrain. Two TSE screening tests and PrP(sc) immunohistochemistry were either negative or barely positive when applied to cerebellum and obex tissues, the target samples for TSE surveillance in sheep and goats. These findings suggest that such cases may have been missed in the past and could be overlooked in the future if sampling and testing procedures are not adapted. The epidemiological and veterinary public health implications of these atypical cases, however, are not yet known.  相似文献   

12.
An accidental infection from a vaccine was suggested as the explanation for the sudden increase in outbreaks of scrapie in Italy in 1997 and 1998. This paper describes a recent outbreak of scrapie in sheep and goats which were exposed to the same vaccine. No ewes or goats had been imported into the herd since 1992, but a vaccine against Mycoplasma agalactiae had been administered twice, in 1995 and 1997. High rates of crude mortality and scrapie incidence were experienced by both species, all birth cohorts were involved and a large proportion of aged animals was affected. A pattern of brain lesions was observed, with slight differences between the sheep and goats, which was very similar to the pattern observed in animals previously exposed to the same vaccine but clearly different from that observed in the brains of sheep with scrapie in a flock not exposed to the vaccine. Regardless of their exposure status, genotype analysis of the sheep showed the presence of polymorphism only at codon 171. The patterns of both incidence and brain lesions provide evidence that the epidemic of scrapie was due to the use of the vaccine.  相似文献   

13.
Small ruminants infected with scrapie show a large range of often unspecific clinical symptoms. The most-often described signs, locomotion, sensibility and behavioural disorders and emaciation, rarely occur together, and cases have been described in which only one of those signs was detectable.Thus, formulating a well-circumscribed definition of a clinical suspect case is difficult. Most animals with CNS-effecting diseases such as listeriosis, polioencephalomacia, cerebrospinal nematidiasis and enterotoxemia will, in a thorough neurological examination, show at least some scrapie-like symptoms. Among the 22 neurological field cases examined in this study, a goat with cerebral gliomatosis and hair lice showed the closest similarity to clinical scrapie. The unilateral deficiency of the cerebral nerves has potential as an clinical exclusion criterion for scrapie. However, the laboratory confirmation--or exclusion--of scrapie remains important. It thus needs to be realized that a consistent and thorough examination of neurologically diseased small ruminants (including fallen stock) is the backbone of a good surveillance system for these diseases. This should be a motivation for submitting adult sheep and goats for neuropathological examination.  相似文献   

14.
The PrP genotypes associated with natural scrapie in Ireland were determined and a comparison was made between genotypes found in scrapie-infected sheep and those found in healthy animals from scrapie-infected flocks. Seven PrP genotypes were identified in scrapie-infected animals: VV(136)RR(154)QQ(171),VA(136)RR(154)QQ(171),VA(136)RR(154)QR(171),VA(136)RR(154)QH(171),AA(136)RR(154)QQ(171),AA(136)RR(154)QH(171) and AA(136)RR(154)HH(171). Of 11 scrapie-infected flocks, 15 genotypes were identified in the healthy flock-mates. The genotypes identified in scrapie-affected animals were also all identified in healthy flock-mates. In 9 of the 11 flocks studied, the genotype frequencies among scrapie-infected animals were significantly different from those among healthy flock-mates. The results show that there is a significant risk of developing the clinical signs of scrapie associated with particular PrP genotypes in the Irish sheep population. The association between the V(136)R(154)Q(171) allele and scrapie was evident, as was the association between A(136)R(154)R(171) and resistance to developing the clinical signs of scrapie. The presence of the A(136)H(154)Q(171) allele in the flocks examined resulted in a decreased risk of developing scrapie compared to the presence of the A(136)R(154)Q(171).  相似文献   

15.
Sheep and goats were shown to be susceptible to experimental infection with bovid herpesvirus 2 (BHV2), administered by either the intradermal or intravenous route. Lesions developing in sheep following intradermal inoculation of virus were similar to those in cattle inoculated intradermally, whereas the lesions in goats resolved without ulceration or scabbing. Disseminated circumscribed skin lesions developed in sheep and goats given BHV2 by the intravenous route. These lesions resolved in four to eight days without significant effect on the skin. BHV2 was isolated from skin lesions of sheep, goats and cattle that were infected intravenously, from sheep and cattle infected intradermally and from the leucocytes of the three species following intravenous inoculation of virus. Latent infection of sheep and goats was demonstrated following corticosteroid treatment 60 days after infection.  相似文献   

16.
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17.
Scrapie first was detected in indigenous sheep in Norway in 1981, and from 1995 to 1997 an increase in the number of flocks with scrapie cases was recorded. These flocks were mainly in one geographical region. A study to identify risk factors for scrapie was conducted. The study had three frequency-matched controls selected for every case within the same Veterinary District. A questionnaire was submitted to 176 sheep flocks (42 had been scrapie flocks). The data obtained by the questionnaire were linked to data collected from governmental and industry registers. After imputing missing data using single random imputation, the statistical analysis was performed using multivariable conditional logistic regression.

Purchase of female sheep from scrapie flocks, sharing of rams, or sharing of pastures between different flocks were the risk factors associated with the occurrence of scrapie. Of factors potentially sustaining and promoting the infection in the flock, number of winter-fed sheep, number of buildings for housing sheep, rams and ewes shared room during mating period and increase in the flock size were associated with scrapie. We interpret these findings to show that factors involving transfer of sheep between flocks or direct contact between sheep of different flocks are important for the spread of scrapie. Management factors are important for the development of scrapie. However, it was not possible to discriminate between the different management factors in this study at the flock level. Also, factors indicating awareness and interest of the farmer (as well as willingness to contact a veterinarian for diseased sheep) were related to the detection of scrapie in the flock.  相似文献   


18.
We did a case–control study of the association of several animal, flock and management factors with scrapie in Irish sheep flocks. The characteristics of 61 sheep flocks with at least one laboratory-confirmed case of scrapie (1990–1998) were compared to 61 flocks with no history of scrapie and matched by geographical location and attending veterinary surgeon. The 61 scrapie-affected flocks were from the database of known scrapie flocks in the Republic of Ireland at the start of the study. In conditional multiple logistic regression, factors associated with increased odds of scrapie in a sheep flock were (i) larger breeding-flock size, (ii) purchasing replacement sheep through the market, (iii) spreading sheep compost on the land and (iv) disposing of the placenta in the compost. Factors associated with decreased odds of scrapie were (i) using cattle slurry on the land and (ii) feeding proprietary concentrates to lambs.  相似文献   

19.
Scrapie: Report of an outbreak and brief review   总被引：1，自引：1，他引：0       下载免费PDF全文
An outbreak of scrapie in western Canada is described. The disease was confirmed in seven sheep, all originating from the same flock; six were Suffolk ewes and one was a Hampshire ewe. The main clinical signs were pruritus with a positive “nibbling reflex”, weight loss and seizures precipitated by handling or excitement. At presentation four ewes were between 35 and 38 months of age; two were approximately four years old and the oldest was six years old. No evidence of scrapie was seen in six goats on the original farm. The clinical signs, epizootiology, pathology, and pathogenesis of the disease are reviewed.  相似文献   

20.
Sheep scab mites, Psoroptes ovis, collected from a Merino donor sheep, were used to infest Merino and Dorper sheep, and Angora and Boer goats. Mites were placed on the sheep on 1 or 2 occasions and on 5 occasions on the goats. All the animals were examined at regular intervals for the presence of scab lesions and living mites. Both sheep breeds developed lesions, but those on the Merino sheep were always larger than those on the Dorper sheep at the same intervals after infestation. None of the goats developed lesions or showed signs of irritation, or harboured any mites.  相似文献   

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