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1.
The term of 'TSE infections in small ruminants' summarises BSE as well as classical and the recently discovered atypical scrapie infections in sheep and goats.There are fundamental differences between the TSE infections in small and large ruminants. Other than in bovines the TSE pathogenesis in small ruminants implies that various peripheral tissues become infectious long before the onset of clinical symptoms. At least in sheep, classical scrapie is efficiently transmitted horizontally within affected flocks. On the other hand, BSE poses a distinctly higher zoonotic risk than scrapie. Therefore, regulatory measures for the protection of animals and humans from a BSE infection must be substantially different for large and small ruminants. While culling of the birth and feeding cohort of a BSE affected cattle is considered to be effective to prevent any further BSE cases in the affected herd, an effective BSE and classical scrapie eradication programme in small ruminants requires a much more stringent eradication strategy and the rendering of all susceptible animals. The situation became even more complicated when atypical scrapie cases with divergent transmission and pathogenesis characteristics and with a novel biochemical phenotype of the infectious agent came into play. The discovery of these atypical scrapie cases has initiated a discussion about the suitability of the current TSE eradication measures in sheep (which are selective breeding and genotype based culling), in particular when such cases were also found in sheep carrying the believed scrapie resistant genotypes.  相似文献   

2.
Following the implementation of a large scale transmissible spongiform encephalopathies (TSE) surveillance programme of small ruminants, evidence for a natural transmission of bovine spongiform encephalopathy (BSE) to a French goat has been found. During the years 2002-2004, a massive TSE rapid testing programme on >250,000 small ruminants was carried out in Germany. In this national survey, 186 scrapie-affected sheep were found which originated from 78 flocks. The majority of these cases were of the classical TSE type (115 sheep belonging to 14 outbreaks). However, 71 cases coming from 64 flocks were of the novel atypical scrapie type. According to the regulation EU 999/2001, all TSE cases in small ruminants have to be examined by strain typing methods to explore any possibility of the existence of BSE cases in the field sheep population. Here we report on a biochemical typing strategy (termed FLI-test), which includes the determination of molecular masses, antibody binding affinities and glycosylation pattern of the TSE induced abnormal prion protein. Based on this typing approach none of the analysed German classical TSE outbreaks (total number of analysed sheep: 36) displayed biochemical features indicative for a BSE infection. However, in two cases distinct but BSE-unrelated PrP(Sc) types were found, which alludes to the existence of different scrapie strains in the German sheep population.  相似文献   

3.
Monitoring of transmissible spongiform encephalopathy (TSE) in Swiss sheep and goats is based on the examination of animals from different sources. In this study, frequencies and proportions of the different diagnoses were compared between routinely submitted sheep and goats, notified scrapie suspects as well as fallen stock. Meningitis/ encephalitis cases were significantly more frequent (OR = 2.2) in the scrapie suspect group when compared to the routine submissions. Metabolic-toxic encephalopathy was seen more frequently within the fallen stock. Rare neurological diagnoses were more frequent among scrapie suspects and routine submissions when compared to fallen stock. Listeriosis was diagnosed equally frequent among the scrapie suspects and routine submissions but less frequent in fallen stock. Scrapie prevalence among the fallen stock and the routine submissions was 0 (zero), with 95% certainty that prevalence is < 1%. The examined animals are representative for most of the Swiss regions with considerable sheep and goat production. Continuation of the detailed neuropathological examination of small ruminants from these three groups, substituted by actively testing a sufficiently large sample of fallen stock and possibly also healthy-slaughtered adult sheep and goats for transmissible spongiform encephalopathies would ensure a good surveillance within the small ruminant population.  相似文献   

4.
Scrapie has been known to occur in sheep and goats for over 250 years. Sheep and goats can be experimentally infected orally with BSE, however BSE infection can only be distinguished from scrapie using costly and extensive laboratory procedures. An overview of both the current state of knowledge on Transmissible Spongiform Encephalopathies (TSE) in small ruminants as well as the TSE monitoring and control strategies in place in Switzerland is presented.  相似文献   

5.
Since January 2, 2001 a large-scale active surveillance programme for BSE started in the Netherlands in addition to the passive surveillance programme of cattle with clinical symptoms compatible with BSE. Based on decisions of the Council of European Ministers of Agriculture, the European Union launched an active surveillance system for BSE in cattle of 30 months and older. Until April 1, more than 100,000 head of cattle were tested in this scheme, including all cattle slaughtered and a large part of the cattle that died on the farm. Four animals were found positive in the active surveillance system and one cow from the passive surveillance tested positive for BSE during the first three months.  相似文献   

6.
Immediately after the detection of the first case of BSE in 2001, the Japanese government introduced active surveillance targeting fallen-stock and all cattle slaughtered for human consumption. By the end of 2004, four million animals were tested with rapid tests under the passive and active surveillance. As a result 13 additional cases were detected. I focused on the 1996 birth cohort, in which nine cases of BSE were detected during 2001–2004, and estimated the prevalence of BSE infection of that birth cohort using maximum-likelihood methods. Using the estimated prevalence of infection as an input variable, I calculated the adjusted incidence risk of BSE by different ages and risk subpopulations (clinical-suspects, fallen-stock, sick-slaughter and healthy-slaughter animals). The adjusted incidence risk of BSE in sick-slaughter animals (animals showing clinical signs not compatible with BSE when slaughtered for human consumption) was 18.7 and 4.5–78.4 times higher than the incidence risk in fallen-stock and healthy-slaughter animals, respectively.  相似文献   

7.
Scrapie is a fatal, neurodegenerative disease of sheep and goats. It is also the earliest known member in the family of diseases classified as transmissible spongiform encephalopathies (TSE) or prion diseases, which includes Creutzfeldt-Jakob disease in humans, bovine spongiform encephalopathy (BSE), and chronic wasting disease in cervids. The recent revelation of naturally occurring BSE in a goat has brought the issue of TSE in goats to the attention of the public. In contrast to scrapie, BSE presents a proven risk to humans. The risk of goat BSE, however, is difficult to evaluate, as our knowledge of TSE in goats is limited. Natural caprine scrapie has been discovered throughout Europe, with reported cases generally being greatest in countries with the highest goat populations. As with sheep scrapie, susceptibility and incubation period duration of goat scrapie are most likely controlled by the prion protein (PrP) gene (PRNP). Like the PRNP of sheep, the caprine PRNP shows significantly greater variability than that of cattle and humans. Although PRNP variability in goats differs from that observed in sheep, the two species share several identical alleles. Moreover, while the ARR allele associated with enhancing resistance in sheep is not present in the goat PRNP, there is evidence for the existence of other PrP variants related to resistance. This review presents the current knowledge of the epidemiology of caprine scrapie within the major European goat populations, and compiles the current data on genetic variability of PRNP.  相似文献   

8.
An abattoir survey was conducted to determine the prevalence of Cysticercus tenuicollis, to find out the association between prevalence and potential risk factors as well as to assess the distribution of C. tenuicollis in visceral organs of slaughtered sheep and goats. Out of the total 768 goats and 630 sheep visceral organs inspected, C. tenuicollis was found in 358 goats (46.6%) and 252 sheep (40.0%), respectively. Adult goats (51.8%) and sheep (47.4%) were more infected than kids (41.4%) and lambs (35.8%), respectively. Goats (58.1%) and sheep (46.5%) from highland areas were more infected than goats (35.2%) and sheep (33.8%) from lowland areas. C. tenuicollis was more frequently detected in the omentum of goats and sheep than any other visceral organs. Appropriate control measures need to be introduced to reduce the prevalence of these parasites in small ruminants.  相似文献   

9.
This paper describes the prevalence of brain lesions in the Swiss fallen stock population of small ruminants. 3075 whole brains (75% sheep, 25% goats) were collected as part of a year-long active survey of transmissible spongiform encephalopathies (TSEs) in small ruminants conducted by the Swiss authorities between July 2004 and July 2005. All fallen stock brains were systematically examined by histopathology to obtain reliable data on histologically identifiable brain lesions. Lesions were found in an unexpectedly high number of animals (8.1% of all examined brains). A wide spectrum of diseases was detected showing that this approach provides an excellent opportunity to screen for the prevalence of neurological diseases. Encephalitic listeriosis was by far the most frequent cause of CNS lesions in both species and its prevalence was unexpectedly high when compared to notified confirmed cases. In conclusion, the prevalence of listeriosis as estimated by passive surveillance based on the notification of clinical suspects has been underestimated in the past.  相似文献   

10.
The prevalence of malignant catarrhal fever (MCF) virus infection in cattle, sheep and goat populations and also the prevalence of recovered and chronic MCF cases in north-western Turkey are reported. A total of 600 animals, 200 individuals of each species, located in four provinces were sampled between December 2003 and July 2005. A monoclonal antibody-based competitive inhibition (ci) ELISA were used to detect infection status of the animals. Detected antibody prevalence was 97.5%, 96.0% and 15.0% in sheep, goats and cattle, respectively. These results showed that MCF related gammaherpesvirus infections are common in north-western Turkey. There was no significant difference between prevalences detected in sheep and goats, as well as various breeds of these species. There was also no significant difference among locations. Results of this study show that sheep and goats may equally be important in the epidemiology of MCF in Turkey. Seropositivity against MCF agents among cattle was 15.0%. The results indicate that MCF infections may be maintained in intensively managed cattle herds having no close contact with small ruminants.  相似文献   

11.
A study on the prevalence and seasonal incidence of cestode parasite infections of sheep and goats was carried out in eastern Ethiopia for 2 years (May 2003-April 2005). During this period, viscera including liver, lungs, heart, kidneys and the gastro-intestinal tract were collected from 655 sheep and 632 goats slaughtered at four abattoirs located in the towns of Haramaya, Harar, Dire Dawa and Jijiga. At the abattoirs the abdominal, thoracic and pelvic cavities as well as the muscle surfaces of all animals were visually examined for the presence of larval (cystic) stages of cestode parasites. The viscera were transported within 24 h to the parasitology laboratory of Haramaya University and were examined for larval and adult cestodes following standard procedures. The most prevalent metacestodes (larval cestodes) were Cysticercus ovis (Taenia ovis), Cysticercus tenuicollis (T. hydatigena) and hydatid cysts (Echinococcus granulosus). In sheep, the overall prevalence was 26% for C. ovis, 79% for C. tenuicollis, and 68% for hydatid cysts. Similarly, for goats, the corresponding prevalence was 22%, 53% and 65%, respectively. The difference between sheep and goats in prevalence of C. tenuicollis was significant. The high prevalence of hydatid cysts in both sheep and goats indicates that cystic echinococcosis/hydatidosis is a public health problem in these regions which requires implementation of control measures, including public health education, strict meat inspection and control of stray dogs. The results of the survey also implies that infections of small ruminants with these metacestodes are responsible for condemnation of substantial quantities of affected organs and muscles and therefore of direct economic importance. Intestinal infections with adult tapeworms of Moniezia expansa, Avitellina centripunctata and Stilesia globipunctata, and bile duct infections with Stilesia hepatica were also common in both sheep and goats. In sheep, the overall prevalence of these tapeworms were 61%, 20%, 24% and 39%, respectively. Similarly, the overall prevalence of these parasites in goats was 53%, 21%, 27% and 36%, respectively.  相似文献   

12.
A serological survey on dermatophilosis was carried out amongst sheep and goats in Kaduna State of Nigeria. Sera were obtained from slaughter animals and from sheep kept on an isolated ranch. The percentage of seropositive animals was 28.0 in slaughter sheep, 0.0 in sheep kept on the ranch, and 23.2 in slaughter goats. The high prevalence of D. congolensis antibodies among small ruminants compares well with the level of prevalence reported of cattle of cattle and calls for a concerted government effort for the control of the disease.  相似文献   

13.
This paper reports further results of a two year livestock mortality survey in Afghanistan, where a war of more than a decade had completely disrupted the veterinary field services. A questionnaire-based survey to measure the impact of a veterinary field programme indicated that average annual mortality in cattle, sheep, and goats was substantially lower in districts that received veterinary services (covered districts) than in districts without any veterinary services (control districts). The impact of the programme varies according to the season and the age group of the animals involved. The programme lacked impact in winter, in particular in adult small ruminants. The highest impact was noted in the spring and autumn for adult goats, and summer and autumn for adult sheep.The impact of the programme was also limited (in small ruminants even completely absent) during the suckling period in young animals. The highest impact was noted in the post-weaning period in small ruminants, when approximately four times more lambs and kids died in the control districts than in the covered districts.It was concluded that the major impact of the veterinary programme was achieved when animals are in contact with other flocks during grazing seasons, when parasitic and infectious diseases are present and against which the veterinary programme is directed. Additional inputs – including extension activities – are therefore required to improve the effect of the programme in the winter and in the neonatal period.  相似文献   

14.
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   

15.
Trypanosomosis is a major impediment to livestock production and economic development in those areas of Africa where it is endemic. Although small ruminants appear to perform better than cattle in various agro-ecological zones, the importance of trypanosomosis has not been extensively investigated in these livestock. This study was designed to investigate the prevalence of trypanosomosis in sheep and goats in an endemic area and to evaluate the performance of different breeds under high tsetse challenge and the potential role of chemoprophylaxis in the control of the disease. The results showed that tsetse flies feed readily on small ruminants, and that these animals are susceptible to trypanosomosis. The Small East African goats acquired fewer infections than the Black Head Persian and Dorper sheep used in the study. In both sheep and goats, chemoprophylaxis with isometamidium chloride (Samorin, Rhone Merieux, Annecy, France) was protective, resulting in fewer infections and higher body weight gain. Trypanosomosis caused anaemia in both sheep and goats, and animals whose PCV fell below 15% rarely recovered, even with trypanocidal drug treatment. The peak transmission period was between 1 and 3 months after the peak tsetse fly density, which raises the possibility of effective strategic prophylaxis.  相似文献   

16.
Monoclonal antibody-based competitive ELISA (C-ELISA) has been used for the specific measurement of antibodies to peste des petits ruminants (PPR) viruses in sheep, goats, cattle and Buffalo. Serum samples from sheep (n = 232), goats (n = 428), cattle (n = 43), buffalo (n = 89) were tested. The animals had not been vaccinated against rinderpest or PPR. Findings suggested that the sero-positive cases were significantly higher in sheep (51.29%) than in goats (39.02%) (P = 0.002). The overall sero-prevalence of PPRV in small ruminants was 43.33%. The PPR antibodies seroprevalence was 67.42% in buffalo and 41.86% in cattle which was significantly higher in buffalo (P = 0.005). The overall sero-prevalence of PPRV in large ruminants was 59.09%. Cattle and buffalo sera showed a high prevalence of antibody against PPR virus which may explain the difficulty experienced in achieving high post-vaccination immunity levels against rinderpest. Because antibodies against PPR virus are both cross-neutralizing and cross-protective against rinderpest virus, further vaccination in the presence of antibodies against PPR virus may be a waste of national resources. It was also suggested that antibodies to PPR virus could prevent an immune response to the rinderpest vaccine. This paper presents serological evidence for the transmission of PPR virus from sheep and goats to cattle and buffalo and highlights the need to include PPR serology in the sero-monitoring programme to give a better indication of national herd immunity of sheep and goats against PPR.  相似文献   

17.
The distribution of livestock in Cyprus was described and analyzed by contingency table methods. Smaller numbers of sheep, goats and cattle were associated with Greek Cypriot villages. Sheep and goat densities were highest in Turkish Cypriot villages. Among the villages in which the slaughter of livestock was reported, the median percent prevalence of hydatid cysts was: 16.5% (range: 0–100%) in slaughtered sheep; 2.1% (0–100%) in slaughtered goats; 0.0% (0–100%) in slaughtered cattle; 0.0% (0–33%) in slaughtered pigs. The median numbers of livestock slaughtered in villages for the 6-month period were 45 sheep, 98 goats, 4 cattle and 32 pigs. The association between the prevalence of Echinococcus granulosus in the slaughtered sheep population (SHPPREV) of 254 villages of Cyprus and human, canine, and environmental factors, for the period June–December, 1972, was analyzed by step-wise multiple regression. Results showed that 25% of the total variation in SHPPREV was explained by 3 independent variables, total rainfall from the previous 6-month period (negatively correlated with SHPPREV), E. granulosus prevalence in dogs (positively correlated) and the percent village population composed of Turkish Cypriots (negatively correlated). Total rainfall from the previous 6-months period, alone, explained 19% of the total variation.  相似文献   

18.
The foot-and-mouth disease epidemic in Dumfries and Galloway in south-west Scotland comprised 177 infected premises (IPS) in 24 geographical clusters, and ran from March 1 until May 23, 2001. Initial seeding of infection was by livestock (predominantly sheep) that had passed through Longtown Market in adjacent Cumbria. Thereafter, spread within existing, and to new, clusters was associated with the movement of personnel and vehicles, with further transmission by Longtown Market contacts and across common boundaries. Sheep and cattle premises were equally affected. After the peak of the epidemic at the beginning of the third week of March, the upper possible limit of attack rates for premises contiguous to IPS, and premises within 3 km, remained around 10 per cent, with new clusters emerging more distantly. Control procedures included traditional methods of slaughter of all animals on IPS and, elsewhere, of animals considered by veterinary assessment to be Dangerous Contacts; movement restrictions; enhanced biosecurity; tracing of potential sources and spread of virus; and surveillance of premises subsequently considered at risk. These methods were supplemented by the novel pre-emptive slaughter, without veterinary assessment, of all susceptible livestock on all premises contiguous to IPS, and of small ruminants and pigs within a 3 km radius (known as the Protection Zone) around IPS. In total, approximately 80,000 cattle, 564,000 sheep, 2600 pigs and 500 goats were slaughtered, the novel methods accounting for 29 per cent of all cattle and 75 per cent of all sheep killed. Limitations of existing national databases necessitated the development of local databases to administer control procedures.  相似文献   

19.

A total of 1000 clinically healthy small ruminants comprising 500 sheep and 500 goats from five districts within Riyadh Province in Saudi Arabia were investigated by routine Giemsa staining for hematozoan parasites. Out of these, 100 sheep and 95 goat samples were investigated by PCR using three pairs of hemoprotozoan-specific primers. Based on microscopic examination, 33.2% of sheep and 25.2% of goats were found infected with hemoprotozoan parasites, while PCR detected hematozoan infection in 46% of sheep and 33.7% of goats. Extensive molecular characterization of hematozoan infection using six pairs of species-specific primers revealed the dominance of Theileria ovis, rather than any other species, which is recorded for the first time in small ruminants in Saudi Arabia. Prevalence of T. ovis in sheep and goats was found to be the highest in Riyadh (32, 48%) followed by AL-Kharj (31, 35%), Ad-Dawadimi (31, 33%), AL-Majmaah (15, 27%), and Rumah (17, 23%). The highest parasite prevalence was recorded in the 3 years of age and >?4 years of age ruminants, while the lowest prevalence was recorded in <?1 year of age ruminants. No noticeable differences in parasite prevalence between male or female ruminants were recorded. Partial sequencing of 18S rRNA gene revealed the infection of the studied ruminants with four new isolates of T. ovis. Further characterization of the pathogenicity and the clinical effects of these T. ovis isolates in sheep and goats is highly needed. The current results can be helpful in protecting and improving livestock industry in the countries that depend on a high number of small ruminants.

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20.
Molecular profiling of the proteinase K resistant prion protein (PrP(res)) is a technique that has been applied to the characterisation of transmissible spongiform encephalopathy (TSE) strains. An interesting example of the application of this technique is the ability to differentiate, at the experimental level, between bovine spongiform encephalopathy (BSE) and scrapie infection in sheep, and to distinguish between classical and atypical BSE and scrapie cases. Twenty-six BSE cases and two scrapie cases from an active TSE surveillance program and diagnosed at the PRIOCAT, TSE Reference Laboratory (Centre de Recerca en Sanitat Animal, Universitat Autònoma de Barcelona, Catalunya, Spain) were examined by Western blotting. Molecular profiling was achieved by comparing the glycosylation profile, deglycosylated PrP molecular weight and 6H4/P4 monoclonal antibody binding ratio. The results obtained during the characterisation of these field cases indicated an absence of atypical BSE cases in Catalunya.  相似文献   

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