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1.
Aleutian mink disease (plasmacytosis) virus (AMDV) in domestic mink (Neovison vison) has been subject to eradication in Denmark since 1976. In 2001, approximately 5% of Danish mink farms were still infected and all were located in the northern part of the peninsula of Jutland. In the present study a total of 274 Danish isolates of AMDV collected during the two seasons of 2004 and 2005 were characterized by partial sequencing of the coding region of the non-structural (NS) proteins. Older AMDV isolates from Denmark, available, were also included. The Danish isolates represent a very homogenous cluster compared with Swedish, Finnish and Dutch isolates and seem to represent a minor fraction of the genetic diversity previously found in Denmark. Stability of nucleotide deviations reveals that the purifying selection of bottlenecks imposed on the AMDV population in Denmark by the stamping out policy for more than 6 years exceeds the rate of mutation driven diversity. Among the isolates from farms in northern Jutland two distinct types could be identified and within each of them a number of sub-types which were all useful in tracking spread of infections. Infection at a farm the preceding season was a predisposing risk parameter for disease outbreak at a farm, and strain identity substantiates the suggestion that inadequate disinfection is involved in the recurrence of outbreaks. In cases of new introductions to farms it is indicated that contact including transport between farms played a most significant role. 相似文献
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Counter current immunoelectrophoresis (CCIE) is the diagnostic method used in the ongoing Aleutian disease virus eradication program on Danish mink farms. There has been an increasing demand for an alternative diagnostic test especially to evaluate suspected false positive CCIE reactions. We compared test results of a number of negative and positive mink sera in indirect counter current immunoelectrophoresis (ICCIE), counter current line absorption immunoelectrophoresis (CCLAIE) and radio immuno assay (RIA) with test results from counter current immunoelectrophoresis and found that counter current line absorption immunoelectrophoresis is the best alternative diagnostic screening test to counter current immunoelectrophoresis for Aleutian disease eradication programs. Not only proved the CCLAIE test to be useful for evaluation of doubtfully positive CCIE reactions, but it was found to have a higher sensitivity than the CCIE test. 相似文献
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An exploratory spatial analysis of Aujeszkys disease virus infection from 2003 to 2007 was conducted in Catalonia (north eastern Spain), the largest pig-producing region in the country. The analysis was divided into four periods in relation to the different eradication phases of the programme established in the region. Different purely spatial analyses, based on the Bernoulli model, were run with SaTScan v6.1 in each period. Clusters of positive sow farms (farrow to weaning and farrow to finish) and/or fattening farms were identified in the four study periods in the western part of the region, in the three first periods in the central part and in the last three periods in the north eastern part of the region. The prevalence ratio values of these clusters increased throughout the study period due to the fact that the risk of disease decreased faster outside the clusters than inside the clusters. In order to study the evolution of the disease, we explored for areas where more negative sow farms became infected and areas where more sow farms eliminated the infection. These analyses demonstrated areas with significantly higher proportions of sow farms that became negative, which indicates that the eradication of the disease had a spatial component. Clusters of negative sow farms that were infected again (reinfections) were also detected in the four study periods. The relative risk values of these clusters were much higher compared to the other cluster analyses. There was a geographical association between the clusters of positive sow farms, positive fattening farms and re-infected sow farms. This association could be attributable to the local spread of Aujeszkys disease virus. Pig farm density could be a factor influencing the local spread of infection and was therefore evaluated for clusters of re-infected sow farms and clusters of sow farms that eliminated the infection. The mean density of pig farms was 0.40 farms/km(2) (median of 0.28 and standard deviation of 0.33) in clusters of sow farms that became negative and 1.51 (median of 0.70 and standard deviation of 1.61) in clusters where more sow farms became positive (p-value<0.05). 相似文献
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An outbreak of excessive neonatal mortality in four Danish mink farms. II. Analytic epidemiological investigations 总被引：1，自引：0，他引：1
Data collected from an outbreak of excessive mortality of mink kits in 4 Danish mink farms in 1982 were analysed. The mortality of the mink kits was found to be highest for the kits from Aleutian Disease (AD)-positive females, and the Scanblack mink was found to be the most frequently affected mink type. Furthermore the mortality was found to depend on the farm of origin and to be highest for the lastest born kits. The age of the females and their location in sheds were found not to influence the mortality of the kits. However, the mortality for the Pastel mink decreased with increasing distance from the Scanblack mink. The possibility that the excess mortality of the kits might be due to an AD-virus infection is discussed.Key words: mink, neonatal mortality, mink kits, Aleutian Disease, analytic epidemiology 相似文献
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Inapparent of nonprogressive Aleutian disease virus (ADV) infection is a subclinical but persistent virus infection of mink. Mink with the inapparent type of ADV infection when subjected to stress did not develop the progessive form of the disease. However, when challenged with a large dose of the virus, these mink did develop progressive Aleutian disease indicating that they were not highly resistant to the virus. Sera of mink with either the progressive of the inapparent type of ADV infection did not neutralise the virus. The anti-ADV antibody activity in mink with inapparent type of ADV infection was in the IgG fraction of the serum the same as in mink with progressive Aleutian disease. These data indicate that the resistance of the mink with inapparent infection as compared to mink with progressive Aleutian disease was not due to a difference in the class of immunoglobulin response to the virus. However, mink with progressive Aleutian disease showed a greatly increased immunoglobulin response. 相似文献
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Parvovirus of Aleutian disease causes mainly damage to kidneys, but immune complexes deposition and damage may occur also in other organs. In mink farms of Latvia the liver dystrophy or hepatic lipidosis of mink is widely distributed. The goal of this study was to examine probability of liver damage and regeneration of mink infected with Aleutian disease virus. Liver injury was assessed histologically. The mink liver demonstrated inflammation of liver parenchyma and foci of fatty liver. In immunohistochemistry, during liver regeneration the matrix metalloproteinases MMP-9, vascular endothelial growth factor and beta-defensin 2 expressions were lower, but MMP-2 and nerve growth factor receptor p75 expression was increased. 相似文献
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This paper describes a new approach for spatial relative risk mapping as a tool for geographical risk assessment. The spatial epidemiological analysis is based on geographically referenced data about pseudorabies (Aujeszky's disease) virus infections at farm level in a region of high animal density in Germany at the beginning of the national eradication project. On the basis of serological findings 186 farms were classified as positive out of a total of 482 investigated farms listed in veterinary administrative registers. Geographical cluster analysis was used to identify two areas of high risk (RR = 2.4 and 3.3). Non‐parametric density estimation was used to estimate the proportion of infected farms per square kilometre. Furthermore, the spatial relative risk function was approximated through the prevalence ratio defined by the ratio of the local prevalence and the overall prevalence of the farms outside the cluster regions. The corresponding approximated relative risk map indicates and quantifies a clear spatial pattern of disease frequency. 相似文献
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Berke O Grosse Beilage E 《Journal of veterinary medicine. B, Infectious diseases and veterinary public health》2003,50(7):322-325
This paper describes a new approach for spatial relative risk mapping as a tool for geographical risk assessment. The spatial epidemiological analysis is based on geographically referenced data about pseudorabies (Aujeszky's disease) virus infections at farm level in a region of high animal density in Germany at the beginning of the national eradication project. On the basis of serological findings 186 farms were classified as positive out of a total of 482 investigated farms listed in veterinary administrative registers. Geographical cluster analysis was used to identify two areas of high risk (RR = 2.4 and 3.3). Non-parametric density estimation was used to estimate the proportion of infected farms per square kilometre. Furthermore, the spatial relative risk function was approximated through the prevalence ratio defined by the ratio of the local prevalence and the overall prevalence of the farms outside the cluster regions. The corresponding approximated relative risk map indicates and quantifies a clear spatial pattern of disease frequency. 相似文献
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近年来,随着水貂养殖行业的不断发展,一些疫病也成为了制约水貂养殖业发展的重要因素。水貂阿留申病作为毛皮动物的三大疫病之一(阿留申病、犬瘟热、病毒性肠炎),是导致母貂产仔率下降、公貂配种能力降低和毛皮质量下降的一种高度接触性传染病。至今为止,还没有商品化的疫苗来控制该病的传播及蔓延。控制水貂阿留申病最好的方法是通过检测淘汰所有抗体为阳性的水貂,进而达到净化貂群的目的。而在抗体检测过程中,诊断抗原的制备和纯化决定着检测方法的敏感性、特异性和准确性。论文对目前阿留申病毒细胞抗原及基因工程抗原研究进展做一综述,为今后该病病原检测工作提供参考。 相似文献
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Knuuttila A Uzcátegui N Kankkonen J Vapalahti O Kinnunen P 《Veterinary microbiology》2009,133(3):229-238
Aleutian mink disease virus (AMDV) is a parvovirus that causes an immune complex-mediated disease in minks. To gain a more detailed view of the molecular epidemiology of mink AMDV in Finland, we phylogenetically analysed 14 new Finnish strains from 5 farms and all 40 strains with corresponding sequences available in GenBank. A part of the major non-structural (NS1) protein gene was amplified and analysed phylogenetically. A rooted nucleotide tree was constructed using the maximum parsimony method. The strains described in this study showed 86-100% nucleotide identity and were nearly identical on each farm. The ratio of synonymous to non-synonymous substitutions was approximately 2.7, indicating a mild purifying selection. Phylogenetic analysis confirmed that AMDV strains form three groups (I-III), all of which contained Finnish strains. The tree inferred that the three lineages of AMDV have been introduced to Finland independently. The analysis suggested that AMDV strains do not cluster into genotypes based on geographical origin, year of isolation or pathogenicity. Based on these data, the molecular clock is not applicable to AMDV, and within this gene area no recombination was detected. 相似文献
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A suspension of tissues from field cases of Aleutian disease was used successfully to reproduce the disease in Aleutian mink. Similarly, suspensions of diseased tissues from the experimentally infected mink were used to transmit the agent of Aleutian disease to both Aleutian mink and standard dark mink. Seitz and millipore filtrates prepared from these tissue suspensions were also infective; a suggestion that the etiologic agent is a virus. Genetic factors and hypersensitivity are discussed as possibly contributing to development of the disease. 相似文献
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An increased incidence of pork-related human salmonellosis in Denmark led to the development of a national control programme for Salmonella in Danish swine herds in 1993. The aim of the programme has been met and now the issue of cost-effectiveness is receiving greater attention. An appropriate way to address this is to bring a risk-based focus to the programme.
We describe a practical approach to risk-based surveillance through spatial risk assessment using serological and questionnaire data from 2280 herds in 1995. A mixed effects logistic regression model was fitted and both first- and second-order spatial properties of the random effects were investigated. We identified wet-feeding (OR: 0.64; 95% CI: 0.54–0.75) and SPF health status (OR: 0.65; 95% CI: 0.52–0.81) as protective factors for Salmonella sero-positivity. Purchasing feed (OR: 1.81; 95% CI: 1.61–2.04) was a risk factor. The west of the study area generally, and the north of Jutland in particular, experienced the greatest disease risk after controlling for the covariates. There was some evidence for spatial dependency between farms at distances of 6 km (95% CI: 2–35 km) on the Jutland peninsula.
We conclude that when farm location details are analysed in conjunction with routinely recorded surveillance information (such as that collected by the Danish swine Salmonella control programme) and targeted industry surveys (such as those conducted by slaughterhouse co-operatives), our knowledge of the behaviour of disease in animal populations is enhanced and this provides a more informed framework for designing efficient, risk-based surveillance strategies. 相似文献
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In apparent or nonprogressive Aleutian disease virus infection was considered a subclinical but persistent viral infection in which infected mink did not develop tissue lesions, hypergammaglobulinemia, or high antibody titers. Transmission of Aleutian disease virus from mink with this type of infection was measured. Mink with inapparent Aleutian disease appeared healthy and had normal gamma-globulin values, but were capable of transmitting the disease by direct and indirect horizontal contact. The risk of direct or indirect horizontal transmission from mink with inapparent infection was less than from mink with progressive Aleutian disease. Infection also was directly transmitted from the dam to the kits, but again the risk of infection from dams with inapparent infection was less than from dams with progressive Aleutian disease. Mink infected from their dams before weaning developed the disease more slowly than mink which became infected after weaning. 相似文献
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Detection of antibody in Aleutian disease of mink: comparison of enzyme-linked immunosorbent assay and counterimmunoelectrophoresis 总被引：1，自引：0，他引：1
Experiments were undertaken to investigate the potential of the enzyme-linked immunosorbent assay (ELISA) as a screening test for the diagnosis of the 2 known naturally occurring forms of Aleutian disease of mink. Anti-Aleutian disease virus (ADV) antibody activity was not detectable in the sera of mink with nonprogressive Aleutian disease despite the demonstration of antibody by counterimmunoelectrophoresis (CIEP) in the same sera. Anti-ADV antibody was detectable in 93% of sera from mink at various stages of experimentally induced progressive Aleutian disease. False-negative reactions occurred in sera which demonstrated high anti-ADV antibody titers by CIEP. As a consequence of the high prevalence of false-negative reactions, the ELISA was not considered to be an effective screening test. However, using CIEP as an indicator of ADV infection, the ELISA may be useful in differentiating mink with nonprogressive Aleutian disease from mink with progressive Aleutian disease. 相似文献
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Paratuberculosis is a chronic infection of economic importance to the cattle industry and a voluntary control programme is offered to Danish dairy farmers. Our objective was to evaluate spatial differences in both control programme participation and paratuberculosis prevalence in Denmark. The study included 4414 dairy herds: 1249 were participating in the control programme, and 1503 were tested for antibodies to Mycobacterium avium subsp. paratuberculosis (MAP). Spatial differences were evaluated by kernel smoothing, kriging, and cluster analysis. Participation was lowest among herds on the island Zealand (≤23%). The risk of a herd being infected with MAP was found to be high on most of Zealand, but the uncertainty of this result was large due to a limited number of tested herds. In the rest of the country, the south western part of the peninsula Jutland had the highest risk of MAP (≥91%). The risk of MAP was also high (86-91%) in the northern part of both Jutland and Funen. The predicted apparent within-herd prevalence was highest (5-8.5%) in some local areas across Jutland, in the north western part of the island Funen, and in the south and western part of Zealand. Scan statistics located the primary cluster of herds with high apparent within-herd prevalence in the western part of Funen. Furthermore, a number of significant clusters were found in Jutland and a single significant cluster in Zealand. Consistency was found between kriging and scan statistics results with respect to location of areas with high apparent within-herd prevalence of MAP. Potential explanations for differences in participation include herd size and local herd health advisers, whereas for example soil characteristics might influence prevalence. Further studies are needed to evaluate these and other risk factors. 相似文献
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目的研究貂阿留申病病毒(ADV)结构蛋白VP1基因分子空间结构特征,探讨貂阿留申病病毒致病机制。方法根据Genbank公布的全基因序列设计三对引物,PCR扩增并克隆到pMD-18T载体,阳性重组质粒鉴定、测序验证,拼接后进行生物信息学分析。结果获得了全长2064bpVP1基因,编码688个氨基酸;与细小病毒属中PPV-Nanjing200801相似性最大(51.2%);遗传进化树显示该基因编码蛋白与细小病毒属VP1亲缘关系最近。该蛋白是一种保守不含信号肽的外膜蛋白,具有7个潜在的N-糖基化位点和34个磷酸化位点。二级结构分析显示无规则卷曲含量最高,达68.75%,α螺旋、β折叠分别为16.42%和14.83%;同源建模比对,构建了具有较高合理性和可靠性的三维空间结构。结论预测抗原表位主要位于肽链第254~265、96~112、317~348、514~523、629~645位区段,可为今后开展基因工程疫苗研究奠定基础。 相似文献