共查询到19条相似文献，搜索用时 343 毫秒
1.
2.
《畜牧兽医科技信息》2019,(12)
<正>禽流感(Avian Influenza,AI)是由A型流感病毒引起的病毒性传染病。被国际兽医局列为A类传染病,我国列为一类传染病。做好高致病性禽流感的防治工作,是动物疫病预防工作的重中之重。我国规定对养殖禽类实行强制免疫高致病性禽流感,通常根据检测禽类血清中高致病性禽流感抗体水平进行免疫效果评价。本研究对免疫蛋禽的血清抗体和卵黄 相似文献
3.
正高致病性禽流感,在禽类中传播快,危害大,死亡率高,高致病性禽流感病毒可以直接感染人类,是人畜共患病,对人类健康、养殖业发展、野生鸟类及生态环境危害极大,已被列为国家动物疫病强制免疫项目。2020年1月至今,我国新疆、湖南、四川三地先后发生6起高致病性禽流感疫情。世界范围内禽流感疫情也呈高发趋势。高致病性禽流感的防控形势更加严重。而对家禽进行高致病性禽流感疫苗强制免疫是防控高致病性禽流感病毒感染的最有效途径。 相似文献
4.
5.
6.
水禽禽流感HI抗体检测方法的探讨 总被引：1，自引：0，他引：1
2003年国家质量监督检验检疫总局出台了<高致病性禽流感诊断技术>(GB/T18936-2003)[1],标准中要求采用鸡红细胞作为血凝与血凝抑制试验的指示细胞监测禽流感抗体,这对于免疫鸡血清中的相应抗体水平监测比较合理[2-4],但对鸭、鹅及其他免疫禽类进行HI抗体水平监测时,常出现非特异性凝集现象[2-3],对检测结果的判定影响较大.有鉴于此,本试验拟对禽流感疫苗免疫后的水禽血清HI抗体检测方法进行探讨,研究适合免疫水禽禽流感HI抗体检测的方法. 相似文献
7.
高致病性禽流感病毒好发于冬、春季节,冬末春初,冷空气活动频繁,气温忽高忽低,候鸟大规模迁徙频繁。我街道禽类饲养以靠近山区的农户散养为主,家养禽类接触候鸟和野生鸟类较多,街道动物防疫站防疫人员主要防疫要求是对所有鸡、水禽（鸭、鹅）和人工饲养的肉鸽等禽只按照免疫程序进行高致病性禽流感强制免疫,实施大规模消毒灭源,广泛开展疫情监测。 相似文献
8.
2021年1月12—19日,山东黄河三角洲国家级自然保护区大汶流管理站出现35只死亡的野生疣鼻天鹅。经现场调查,市级和省级实验室检测,诊断为疑似H5N8亚型高致病性禽流感,经国家禽流感参考实验室进行病毒分离鉴定,最终确定为H5N8亚型高致病性禽流感疫情。疫情发生后,通过现场调查、座谈及实验室检测等方式,对此次疫情开展了紧急流行病学调查,追溯疫情的可能来源,分析疫情的扩散风险,继而提出针对性的应急处置措施。调查发现,此次疫情由迁徙候鸟带毒引入引起的可能性较大;野生鸟类未及时开展免疫,导致体内抗体水平低下是疫情暴发的内源因素。由于迅速采取了合理的应急处理措施,此次疫情得到迅速控制,避免了疫情扩散。本次疫情警示,必须切实做好禽流感的强制免疫和监测工作,高度重视自然保护区及其附近场所珍稀禽类的免疫,以降低疫情发生风险。 相似文献
9.
10.
肉鸭禽流感母源抗体水平的检测 总被引：2，自引：0，他引：2
高致病性禽流感(HPAI)是由正粘病毒科A型流感病毒属禽流感病毒高致病力毒株引起的禽类烈性传染病,高密度的免疫注射是预防和控制HPAI最有效的方法,但是有学者认为,肉鸭由于受母源抗体影响,出栏前免疫无法达到有效保护水平,可以不免。母源抗体的水平是决定雏鸭免疫时间一个关键因素,为此,我们对南京市部分养殖户饲养肉鸭进行禽流感抗体水平检测,现将结果报告如下。1材料与方法免疫疫苗:H5N1型重组灭活苗,哈尔滨维科生物技术开发公司,批号2005106。检测试剂:禽流感H5亚型抗原及阳性血清:中国农科院哈尔滨兽医研究所生产。待检血清:采自南… 相似文献
11.
Highly pathogenic avian influenza (HPAI) H5N1 continues to threaten domestic and wild birds, as well as human health. However, the mechanism of spatial transmission of HPAI is still unclear. We analyzed the current distribution of HPAI occurrences based on World Organization for Animal Health reported data from 3049 sites in the world from December 2003 to June 2006, and found that these sites were spaced at distances with a frequency peak of 100–200 km. We built a cellular automata model to simulate the spatial transmission process of HPAI as a function of transmission distance, variance of the transmission distance, infection rate, and transmission times (how many times HPAI transmits from one host to another before suppression). We determined that the transmission distance between HPAI occurrences is approximately 100 km on the basis of historical HPAI occurrences from 2003 to 2006 in both wild and domestic birds. To effectively reduce the long‐distance spreading of HPAI, preventing close contact between domestic birds and waterfowl within a radius of 100 km around HPAI occurrence sites is essential. 相似文献
12.
Ebrahim Kord Amir Kaffashi Hadi Ghadakchi Fatemeh Eshratabadi Zakaria Bameri Abdelhamed Shoushtari 《Tropical animal health and production》2014,46(3):549-554
Highly pathogenic avian influenza (HPAI) H5N1 virus is causing the death of a large number of wild birds and poultry. HPAI H5N1 was reported in the north of Iran in 2011. In this study, two A/Chicken/Iran/271/2011 and A/Duck/Iran/178/2011 viruses were genetically characterized by sequence analysis of Hemagglutinin (HA) and Neuraminidase (NA) genes. Phylogenetic analysis revealed that these viruses were different from previous Iranian isolates (Clade 2.2) and belonged to the subclade 2.3.2.1. The results showed that the detected viruses are almost identical to each other and closely related to HPAI H5N1 strains isolated in Mongolia in 2010. Based on the amino acid sequence analysis, these viruses at their HA cleavage sites contained the multibasic amino acid motif PQRERRRK-R/GLF lacking a lysine residue compared with the previous reports of the same motif. There is also a 20-amino acid deletion (resides 49–69) in the NA stalk similar to other viruses isolated after 2000. It seems that introduction of HPAI H5N1 to Iran might have happened by wild birds from Mongolian origin virus. 相似文献
13.
Theodore J.D. Knight-Jones Ruth Hauser Doris Matthes Katharina D.C. St?rk 《Veterinary research》2010,41(4)
This study aimed to assess which method of wild waterbird surveillance had the greatest probability of detecting highly pathogenic avian influenza (HPAI) H5N1 during a period of surveillance activity, the cost of each method was also considered. Lake Constance is a major wintering centre for migratory waterbirds and in 2006 it was the site of an HPAI H5N1 epidemic in wild birds. Avian influenza surveillance was conducted using harmonised approaches in the three countries around the lake, Austria, Germany and Switzerland, from 2006–2009. The surveillance consisted of testing birds sampled by the following methods: live birds caught in traps, birds killed by hunters, birds caught in fishing nets, dead birds found by the public and catching live Mute Swans (Cygnus olor); sentinel flocks of Mallards (Anas platyrhynchos) were also used. Scenario tree analysis was performed including sensitivity analysis, followed by assessment of cost-effectiveness. Results indicated that if HPAI H5N1 was present at 1% prevalence and assuming HPAI resulted in bird mortality, sampling dead birds found by the public and sentinel surveillance were the most sensitive approaches despite residual uncertainty over some parameters. The uncertainty over the mortality of infected birds was an influential factor. Sampling birds found dead was most cost-effective, but strongly dependent on mortality and awareness of the public. Trapping live birds was least cost-effective. Based on our results, we recommend that future HPAI H5N1 surveillance around Lake Constance should prioritise sentinel surveillance and, if high mortality is expected, the testing of birds found dead. 相似文献
14.
In the light of experience gained with avian influenza (AI) outbreaks in Europe and elsewhere in the world, the European Union (EU) legislation has recently been updated. The strategy to control the introduction and spread of AI relies on rapid disease detection, killing of infected birds, movement restrictions for live birds and their products, cleaning and disinfection and vaccination. Measures are not only to be implemented in case of outbreaks of highly pathogenic AI (HPAI), but are now also directed against occurrence of low pathogenic AI of H5 and H7 (LPAI) subtypes in poultry, albeit in a modified manner proportionate to the risk posed by these pathotypes. Enhanced surveillance in poultry holdings and wild birds, as well as preventive vaccination, has also been introduced. EU Measures are flexible and largely based on risk assessment of the local epidemiological situation. The occurrence of HPAI H5N1 of the Asian lineage in the EU and its unprecedented spread by wild migratory birds necessitated the adoption of additional control measures. Although HPAI H5N1 has affected wild birds and poultry holdings in several EU Member States, EU legislation and its implementation in Member States has so far successfully limited the impact of the disease on animal and human health. 相似文献
15.
Kosuke SODA Hiroichi OZAKI Hiroshi ITO Tatsufumi USUI Masatoshi OKAMATSU Keita MATSUNO Yoshihiro SAKODA Tsuyoshi YAMAGUCHI Toshihiro ITO 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2021,83(12):1891
Large highly pathogenic avian influenza (HPAI) outbreaks caused by clade 2.3.4.4e H5N6 viruses occurred in Japan during the 2016–2017 winter. To date, several reports regarding these outbreaks have been published, however a comprehensive study including geographical and time course validations has not been performed. Herein, 58 Japanese HPAI virus (HPAIV) isolates from the 2016–2017 season were added for phylogenetic analyses and the antigenic relationships among the causal viruses were elucidated. The locations where HPAIVs were found in the early phase of the outbreaks were clustered into three regions. Genotypes C1, C5, and C6–8 HPAIVs were found in specific areas. Two strains had phylogenetically distinct hemagglutinin (HA) and non-structural (NS) genes from other previously identified strains, respectively. The estimated latest divergence date between the viral genotypes suggests that genetic reassortment occurred in bird populations before their winter migration to Japan. Antigenic differences in 2016–2017 HPAIVs were not observed, suggesting that antibody pressure in the birds did not contribute to the selection of HPAIV genotypes. In the late phase, the majority of HPAI cases in wild birds occurred south of the lake freezing line. At the end of the outbreak, HPAI re-occurred in East coast region, which may be due to the spring migration route of Anas bird species. These trends were similar to those observed in the 2010–2011 outbreaks, suggesting there is a typical pattern of seeding and dissemination of HPAIV in Japan. 相似文献
16.
Marina A. Gulyaeva Kirill A. Sharshov Anna V. Zaykovskaia Lidia V. Shestopalova Aleksander M. Shestopalov 《Journal of veterinary science (Suw?n-si, Korea)》2016,17(2):179-188
During 2006, H5N1 HPAI caused an epizootic in wild birds, resulting in a die-off of Laridae in the Novosibirsk region at Chany Lake. In the present study, we infected common gulls (Larus canus) with a high dose of the H5N1 HPAI virus isolated from a common gull to determine if severe disease could be induced over the 28 day experimental period. Moderate clinical signs including diarrhea, conjunctivitis, respiratory distress and neurological signs were observed in virus-inoculated birds, and 50% died. The most common microscopic lesions observed were necrosis of the pancreas, mild encephalitis, mild myocarditis, liver parenchymal hemorrhages, lymphocytic hepatitis, parabronchi lumen hemorrhages and interstitial pneumonia. High viral titers were shed from the oropharyngeal route and virus was still detected in one bird at 25 days after infection. In the cloaca, the virus was detected sporadically in lower titers. The virus was transmitted to direct contact gulls. Thus, infected gulls can pose a significant risk of H5N1 HPAIV transmission to other wild migratory waterfowl and pose a risk to more susceptible poultry species. These findings have important implications regarding the mode of transmission and potential risks of H5N1 HPAI spread by gulls. 相似文献
17.
Abolnik C 《Avian diseases》2007,51(4):873-879
Highly pathogenic avian influenza (HPAI) H5N2 reemerged in ostriches in South Africa during 2006, and a low-pathogenic AI H5N2 virus was also isolated. Molecular and phylogenetic characterization was performed to determine whether the outbreak strains were genetically derived from the supposedly eradicated Eastern Cape ostrich outbreak HPAI H5N2 strain of 2004. It was demonstrated that although the 2004 and 2006 South African H5N2 strains shared a common ancestor, the two outbreaks were not related. Not only were extensive reassortments with wild bird viruses involved in the evolution of the 2006 strains, but the precursor HA molecule HA0 cleavage site sequence of the 2006 HPAI H5N2 virus also contained fewer basic amino-acid insertions. Multiple transmission events occurred from wild birds to ostriches in 2006, and it appears that a reservoir of H5N2 with pathogenic potential for poultry is established in the South African wild duck population. 相似文献
18.
为明确浙江省高致病性禽流感(HPAI)发生的风险水平,我们开展了相关风险因子调查和分析工作.本研究将风险因子等级分为高、较高、中和低4个风险等级,对母源抗体、免疫抗体、家禽密度、饲养设施、禽类混养、饲养场地理位置、水禽和迁徙鸟、活禽市场等风险因子进行了定量评估.通过权重赋值评估浙江省发生的HPAI的风险水平为0.66875,判定为中等,提示浙江省发生禽流感疫情的可能性时刻存在.通过风险因子分析,发现了高致病禽流感防控工作中存在的薄弱环节,明确今后工作的重点,为浙江省HPAI管理和决策提供了依据. 相似文献
19.
A review of avian influenza in different bird species 总被引：6，自引：0，他引：6
Alexander DJ 《Veterinary microbiology》2000,74(1-2):3-13
Only type A influenza viruses are known to cause natural infections in birds, but viruses of all 15 haemagglutinin and all nine neuraminidase influenza A subtypes in the majority of possible combinations have been isolated from avian species. Influenza A viruses infecting poultry can be divided into two distinct groups on the basis of their ability to cause disease. The very virulent viruses cause highly pathogenic avian influenza (HPAI), in which mortality may be as high as 100%. These viruses have been restricted to subtypes H5 and H7, although not all viruses of these subtypes cause HPAI. All other viruses cause a much milder, primarily respiratory disease, which may be exacerbated by other infections or environmental conditions. Since 1959, primary outbreaks of HPAI in poultry have been reported 17 times (eight since 1990), five in turkeys and 12 in chickens. HPAI viruses are rarely isolated from wild birds, but extremely high isolation rates of viruses of low virulence for poultry have been recorded in surveillance studies, giving overall figures of about 15% for ducks and geese and around 2% for all other species. Influenza viruses have been shown to affect all types of domestic or captive birds in all areas of the world, but the frequency with which primary infections occur in any type of bird depends on the degree of contact there is with feral birds. Secondary spread is usually associated with human involvement, probably by transferring infective faeces from infected to susceptible birds. 相似文献