境外媒体关于中国发现猪感染禽流感的报道不实

专家认为在猪身上分离到禽流感病毒，并不意味着猪已感染禽流感，也不表明分离出禽流感病毒的地区有猪禽流感流行     

鸡流感的综合防治

1878年，Perroncito首次报道了意大利鸡群发生禽流感，自1997年以来东南亚地区重新流行，世界上有一半的国家发生过禽流感。虽然采取了从扑杀隔离到免疫的各种措施，但是并不能非常有效地控制禽流感在世界各地的流行，主要原因是候鸟迁徙把病毒传播到世界各地。禽流感是一个世界性问题，将长期存在。由于禽流感传染源广泛，病毒非常容易突变，所以对鸡流感必须进行综合防治。     

禽流感防控中的三个关键点

一禽流感与候鸟和湿地的关系 将禽流感流行区域与地图对比发现，检测到禽流感流行最多的区域就是河流（湿地）分布的区域。禽流感的发生和传播与湿地的分布有着密切的关系，与候鸟迁徙也有很大关系。山东烟台属于多湿地地区，所以很容易受禽流感侵袭。     

国外如何控制禽流感

1878年意大利鸡群暴发了一种严重疾病，当时称为欧洲鸡瘟。现已知是高致病性禽流感病毒所致。此后到20世纪30年代，禽流感在意大利一直流行。德国1890年首次报道了禽流感。文献记载表明，上个世纪的二三十年代，高致病性禽流感在欧洲如法国、英国、德国、意大利；在东亚如中国、日本；在美洲如美国、巴西、阿根廷等都有流行。如美国在1924—1925年发生了高致病性的禽流感，疫情遍及到美国的东海岸9个州，1929年再次暴发。此后禽流感在非洲、亚洲、东欧时有发生和流行。     

从禽流感的流行谈我国动物疫病防制中存在的问题及对策

去年底今年初，韩国、越南、日本、泰国、老挝、巴基斯坦、柬埔寨、印度尼西亚等东南亚国家及我国十几个省份相继暴发了高致病性禽流感，大批家禽被紧急销毁。我国政府为控制禽流感的流行也投入了大量的人力、物力和财力，禽流感的流行对我国国民经济发展影响巨大。禽流感在短时间内在我国从南到北的十几个省份发生和流行，     

禽流感,警钟已呜,亟待防范

禽流行性感冒简称禽流感，在世界上不少国家流行。我国陈伯伦等（１９９４）从发病鸡群中采取病料，先后分离到六个毒株。通过血清学、人工发病等试验，鉴定为Ａ型禽流感病毒，属ＨＡ亚型Ｈ９。在国内首次证实广东省有禽流感流行，并首次从发病鸡群中分离到Ａ型禽流感病毒。从而敲响了禽流感的警钟。如不予以足够重视，不尽快制定防范措施，不抓紧采取适合国情的防制办法，就很有可能在不长的时间内播及全国，将使养禽业又受到一次比     

禽流感诊断技术研究进展

近年来，禽流感已严重威胁到人类的健康，快速、准确的诊断技术对于禽流感的预防显得非常重要。作者就禽流感病毒的诊断技术研究进展作一综述，从而为有效预防和控制禽流感的流行和暴发提供简便、高效的检测技术。     

重新审视禽流感

禽流行性感冒 (简称禽流感， Avian Influenza,AI)是由 A型流感病毒引起的禽类烈性传染病，被国际兽疫局定为 A类传染病，同时被列为国际生物武器公约动物传染病名单和中国进口动物检疫的严重疾病之一，可表现为急性致死性疾病到轻度呼吸系统疾病到亚临诊等多种形式。在禽流感发现流行以来的一百多年中，世界各地都有特定毒株引起的禽流感暴发和流行，造成了巨大的经济损失，禽流感在我国出现的时间虽短，但已经并正在给我国养禽业造成一定的经济损失，很可能成为威胁养禽业的头号大敌。 　　本文将就禽流感在世界各地及中国范围内的暴…     

新疆主要野生鸟类的生态环境、迁徙路线及其对禽流感发生与流行的影响

禽流感是严重危害人畜健康的重大传染性疾病,随着禽流感病毒感染宿主范围的不断扩大,从越来越多的动物及人体内分离到了禽流感病毒.野生鸟类被认为是所有亚型禽流感病毒的储存器,并以其特定的迁徙路线及生活环境,在禽流感的传播中起着不可忽视的作用.因此,研究野生鸟类在禽流感发生与流行中的作用对禽流感防控具有重要的公共卫生意义.论文综述了新疆野生鸟类的种类、习性及其生态环境、迁徙路线及其对禽流感发生与流行的影响.     

禽流感发生的流行病

今年以来，国外高致病性禽流感疫情呈明显扩大态势，特别是进入秋冬季以后，候鸟向南迁徙，家禽调运频繁，极易造成疫情传人和爆发。禽流感虽然没有像2003年的SARS疫情那样明显地影响和改变我们的生活，但接连由动物引发的威胁到人类健康甚至生存的疫情，还是让人产生很多的联想和思索。微生物远在人类出现之前就存在于这个星球上了，也将伴随着人类生命的进化而进化，或许它在人类生命消失之后还会存在于这个星球。而由于微生物对环境的适应力极强，它不会像动物或者植物那样出现某个种类的灭绝，科学的发展，也只能是尽力控制病毒。流感病毒也是如此。禽流感的发生和流行有其必然的因素。今年导致禽流感流行传染的原因除了周边国家发生禽流感以外，主要如下：对禽粪检疫力度不够或缺少主动监测；候鸟迂徙导致疫情蔓延；人畜禽间保持密切接触等。农业部对全国部分地区发生的禽流感疫情高度重视，特别派国家动物流行病学研究中心专家赴疫区，协助开展流行病学调查和疫情追踪工作。总结禽流感的发生与流行，希望能对禽流感的防制提供参考。     

Control and eradication strategies for classic fowl plague in Germany and the European Union

The huge potential economic impact of highly pathogenic avian influenza (HPAI) substantiates specific and rigorous legal regulations worldwide. According to the O.I.E. Terrestrial Animal Health Code fowl plague is a notifiable disease. International trading activities concerning poultry and poultry products originating from countries with active HPAI are rigorously restricted. In EU member states directive 92/40/EEC subsumes measures against fowl plague and has been transferred into German legislation by the "Geflügelpest-Verordnung". These acts specify that vaccination against HPAI is principally prohibited. The aim of all sanctions is the extinction of disease and the eradication of the causative agent. However, HPAI viruses, exclusively belonging to subtypes H5 and H7, can re-emerge de novo from progenitor viruses of low pathogenicity which are perpetuated in the wild bird population. An outbreak of HPAI requires prompt action by a stamping out strategy. Fast and accurate diagnosis, a strict stand-still and the culling of affected flocks are at the basis of success. In areas with a high density of poultry holdings preemptive culling and creation of buffer zones, devoid of susceptible poultry, may be neccessary. In these cases emergency vaccinations can be considered as a supportive measure in order to limit mass culling. Vaccinations on merely prophylactic grounds, not being connected to acute outbreaks, should be avoided beware of selective pressures on the virus leading to antigenic drift and escape of vaccine-induced immunity. Instead, high standard biosecurity measures, particularly limiting direct and indirect contacts with wild birds, should be maintained.     

基于地理信息系统的动物疫病应急辅助支持系统研究

构建动物疫病应急辅助支持系统来动态监控处理诸如禽流感、口蹄疫等动物疫病的发生、蔓延已成必要。地理信息系统（geographic information system,GIS）强大的数据管理分析和显示功能,可与动物疫病信息相结合,通过搭建疫病应急辅助支持系统,对疫病应急实施动态监控,为动物疫病应急提供决策支持,减少损失。     

The Perceived Value of Passive Animal Health Surveillance: The Case of Highly Pathogenic Avian Influenza in Vietnam

Economic evaluations are critical for the assessment of the efficiency and sustainability of animal health surveillance systems and the improvement of their efficiency. Methods identifying and quantifying costs and benefits incurred by public and private actors of passive surveillance systems (i.e. actors of veterinary authorities and private actors who may report clinical signs) are needed. This study presents the evaluation of perceived costs and benefits of highly pathogenic avian influenza (HPAI) passive surveillance in Vietnam. Surveys based on participatory epidemiology methods were conducted in three provinces in Vietnam to collect data on costs and benefits resulting from the reporting of HPAI suspicions to veterinary authorities. A quantitative tool based on stated preference methods and participatory techniques was developed and applied to assess the non‐monetary costs and benefits. The study showed that poultry farmers are facing several options regarding the management of HPAI suspicions, besides reporting the following: treatment, sale or destruction of animals. The option of reporting was associated with uncertain outcome and transaction costs. Besides, actors anticipated the release of health information to cause a drop of markets prices. This cost was relevant at all levels, including farmers, veterinary authorities and private actors of the upstream sector (feed, chicks and medicine supply). One benefit associated with passive surveillance was the intervention of public services to clean farms and the environment to limit the disease spread. Private actors of the poultry sector valued information on HPAI suspicions (perceived as a non‐monetary benefit) which was mainly obtained from other private actors and media.     

A review of avian influenza in different bird species

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.     

Animal Health Policy Principles for Highly Pathogenic Avian Influenza: Shared Experience from China and Canada

Animal health policy for highly pathogenic avian influenza (HPAI) must, for the time being, be based on expert opinion and shared international experience. We used the intellectual capital and knowledge of experienced Chinese and Canadian practitioners and policy makers to inform policy options for China and find shared policy elements applicable to both countries. No peer‐reviewed comprehensive evaluations or systematic regulatory impact assessments of animal health policies were found. Sixteen guiding policy principles emerged from our thematic analysis of Chinese and Canadian policies. We provide a list of shared policy goals, targets and elements for HPAI preparedness, response and recovery. Policy elements clustered in a manner consistent with core public health competencies. Complex situations like HPAI require complex and adaptive policies, yet policies that cross jurisdictions and are fully integrated across agencies are rare. We encourage countries to develop or deploy capacity to undertake and publish regulatory impact assessments and policy evaluation to identify policy needs and provide a basis for evidence‐based policy development.     

中国高致病性禽流感免疫预防风险评估

疫苗接种是当前我国预防和控制HPAI疫情的有效手段之一.由于影响HPAI免疫预防效果的因素众多,会给免疫预防带来风险.对这些风险因子进行识别,并系统分析其所引起的风险程度的高低,进而采取针对性的风险管理措施,能有效提高免疫预防的效果.本研究首次运用层次分析法（Analytic Hierarchy Process, AHP）构建了HPAI免疫预防风险评估模型,通过确定风险因子权重,依权重大小对风险因子进行排序,确定风险等级.分析结果表明：管理不良、接种操作不规范、实验室监测等是我国免疫预防的高风险因素.通过对免疫预防风险进行综合分析,为HPAI免疫预防管理和决策提供了科学依据.     

基层动物防疫问题及应对建议

经济社会的迅速发展推动畜牧业发展的同时,也带来诸多挑战,其中动物疫病的防控是一项重大难题。动物疫病的发生会严重影响畜牧业经济发展的速度和质量,甚至还会带来巨大的经济损失。做好动物疫病防控工作显得尤为重要。该文主要论述基层动物防疫工作中存在的问题,并针对问题提出具体的应对举措,减少动物疫病的发生,进而推动畜牧业健康稳定的长足发展。     

绒毛用羊常见食源性中毒病的探讨

由工业污染、农药、有毒植物、饲喂不当等引起的动物中毒性疾病,因其给养殖业带来的巨大经济损失,及其毒物残留对动物源性食品安全的影响,在养殖生产中越来越受到重视。作者列举了几种绒毛用羊生产中常见的食源性中毒性疾病,并详细阐述了各中毒病的临床诊断要点及综合防治措施,供广大兽医工作者和养殖户参考。     

Impact of different husbandry conditions on contact and airborne transmission of H5N1 highly pathogenic avian influenza virus to chickens

Typically highly pathogenic avian influenza (HPAI) viruses spread very rapidly among chickens within sheds. However, the spread was slower than expected for the initial 10 days of the index farm in Japan during 2004. This slow spread, as well as the lack of gross lesions, clinical signs, or high mortality, hindered the field veterinarian from reporting a suspected HPAI outbreak to the veterinary office. To understand the field conditions for the slow virus spread, we examined contact and airborne transmission of the H5N1 virus to chickens in a negative-pressure isolator using various numbers of infected chickens and separate compartments. We found that the contact transmission did occur inefficiently when one or two chickens were infected, whereas the transmission was efficient when four chickens were infected. Airborne transmission of the HPAI virus was also dependent on the number of infected chickens and was less efficient than contact transmission. These data together with field observations suggested that number of infected chickens, chicken house types, and amount of environmental contamination might affect the virus transmission efficiency to chickens.     

Spatial transmission of avian influenza (type H5) in birds

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.