浙江省引起高致病性禽流感暴发流行的风险因子调查与分析

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.     

2012年盐城地区部分规模禽场禽流感疫病监测分析与防治

禽流感是禽流行性感冒的简称,是由A型流感病毒引起的一种禽类传染病。根据其致病性和毒力的不同分为高致病性禽流感(HPAI)、低致病性禽流感(LPAI)以及无致病性禽流感。HPAI因其传播快、危害大,被世界动物卫生组织定为A类传染病。2004年初,越南、泰国境内的H5N1亚型高致病性禽流感大流行已经使数十人死亡,随后传入我国,使成千上万只鸡死亡。禽流感疫情的发生越来越频繁,发病的地区也越来越多,受疫情影响的范围越来越广。禽流感在造成巨大直接和间接经济损失的同时,也威胁着人类的生命安全,已成为重大的公共卫生问题。盐城市位于苏北黄海之滨,是江苏省畜禽养殖大市和主产区。家禽业作为盐城市畜牧业的传统产业,近年来发展迅速,做好禽流感的防控工作更是重中之重。     

新疆高致病性禽流感流行病学调查与疫源分析

2004年以来,世界范围内暴发了高致病性禽流感(High Pathogenic A-vian Influenza,HPAI)疫情,疫情波及亚洲、欧洲、非洲及北美洲,中国有多个省区发生了HPAI疫情。2005年的11月11日新疆喀什地区泽普县发生了HPAI疫情,并在短短的1个月内,     

高致病性禽流感防治技术问答

<正>禽流感是禽流行性感冒的简称,是由A型禽流行性感冒病毒引起的一种禽类(家禽和野禽)传染病。根据禽流感病毒致病性的不同,分为高致病性禽流感(HPAI)和低致病性禽流感(LPAI)。HPAI表现为较严重     

2020—2021年冬春季铜仁市家禽高致病性禽流感专项监测

为掌握铜仁市家禽高致病性禽流感病毒的感染情况,及时研判疫情风险,保障养禽业的健康发展,2020年12月至2021年3月在全市10个县(区)随机选择1个规模场(或种禽场)、1个活禽交易市场(或禽屠宰点),采集咽肛双棉拭子样品和环境拭子样品共计890份,通过实时荧光定量PCR方法检测高致病性禽流感病毒(H5、H7亚型)。结果：13个家禽规模场和9个活禽交易市场全部样品的高致病性禽流感病毒(H5、H7亚型)核酸检测均为阴性。结论：2020—2021年冬春季铜仁市养殖家禽无高致病性禽流感病毒(H5、H7亚型)感染,发生高致病性禽流感疫情的风险较低。     

重组禽流感病毒H5亚型二价灭活疫苗(H5N1,Re-5+Re-4)免疫鸡和鸭后抗体消长规律

禽流感(AI)是由A型流感病毒引起的一种禽类传染病.根据致病性的不同将禽流感分为高致病性禽流感(HPAI)和低致病性禽流感(IPAI),HPAI被世界动物卫生组织(OIE)列为A类传染病,我国将其列为一类动物疫病 [1].近几年来,禽流感在世界各地反复出现,2004年亚洲发生了高致病性禽流感,2006年底和2007年初东南亚又出现疫情,并发现了人感染禽流感.我国养禽业也一直受到禽流感的威胁.因此,它不仅给畜牧业造成了巨大的损失,而且给人们的公共卫生安全带来了严重的威胁.     

反思HPAI疫情频发探讨行业应对策略

自2003年12月26日至2005年11月14日,全世界共报告126人感染禽流感病例,其中64人死亡。2004年1月27日,我国首次公布确诊湖北鄂州、广西隆安等地发生高致病性禽流感(HPAI)疫情。2005年5月至11月30日,我国的青海、湖南、安徽、新疆等地又相继发生高致病性禽流感疫情30起,发生的疫情已得到较好的控制,确诊有3例人感染禽流感病例,其中2例死亡。近两年频发的高致病性禽流感疫情给我国家禽养殖业带来了严峻挑战。疫情发生后,家禽生产销售均普遍受阻。汉川广东温氏家禽有限公司是湖北省家禽养殖的龙头企业,年出栏肉鸡1000多万只,60%在湖北省内销售…     

2020—2022年H5亚型高致病性禽流感流行情况分析

了解H5亚型高致病性禽流感发展现状,为优化相关政策提供信息支持,本文简述了全球高致病性禽流感（HPAI）的流行现状。2020—2022年,全球累计91个国家/地区报告发生HPAI疫情,累计报告疫情16 146起,累计发病禽为4 449.5万余只,累计扑杀销毁禽2.51亿只。其中,H5N1亚型是目前全球流行的主要血清型,欧洲、美洲、亚洲等国家累计报告的疫情数占比超过90%。鉴于H5亚型禽流感病毒是当前全球危害养禽业的主要流行亚型,本文进一步分析了H5N1、H5N6、H5N8等亚型的流行特点,概述了我国H5亚型HPAI流行现状,并强调了我国实施的强制免疫与扑杀相结合的禽流感综合防控策略已取得显著成效。此外,全球H5亚型HPAI疫情启示,我国应持续加大HPAI防控力度,推进养禽业产业结构优化升级,提高生物安全水平,加强疫情信息分析,强化野生动物和病原变异情况监测力度,坚定实施扑杀感染禽和疫苗免疫相结合等综合防控策略。     

我国禽流感疫情的新特点、新趋势及应对措施

近三年来，我国不断有高致病性禽流感疫情发生，特别是2004、2005年高致病性禽流感疫情大面积发生，并且呈现出一些新特点，从2004年的点发到2005年的散发；发生疫情的季节性不明显，几乎全年都有发生；禽流感病毒的毒力在增强，主要表现在引起了候乌的大量死亡；2004年前水禽多带毒而不发病，但是2005年发生的疫情中有多起疫情都有鸭子和鹅死亡；2004年只是禽只感染，2005年以来候鸟、留鸟和禽只交叉感染，并陆续致人感染发病。从流行趋势看，高致病性禽流感疫情进一步发生的几率较大。     

美国拟对丹麦与法国亚型高致病性禽流感疫情进行评估

2008年6月18日,美国拟对丹麦与法国亚型高致病性禽流感疫情进行评估。美国动植物健康检验局通知,自丹麦与法国家禽各发生一例H5N1亚型HPAI后,该局已完成了一份有关丹麦与法国H5N1亚型高致病性禽流感（HPAI）动物健康状况的评估报告。该评估报告介绍了我们在丹麦和法国暴发疫情时,对H5N1亚型HPAI发现、控制和根除的评估结果、各国对疫情暴发采取的措施及对各国H5N1亚型HPAI疫情现状作出的评估。拟将这些风险评估报告提交公众评议。     

Use of personal protective measures by Thai households in areas with avian influenza outbreaks

Thailand has had multiple poultry outbreaks of highly pathogenic avian influenza (HPAI) H5N1 since its first emergence in 2004. Twenty-five human cases of HPAI H5N1 avian influenza have been reported in the country, including 17 fatalities, and contact with infected dead or dying poultry has been identified as a risk factor for human infection. This study assessed the use of protective equipment and hand hygiene measures by Thai poultry-owning households during activities involving poultry contact. Surveys conducted in 2008 included questions regarding poultry-related activities and protective measures used during an HPAI outbreak (2005) and 3 years after the study location's last reported outbreak (2008). For both time periods, poultry owners reported limited use of personal protective equipment (PPE) during all activities and inconsistent hand washing practices after carrying poultry and gathering eggs. This is the first time that PPE use in Thailand has been quantified for a large study group. These data are important for ongoing characterization of HPAI risk and for the crafting of educational messages.     

我国H5和H7N9亚型高致病性禽流感的监测及疫情暴发分析

禽流感病毒（avian influenza virus,AIV）是一种重要的人兽共患病病原,严重制约养禽业的健康发展,并对公共卫生安全构成极大威胁。其中,H5（H5N1、H5N2、H5N6、H5N8等）和H7N9亚型高致病性禽流感病毒（highly pathogenic avian influenza virus,HPAIV）引起的高致病性禽流感（highly pathogenic avian influenza,HPAI）对我国养禽业危害巨大。通过实施强制免疫,疫情得到了控制,但在禽群中仍散状暴发,并出现多种新型病毒,防控形势依然严峻。本文总结了截至2021年9月我国禽类暴发H5和H7N9亚型HPAI的所有官方公布的疫情暴发事件以及监测数据,分析了其流行特点,以期为禽流感的预警和防控提供参考。     

武汉市新洲区2021年高致病性禽流感和新城疫免疫抗体监测数据浅析

高致病性禽流感（highly pathogenic avian influenza, HPAI）和新城疫（newcastle disease, ND）等烈性传染病对养禽业危害严重,是养禽业需重点防控的疾病,其中HPAI是国家规定的强制免疫疫病。武汉市新洲区为家禽养殖大区,有规模禽场350余家,养殖规模近1140万只。为了解2021年度武汉市新洲区规模养殖场高致病性禽流感和新城疫免疫抗体合格率,武汉市新洲区农业技术推广服务中心连续12个月对辖区内规模鸡场进行蛋样抽检,运用血凝和血凝抑制试验,分别检测了高致病性禽流感H5亚型、H7亚型和新城疫的免疫抗体。结果显示,高致病性禽流感H5亚型、H7亚型和新城疫的整体免疫抗体合格率分别为94.1%、96.4%和88.9%,均达到了农业农村部规定的免疫抗体合格率不低于70.0%的标准。     

Impact of inland waters on highly pathogenic avian influenza outbreaks in neighboring poultry farms in South Korea

BackgroundSince 2003, the H5 highly pathogenic avian influenza (HPAI) subtype has caused massive economic losses in the poultry industry in South Korea. The role of inland water bodies in avian influenza (AI) outbreaks has not been investigated. Identifying water bodies that facilitate risk pathways leading to the incursion of the HPAI virus (HPAIV) into poultry farms is essential for implementing specific precautionary measures to prevent viral transmission.ObjectivesThis matched case-control study (1:4) examined whether inland waters were associated with a higher risk of AI outbreaks in the neighboring poultry farms.MethodsRivers, irrigation canals, lakes, and ponds were considered inland water bodies. The cases and controls were chosen based on the matching criteria. The nearest possible farms located within a radius of 3 km of the case farms were chosen as the control farms. The poultry farms were selected randomly, and two HPAI epidemics (H5N8 [2014–2016] and H5N6 [2016–2017]) were studied. Conditional logistic regression analysis was applied.ResultsStatistical analysis revealed that inland waters near poultry farms were significant risk factors for AI outbreaks. The study speculated that freely wandering wild waterfowl and small animals contaminate areas surrounding poultry farms.ConclusionsPet birds and animals raised alongside poultry birds on farm premises may wander easily to nearby waters, potentially increasing the risk of AI infection in poultry farms. Mechanical transmission of the AI virus occurs when poultry farm workers or visitors come into contact with infected water bodies or their surroundings. To prevent AI outbreaks in the future, poultry farms should adopt strict precautions to avoid contact with nearby water bodies and their surroundings.     

Influenza vaccines and vaccination strategies in birds

Although it is well accepted that the present Asian H5N1 panzootic is predominantly an animal health problem, the human health implications and the risk of human pandemic have highlighted the need for more information and collaboration in the field of veterinary and human health. H5 and H7 avian influenza (AI) viruses have the unique property of becoming highly pathogenic (HPAI) during circulation in poultry. Therefore, the final objective of poultry vaccination against AI must be eradication of the virus and the disease. Actually, important differences exist in the control of avian and human influenza viruses. Firstly, unlike human vaccines that must be adapted to the circulating strain to provide adequate protection, avian influenza vaccination provides broader protection against HPAI viruses. Secondly, although clinical protection is the primary goal of human vaccines, poultry vaccination must also stop transmission to achieve efficient control of the disease. This paper addresses these differences by reviewing the current and future influenza vaccines and vaccination strategies in birds.     

Novel reassortant H5N5 viruses bind to a human-type receptor as a factor in pandemic risk

Highly pathogenic avian influenza A(HPAI) H5N1 viruses pose a serious pandemic threat due to their virulence and high mortality in humans, and their increasingly expanding host range and significant ongoing evolution could enhance their human-to-human transmissibility. Recently, various reassortant viruses were detected in different domestic poultry, with the HA gene derived from the A/goose/Guangdong/1/96-like (Gs/GD-like) lineage and the NA gene from influenza viruses of other subtypes. It is reported that some natural reassortant H5N5 highly pathogenic avian influenza viruses were isolated from poultry in China. And their HA genes were belonged to a new clade 2.3.4.4. We evaluated the receptor binding property and transmissibility in guinea pigs of these reassortant H5N5 HPAIVs. The results showed that these viruses bound to both avian-type (α-2,3) and human-type (α-2,6) receptors. In addition, we found that one of these viruses, 031, not only replicated but also transmitted efficiently in guinea pigs. Therefore, such reassortant influenza viruses may pose a pandemic threat.     

Are the Australian poultry industries vulnerable to large outbreaks of highly pathogenic avian influenza?

Objective   To describe the structure of the Australian poultry industry and discuss the potential for highly pathogenic avian influenza (HPAI) to spread between Australian poultry farms.
Procedure   High densities of poultry farms, frequent contacts between farms by service providers, the supply of live poultry markets (LPM) and the presence of free-range duck flocks in affected regions have been identified as risk factors for the spread of HPAI between flocks in outbreaks causing the death or destruction of over 1 million poultry overseas. Data on 1,594 commercial Australian chicken meat, chicken egg, duck and turkey farms were collected by a telephone questionnaire of farm managers to assess the risk of a HPAI outbreak in Australia.
Results and Discussion   Five regions of Australia had farm densities comparable to overseas regions that experienced widespread HPAI. Common service providers routinely contacted different classes and types of farms over wide geographic areas. However, no responding farms supplied LPM and the majority of duck farms did not produce free-range ducks.
Conclusion   Outbreaks of HPAI have the potential to cause serious impacts on the Australian poultry industry. The risk posted by LPM and free-range ducks is limited, but the movement of genetic stock and common service providers could spread infection between companies, industries or geographical regions. Biosecurity measures are therefore considered critical to limit the secondary spread of infection should an outbreak occur.     

Clade 2.3.4.4 avian influenza A (H5N8) outbreak in commercial poultry,Iran, 2016: the first report and update data

Tropical Animal Health and Production - In 2010, H5N8 highly pathogenic avian influenza (HPAI) viruses of the A/Goose/Guangdong/1/1996 lineage dramatically affected poultry and wild birds in Asia,...     

"Constanze": a trinational project on avian influenza in wild birds at Lake Constance

When highly pathogenic avian influenza H5N1 (HPAI H5N1) arrived at Lake Constance in February 2006, little was known about its ecology and epidemiology in wild birds. In order to prevent virus transmission from wild birds to poultry, the adjacent countries initiated the tri-national, interdisciplinary research program ?Constanze? to investigate avian influenza infections in water birds at Lake Constance. In collaboration with government agencies scientists examined the prevalence of AI virus in the region of Lake Constance for a period of 33 months, compared the effectiveness of different surveillance methods and analysed the migration behaviour of water birds. Although virus introduction from regions as far as the Ural Mountains seemed possible based on the migration behaviour of certain species, no influenza A viruses of the highly pathogenic subtype H5N1 (HPAIV) was found. However, influenza A viruses of different low pathogenic subtypes were isolated in 2.2 % of the sampled birds (swabs). Of the different surveillance methods utilised in the program the sampling of so called sentinel birds was particularly efficient.