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。     

活禽交易市场消毒前后禽流感病毒核酸污染状况调查

为掌握乌鲁木齐市某活禽交易市场的活禽交易点及市场外环境中禽流感病毒污染情况及其流行规律,制定科学有效的活禽交易市场的日常管理及消毒措施。消毒休市前后分别在相同活禽交易点及活禽交易市场车辆通道采集棉拭子样品。采用实时荧光定量(RT-PCR)方法检测通用型禽流感病毒核酸污染状况,比较活禽交易市场的关键风险点消毒休市前后消毒效果的差异情况。结果表明:该活禽交易市场的消毒技术规范及休市制度对禽流感病毒的作用较为明显,通用型禽流感病毒核酸阳性率从23.9%降至5.4%。     

环洞庭湖区鸭场低致病性禽流感监测分析

为了解环洞庭湖区鸭场低致病性禽流感隐性带毒情况,2011～2012年先后3次对东洞庭湖、南洞庭湖和西洞庭湖区的149个鸭场进行监测,在40个鸭场检测到低致病性禽流感病毒,场间阳性率为26.8％,其中有2个鸭场混合感染多种低致病性禽流感病毒.在鸭拭子和环境拭子中共分离到有H3、H4、H6、H9、H10、H11和H12等7种亚型的低致病性禽流感病毒,其中H3和H4亚型的分离率较高,拭子的病毒分离率为3.88％,表明在洞庭湖区鸭场低致病性禽流感隐性带毒情况较为严重.     

从活禽交易的干预效果看我国禽流感的流行与防控

我国当前的禽流感防控形势依然严峻,除高致病性禽流感的威胁外,还需要警惕能感染人的重组病毒。其中活禽交易市场在禽流感病毒传播中扮演重要角色,它是禽流感病毒重要的集散地和疫病传播环节,但禽流感的防控不能仅限于干预活禽交易市场,还有赖于行政部门和养禽企业多方共同努力。     

新疆乌鲁木齐市某活禽交易市场禽流感病毒污染状况调查

为了解新疆乌鲁木齐市活禽交易市场内禽流感病毒污染状况以及亚型分布情况,掌握活禽档口、活禽屠宰点及活禽运输车辆的禽流感病毒流行规律,对采集的437份棉拭子样本,采用实时荧光定量RT-PCR方法检测禽流感病毒核酸,再对阳性样品进行核酸分型。结果显示:473份样品中,检出禽流感病毒核酸阳性115份,阳性检出率为24.31%,其中H5亚型26份,阳性检出率为22.6%,H9亚型45份,阳性检出率为39.13%,未定型44份,阳性检出率为38.26%,未检出H7亚型;活禽运输车、活禽档口和活禽屠宰点的阳性检出率分别为29.69%、24.15%和21.74%;活禽档口中的污水(44.90%)、笼具(34.69%)、粪便(24.49%),活禽屠宰点的脱毛机(47.80%)、接血槽(34.78%),以及活禽运输车的装载笼具(56.25%)的阳性检出率较高。结果表明:该活禽交易市场禽流感病毒污染状况较为严重,污染范围较广,活禽运输车、活禽档口和活禽屠宰点均有污染;活禽档口中的污水、笼具、粪便,活禽屠宰点的脱毛机、接血槽,以及活禽运输车的装载笼具为禽流感病毒散播的关键风险点。结果提示,需加强市场日常管理及清洗消毒,降低禽源流感病毒通过活禽交易市场传播的风险。本调查为制定科学有效的活禽交易市场日常管理及消毒措施提供了技术支持。     

2017—2018年西藏拉萨市养殖场及活禽交易市场禽流感流行病学调查

为了解拉萨市禽流感流行情况,2017年11月—2018年3月,在拉萨市6个养殖场和11个活禽交易市场,随机采集1 394份棉试子进行禽流感病毒分离和分型鉴定。结果显示： H9亚型禽流感病毒阳性率为2.87%,未检出H3、H5、H6、H7等其他亚型病毒;活禽市场H9亚型阳性率（4.64%）显著高于养殖场阳性率（0.35%,P<0.01）。结果表明,拉萨市高致病性禽流感流行风险较小,低致病性禽流感流行以H9亚型为主,且流行率不高,但应进一步加强养殖环节的防疫、检疫,以及活禽市场的清洗、消毒等工作,防止禽流感传入和流行。     

东兴市活禽市场禽流感流行病学调查

为掌握中越边境地区禽流感流行趋势,2013年10月～2020年10月对辖区内活禽销售市场进行系统监测。监测结果显示:活禽市场内常年都有病毒循环,呈多亚型病毒共存状态;环境样品的阳性率高达30.82%,家禽样品阳性率为20.77%。市场调查发现:东兴市的活禽销售市场规模不大而交易频繁;市场交易活禽主要来自本地小型养殖场、广西其他地区活禽交易批发市和规模养殖场以及边境走私家禽;活禽市场生物安全措施不到位,也未严格执行休市制度。监测和调查结果表明,东兴市活禽销售市场管理水平低,家禽来源复杂;市场环境污染严重,多种亚型禽流感病毒共存,且存在家禽隐性带毒现象,因而有病毒散播风险。因此需要加强禽流感监测力度,提高活禽市场的管理水平和生物安全措施。     

新疆乌鲁木齐市某活禽交易市场禽流感流行病学调查

为了解冬季新疆乌鲁木齐市活禽市场交易禽类及市场外环境中禽流感病毒污染情况及其流行规律,对某交易市场内的鸡、鸭、鹅、鸽等活禽,采集85份活禽全血样本和143份棉拭子样本(103份活禽泄殖腔/咽喉棉拭子、40份环境棉拭子),分别采用血清学和实时荧光定量(rRT-PCR)方法,检测禽流感免疫抗体和禽流感病毒核酸,并对核酸阳性样品进行病毒亚型确定。结果显示:85份全血样本中,H5(Re-11)株免疫抗体合格32份,合格率为37.6%;H5(Re-12)株免疫抗体合格34份,合格率为40%;H7(Re-2)株免疫抗体合格46份,合格率为54.2%。143份棉拭子样本中,禽流感病毒核酸阳性36份,阳性率为25.17%。其中:活禽棉拭子阳性29份,阳性率为28.15%;交易区外环境棉拭子阳性7份,阳性率为17.5%。36份禽流感病毒核酸阳性样本中,H5亚型3份,阳性率为8.33%;H9亚型22份,阳性率为61.11%;未定型11份,阳性率为30.56%。结果表明:该市场交易活禽流感病毒感染率较高,且强制免疫的H5、H7亚型禽流感免疫抗体合格率较低,存在疫情发生和散播风险。结果提示,应加强活禽交易市场的消毒与管理,降低禽流感病毒通过活禽交易市场传播的风险。     

2017年湖南省永州市活禽市场禽流感污染状况调查

为了解湖南省永州市活禽市场禽流感病毒污染状况,2017年4—12月,永州市动物疫病预防控制中心在冷水滩区采集571份家禽和环境样品,进行了H5、H7亚型禽流感病毒核酸实时荧光定量RT-PCR 检测。结果显示：571份样品中,检出H5亚型禽流感病毒核酸阳性样品44份,阳性检出率为7.7%,未检出H7亚型禽流感病毒阳性样品;除5月份外,每月都能监测到阳性样品,且冬季阳性检出率明显偏高;活禽在摊位中停留时间越长,禽流感病毒阳性率越高;鸭源样品和污水样品中的禽流感病毒检出率最高,城乡农贸市场的病毒阳性检出率高于城区活禽交易市场。调查结果表明,活禽市场中的H5亚型禽流感病毒污染率较高,尤其是水禽和污水以及卫生条件较差的市场。因此,要严把市场休市清洗消毒关,提升市场环境卫生水平,严格活禽调运检疫和监管,禁止陆禽和水禽混合销售。     

华南农业大学教授廖明:审时度势,建立全产业链可持续发展养禽模式

<正>H7N9亚型禽流感流行特点今年新出现高致病性H7N9亚型禽流感病毒,污染范围不断扩大,形成高致病性和低致病性毒株同时流行的局面,给养鸡业造成严重危害。综合来讲,其流行特点主要集中在以下几个方面:H7N9亚型禽流感病毒出现同源性、致病性和抗原性等方面的差异。活禽交易市场(主要是农贸市场)在家禽生产和贸易链中仍是H7N9亚型禽流感病毒污染率最高的环节,相关的运输、市场屠宰和销售等行为都有助于     

两株H6N2亚型鸡源禽流感病毒的分离鉴定

本研究利用血凝抑制试验(HI)、反转录-聚合酶链式反应(RT-PCR)、基因测序等方法,对广东省某活禽交易市场进行流行病学调查时获得的两株非H5、H9亚型禽流感病毒65株和C7株进行了亚型鉴定。结果表明这两株病毒均具有血凝活性,且能被抗H6亚型禽流感病毒标准阳性血清特异性抑制。用针对禽流感病毒的M基因、H6亚型禽流感病毒HA基因、N2亚型禽流感病毒NA基因特异性鉴定引物对65株和C7株进行RT-PCR扩增,分别获得特异性目的片段。测序及BLAST分析表明两株分离株与H6N2亚型禽流感广东分离株的HA基因和NA基因核苷酸序列相似性均高达95%以上。将该两分离株鉴定为H6N2亚型禽流感病毒,并命名为A/Chicken/Guangdong/65/2009、A/Chicken/Guangdong/C7/2009。     

湖北省禽流感的诊断及病毒株的分离与初步鉴定

通过采用琼脂扩散法（AGP）对湖北省8个发病鸡场进行禽流感抗体的检测，证实了禽流感的存在。从某鸡场5只濒死鸡气管刮屑及内脏材料中分离到了一株病毒。应用HI试验和电镜负染技术确证该分离物为A型流感病毒，其血凝价可达1：2560。该病毒粒子有囊膜，呈球形或椭圆形，大小为80－120nm，其血清型为H9N2型。     

禽流感检测方法研究进展

禽流感不仅对世界养禽业带来巨大的经济损失，而且可以感染人，公共卫生意义重大。由于其病毒亚型众多，抗原性变异极快，毒株的致病性也相差很大，早期快速诊断和血清学检测就成为预防和控制禽流感的前提条件。禽流感病毒的传统诊断方法是分离病毒和检测抗体。近年来，又相继建立了血凝抑制试验、神经氨酸酶抑制试验、酶联免疫吸附试验等血清学诊断技术及分子诊断技术。文章对禽流感检测方法快速诊断进行了概述。     

山东省首起野生天鹅H5N8高致病性禽流感疫情的紧急调查及处置

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...     

Prevalence and incidence of Newcastle disease and prevalence of Avian Influenza infection of scavenging village chickens in Timor-Lesté

A longitudinal study to monitor prevalence and incidence of antibodies against Newcastle disease (ND) virus and prevalence of antibodies against Avian Influenza (AI) virus in scavenging village chickens was conducted in 20 villages within 4 districts of Timor-Lesté. A total of 3600 blood samples was collected from 1674 individual birds in 300 household chicken flocks during three sampling periods (December 2008-February 2009, March-May 2009, and June-August 2009). The mean interval between household visits was 101.6±1.9 days. None of the birds enrolled in the study was vaccinated against ND or AI. A haemagglutination inhibition (HI) test was used to determine antibody titres against ND virus and a competitive ELISA and HI tests were used to detect antibody against AI virus. The bird-level ND seroprevalence pooled across all samplings (adjusted for clustering by households) was 4.4% (95% CI 3.5-5.2). The bird-level ND seroprevalence in each of the three sampling periods (adjusted for clustering by household) was 3.0% (95% CI 2.0-4.0), 6.6% (95% CI 5.1-8.0) and 3.6 (95% CI 2.5-4.6), respectively. A total of 12.6% individual birds tested ND seropositive at least once over the total study period (95% CI 10.5-14.7). The flock-level ND seroprevalence (at least one bird tested had antibodies against ND virus) pooled across all samplings was 15.9% (95% CI 13.5-18.3). A total of 35.3% flocks had a minimum of one bird being ND seropositive at least once over the study period. The bird-level incidence rate for the period between the first and the second sampling and between the second and the third sampling was 5.6 (95% CI 4.1-7.5) and 0.5 (95% CI 0.5-3.8) per 10,000 bird-years-at-risk, respectively. A total of 1134 serum samples from the last sampling period between June and August 2009 was tested for antibodies against AI virus. Only 4 samples tested Influenza A positive, indicating a bird-level seroprevalence level for Influenza A of 0.4% (CI 0.0-0.7%). These Influenza A positive samples were further tested for HI antibodies against AI virus subtypes of H5N1, H5N3, H7N3 and H9N2, but all tested negative, suggesting that the influenza antibodies in those four birds resulted from exposure to low pathogenic AI viruses of different H subtypes. Our results indicate that village chickens in Timor-Lesté are exposed to ND virus; there was a higher risk of infection during the early months of 2009 than either immediately prior or subsequent to this. No evidence of infection of village chickens with H5, H7 or H9 AI viruses was detected in this study.     

商品代AA肉鸡接种禽流感疫苗的免疫效力观察

分别应用不同禽流感疫苗接种不同批次的商品代AA肉鸡,通过血凝抑制试验测定免疫后不同时期的抗体水平,确定各种疫苗对商品代AA肉鸡的免疫效果。结果表明,在免疫20天后,禽流感（H5＋H9）二价灭活疫苗（H5N1 Re-1＋H9N2 Re-2株）刺激肉鸡群产生的HI抗体均高于禽流感灭活疫苗（H5亚型,N28株）、禽流感（H5N2＋H9N2）二价灭活疫苗（N28株＋SD696株）和禽流感-新城疫重组二联活疫苗（rL-H5株）,与后三种疫苗接种商品代AA肉鸡的免疫抗体相比差异显著（P〈0.05）。     

Research Progress on Novel Vaccine of Avian Influenza

Avian influenza (AI) is an acute respiratory disease caused by influenza A virus.Avian influenza virus (AIV) can infect poultry,wild birds and some mammals including human.AI is a big threat to both poultry and human health because the virus can cross the species barrier to get the capacity of transmitting from poultry to human.Vaccination is the most efficient measure against AI outbreaking.Traditional vaccines include inactivated vaccine based on chick embryo and attenuated vaccine.Although the traditional vaccines play important roles in the past AI epidemics,many disadvantages have been proved to exist in traditional vaccines.Forced by major drawbacks of traditional vaccines,several studies focused on the development of novel vaccines.In this review,we reviewed recombinant live vector vaccine,subunit vaccine,DNA vaccine and virus-like particle vaccine of AI in order to provide some references for prevention and control of AI.     

禽流感新型疫苗研究进展

禽流感是由A型流感病毒引起的一种急性呼吸道传染病,家禽、野鸟和部分哺乳动物均可感染.禽流感给中国养殖业造成了巨大的损失,同时,随着病毒的种间传播,人类的生命安全也受到了严重威胁.目前,疫苗免疫仍是防控禽流感最主要的手段,传统的疫苗主要有鸡胚灭活苗和禽流感弱毒疫苗.虽然在过往几次禽流感暴发过程中,传统疫苗发挥了重要作用,但其自身却存在诸多弊端,因此研制新型疫苗来弥补传统疫苗的不足是很有必要的.文章主要对禽流感重组活载体疫苗、基因工程亚单位疫苗、DNA疫苗和病毒样颗粒疫苗等新型疫苗的研究进展进行综述,旨在为禽流感的防控提供参考.     

新疆一起鹅源高致病性禽流感病毒鉴定初报

对新疆塔城市发生的一起临床怀疑为高致病性禽流感疫情进行流行病学调查,并采用血凝抑制试验、RT—PCR和禽流感通用荧光RT—PCR对血清及病料进行初步鉴定和诊断,结果表明,该病例为高致病性禽流感疑似疫情,后经国家禽流感参考实验室确诊为H5NI型高致病性禽流感,这是新疆首次发现鹅高致病性禽流感。     

Surveillance for highly pathogenic avian influenza in wild birds in the USA

As part of the USA's National Strategy for Pandemic Influenza, an Interagency Strategic Plan for the Early Detection of Highly Pathogenic H5N1 Avian Influenza in Wild Migratory Birds was developed and implemented. From 1 April 2006 through 31 March 2009, 261 946 samples from wild birds and 101 457 wild bird fecal samples were collected in the USA; no highly pathogenic avian influenza was detected. The United States Department of Agriculture, and state and tribal cooperators accounted for 213 115 (81%) of the wild bird samples collected; 31, 27, 21 and 21% of the samples were collected from the Atlantic, Pacific, Central and Mississippi flyways, respectively. More than 250 species of wild birds in all 50 states were sampled. The majority of wild birds (86%) were dabbling ducks, geese, swans and shorebirds. The apparent prevalence of low pathogenic avian influenza viruses during biological years 2007 and 2008 was 9.7 and 11.0%, respectively. The apparent prevalence of H5 and H7 subtypes across all species sampled were 0.5 and 0.06%, respectively. The pooled fecal samples (n= 101 539) positive for low pathogenic avian influenza were 4.0, 6.7 and 4.7% for biological years 2006, 2007 and 2008, respectively. The highly pathogenic early detection system for wild birds developed and implemented in the USA represents the largest coordinated wildlife disease surveillance system ever conducted. This effort provided evidence that wild birds in the USA were free of highly pathogenic avian influenza virus (given the expected minimum prevalence of 0.001%) at the 99.9% confidence level during the surveillance period.