金湖农村散养家禽禽流感免疫失败的主要原因及应对措施

高致病性禽流感（Highly Pathogenic Avian Influenza，HPAI）是由正黏病毒科流感病毒属A型流感病毒引起的禽类烈性传染病，对人畜健康危害严重。世界动物卫生组织（OIE）将其列为A类动物疫病，我国将其列为一类动物疫病。     

规模化猪场种猪猪瘟免疫方式和剂量探讨

猪瘟（CSF）是由猪瘟病毒（CSFV）引起的一种高度致死性、接触性传染病，是世界动物卫生组织（OIE）规定必须报告的动物疫病之一，在我国被归为一类动物疫病。     

新城疫流行病学变化及综合防制进展

新城疫（ND）是由新城疫病毒（NDV）引起的一种禽类急性、高度接触性、致死性传染病,被国际动物卫生组织（OIE）列为危害禽类的两种A类传染病之一。尽管世界各国对ND采取了严格的防控措施,如对强毒感染的扑杀措施、限制使用中等毒力疫苗及强制性免疫等措施,但它仍然是危害禽类的主要传染病,并且呈现新的流行趋势,使防制工作变得复杂化。     

浅谈鸡新城疫的免疫

新城疫是一种由NDV（副黏毒）引起禽的一种急性、热性、败血性和高度接触性的传染病。其主要的特征为呼吸困难、下痢、神经紊乱、黏膜和浆膜出血、严重的产蛋下降。具有很高的发病率和病死率，是严重危害养禽业的一种主要传染病，OIE将其列为A类疫病。     

玉林市口蹄疫免疫水平监测与免疫效果分析

口蹄疫（foot-and—mouth disease,FMD）是由口蹄疫病毒（foot．and—mouth disease virus,FMDV）引起的一类高度接触性传染病,被世界动物卫生组织列为必须报告的A类动物疫病,我国农业部第1125号公告将其列为一类动物疫病。     

全球家禽流感疫苗的研制与使用现状

一、禽流感概述 禽流感（Avian Influenza，简称AI）是由正粘病毒科流感病毒属A型流感病毒引起的多种家禽及野生禽类均可感染的病毒性传染病。高致病性禽流感（Hign Pathogenicity Avian Influenza，简称HPAI）是世界范围内严重危害家禽业的四大传染性疾病之一，是国际兽医局（OIE）规定的A类动物传染病，中国政府也将其列为一类动物疫病。     

当前养禽业中禽流感的流行及免疫现状

禽流感（Avian influenza，AI）是由正粘病毒科A型流感病毒引起的一种禽类的烈性传染病。自1978年在意大利的鸡群中首次发现本病以来，已在美洲、欧洲等世界上许多国家和地区发现有本病流行。     

鸡新城疫疫苗的研究进展

新城疫（ND），又称亚洲鸡瘟、伪鸡瘟等。是由新城疫病毒（NDV）引起的主要感染鸡、鸽、鹌鹑、火鸡等家禽和野生禽类的一种急性、败血性、高度接触性传染病。可感染50个鸟目中27个目240种以上的禽类，世界各国都十分重视该病。世界动物卫生组织（0IE）将其列为动物法定必报传染病。ND不但给禽类带来灾难性损失，而且还严重影响禽及禽类制品的国际贸易。因此，世界各国对该病的发生流行都采取极为严格的防控措施。     

新城疫的流行动态和防控策略

一．正确看待新城疫及其危害 新城疫（ND）是世界禽类两个重大传染病之一，是国家中长期动物疫病防治规划（2012～2020）优先防治病种，ND还是免疫次数最多的病种，长期危害中国养禽业最严重的疫病之一。     

禽流感免疫十要点

禽流感又称真性鸡瘟、欧洲鸡瘟.是由A型流感病毒引起的禽类的一种烈性传染病.国际兽医局(OIE)将高致病性禽流感划分为A类疫病,我国亦将其列为一类动物传染病,是国家规定强制免疫的疫病.免疫是当前防控禽流感的有效措施,是避免和减少疫情发生的关键,广大养禽户和动物防疫工作者必须高度重视,做好免疫接种工作,增强禽群的特异性抵抗力,建立有效免疫屏障.在生产中搞好禽流感免疫要把握以下十要点.     

禽流感与新城疫的鉴别诊断

收稿日期：２００２－０１－１４禽流感（AI）是危害世界养鸡业的最为严重的传染病之一，由于该病与新城疫（ND）在临床症状及病理变化上有许多相似之处，因而临床上容易造成误诊。现将二者的区别介绍如下：１病原禽流感病毒（AIV）是正粘病毒科正粘病毒属的A型流感病毒。流感病毒有两种重要的表面抗原，即血细胞凝集素（HA）和神经氨酸酶（NA）。AIV至少有１５种血细胞凝集素和９种神经氨酸酶，这样便可能组成大量的病毒亚型，各亚型之间不发生交叉的保护作用。各种AIV之间致病力差异很大，致病力弱的毒株只能引起轻微的症状，而高…     

Newcastle disease and avian influenza A virus in wild waterfowl in South Africa

In an intensive ostrich farming area in South Africa with a history of ostrich influenza outbreaks, we conducted a survey of avian influenza virus (AIV) and Newcastle disease virus (NDV) in wild aquatic birds. During late autumn and winter 1998, the time of year when outbreaks in ostriches typically start to occur, 262 aquatic birds comprising 14 species were sampled and tested for both virus infections. From eight samples, AIV, serotype H10N9, could be isolated. All isolates were apathogenic as determined by the intravenous pathogenicity index (0.00). Conversely, none of 33 sera of these wild birds showed antibodies against H10. However, one bird was found serologically positive for H6 AIV. This AIV serotype was later isolated from ostriches during an avian influenza outbreak in this area. No NDV was isolated although 34 of 46 serum samples contained NDV-specific antibodies. This is the first H10N9 isolate to be reported from Africa. In addition, our data support the notion that wild aquatic birds may function as a reservoir for AIV and NDV in South Africa.     

Comparison of electrocardiograms of chickens infected with viscerotropic velogenic Newcastle disease virus and virulent avian influenza virus

Electrocardiograms of chickens infected with viscerotropic velogenic Newcastle disease virus (NDV) or virulent avian influenza virus (AIV) were characterized and compared. The ECG were monitored by radiotelemetry and were recorded twice daily before virus infection and during the course of the infection. Thirteen lead II intervals, segments, and amplitudes were measured and analyzed. The ECG of NDV-infected chickens were characterized by lengthened (P less than or equal to 0.05) ST segments and increased (P less than or equal to 0.05) P amplitudes. The ECG of AIV-infected chickens were characterized by lengthened (P less than or equal to 0.05) RS intervals, ST segments, TP intervals, and PR segments and by increased (P less than or equal to 0.05) P amplitudes. The TP intervals and PR segments of ECG of AIV-infected chickens were significantly (P less than or equal to 0.05) longer than those of NDV-infected chickens. The pronounced conduction delays indicated in the ECG of AIV-infected chickens may have diagnostic importance.     

Evaluation of different methods of inactivation of Newcastle disease virus and avian influenza virus in egg fluids and serum

Viruses conveyed in shipments of eggs, viral diagnostic reagents, or avian serum samples are a potential hazard for susceptible poultry. Different methods of treatment of those materials to eliminate the hazard of virulent and avirulent strains of Newcastle disease virus (NDV) or avian influenza virus (AIV) were evaluated. The NDV strains tested were more thermostable than the AIV strains. The results suggest that standard pasteurization methods would not reliably inactivate the concentrations of NDV used. beta-Propiolactone (BPL) (greater than or equal to 0.025%) inactivated NDV or AIV in allantoic fluid, but higher concentrations were needed to inactivate virus diluted in serum. Hemagglutination (HA) of NDV and AIV and hemolysis (HL) activity of NDV were reduced or eliminated by 0.4% BPL. Formalin (greater than or equal to 0.04%) inactivated either virus but adversely affected HA and HL activity. NDV or AIV was inactivated by binary ethylenimine (BEI) (0.01 M) with no adverse effect on HA or HL. Heat (56 C) or BEI (0.01 M) had no apparent effect on hemagglutination-inhibition (HI) titers of NDV and AIV antisera, the effect of formalin (0.1%) was variable, and BPL (greater than or equal to 0.25%) depressed the HI titers of both antisera. The optimum method should achieve virus inactivation without harming the treated material.     

鸡新城疫、传染性支气管炎、禽流感(H9亚型)三联灭活疫苗对禽流感H9亚型流行株攻毒的保护作用

为了监测鸡新城疫、传染性支气管炎、禽流感(H9亚型)三联灭活疫苗(LaSota株+M41株+SS/94株)对H9亚型禽流感病毒流行毒株的免疫保护效果,采用H9亚型禽流感病毒SS/94株及2009—2010年现地分离的3株H9亚型禽流感病毒对已免疫上述三联灭活苗的SPF鸡进行攻毒试验。结果显示,试验鸡以0.3 mL/只的剂量免疫三联灭活苗后21 d,其H9亚型禽流感病毒的HI抗体效价可达8～11log2,此抗体水平可抵抗2×106EID50的H9亚型禽流感病毒SS/94株、BLCN09株、WDZ09株、YT10株的攻击,攻毒保护率均达90%(9/10)以上。可见,以SS/94株作为禽流感疫苗抗原制备的三联灭活苗具有良好的免疫原性,能使免疫鸡抵抗2009—2010年期间现地分离的多株H9亚型禽流感病毒的攻击。     

1株鸡新城疫强毒株的分离鉴定及致病性

从山东省一发病率、死亡率高的肉鸡群中分离到1株病毒,经HA、HI试验和动物回归试验确定所分离的毒株为新城疫病毒,命名为新城疫LVCX株。按常规方法测得LVCX株的MDT、ICPI和IVPI分别为47.4h、1.975和2.85,鸡胚半数致死量LD50为10-9.8。F基因分析表明分离株LVCX为基因Ⅶ型,其多肽裂解位点为112-RRQKRF-117,表明LVCX株为新城疫病毒强毒株。该毒株F基因核苷酸同源性与近几年分离的基因Ⅶ型鸡源毒株同源性在93.5%～98.3%之间;与经典强毒株F48E9和Lasota株的核苷酸和氨基酸同源性分别为85.8%、91.3%和83.3%、88.4%;且与近几年分离的几株鹅源、鸭源核苷酸同源性也较高,在95.2%～96.5%之间。     

Previous infection with virulent strains of Newcastle disease virus reduces highly pathogenic avian influenza virus replication,disease, and mortality in chickens

Highly pathogenic avian influenza virus (HPAIV) and Newcastle disease virus (NDV) are two of the most important viruses affecting poultry worldwide and produce co-infections especially in areas of the world where both viruses are endemic; but little is known about the interactions between these two viruses. The objective of this study was to determine if co-infection with NDV affects HPAIV replication in chickens. Only infections with virulent NDV strains (mesogenic Pigeon/1984 or velogenic CA/2002), and not a lentogenic NDV strain (LaSota), interfered with the replication of HPAIV A/chicken/Queretaro/14588-19/95 (H5N2) when the H5N2 was given at a high dose (10^6.9 EID₅₀) two days after the NDV inoculation, but despite this interference, mortality was still observed. However, chickens infected with the less virulent mesogenic NDV Pigeon/1984 strain three days prior to being infected with a lower dose (10^5.3–5.5 EID₅₀) of the same or a different HPAIV, A/chicken/Jalisco/CPA-12283-12/2012 (H7N3), had reduced HPAIV replication and increased survival rates. In conclusion, previous infection of chickens with virulent NDV strains can reduce HPAIV replication, and consequently disease and mortality. This interference depends on the titer of the viruses used, the virulence of the NDV, and the timing of the infections. The information obtained from these studies helps to understand the possible interactions and outcomes of infection (disease and virus shedding) when HPAIV and NDV co-infect chickens in the field.

Electronic supplementary material

The online version of this article (doi:10.1186/s13567-015-0237-5) contains supplementary material, which is available to authorized users.     

不同宿主源NDV毒株对SPF鸡致病性研究

为阐明不同宿主及不同基因型新城瘦病毒(NOV)对SPF鸡致病性,选择分离自鸡、番鸭、鹅、健康野鸟的基因VIId亚型NDV 6株,鸡源基因Ⅲ型和鸽源基因VIb型毒株各1株,以及基因Ⅸ型强毒F48E9,共9株NDV毒株进行致病性试验.在对各毒株的EID50及主要致病指数MDT、ICPI测定基础之上,以相同剂量感染15日龄SPF鸡,观察临床症状及剖检病变,计算发病率和死亡率,并在攻毒后不同时间采集主要组织样品.以SYBR Green I Real-time PCR检测病毒最早出现时间及病毒载量.结果表明,6株基因VIId亚型NDV毒株导致SPF鸡100%发病,死亡率90%以上,属于高致病性毒株;基因Ⅲ、VIb型毒株导致SPF鸡发病但不死亡,属于中等毒力毒株.VIId亚型毒株与F48E9株攻毒后SPF鸡在病理变化、组织嗜性及病毒载量上没有显著差异.根据毒株的MDT、ICPI指数及攻毒鸡病程综合判断,VIId亚型毒株在致病性上与F48E9株差异不显著.健康野鸟携带基因VIId亚型高致病性NDV,在NDV的自然生态传播过程中起重要作用,提示应该加强对野鸟的流行病学监测及相关研究.