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1.
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...  相似文献   

2.
为监测河南省高致病性禽流感免疫抗体和野毒感染情况,笔者按照《河南省2022年动物疫病监测与流行病学调查计划》的要求,采用HI试验检测禽流感免疫抗体,采用荧光RT-PCR方法检测病毒核酸,在全省开展禽流感专项监测工作。结果表明,河南省高致病性禽流感免疫抗体群体合格率为93.2%,禽流感H5亚型平均个体抗体合格率为94.04%,H7N9亚型平均个体抗体合格率为96.32%。不同地区的禽流感H5亚型和H7N9亚型免疫抗体合格率均>90%,种禽场、商品代场和屠宰场采集的血清样本免疫抗体合格率均在92%以上。未检出H5亚型和H7亚型禽流感病毒核酸。共检出76份禽流感病毒H9亚型阳性样本,阳性率为2.07%。结果表明,河南省高致病性禽流感整体防控效果良好,免疫抗体水平均高于国家标准;未检出高致病性禽流感病毒,但有低致病性禽流感感染的现象。本次调查将为河南省进一步做好禽流感防控工作提供数据支撑。  相似文献   

3.
为了解云南省玉溪市活禽交易市场禽流感病毒污染情况,2021年对该市8个县(市、区)活禽市场进行采样检测。全年共采集63场次1 455份棉拭子样品(禽咽喉/泄殖腔双拭子860份、环境拭子317份、运输工具拭子278份),采用荧光RT-PCR方法进行流感病毒A型、H5/H7/H9亚型流感病毒核酸检测。共检出A型流感病毒核酸阳性435份,未检测到H5和H7亚型病毒核酸阳性;除检出7份未分型阳性样品外,在44场次检出H9亚型病毒核酸阳性428份,场次阳性率为69.84%,样品阳性率为29.42%,其中活禽、环境、运输工具样品阳性率分别为32.56%、25.87%、23.74%,差异具有统计学意义(P<0.05)。一年四季均能检测到H9亚型病毒阳性,但3—6月份样品阳性率低于年均阳性率,1、2、7、10、12月样品阳性率明显高于其他月份,各月份间样品阳性率差异具有统计学意义(P<0.01)。各县(市、区)的场次阳性率存在差异(P<0.05),但样品阳性率差异无统计学意义(P>0.05)。结果表明:玉溪市活禽市场H5、H7亚型高致病性禽流感病毒的污染状况得到有效控制,但H9亚型禽流感病毒污染面依然广,污染率较高;不同月份间阳性率差异明显,但季节性差异缩小。结果提示,应继续加强活禽市场H9亚型禽流感病毒污染监测,同时强化活禽市场的检疫监管,严格执行消毒和休市制度,防止活禽市场禽流感病毒传入养殖环节。  相似文献   

4.
为了研究湘西自治州规模化鸭场的高致病性禽流感的免疫情况和潜在的感染风险,笔者于2008年从湘西自治州各县市采集了规模化鸭场血清标本共480份,采用血凝试验和血凝抑制试验对4个免疫了H5亚型禽流感病毒灭活疫苗的规模化鸭场的不同日龄家鸭进行了H5和H7亚型禽流感病毒抗体的检测。结果表明:4个规模化鸭场H5亚型禽流感病毒抗体合格率分别为65.56%(59/90)、67.78%(61/90)、53.33%(48/90)、47.78%(43/90),说明规模化鸭场的H5亚型免疫抗体水平还有待提高,以对家鸭提供确实的保护;H7亚型禽流感病毒抗体阳性率为0,规模化鸭场没有H7亚型禽流感病毒感染。  相似文献   

5.
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。  相似文献   

6.
为了解广西柳州市活禽市场低致病性禽流感病毒的流行及分布情况,2015年6月—2019年5月持续在柳州市8个活禽市场采集鸡鸭喉头/泄殖腔棉拭子样品1 425份(麻花鸡500份、麻鸭925份),通过SPF鸡胚培养,采用HA和HI试验进行鉴定,并对结果进行统计分析。结果显示:共检出阳性样品156份,阳性率为10.95%(156/1 425);分离出6种亚型,阳性率从高到低依次为H3、H4、H9、H6、H11和H13,其中H13亚型为广西地区首次报道发现,样品来源于麻鸭;从种属分布和混合感染情况来看,鸭群中6种亚型均有感染,但以H3、H4亚型为主,主要表现为混合感染,而鸡群中只有4种亚型,以H9亚型为主。结果表明,柳州市活禽交易市场低致病性禽流感病毒亚型复杂,尤其是麻鸭,且有新亚型出现,病毒变异重组风险加剧,需要坚持活禽市场禽流感病毒长期监测。  相似文献   

7.
为了解玉林市2020年上半年规模禽场重组禽流感病毒(AIV)(H5+H7)三价灭活疫苗(H5N1 Re-11株+Re-12株,H7N9 Re-2株)的免疫效果以及该疫苗不同厂家的田间免疫效果,本研究采用血凝(HA)和血凝抑制(HI)方法对玉林市2020年上半年7个县(市、区)21家规模化禽场采集的1 260份血清进行了H5和H7亚型高致病性禽流感病毒(HPAIV)抗体检测。结果显示,玉林市规模鸡场和规模鸭场使用该疫苗免疫,H5亚型HPAIV免疫抗体合格率在免疫后21天分别为99.05%和100%,在免疫后42天分别为99.29%和100%;H7亚型HPAIV免疫抗体合格率在免疫后21天分别为99.29%和99.52%,在免疫后42天分别为99%和100%。3个不同疫苗厂家的疫苗免疫后21天,规模鸡场和规模鸭场的抗体合格率分别为100%和100%,98.33%和99.17%,100%和98.33%;免疫后42天,规模鸡场和规模鸭场抗体合格率均为100%。本结果表明,玉林市2020年上半年规模禽场H5和H7亚型HPAIV免疫抗体合格率均高于国家规定的70%标准,免疫效果较好,同时3个不同疫苗厂家的疫苗田间免疫效果均较好。  相似文献   

8.
为了解湖南省家禽(鸡、鸭、鹅)H7N9亚型禽流感的免疫抗体水平及其流行情况,2022年在全省14个市州,采用配额抽样方法,在种禽场、商品代场、散养户和活禽市场共采集46 112份禽血清和53 246份禽拭子样品,通过血凝抑制试验、荧光定量PCR方法分别进行免疫抗体和病毒核酸检测。结果显示:H7N9亚型禽流感免疫抗体平均场群合格率为93.27%,平均个体合格率为90.60%,仅在活禽市场的1份鸡拭子样品中检测到病毒核酸阳性;鸡H7N9亚型禽流感免疫抗体平均场群合格率和个体合格率(94.66%和91.51%)均高于水禽(83.26%和81.86%);种禽场的免疫抗体平均场群合格率和个体合格率最高,活禽市场最低,两者差异具有统计学意义(P <0.05);全省14个市州的H7N9亚型禽流感免疫抗体平均场群合格率和个体合格率均在70%以上。结果表明:2022年湖南省家禽H7N9亚型禽流感免疫效果较好,在饲养场禽群中也未检出病原,发生大规模疫情的风险较低,但在活禽市场中仍检出病原,且水禽以及散养户和活禽市场禽群的免疫抗体水平略低,疫情散发风险依然存在。建议进一步加强对H7N9亚型禽流感的免疫...  相似文献   

9.
为掌握玉溪市禽流感在养殖场和活禽市场流行情况,2022年采集玉溪市9个县(市、区)32个乡(镇)62个村90个养殖场(户)及21个活禽市场2 280份样品进行监测。采用荧光RT-PCR方法对A型禽流感病毒检测并进行H5/H7/H9亚型禽流感病毒核酸分型。2022年全市共检出A型禽流感病毒核酸阳性240份,样品阳性率为10.53%,其中H9亚型233份、不确定型7份,未检出H5/H7亚型。活禽市场A型禽流感病毒核酸阳性率(31.47%)显著高于养殖场阳性率(0.27%),差异具有统计学意义(P<0.01);秋冬季节样品阳性率较高,差异具有统计学意义(P<0.01)。结果:玉溪市禽流感病毒主要分布于活禽市场,且以H9亚型流行为主,污染面较广,不同季度阳性率差异明显,但季节性差异缩小。结果提示:活禽市场是当前禽流感防控的重点,继续加强活禽市场的监测,同时强化活禽市场的检疫监管,严格执行消毒和休市制度,防止活禽市场禽流感病毒进入养殖环节。  相似文献   

10.
根据GenBank中H9亚型禽流感病毒HA基因和禽肺病毒F基因的保守序列,通过Blast进行比对,在各自保守的基因序列中分别设计了两对特异性扩增引物,引物扩增的片段大小分别为569bp和424bp,应用这两对引物建立了H9亚型禽流感病毒和禽肺病毒的二重RT-PCR检测方法,对建立的方法进行了特异性试验、敏感性试验和临床样品验证。对检测为阳性的样品进行克隆和序列分析,以验证本方法的准确性。特异性试验结果表明,所有参试的H9亚型禽流感病毒都能扩增出大小为569bp的片段,参试的禽肺病毒毒株扩增出424bp的片段,没有其他条带出现,而对照的参试毒株在569bp和424bp处没有任何条带;敏感性试验结果表明,本试验建立的方法能检测到10pg的H9亚型禽流感病毒和禽肺病毒RNA模板。应用本试验建立的方法对广西采集的病鸡样品132份进行检测,H9亚型禽流感病毒阳性的样品有6份,禽肺病毒阳性的样品2份;随机各挑取2份H9亚型禽流感病毒和禽肺病毒阳性PCR产物进行克隆和序列分析,经比对分析,2份H9亚型禽流感病毒阳性PCR产物与H9亚型禽流感病毒(No.JF715045.1)100%同源,2份禽肺病毒阳性PCR产物与禽肺病毒株(No.AF187154)100%同源。本试验建立的H9亚型禽流感病毒和禽肺病毒二重RT-PCR检测方法具有特异、敏感、快速的特点,可以用于临床快速准确检测H9亚型禽流感病毒和禽肺病毒。  相似文献   

11.
从西藏地区病死鸡体内分离鉴定到1株H5N2亚型禽流感病毒,基因组序列测定与分析显示,此H5N2毒株可能是由H5NI和H9N22种亚型的病毒重配形成,其PB2、HA、NS片段与高致病性H5NI亚型高度同源,PBI、PA、NP、NA、M均与低致病性H9N2亚型亲缘关系相近。尽管HA蛋白切割位点有多个碱性氨基酸序列,但静脉接种指数只有0.59,表现为低致病力。  相似文献   

12.
Zoonotic agents challenging the world every year afresh are influenza A viruses. In the past, human pandemics caused by influenza A viruses had been occurring periodically. Wild aquatic birds are carriers of the full variety of influenza virus A subtypes, and thus, most probably constitute the natural reservoir of all influenza A viruses. Whereas avian influenza viruses in their natural avian reservoir are generally of low pathogenicity (LPAIV), some have gained virulence by mutation after transmission and adaptation to susceptible gallinaceous poultry. Those so-called highly pathogenic avian influenza viruses (HPAIV) then cause mass die-offs in susceptible birds and lead to tremendous economical losses when poultry is affected. Besides a number of avian influenza virus subtypes that have sporadically infected mammals, the HPAIV H5N1 Asia shows strong zoonotic characteristics and it was transmitted from birds to different mammalian species including humans. Theoretically, pandemic viruses might derive directly from avian influenza viruses or arise after genetic reassortment between viruses of avian and mammalian origin. So far, HPAIV H5N1 already meets two conditions for a pandemic virus: as a new subtype it has been hitherto unseen in the human population and it has infected at least 438 people, and caused severe illness and high lethality in 262 humans to date (August 2009). The acquisition of efficient human-to-human transmission would complete the emergence of a new pandemic virus. Therefore, fighting H5N1 at its source is the prerequisite to reduce pandemic risks posed by this virus. Other influenza viruses regarded as pandemic candidates derive from subtypes H2, H7, and H9 all of which have infected humans in the past. Here, we will give a comprehensive overview on avian influenza viruses in concern to their zoonotic potential.  相似文献   

13.
Two different wild duck species common in Chile and neighboring countries, Chiloe wigeon (Anas sibilatrix) and cinnamon teal (Anas cyanoptera), were intranasally inoculated with 10(6) mean embryo infective dose (EID50) of the H7N3 low pathogenicity (LP) avian influenza virus (AIV) (A/chicken/Chile/176822/02) or high pathogenicity (HP) AIV (A/chicken/Chile/ 184240-1/02), in order to study the infectivity and pathobiology of these viruses. None of the virus-inoculated ducks had clinical signs or died, but most seroconverted by 14 days postinoculation (DPI), indicating a productive virus infection. Both LPAIV and HPAIV were isolated from oral swabs from two of six Chiloe wigeons and from oral and/or cloacal swabs from all five of the cinnamon teal at 2 DPI. Both LPAIV and HPAIV were efficiently transmitted to cinnamon teal contacts but not to Chiloe wigeon contacts. This study demonstrates that the cinnamon teal and Chiloe wigeons were susceptible to infection with both Chilean H7N3 LPAIV and HPAIV, but only the cinnamon teal showed contact transmission of the virus between birds, suggesting that the cinnamon teal has the potential to be a reservoir for these viruses, especially the LPAIV, as was demonstrated in 2001 with isolation of a genetically related H7N3 LPAIV strain in a cinnamon teal in Bolivia. However, the definitive source of the H7N3 Chilean LPAIV still remains unknown.  相似文献   

14.
15.
ABSTRACT: An experimental infection with highly pathogenic avian influenza virus (HPAIV) and low pathogenic avian influenza virus (LPAIV) was carried out in red-legged partridges (Alectoris rufa) in order to study clinical signs, gross and microscopic lesions, and viral distribution in tissues and viral shedding. Birds were infected with a HPAIV subtype H7N1 (A/Chicken/Italy/5093/1999) and a LPAIV subtype H7N9 (A/Anas crecca/Spain/1460/2008). Uninoculated birds were included as contacts in both groups. In HPAIV infected birds, the first clinical signs were observed at 3 dpi, and mortality started at 4 dpi, reaching 100% at 8 dpi. The presence of viral antigen in tissues and viral shedding were confirmed by immunohistochemistry and quantitative real time RT-PCR (qRRT-PCR), respectively, in all birds infected with HPAIV. However, neither clinical signs nor histopathological findings were observed in LPAIV infected partridges. In addition, only short-term viral shedding together with seroconversion was detected in some LPAIV inoculated animals. The present study demonstrates that the red-legged partridge is highly susceptible to the H7N1 HPAIV strain, causing severe disease, mortality and abundant viral shedding and thus contributing to the spread of a potential local outbreak of this virus. In contrast, our results concerning H7N9 LPAIV suggest that the red-legged partridge is not a reservoir species for this virus.  相似文献   

16.
Birds of the order Psittaciformes are - besides chickens, turkeys and other birds - also susceptible to infection with avian influenza A viruses (AIV) and succumb following severe disease within one week. Published data prove that various parakeets, amazons, cockatoos, African grey parrots and budgerigars (genera Barnardius, Psittacula, Cacatua, Eolophus, Amazona, Myiopsitta, Psittacus and Melopsittacus) were found dead following natural infections. Natural infections of highly pathogenic avian influenza viruses (HPAIV) of the haemagglutinin subtypes H5 and H7 cause severe disease and high rates of mortality. Experimental transmission studies with AlVs of the subtypes H5 and H7 confirm these data. Viruses of the subtypes H3N8, H4N6, H4N8, H11N6 and H11N8 may cause also clinical signs and occasionally losses in naturally infected psittacine birds. Clinical signs and losses were also noted following experimental infection of budgerigars with a H4N6 virus. In the EU and in other countries, vaccination of exposed exotic and rare birds and poultry is a possible and an acceptable measure to provide protection. Currently, the EU Commission accepts inactivated adjuvanted vaccines whereas in some other countries recently developed vector vaccines are applied. However, birds remain susceptible during the time interval between application of any vaccine and the development of immunity. This critical period can be bridged with antiviral drugs. Our in ovo studies demonstrate that the neuraminidase inhibitor oseltamivir is non-toxic for chicken embryos at concentrations of 0.1, 1.0 and 10.0 mg/kg body weight. These dosages prevented entirely the replication of a HPAIV of the subtype H7N1 when this drug is given shortly prior to, simultaneously or soon after inoculation of chicken embryos with this AIV. Thus, we speculate that exposed valuable birds such as psittacines at risk can be successfully treated.  相似文献   

17.
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。  相似文献   

18.
As well as H5 highly pathogenic avian influenza viruses (HPAIV), H7 HPAIV strains have caused serious damages in poultry industries worldwide. Cases of bird-to-human transmission of H7 HPAIV have also been reported [11]. On the outbreak of avian influenza, rapid diagnosis is critical not only for the control of HPAI but also for human health. In the present study, a rapid diagnosis kit based on immunochromatography for the detection of H7 hemagglutinin (HA) antigen of influenza A virus was developed using 2 monoclonal antibodies that recognize different epitopes on the H7 HAs. The kit detected each of the tested 15 H7 influenza virus strains and did not react with influenza A viruses of the other subtypes than H7 or other avian viral and bacterial pathogens. The kit detected H7 HA antigen in the swabs and tissue homogenates of the chickens experimentally infected with HPAIV strain A/chicken/Netherlands/2586/03 (H7N7). The results indicate that the present kit is specific and sensitive enough for the diagnosis of HPAI caused by H7 viruses, thus, recommended for the field application as a pen-site test kit.  相似文献   

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为了解广西边境地区低致病性禽流感病毒(low pathogenic Avian influenza virus,LPAIV)的流行情况,本研究对2013-2019年在广西边境地区的规模养殖场和活禽市场采集的33 964份家禽棉拭子样品,采用鸡胚接种方法进行病毒分离,并结合血凝抑制试验和RT-PCR等方法鉴定禽流感病毒的亚型。结果显示,共有3 892份样品分离到LPAIV,2013-2019年的样品病毒分离率分别为17.39%、11.23%、13.59%、9.31%、9.09%、9.12%和15.21%,总分离率为11.46%,其中2013年样品的病毒分离率最高。分离到的LPAIV包括H1、H3、H4、H6、H9、H10和H11 7种亚型,样品病毒分离率分别为0.14%、4.37%、0.19%、4.06%、2.69%、0.01%和0.003%。其中活禽市场分离到H1、H3、H4、H6、H9、H10和H11 7种亚型流感病毒,样品病毒分离率分别为0.19%、5.53%、0.21%、5.29%、3.41%、0.01%和0.004%,总分离率为14.64%;而养殖场分离到H3、H4、H6和H9 4种亚型流感病毒,样品病毒分离率分别为1.26%、0.12%、0.79%和0.78%,总分离率为2.95%,养殖场的分离率远低于活禽市场(14.64%)。鸡源样品的病毒分离率为5.77%,水禽样品的病毒分离率为15.10%,环境样品的病毒分离率为21.67%,水禽和环境样品的病毒分离率远高于鸡。结果表明,当前广西边境地区家禽携带多种亚型LPAIV,水禽是高风险禽群,应进一步加强监测和防控;活禽市场污染严重,应进一步加强对活禽市场的监管力度,建立和实施更加科学有效的活禽市场运营机制。  相似文献   

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