昌吉州职业暴露人群及外环境中禽流感病毒的感染及分布情况调查

目的通过对职业暴露人群感染状况及外环境因素调查,探索新疆昌吉回族自治州人禽流感感染危险因素,为制定预防控制策略提供科学依据。方法对外环境样本进行禽流感病毒核酸检测,对职业暴露人群进行高致病性禽流感病毒H5N1血清抗体监测。结果 2011年11月采集昌吉州高危职业暴露人群血清标本50份,检出H5N1抗体阳性1份,说明职业暴露人群中存在人禽流感病毒H5N1隐性感染者;外环境中高致病性禽流感病毒H5N1持续存在。结论昌吉州人感染高致病性禽流感的风险依然存在,不明原因肺炎监测工作应常抓不懈。     

甘肃省武威市职业暴露人群血清学和环境高致病性禽流感监测分析

目的动态掌握甘肃省武威市职业暴露人群人感染H5N1禽流感病毒和环境标本中禽流感病毒的分布,从而了解职业暴露人群和环境标本中H5、H7和H9高致病性禽流感亚型病毒感染情况,为今后武威市人感染高致病性禽流感的防控提供科学依据。方法根据职业暴露人群血清学和环境高致病性禽流感监测方案要求,对从事家禽养殖、屠宰等职业暴露人群,采集血清标本进行马血球血凝抑制实验(HI)检测人感染H5N1高致病性禽流感病毒抗体,对家禽粪便和环境标本采用实时荧光定量法(PCR)进行禽流感病毒A型核酸检测,禽流感病毒A型核酸阳性标本进一步进行H5、H7和H9亚型检测。结果不同场所共采集职业暴露人群血清标本228份,结果均为阴性;不同养殖场所均未监测出禽流感病毒,不同活禽交易市场均检测出禽流感病毒;活禽交易市场普遍存在禽流感病毒,阳性检出率差异有统计学意义(χ2=24.59,P0.05);110份禽流感病毒核酸阳性标本中,H5型占3.64%,H7型未检出,H9型占96.36%,H9亚型是武威市禽流感病毒的主要病原体,差异有统计学意义(χ2=37.60,P0.05);清洗禽类的污水标本禽流感阳性检出率明显高于其他环境标本检出率,差异有统计学意义(χ2=23.85,P0.05);第四季度禽流感阳性检出率明显高于其他季度,差异有统计学意义(χ2=17.38,P0.05)。结论人感染高致病性禽流感病毒在武威市职业暴露人群中未发现隐性感染,活禽市场环境普遍存在禽流感病毒污染,应加强主动监测防止高致病性禽流感暴发流行。     

新疆2例人感染高致病H5N1禽流感疫情应急处置与分析

目的分析新疆2起人感染H5N1高致病性禽流感疫情应急处置措施,提出针对性防控策略。方法采用流行病学方法分析新疆2例人感染H5N1高致病性禽流感疫情发生过程和处置情况。结果 2例病例均在发病后第10d才首次检测血常规,由于发病前期的诊疗规范性不佳,错过了针对人感染高致病性禽流感抗病毒治疗的最佳时间和未采用有效抗病毒药物(48 h内服用神经氨酸酶抑制剂如达菲)及时治疗,虽然治疗后期多部门联合、专家组会诊,诊疗规范,但最终2例病例分别以合并感染和多器官衰竭死亡为结局;其中1例病例发病前有活禽宰杀市场暴露史,环境监测证实了病例的感染来源于活禽市场。结论对于人感染H5N1高致病性禽流感防控需要多部门、多系统联合,要做到早诊断、早治疗和早隔离,定期培训医护人员尤其是基层人员;应做好环境监测和公众的宣传,均是疾病防控的关键。     

上海市黄浦区1例人感染高致病性禽流感病例现场流行病学分析

人感染高致病性禽流感是由H5N1血清型引起的禽流感,其发病率和死亡率都很高,危害巨大。1997年中国香港首次证实禽流感病毒（H5N1）感染人类以后,世界各地相继报道了多例禽流感病毒感染人并导致死亡事件,禽流感病毒已对人类健康构成严重威胁,引起了全世界的关注。     

如何早期甄别高致病性禽流感A/H5N1病毒感染病例

高致病性禽流感A/H5N1病毒感染(简称人禽流感)是近几年来新发的一种呼吸道传染病,对人类首例禽流感A/H5N1病毒感染病例的确诊,标志着禽流感A/H5N1病毒已冲破种属的界线,成功实现了向人类的"跳跃式"感染.截止到2009年2月27日,全球人禽流感病例共408例,死亡256例,病死率约为63%[1].     

美国《Emerging infectious diseases》2006年第10期有关人兽共患病论文摘译

P1486H5N1型禽流感病毒在北美出现并蔓延//RappoleJH,Hub偄lek Z在2005年和2006年初,高致病性禽流感病毒H5N1型在禽类宿主的种类和地理分布上都有明显的蔓延趋势。H5N1型禽流感可感染家禽和野禽,但其致命性只限于几种候鸟宿主。但由于近年来高致病性禽流感病毒H5N1型在欧亚大陆蔓延并进入欧洲和非洲,这种情况发生了改变。通过鸟类的迁徙和人口流动可将H5N1型禽流感病毒传播至西半球。这种两半球间的传播似乎并不像是通过野禽和候鸟的迁徙,而更有可能是通过进口家禽和宠物鸟。如果病毒发生变异后可以在人群中快速传播,那么由于宿主种…     

人感染高致病性H5N1亚型禽流感一例报告并文献复习

目的 探讨人感染高致病性H5N1亚型禽流感的临床特征及防治手段。方法 2005年11月，救治1例确诊为感染高致病性H5N1亚型禽流感的青年女性患者，分析其临床表现、影像学及流行病学特点。结果 患者发病前与病死家禽有密切接触史，从发病至死亡约10d。在呼吸困难发生前，发热持续了5d，以急性社区获得性肺炎及急性呼吸窘迫综合征（ARDS）为主要特征入院，X线胸片示双肺大片实变影并进行性进展，入院至死亡不足3d。中国疾病预防控制中心应用逆转录-聚合酶链反应（RT—PCR）、实时聚合酶链反应（real-time PCR）技术检测患者下呼吸道吸出物标本，发现禽流感病毒血凝素（HA）5型特异性基因片段呈阳性；尸检肉眼所见主要有支气管充血、双肺实变，多浆膜腔积液；弥漫性血管内凝血（DIC）及多脏器功能衰竭（MOF）。结论 人感染高致病性H5N1亚型禽流感是一种致命的传染性疾病。提高认识，重视流行病学调查并及早干预是降低病死率的主要手段。     

福建省人感染H5N1禽流感病毒血凝素基因测定和分析

目的了解我省人感染高致病性禽流感H5N1亚型病毒血凝素基因的特点以及和其他毒株序列间的关系。方法从采集自两例福建省感染者的标本中扩增H5N1禽流感病毒血凝素基因并作序列测定,获得的序列同其他H5N1禽流感病毒的血凝素基因进行比较并作进化分析。结果获得福建省的两例感染者中的H5N1禽流感病毒血凝素基因,并推导出该基因的氨基酸序列。结果表明,两株病毒的血凝素基因在蛋白酶水解位点均含有多个连续的碱性氨基酸,符合高致病性禽流感病毒的特征。经Blast程序检索发现,我省两例感染者与国内其他省份的感染者携带的病毒血凝素基因具有很高的相似性,提示国内的H5N1禽流感病毒感染者的病毒来源可能有一定的关系。结论通过对两例福建省感染者标本中的H5N1禽流感病毒血凝素基因进行序列测定,了解病毒基因的部分特点。通过序列比较分析为分子流行病学调查提供线索,但还需对其他基因序列以及病毒的致病性等生物学特征作进一步分析。     

人感染高致病性禽流感病毒A/Fujian/1/2007(H5N1)株基因组序列测定及分析

目的对福建省分离的高致病性禽流感病毒A／Fujian／1／2007（H5N1）株进行全基因组序列测定，了解病毒序列及进化特征。方法SPF鸡胚分离法分离A／Fujian／1／2007（H5N1）株病毒，并提取病毒RNA。病毒RNA经通用引物逆转录后，应用特异性引物分别扩增病毒各节段，产物经TA克隆到载体中进行测序并对结果进行排列、拼接成完整的病毒基因组。分析病毒重要位点特征，并参照已发表的病毒序列，对A／Fujian／1／2007（H5N1）株作系统进化分析。结果应用自行设计的引物，扩增并获得完整的A／Fujian／1／2007（H5N1）株基因组序列。病毒重要位点的分析表明．该株病毒为禽源高致病性禽流感病毒，病毒对达菲敏感而对金刚烷胺类药物则具有耐药性。病毒特征有待进一步的生物学验证。系统进化分析显示，在亚洲各国引起人类感染的高致病性禽流感病毒具有明显的地理分布特征，A／Fujian／1／2007（H5N1）病毒与国内以往毒株属同一进化分支。结论获得人感染高致病性禽流感病毒A／Fujian／1／2007株全基因组序列，了解病毒重要的氨基酸位点特征以及亚洲人感染病毒间的亲缘关系，为进一步探讨福建省禽流感病毒变异、传播机制等奠定基础。     

中国高致病性禽流感A/H5N1病毒感染病例临床管理专家共识(草案)

自2003年末起,在家禽与鸟类中广泛传播的高致病性禽流感A/H5 N1病毒(简称A/H5 N1病毒)感染几乎覆盖了全球大部分地庆,导致A/H5 N1病毒感染病例(简称人禽流感)不时出现,流感大流行的危险性日益增加.     

Genomic and Phylogenetic Characterization of Novel,Recombinant H5N2 Avian Influenza Virus Strains Isolated from Vaccinated Chickens with Clinical Symptoms in China

Infection of poultry with diverse lineages of H5N2 avian influenza viruses has been documented for over three decades in different parts of the world, with limited outbreaks caused by this highly pathogenic avian influenza virus. In the present study, three avian H5N2 influenza viruses, A/chicken/Shijiazhuang/1209/2013, A/chicken/Chiping/0321/2014, and A/chicken/Laiwu/0313/2014, were isolated from chickens with clinical symptoms of avian influenza. Complete genomic and phylogenetic analyses demonstrated that all three isolates are novel recombinant viruses with hemagglutinin (HA) and matrix (M) genes derived from H5N1, and remaining genes derived from H9N2-like viruses. The HA cleavage motif in all three strains (PQIEGRRRKR/GL) is characteristic of a highly pathogenic avian influenza virus strain. These results indicate the occurrence of H5N2 recombination and highlight the importance of continued surveillance of the H5N2 subtype virus and reformulation of vaccine strains.     

Physician's knowledge,attitudes, and practices regarding seasonal influenza,pandemic influenza,and highly pathogenic avian influenza A (H5N1) virus infections of humans in Indonesia

Indonesia has reported highest number of fatal human cases of highly pathogenic avian influenza (HPAI) A (H5N1) virus infection worldwide since 2005. There are limited data available on seasonal and pandemic influenza in Indonesia. During 2012, we conducted a survey of clinicians in two districts in western Java, Indonesia, to assess knowledge, attitudes, and practices (KAP) of clinical diagnosis, testing, and treatment of patients with seasonal influenza, pandemic influenza, or HPAI H5N1 virus infections. Overall, a very low percentage of physician participants reported ever diagnosing hospitalized patients with seasonal, pandemic, or HPAI H5N1 influenza. Use of influenza testing was low in outpatients and hospitalized patients, and use of antiviral treatment was very low for clinically diagnosed influenza patients. Further research is needed to explore health system barriers for influenza diagnostic testing and availability of antivirals for treatment of influenza in Indonesia.     

Serologic evidence of human influenza virus infections in swine populations,Cambodia

Background This study was conducted from 2006 to 2010 and investigated the seroprevalence of influenza A viruses in Cambodian pigs, including human H1N1, H3N2, 2009 pandemic H1N1 (A(H1N1)pdm09), and highly pathogenic avian H5N1 influenza A viruses. Methods A total of 1147 sera obtained from pigs in Cambodia were tested by haemagglutination inhibition (HI) assays for antibody to human influenza A viruses along with both HI and microneutralization (MN) tests to assess immunological responses to H5N1 virus. The results were compared by year, age, and province. Results Antibodies against a human influenza A virus were detected in 14·9% of samples. A(H1N1)pdm09 virus were dominant over the study period (23·1%), followed by those to human H1N1 (17·3%) and H3N2 subtypes (9·9%). No pigs were serologically positive for avian H5 influenza viruses. The seroprevalence of human H1N1 and H3N2 influenza viruses peaked in 2008, while that of A(H1N1)pdm09 reached a peak in 2010. No significant differences in seroprevalence to human influenza subtypes were observed in different age groups. Conclusions Cambodian pigs were exposed to human strains of influenza A viruses either prior to or during this study. The implications of these high prevalence rates imply human‐to‐swine influenza virus transmission in Cambodia. Although pigs are mostly raised in small non‐commercial farms, our preliminary results provide evidence of sustained human influenza virus circulation in pig populations in Cambodia.     

Isolation of clade 2.3.4.4b A(H5N8), a highly pathogenic avian influenza virus,from a worker during an outbreak on a poultry farm,Russia, December 2020

This study presents the isolation of influenza A(H5N8) virus clade 2.3.4.4b from a poultry worker during an outbreak of highly pathogenic avian influenza A(H5N8) among chickens at a poultry farm in Astrakhan, Russia in December 2020. Nasopharyngeal swabs collected from seven poultry workers were positive for influenza A(H5N8), as confirmed by RT-PCR and sequencing. The influenza A(H5N8) virus was isolated from one of the human specimens and characterised. Sporadic human influenza A(H5)2.3.4.4. infections represent a possible concern for public health.     

Avian influenza virus infections in humans

Seroepidemiologic and virologic studies since 1889 suggested that human influenza pandemics were caused by H1, H2, and H3 subtypes of influenza A viruses. If not for the 1997 avian A/H5N1 outbreak in Hong Kong of China, subtype H2 is the likely candidate for the next pandemic. However, unlike previous poultry outbreaks of highly pathogenic avian influenza due to H5 that were controlled by depopulation with or without vaccination, the presently circulating A/H5N1 genotype Z virus has since been spreading from Southern China to other parts of the world. Migratory birds and, less likely, bird trafficking are believed to be globalizing the avian influenza A/H5N1 epidemic in poultry. More than 200 human cases of avian influenza virus infection due to A/H5, A/H7, and A/H9 subtypes mainly as a result of poultry-to-human transmission have been reported with a > 50% case fatality rate for A/H5N1 infections. A mutant or reassortant virus capable of efficient human-to-human transmission could trigger another influenza pandemic. The recent isolation of this virus in extrapulmonary sites of human diseases suggests that the high fatality of this infection may be more than just the result of a cytokine storm triggered by the pulmonary disease. The emergence of resistance to adamantanes (amantadine and rimantadine) and recently oseltamivir while H5N1 vaccines are still at the developmental stage of phase I clinical trial are causes for grave concern. Moreover, the to-be pandemic strain may have little cross immunogenicity to the presently tested vaccine strain. The relative importance and usefulness of airborne, droplet, or contact precautions in infection control are still uncertain. Laboratory-acquired avian influenza H7N7 has been reported, and the laboratory strains of human influenza H2N2 could also be the cause of another pandemic. The control of this impending disaster requires more research in addition to national and international preparedness at various levels. The epidemiology, virology, clinical features, laboratory diagnosis, management, and hospital infection control measures are reviewed from a clinical perspective.     

Engineered viral vaccine constructs with dual specificity: avian influenza and Newcastle disease

Avian influenza viruses of the H5 and H7 hemagglutinin subtypes, and Newcastle disease virus (NDV), are important pathogens in poultry worldwide. Specifically, the highly pathogenic H5N1 avian influenza virus is a particular threat because it has now occurred in more than 40 countries on several continents. Inasmuch as most chickens worldwide are vaccinated with a live NDV vaccine, we embarked on the development of vaccine prototypes that would have dual specificity and would allow a single immunization against both avian influenza and Newcastle disease. Using reverse genetics, we constructed a chimeric avian influenza virus that expressed the ectodomain of the hemagglutinin-neuraminidase gene of NDV instead of the neuraminidase protein of the H5N1 avian influenza virus. Our second approach to creating a bivalent vaccine was based on expressing the ectodomain of an H7 avian influenza virus hemagglutinin in a fusogenic and attenuated NDV background. The insertion into the NDV genome of the foreign gene (containing only its ectodomain, with the transmembrane and cytoplasmic domains derived from the F protein of NDV) resulted in a chimeric virus with enhanced incorporation of the foreign protein into virus particles. A single immunization of chickens with this improved vaccine prototype virus induced not only a 90% protection against an H7N7 highly pathogenic avian influenza virus, but also complete immunity against a highly virulent NDV. We propose that chimeric constructs should be developed for convenient, affordable, and effective vaccination against avian influenza and Newcastle disease in chickens and other poultry.     

人感染高致病性禽流感A/H5N1研究现状

1997年,在香港发生禽流感病毒A/HSNl首次突破种间屏障感染人类的病例.21世纪以来,A/HSN1亚型高致病性禽流感疫情的传播范围、规模以及蔓延速度达到了前所未有的程度.世界上许多国家受到冲击,世界范围内病死率超过60%.鉴于目前全球可能出现新一次流感大流行的严峻形势,加强人禽流感的研究迫在眉睫.本文就人禽流感的病毒研究、流行病学特征、病理改变、发病机制等方面进展进行简要综述.     

The evolution of H5N1 influenza viruses in ducks in southern China

The pathogenicity of avian H5N1 influenza viruses to mammals has been evolving since the mid-1980s. Here, we demonstrate that H5N1 influenza viruses, isolated from apparently healthy domestic ducks in mainland China from 1999 through 2002, were becoming progressively more pathogenic for mammals, and we present a hypothesis explaining the mechanism of this evolutionary direction. Twenty-one viruses isolated from apparently healthy ducks in southern China from 1999 through 2002 were confirmed to be H5N1 subtype influenza A viruses. These isolates are antigenically similar to A/Goose/Guangdong/1/96 (H5N1) virus, which was the source of the 1997 Hong Kong "bird flu" hemagglutinin gene, and all are highly pathogenic in chickens. The viruses form four pathotypes on the basis of their replication and lethality in mice. There is a clear temporal pattern in the progressively increasing pathogenicity of these isolates in the mammalian model. Five of six H5N1 isolates tested replicated in inoculated ducks and were shed from trachea or cloaca, but none caused disease signs or death. Phylogenetic analysis of the full genome indicated that most of the viruses are reassortants containing the A/Goose/Guangdong/1/96-like hemagglutinin gene and the other genes from unknown Eurasian avian influenza viruses. This study is a characterization of the H5N1 avian influenza viruses recently circulating in ducks in mainland China. Our findings suggest that immediate action is needed to prevent the transmission of highly pathogenic avian influenza viruses from the apparently healthy ducks into chickens or mammalian hosts.