辽宁省低致病性禽流感（H9）带毒情况调查

为确实掌握辽宁省家禽低致病性禽流感（H9）带毒或感染情况,2011～2012年,辽宁省动物疫病预防控制中心对全省共64个禽场（户）进行低致病性禽流感带毒或感染情况调查。结果表明,近7成以上的场（户）未进行H9亚型禽流感免疫。在所监测的5例H9亚型禽流感阳性禽群中,除1例免疫情况不明外,其他均未进行免疫,阳性场比率有逐年升高之势,其危害应引起高度重视。     

高致病性禽流感的控制措施

日本、韩国、越南和泰国等国家相继发生了高致病性禽流感,不仅给这些国家的养禽业带来巨大经济损失,而且还出现了人感染禽流感死亡的情况,严重地威胁了人类的健康。我国广西、上海、广东等十几个     

美三州发现低致病性禽流感

正1美国宾夕法尼亚州、纽约州和新泽西州的活禽市场发现低致病性禽流感感染鸡在美国宾夕法尼亚州、纽约州和新泽西州的活禽市场发现低致病性禽流感阳性鸡。检测由美国农业部动物与植物卫生监督所(USDA Animal and Plant Health Inspection Service,APHIS)和美国明尼苏达大学的传染病研究和政策中心(Center for Infectious Disease Research and Policy,     

鹅高致病性禽流感病理组织学观察

本文对发生H5N1高致病性禽流感禽场的鹅进行了病理学观察，证实此场鹅禽流感在剖检上以眼结膜潮红出血；心肌条纹状坏死，条带样出血；胰腺有白垩状或透明坏死点；胃肠出血等为特征。组织学观察以非化脓性脑炎，胰腺坏死，心肌坏死，坏死性脾炎为主要病变，揭示了鹅禽流感的病理学变化特征。     

(Highly pathogenic) avian influenza as a zoonotic agent

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.     

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.