Update on molecular epidemiology of H1, H5, and H7 influenza virus infections in poultry in North America
Update on molecular epidemiology of H1, H5, and H7 influenza virus infections in poultry in North America
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DOI：
10.1637/0005-2086-47.s3.888
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发表时间：
2003-01-01
期刊：
影响因子：
1.4
通讯作者：
Senne, DA
中科院分区：
文献类型：
--
作者：
Suarez, DL;Spackman, E;Senne, DA
禽流感在北美的野鸟中流行，病毒通常从这个宿主传播给家禽。流感一旦传入家禽，可在家禽种群中成为地方性流行病。它可能通过人为干预成功根除，或者病毒可能无法成功自行传播。在过去的5年中，流感病毒已被分离出家禽在美国的许多场合，并与使用分子流行病学，这些不同的病毒的关系可以确定。禽流感病毒有15种不同的血凝素亚型，但感染H5和H7亚型病毒是最令人关注的，因为这些病毒有可能突变为高致病性病毒。美国大部分流感隔离都与东北部的活禽市场有关。这主要包括H7N2流感病毒，但也包括H7N3，H5N2和其他亚型。大多数H7N2病毒是1994年首次观察到的单一谱系的一部分，但也观察到了H7N2和H7N3的新引入。自1997年以来，主要的H7N2 LBM病毒谱系至少三次传播到大型商业家禽养殖场，其中最大的一次爆发发生在2002年的弗吉尼亚州。LBM中的H5N2病毒包括来自家鸭、猎鸟和环境样本的病毒。一些在不同年份和不同地点分离的H5N2病毒具有高度的序列相关性，尽管尚未确定储存源（如果是地方性的）。最后，1999年在密苏里州的火鸡中分离出一种与产蛋量下降有关的H1N2病毒。该病毒是一种具有猪、人和禽流感基因的复合型毒株，与最近从中西部分离的猪流感病毒相似。其他血清学证据表明，其他州的鸡群感染了H1N2病毒。
Avian influenza is endemic in wild birds in North America, and the virus routinely has been transmitted from this reservoir to poultry. Influenza, once introduced into poultry, can become endemic within the poultry population. It may be successfully eradicated by human intervention, or the virus may fail to successfully spread on its own. In the last 5 yr, influenza virus has been isolated from poultry in the United States on numerous occasions, and, with the use of molecular epidemiology, the relationships of these different viruses can be determined. There are 15 different hemagglutinin subtypes of avian influenza viruses, but infections with virus of H5 and H7 subtypes are of the most concern because of the potential for these viruses to mutate to the highly pathogenic form of the virus. Most of the influenza isolations in the United States have been associated with the live-bird markets (LBMs) in the Northeast. This has included primarily H7N2 influenza viruses, but also H7N3, H5N2, and other subtypes. Most of the H7N2 viruses were part of a single lineage that was first observed in 1994, but new introductions of H7N2 and H7N3 were also observed. The predominant H7N2 LBM lineage of virus spread to large commercial poultry operations on at least three occasions since 1997, with the largest outbreak occurring in Virginia in 2002. The H5N2 viruses in the LBMs included viruses from domestic ducks, gamebirds, and environmental samples. Some H5N2 viruses isolated in different years and in different locations had a high degree of sequence relatedness, although the reservoir source, if it is endemic, has not been identified. Finally, an H1N2 virus, associated with a drop in egg production, was isolated from turkeys in Missouri in 1999. This virus was a complex reassortant with swine, human, and avian influenza genes that was similar to recent swine isolates from the Midwest. Additional serologic evidence suggests that flocks in other states were infected with a H1N2 virus.