Influenza in migratory birds and evidence of limited intercontinental virus exchange.
Influenza in migratory birds and evidence of limited intercontinental virus exchange.
复制标题
迁徙鸟类中的流感和洲际病毒交换有限的证据。
DOI：
10.1371/journal.ppat.0030167
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发表时间：
2007-11
期刊：
影响因子：
6.7
通讯作者：
Webster, Robert G
中科院分区：
文献类型：
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作者：
Krauss, Scott;Obert, Caroline A;Franks, John;Walker, David;Jones, Kelly;Seiler, Patrick;Niles, Larry;Pryor, S Paul;Obenauer, John C;Naeve, Clayton W;Widjaja, Linda;Webby, Richard J;Webster, Robert G
世界上迁徙的水禽是所有已知亚型流感病毒的天然宿主。然而，尚不清楚这些水禽是否携带高致病性（HP）H5和H7禽流感病毒。在这里，我们报告从2001年至2006年在加拿大的阿尔伯塔的野鸭，并在特拉华州湾（新泽西），美国的滨鸟和海鸥流感病毒的监测，并检查欧亚大陆和美国的病毒进化枝，或超家族之间的流感病毒的交流频率。在这些水禽中检测到属于H1至H13和N1至N9亚型的流感病毒，但没有发现H14和H15亚型。没有检测到HP亚洲H5 N1亚型的病毒，成年绿头鸭的血清学研究也没有提供它们循环的证据。最近描述的H16亚型流感病毒在美国水鸟和海鸥中检测到，但在鸭子中没有检测到。我们还在水鸟和海鸥中发现了一种不寻常的H7 N3流感病毒簇，这种病毒能够在鸡中很好地复制并杀死鸡胚胎。对6，767个禽流感基因片段和248个完整的禽流感病毒进行的遗传分析支持这样一种观点，即整个流感病毒在欧亚和美洲分支之间的交换并不经常发生。总体而言，现有证据不支持候鸟中的HP H5 N1流感持续存在，并表明候鸟将HP亚洲H5 N1引入美洲可能是罕见事件。在北美的两个地点对野生候鸟进行了流感监测：1）在加拿大的阿尔伯塔，过去31年; 2）在美国的沿着特拉华州湾，过去22年。这些研究支持了野生候鸟是所有甲型流感病毒的宿主的概念，并且世界上的流感病毒可以分为两个不同的超家族，一个在欧亚大陆，另一个在美洲。这些病毒不时地传播给家禽和人类，引起疾病的大流行。许多研究人员已经扩大了这些研究，特别是在欧洲，亚洲和美洲。10年前在亚洲出现的高致病性H5 N1病毒以及这些H5 N1病毒的持续演变和向整个欧亚大陆的传播是兽医和人类公共卫生的一个持续问题。来自欧亚大陆的现有证据表明，候鸟可被感染，并可能参与高致病性H5 N1病毒的当地传播。本研究所要解决的问题是，为什么高致病性H5 N1流感病毒尚未到达美洲，尽管候鸟的路径重叠，特别是在阿拉斯加。对我们储存库中流感病毒的基因组分析未能提供流感病毒全基因组起源于欧亚大陆的证据。然而，我们偶尔发现来自北美的流感病毒具有起源于欧亚大陆的单个或多个基因。我们的解释是，虽然流感病毒确实在两个半球之间交换，但这种情况很少发生。无论如何，在美洲应继续加强监测，以防这种罕见事件发生。
Migratory waterfowl of the world are the natural reservoirs of influenza viruses of all known subtypes. However, it is unknown whether these waterfowl perpetuate highly pathogenic (HP) H5 and H7 avian influenza viruses. Here we report influenza virus surveillance from 2001 to 2006 in wild ducks in Alberta, Canada, and in shorebirds and gulls at Delaware Bay (New Jersey), United States, and examine the frequency of exchange of influenza viruses between the Eurasian and American virus clades, or superfamilies. Influenza viruses belonging to each of the subtypes H1 through H13 and N1 through N9 were detected in these waterfowl, but H14 and H15 were not found. Viruses of the HP Asian H5N1 subtypes were not detected, and serologic studies in adult mallard ducks provided no evidence of their circulation. The recently described H16 subtype of influenza viruses was detected in American shorebirds and gulls but not in ducks. We also found an unusual cluster of H7N3 influenza viruses in shorebirds and gulls that was able to replicate well in chickens and kill chicken embryos. Genetic analysis of 6,767 avian influenza gene segments and 248 complete avian influenza viruses supported the notion that the exchange of entire influenza viruses between the Eurasian and American clades does not occur frequently. Overall, the available evidence does not support the perpetuation of HP H5N1 influenza in migratory birds and suggests that the introduction of HP Asian H5N1 to the Americas by migratory birds is likely to be a rare event. Influenza surveillance in wild migratory birds has been done at two sites in North America: 1) in Alberta, Canada, for the past 31 years, and 2) along Delaware Bay, United States, for the past 22 years. These studies support the concept that wild migratory birds are the reservoirs of all influenza A viruses and that the influenza viruses in the world can be divided into two distinct superfamilies, one in Eurasia and the other in the Americas. From time to time these viruses spread to domestic poultry and to humans and cause pandemics of disease. Many investigators have expanded these studies particularly in Europe, Asia, and the Americas. The emergence of highly pathogenic H5N1 in Asia a decade ago and the continuing evolution and spread of these H5N1 viruses to the whole of Eurasia is a continuing problem for veterinary and human public health. The available evidence from Eurasia is that migratory birds can be infected and may be involved in local spread of the highly pathogenic H5N1 virus. The question addressed in the present study is why the highly pathogenic H5N1 influenza virus has not yet reached the Americas despite the overlap in migratory bird pathways, particularly in Alaska. Genomic analysis of influenza viruses from our repository failed to provide evidence of influenza viruses with their whole genome originating from Eurasia. However, we found occasional influenza viruses from North America with single or multiple genes that originated in Eurasia. Our interpretation is that while influenza viruses do exchange between the two hemispheres, this is a rare occurrence. Regardless, enhanced surveillance should be continued in the Americas in case this rare event occurs.