Department of Basic Science, College of Veterinary Medicine, Mississippi State University, Mississippi State, Mississippi, USA.
United States Geological Survey National Wildlife Health Center, Madison, Wisconsin, USA.
J Virol. 2019 Jun 14;93(13). doi: 10.1128/JVI.00282-19. Print 2019 Jul 1.
Subtype H10 influenza A viruses (IAVs) have been recovered from domestic poultry and various aquatic bird species, and sporadic transmission of these IAVs from avian species to mammals (i.e., human, seal, and mink) are well documented. In 2015, we isolated four H10N7 viruses from gulls in Iceland. Genomic analyses showed four gene segments in the viruses were genetically associated with H10 IAVs that caused influenza outbreaks and deaths among European seals in 2014. Antigenic characterization suggested minimal antigenic variation among these H10N7 isolates and other archived H10 viruses recovered from human, seal, mink, and various avian species in Asia, Europe, and North America. Glycan binding preference analyses suggested that, similar to other avian-origin H10 IAVs, these gull-origin H10N7 IAVs bound to both avian-like alpha 2,3-linked sialic acids and human-like alpha 2,6-linked sialic acids. However, when the gull-origin viruses were compared with another Eurasian avian-origin H10N8 IAV, which caused human infections, the gull-origin virus showed significantly higher binding affinity to human-like glycan receptors. Results from a ferret experiment demonstrated that a gull-origin H10N7 IAV replicated well in turbinate, trachea, and lung, but replication was most efficient in turbinate and trachea. This gull-origin H10N7 virus can be transmitted between ferrets through the direct contact and aerosol routes, without prior adaptation. Gulls share their habitat with other birds and mammals and have frequent contact with humans; therefore, gull-origin H10N7 IAVs could pose a risk to public health. Surveillance and monitoring of these IAVs at the wild bird-human interface should be continued. Subtype H10 avian influenza A viruses (IAVs) have caused sporadic human infections and enzootic outbreaks among seals. In the fall of 2015, H10N7 viruses were recovered from gulls in Iceland, and genomic analyses showed that the viruses were genetically related with IAVs that caused outbreaks among seals in Europe a year earlier. These gull-origin viruses showed high binding affinity to human-like glycan receptors. Transmission studies in ferrets demonstrated that the gull-origin IAV could infect ferrets, and that the virus could be transmitted between ferrets through direct contact and aerosol droplets. This study demonstrated that avian H10 IAV can infect mammals and be transmitted among them without adaptation. Thus, avian H10 IAV is a candidate for influenza pandemic preparedness and should be monitored in wildlife and at the animal-human interface.
亚型 H10 甲型流感病毒（IAV）已从家禽和各种水禽中分离出来，这些 IAV 从禽类传播到哺乳动物（即人类、海豹和水貂）的散发性传播已有充分记录。2015 年，我们从冰岛的海鸥中分离出四种 H10N7 病毒。基因组分析表明，这些病毒的四个基因片段在遗传上与 2014 年导致欧洲海豹流感暴发和死亡的 H10 IAV 有关。抗原特征表明，这些 H10N7 分离株与其他从亚洲、欧洲和北美的人类、海豹、水貂和各种禽类中回收的存档 H10 病毒之间的抗原变异最小。糖结合偏好分析表明，与其他禽源 H10 IAV 类似，这些海鸥源 H10N7 IAV 与禽源α2,3 连接的唾液酸和人类源α2,6 连接的唾液酸都有结合。然而，当将海鸥源病毒与另一种引起人类感染的欧亚禽源 H10N8 IAV 进行比较时，海鸥源病毒对人类源聚糖受体的结合亲和力明显更高。雪貂实验的结果表明，一种海鸥源 H10N7 IAV 在鼻甲、气管和肺中复制良好，但在鼻甲和气管中复制效率最高。这种海鸥源 H10N7 病毒可以通过直接接触和空气传播途径在雪貂之间传播，无需预先适应。海鸥与其他鸟类和哺乳动物共享栖息地，经常与人类接触；因此，海鸥源 H10N7 IAV 可能对公共卫生构成威胁。应继续在野生鸟类-人类界面监测和监测这些 IAV。亚型 H10 禽流感病毒（IAV）已导致散发性人类感染和海豹地方性暴发。2015 年秋季，冰岛的海鸥中分离出 H10N7 病毒，基因组分析表明，这些病毒与一年前在欧洲导致海豹暴发的 IAV 具有遗传关系。这些海鸥源病毒对人类源聚糖受体具有高结合亲和力。雪貂传播研究表明，海鸥源 IAV 可以感染雪貂，并且该病毒可以通过直接接触和气溶胶飞沫在雪貂之间传播。本研究表明，禽源 H10 IAV 可以在哺乳动物中感染并在它们之间传播而无需适应。因此，禽源 H10 IAV 是流感大流行准备的候选者，应在野生动物和动物-人界面进行监测。
