美国康奈尔大学Diego G. Diel等研究人员合作发现高致病性禽流感H5N1病毒向奶牛的扩散。相关论文于2024年7月25日在线发表于国际学术期刊《自然》。

研究人员报告了高致病性禽流感（HPAI）H5N1病毒在美国多个州的奶牛群中的溢出事件。受感染的奶牛表现出临床症状，包括采食量减少、粪便异常、呼吸窘迫和乳量减少且乳汁异常。在受感染奶牛的乳汁中 持续检测到传染性病毒和病毒RNA。通过免疫组织化学和原位杂交在组织中的病毒分布显示，该病毒对奶牛乳腺泡上皮细胞具有明显的亲嗜性。

从受影响的农场中的奶牛、鸟类、家猫和浣熊中提取的完整病毒基因组序列，显示出多方向的跨物种传播。流行病学和基因组数据揭示，来自受影响农场的看似健康的奶牛被运输到其他州的场所后，牛之间的传播效率很高。这些结果表明HPAI H5N1 2.3.4.4b分支病毒能够跨越物种屏障，并在非传统界面上传播。

研究人员表示，自2022年1月以来，HPAI H5N1 2.3.4.4b分支病毒在美国造成了数百万家禽和数千只野生鸟类的死亡。在此期间，该病毒频繁传播给哺乳动物。

附：英文原文

Title: Spillover of highly pathogenic avian influenza H5N1 virus to dairy cattle

Author: Caserta, Leonardo C., Frye, Elisha A., Butt, Salman L., Laverack, Melissa, Nooruzzaman, Mohammed, Covaleda, Lina M., Thompson, Alexis C., Koscielny, Melanie Prarat, Cronk, Brittany, Johnson, Ashley, Kleinhenz, Katie, Edwards, Erin E., Gomez, Gabriel, Hitchener, Gavin, Martins, Mathias, Kapczynski, Darrell R., Suarez, David L., Alexander Morris, Ellen Ruth, Hensley, Terry, Beeby, John S., Lejeune, Manigandan, Swinford, Amy K., Elvinger, Franois, Dimitrov, Kiril M., Diel, Diego G.

Issue&Volume: 2024-07-25

Abstract: Highly pathogenic avian influenza (HPAI) H5N1 clade 2.3.4.4b virus has caused the death of millions of domestic birds and thousands of wild birds in the U.S. since January, 20221–4 Throughout this outbreak, spillovers to mammals have been frequently documented5–12. We report spillover of HPAI H5N1 virus in dairy cattle herds across several states in the U.S. The affected cows displayed clinical signs encompassing decreased feed intake, altered fecal consistency, respiratory distress, and decreased milk production with abnormal milk. Infectious virus and viral RNA were consistently detected in milk from affected cows. Viral distribution in tissues via immunohistochemistry and in situ hybridization revealed a distinct tropism of the virus for the epithelial cells lining the alveoli of the mammary gland in cows. Whole viral genome sequences recovered from dairy cows, birds, domestic cats, and a raccoon from affected farms indicated multidirectional interspecies transmissions. Epidemiologic and genomic data revealed efficient cow-to-cow transmission after apparently healthy cows from an affected farm were transported to a premise in a different state. These results demonstrate the transmission of HPAI H5N1 clade 2.3.4.4b virus at a non-traditional interface underscoring the ability of the virus to cross species barriers.

DOI: 10.1038/s41586-024-07849-4

Source: https://www.nature.com/articles/s41586-024-07849-4