Ayudhya Syriam Sooksawasdi Na, Leijten Lonneke, Rijnink Willemijn F, Spronken Monique I, Kuiken Thijs, Bauer Lisa, van Riel Debby
Emerg Infect Dis. 2025 Sep;31(9):1729-1737. doi: 10.3201/eid3109.250499. Epub 2025 Aug 5.
Highly pathogenic avian influenza A(H5N1) clade 2.3.4.4b virus infections have caused substantial mortality events in marine mammals in recent years. We hypothesized that the high number of infections and disease severity could be related to cell tropism in respiratory tracts. Therefore, we examined the attachment pattern of an H5N1 clade 2.3.4.4b virus (H5) as a measure for cell tropism in the respiratory tracts of harbor seals, gray seals, harbor porpoises, and bottlenose dolphins and compared it with an H5N1 clade 2.1.3.2 virus (H5) and a human seasonal H3N2 virus using virus histochemistry. Both H5 viruses attached abundantly to olfactory and respiratory mucosa in the upper respiratory tract of both seal species. H5 attached more abundantly than H5 to epithelial cells in the lower respiratory tract of all species. The observed attachment possibly explains the susceptibility of marine mammal species for recent H5N1 viruses and the observed development of severe disease.
近年来，高致病性甲型禽流感病毒（H5N1）2.3.4.4b分支感染已在海洋哺乳动物中引发了大量死亡事件。我们推测，感染数量众多及疾病严重程度可能与呼吸道中的细胞嗜性有关。因此，我们检测了一株H5N1 2.3.4.4b分支病毒（H5）的附着模式，以此作为港海豹、灰海豹、港湾鼠海豚和宽吻海豚呼吸道中细胞嗜性的一种衡量指标，并使用病毒组织化学方法将其与一株H5N1 2.1.3.2分支病毒（H5）以及一种人类季节性H3N2病毒进行比较。两种H5病毒均大量附着于两种海豹上呼吸道的嗅觉和呼吸黏膜。在所有物种的下呼吸道中，H5比H5更大量地附着于上皮细胞。观察到的附着情况可能解释了海洋哺乳动物物种对近期H5N1病毒的易感性以及所观察到的严重疾病的发展情况。
