Department of Population Medicine and Diagnostic Sciences, Animal Health Diagnostic Center, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA.
New York State Department of Environmental Conservation, Wildlife Health Program, Albany, NY, USA.
Emerg Microbes Infect. 2023 Dec;12(2):2249554. doi: 10.1080/22221751.2023.2249554. Epub 2023 Aug 17.
Avian influenza H5N1 is a highly pathogenic virus that primarily affects birds. However, it can also infect other animal species, including mammals. We report the infection of nine juvenile red foxes () with Highly Pathogenic Avian Influenza A type H5N1 (Clade 2.3.4.4b) in the spring of 2022 in the central, western, and northern regions of New York, USA. The foxes displayed neurologic signs, and examination of brain and lung tissue revealed lesions, with brain lesions ranging from moderate to severe meningoencephalitis. Analysis of tissue tropism using RT-PCR methods showed a comparatively lower Ct value in the brain, which was confirmed by hybridization targeting Influenza A RNA. The viral RNA labelling was highly clustered and overlapped the brain lesions, observed in neurons, and grey matter. Whole viral genome sequences obtained from the affected foxes were subjected to phylogenetic and mutation analysis to determine influenza A clade, host specificity, and potential occurrence of viral reassortment. Infections in red foxes likely occurred due to preying on infected wild birds and are unlikely due to transmission between foxes or other mammals.
禽流感 H5N1 是一种高致病性病毒，主要影响鸟类。然而，它也可以感染其他动物物种，包括哺乳动物。我们报告了 2022 年春天在美国纽约州中部、西部和北部地区的九只幼年赤狐（）感染高致病性禽流感 A 型 H5N1（Clade 2.3.4.4b）的情况。这些狐狸表现出神经症状，大脑和肺部组织检查显示出病变，大脑病变从中度到重度脑膜脑炎不等。使用 RT-PCR 方法分析组织嗜性的结果显示，大脑中的 Ct 值相对较低，这一结果通过针对流感 A RNA 的杂交得到了证实。病毒 RNA 标记高度聚集，与神经元和灰质中的大脑病变重叠。从受感染的狐狸中获得的全病毒基因组序列进行了系统发育和突变分析，以确定流感 A 分支、宿主特异性以及病毒重组的潜在发生。赤狐的感染可能是由于捕食受感染的野生鸟类所致，不太可能是由于狐狸或其他哺乳动物之间的传播所致。
