Chemical and Veterinary Investigation Centre Westphalia, Arnsberg, Germany.
Institute of Diagnostic Virology, Friedrich-Loeffler-Institute, Greifswald-Insel Riems, Germany.
Vet Microbiol. 2022 Jul;270:109461. doi: 10.1016/j.vetmic.2022.109461. Epub 2022 May 13.
Despite the increasing frequency of avian influenza (AI) cases in wild birds in Europe during the last decade, doves and pigeons were not recognized to be part of the AI epidemiology. Here we describe a natural, lethal HPAIV infection of subtype H5N1, clade 2.3.4.4b, in a wood pigeon (Columba palumbus) in Germany, 2022. The animal was housed in a bird sanctuary that suffered an HPAI-outbreak with multiple bird species affected. The pigeon's post mortem findings were dominated by an acute lymphohistiocytic meningoencephalitis as well as neuronal necrosis in the grey matter of the cerebral hemispheres and in the brain stem. Influenza A viral antigen was associated to these alterations with a striking ependymal and periventricular distribution most probably indicating intraventicular liquorogenic spread of the virus. In addition, typical severe multifocal to coalescing necrotizing pancreatitis was evident. Occasionally, vascular endothelial cells showed an intense viral antigen staining. Examination of oropharyngeal and cloacal swabs and of various tissues by real-time RT-PCR corroborated systemic infection with highly pathogenic (HP) AIV of subtype H5N1. Viral loads soared in brain and pancreas samples. Full genome sequencing directly from brain tissue confirmed the assignment of the virus to clade 2.3.4.4b of the goose/Guangdong lineage bearing a polybasic hemagglutinin cleavage site. Our results demonstrate the principal susceptibility of wood pigeons to HPAIV H5N1 resulting in a sporadic infection. Considering the wide distribution and roaming of wild, feral, and racing pigeons with often close contact to humans, thorough investigation of suspected cases including pathological manifestation is advisable.
尽管在过去十年中，欧洲野生鸟类中的禽流感（AI）病例越来越频繁，但鸽子和斑鸠并未被认为是 AI 流行病学的一部分。在这里，我们描述了 2022 年在德国一只木鸽（Columba palumbus）中发生的自然、致命的 HPAIV H5N1 感染，该病毒属于 2.3.4.4b 分支。该动物被安置在一个鸟类保护区内，该保护区爆发了 HPAI，多种鸟类受到影响。鸽子的尸检结果主要表现为急性淋巴组织细胞性脑膜脑炎，以及大脑半球和脑干灰质中的神经元坏死。流感 A 病毒抗原与这些变化相关联，在脑室周围和脑室周围区域呈现出明显的分布，这很可能表明病毒在脑室内部有液体传播。此外，还出现了典型的严重多灶性至融合性坏死性胰腺炎。偶尔，血管内皮细胞显示出强烈的病毒抗原染色。实时 RT-PCR 对口咽和泄殖腔拭子以及各种组织的检查证实了全身性感染高致病性（HP）AIV H5N1。脑和胰腺样本中的病毒载量飙升。直接从脑组织进行的全基因组测序证实了该病毒属于鹅/广东谱系 2.3.4.4b 分支，具有多碱性血凝素裂解位点。我们的结果表明，木鸽对 HPAIV H5N1 具有主要易感性，导致散发性感染。考虑到野生、野生和赛鸽的广泛分布和漫游，它们经常与人类密切接触，因此建议对疑似病例进行彻底调查，包括病理表现。
