In the 2014-2015 Eurasian lineage clade 2.3.4.4A H5 highly pathogenic avian influenza (HPAI) outbreak in the U.S., backyard flocks with minor gallinaceous poultry and large commercial poultry (chickens and turkeys) operations were affected. The pathogenesis of the first H5N8 and reassortant H5N2 clade 2.3.4.4A HPAI U.S. isolates was investigated in six gallinaceous species: chickens, Japanese quail, Bobwhite quail, Pearl guinea fowl, Chukar partridges, and Ring-necked pheasants. Both viruses caused 80-100% mortality in all species, except for H5N2 virus that caused 60% mortality in chickens. The surviving challenged birds remained uninfected based on lack of clinical disease and lack of seroconversion. Among the infected birds, chickens and Japanese quail in early clinical stages (asymptomatic and listless) lacked histopathologic findings. In contrast, birds of all species in later clinical stages (moribund and dead) had histopathologic lesions and systemic virus replication consistent with HPAI virus infection in gallinaceous poultry. These birds had widespread multifocal areas of necrosis, sometimes with heterophilic or lymphoplasmacytic inflammatory infiltrate, and viral antigen in parenchymal cells of most tissues. In general, lesions and antigen distribution were similar regardless of virus and species. However, endotheliotropism was the most striking difference among species, with only Pearl guinea fowl showing widespread replication of both viruses in endothelial cells of most tissues. The expression of IFN-γ and IL-10 in Japanese quail, and IL-6 in chickens, were up-regulated in later clinical stages compared to asymptomatic birds.

中文翻译：

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鸡胆对进化枝2.3.4.4A H5Nx高致病性禽流感病毒感染的病理生物学和先天免疫反应。

在2014年至2015年的欧亚血统进化枝2.3.4.4A H5高致病性禽流感（HPAI）爆发中，后院鸡群的鸡只和小家禽和大型家禽（鸡和火鸡）均受到感染。第一个H5N8和重配H5N2进化枝2.3.4.4A HPAI US分离株的发病机理已在以下六个鸡样物种中进行了研究：鸡，日本鹌鹑，鲍勃怀特鹌鹑，珍珠鸡，Chukar kar和环颈山鸡。两种病毒均在所有物种中导致80-100％的死亡率，除了H5N2病毒在鸡中引起60％的死亡率。由于缺乏临床疾病和血清转换，幸存的受挑战的鸟类仍未受到感染。在受感染的鸟类中，处于临床早期（无症状和无精打采）的鸡和日本鹌鹑缺乏组织病理学发现。相比之下，处于临床后期（濒死和死亡）的所有物种的鸟类的组织病理学损伤和全身病毒复制与鸡禽的HPAI病毒感染一致。这些禽类具有广泛的多灶性坏死区域，有时在大多数组织的实质细胞中具有嗜异性或淋巴浆细胞性炎症浸润，以及病毒抗原。通常，无论病毒和物种如何，病变和抗原分布都是相似的。但是，内胚层性是物种之间最显着的差异，只有珍珠珍珠鸡在大多数组织的内皮细胞中都显示出两种病毒的广泛复制。与无症状鸟类相比，日本鹌鹑中IFN-γ和IL-10的表达以及鸡IL-6的表达在以后的临床阶段均被上调。在以后的临床阶段（濒死和死亡）的所有物种的鸟类的组织病理学病变和全身病毒复制与鸡禽的HPAI病毒感染一致。这些禽类具有广泛的多灶性坏死区域，有时在大多数组织的实质细胞中具有嗜异性或淋巴浆细胞性炎症浸润，以及病毒抗原。通常，无论病毒和物种如何，病变和抗原分布都是相似的。但是，内胚层性是物种之间最显着的差异，只有珍珠珍珠鸡在大多数组织的内皮细胞中都显示出两种病毒的广泛复制。与无症状鸟类相比，日本鹌鹑中IFN-γ和IL-10的表达以及鸡IL-6的表达在以后的临床阶段均被上调。在以后的临床阶段（濒死和死亡）的所有物种的鸟类的组织病理学病变和全身病毒复制与鸡禽的HPAI病毒感染一致。这些禽类具有广泛的坏死性多灶性区域，有时在大多数组织的实质细胞中具有嗜异性或淋巴浆细胞性炎症浸润，以及病毒抗原。通常，无论病毒和物种如何，病变和抗原分布都是相似的。但是，内胚层性是物种之间最显着的差异，只有珍珠珍珠鸡在大多数组织的内皮细胞中都显示出两种病毒的广泛复制。与无症状鸟类相比，日本鹌鹑中IFN-γ和IL-10的表达以及鸡IL-6的表达在以后的临床阶段均被上调。