2021年北京市野生天鹅死亡案例的诊断及其H5N8禽流感病毒的遗传变异分析

Diagnosis of Fatal Cases of Wild Swans in Beijing in 2021 and Genetic Variation Analysis of H5N8 Avian Influenza Virus

为探明2021年2月北京市海淀区圆明园遗址公园内3只野生天鹅异常死亡的原因,本试验通过临床剖检和实验室检测进行综合分析,并对临床样品进行病毒分离和基因组测序分析。结果显示:病死天鹅头面部水肿,角膜充血,消化道、呼吸道黏膜广泛充血、出血等典型禽流感特征,实验室检测确诊病原为H5N8亚型禽流感病毒;遗传进化分析显示,该病毒属于2.3.4.4分支;分离到的毒株HA裂解位点符合高致病性禽流感分子特征;氨基酸位点分析显示,该病毒含有典型的禽型α2-3受体结合位点。本研究结果对北京地区及时、准确地防控H5N8亚型禽流感病毒具有重要意义。

In order to determine the cause of abnormal death of three wild swans in Yuanmingyuan Heritage Park in Haidian District of Beijing in February 2021,this study conducted clinical autopsy,laboratory identification,virus isolation and genome sequencing analysis on clinical samples.The results showed that the dead swans presented typical avian influenza characteristics such as head and face edema,corneal congestion,extensive congestion and bleeding of digestive tract and respiratory tract mucosa.Laboratory identification confirmed H5N8 subtype avian influenza virus.Genetic evolution analysis revealed that the virus belonged to branch 2.3.4.4.The HA cleavage site of the isolated strain was highly pathogenic.Amino acid analysis indicated that the virus contained a typical avian typeα2-3 receptor binding sites.Thus,this study facilitated the timely and accurate prevention and control of H5N8 subtype avian influenza virus in Beijing.