Sites of live poultry trade and marketing are hot spots for avian influenza virus (AIV) transmission. We conducted active surveillance at a local live poultry market (LPM) in northern Vietnamese provinces in December 2016. Feces samples from the market were collected and tested for AIV. A new reassorted AIV strain was isolated from female chickens, named A/chicken/Vietnam/AI-1606/2016 (H5N6), and was found to belong to group C of clade 2.3.4.4 H5N6 highly pathogenic (HP) AIVs. The neuraminidase gene belongs to the reassortant B type. The viral genome also contained polymerase basic 2 and polymerase acidic, which were most closely related to domestic-duck-origin low pathogenic AIVs in Japan (H3N8) and Mongolia (H4N6). The other six genes were most closely related to poultry-origin H5N6 HP AIVs in Vietnam and had over 97% sequence identity with human AIV isolate A/Guangzhou/39715/2014 (H5N6). The new reassorted AIV isolate A/chicken/Vietnam/AI-1606/2016 (H5N6) identified in this study exemplifies AIVs reassortment and evolution through contact among wild birds, poultry farms, and LPMs. Therefore, active surveillance of AIVs is necessary to prevent potential threats to human and animal health.

活禽贸易和营销场所是禽流感病毒（AIV）传播的热点。我们于 2016 年 12 月在越南北部省份的当地活禽市场 (LPM) 进行了主动监测。收集了来自市场的粪便样本并进行了 AIV 检测。从雌性鸡中分离出一种新的重组 AIV 毒株，命名为 A/chicken/Vietnam/AI-1606/2016 (H5N6)，发现属于进化枝 2.3.4.4 H5N6 高致病性 (HP) AIV 的 C 组。神经氨酸酶基因属于重配B型。病毒基因组还含有聚合酶碱性 2 和聚合酶酸性，它们与日本 (H3N8) 和蒙古 (H4N6) 的家鸭来源的低致病性 AIV 最密切相关。其他六个基因与越南的禽源 H5N6 HP AIV 最密切相关，并且与人类 AIV 分离株 A/Guangzhou/39715/2014 (H5N6) 具有超过 97% 的序列同一性。本研究中鉴定的新重组 AIV 分离株 A/chicken/Vietnam/AI-1606/2016 (H5N6) 证明了 AIV 通过野生鸟类、家禽养殖场和 LPM 之间的接触进行重组和进化。因此，有必要对 AIV 进行主动监测，以防止对人类和动物健康的潜在威胁。