Detection and phylogenetic analysis of contemporary H14N2 Avian influenza A virus in domestic ducks in Southeast Asia (Cambodia)

Avian influenza virus (AIV) in Asia is a complex system with numerous subtypes and a highly porous wild birds-poultry interface. Certain AIV subtypes, such as H14, are underrepresented in current surveillance efforts, leaving gaps in our understanding of their ecology and evolution. The detection of rare subtype H14 in domestic ducks in Southeast Asia comprises a geographic region and domestic bird population previously unassociated with this subtype. These H14 viruses have a complex evolutionary history involving gene reassortment events. They share sequence similarity to AIVs endemic in Cambodian ducks, and Eurasian low pathogenicity and high pathogenicity H5Nx AIVs. The detection of these H14 viruses in Southeast Asian domestic poultry further advances our knowledge of the ecology and evolution of this subtype and reinforces the need for continued, longitudinal, active surveillance in domestic and wild birds. Additionally, in vivo and in vitro risk assessment should encompass rare AIV subtypes, as they have the potential to establish in poultry systems.亚洲禽流感病毒（Avian influenza virus, AIV）是一个涵盖众多亚型的复杂系统，且野鸟与家禽间的传播界面高度开放，病毒极易跨界传播。当前监测工作对H14等少数AIV亚型的覆盖程度不足，导致我们对其生态学特征与进化历程的认知存在空白。此次在东南亚家鸭中检出的罕见H14亚型病毒，其检出的地理区域与家禽种群此前均未被报道与该亚型存在关联。这些H14病毒具有复杂的进化历程，涉及多基因重排事件。其序列与柬埔寨本土鸭群中流行的AIV、欧亚地区低致病性及高致病性H5Nx亚型AIV具有较高同源性。此次在东南亚家禽中检出H14病毒，进一步完善了我们对该亚型生态学特征与进化历程的认知，同时也凸显了持续开展纵向主动监测的必要性，监测对象应覆盖家禽与野鸟两类种群。此外，体内（in vivo）与体外（in vitro）风险评估应将罕见AIV亚型纳入考量范围，因为这类病毒具备在家禽系统中定植的潜在能力。