武汉沉湖湿地候鸟、留鸟和家禽间禽流感病毒的传播

本课题的目的是研究越冬地候鸟禽流感病毒的多样性，病毒从候鸟传给留鸟或者家禽的可能性以及病毒在越冬地不同宿主间的动态传播。本课题拟在武汉沉湖湿地核心区开展以下研究内容：（1）在候鸟抵达前秋季，调查散养家禽、留鸟的种类、数量、密度及禽流感病毒流行情况的本底数据；（2）在候鸟抵达后的冬春季，采集候鸟聚集区新鲜粪便及水体、留鸟筑巢点新鲜粪便、家禽拭子或新鲜粪便；分离鉴定不同宿主流行毒株，确定采集样品所属宿主种类，分析不同时间和空间、不同宿主流行毒株的遗传信息，以此阐明冬春季越冬地禽流感病毒的动态分布；（3）在候鸟飞离后，监测湿地核心区散养家禽、留鸟是否继续存在禽流感病毒流行；（4）对部分毒株的生物学特性如：受体结合，耐酸碱、耐热，体外生长及致病性进行分析，评估病毒风险。通过本研究，掌握禽流感病毒生态传播链，为有效控制传染源、切断传播途径和防止禽流感的发生与流行提供重要依据。

The purpose of this study is to uncover the circulation and diversity of avian influenza viruses (AIVs) in the wintering migratory birds, the transmission potential of AIVs from migratory birds to resident birds or domestic poultry, and the dynamic transmission of AIVs among multiple hosts in wintering wetland. The following research will be performed in the core area in Chenhu wetland, Wuhan City. First, the species, quality and density of resident birds and domestic poultry will be investigated before wintering birds arrive in wintering area; The prevalence of AIVs in these hosts will also be determined. Second, after wintering birds arrive in wintering area, the fresh droppings and water in habitats of migratory birds, the fresh droppings around the nesting area of resident birds, and the swabs and fresh droppings of domestic poultry will be collected; Viruses will be isolated and the subtypes, genome sequences will be determined; The hosts of the AIV-positive samples will be identified with a mitochondrial analysis; The spatial and temporary pattern of AIVs in the wintering area will be demonstrated through analyzing the genetic characteristics of virus strains; The results will shed light to the dynamic distribution of AIVs in wintering area. Third, the prevalence of AIVs in resident birds and domestic poultry will be determined after the migratory birds’ departure. Fourth, evaluate of the potential risk of infection will be performed via determine the characteristics of some isolates: the viruses will be tested for receptor binding activities, resistance in different pH and temperature, growth curve in vitro, pathogenicity in animal model. The results will reveal the ecological transmission chains of AIVs in wintering area. The results will also provide the key basis for controlling the source of infection, cutting the way of transmission, and preventing the epidemic and circulation of AIVs.