猪流感不仅是养猪业重要的传染病，而且具有重要的公共卫生意义，猪被认为是新型流感病毒产生的发生器。但我国多年来缺乏猪流感病毒流行的系统监测，对新出现猪流感病毒特性缺乏了解。本研究以猪流感病毒遗传进化和病毒特性鉴定为核心研究内容，拟对我国华南（广东）、华东（山东、江苏）、华北（北京、河北）等地区猪群进行流感病毒系统调查，通过病毒全基因组测序和信息学分析，揭示我国猪流感病毒的基因演化规律；在此基础上，对新型重排猪流感病毒的致病性、传播性等特性进行鉴定，评估新型猪流感病毒对公共卫生的潜在威胁，同时解析导致新特性出现的分子基础。本研究不仅揭示我国猪流感病毒分子变异和进化规律，更为重要的是为人间流感的预警预报提供理论依据，对猪流感及人间流感的防控具有重要意义。

Swine influenza is a highly contagious respiratory disease caused by the swine influenza virus (SIV). Pigs are susceptible to both avian and human influenza A viruses, and they have been proposed to be the “mixing vessel” for generation of pandemic virus through reassortment. However, due to a lack of systematic surveillance, the prevalence of SIV in China and the biological characteristics of novel reassortant SIV have not yet been identified. To investigate the prevalence and genetic evolution of SIV in China, we will carry out routine surveillance for SIV in southern China (Guangdong), eastern China (Shandong, Jiangsu), and northern China (Beijing, Hebei), and study on the biological characteristics, such as receptor binding specificity, polymerase activity, pathogenicity, and transmissibility of novel reassortant SIV. In addition, we will examin the molecular basis for the increased transmissibility of SIV among ferrets and explore the possible underlying mechanisms. The results can not only enrich the content of molecular epidemiology, deepen the understanding of current situation of SIV in China, but also have great significance to the prediction and controlment of SIV and human influenza pandemic.