基于动力学评估病毒变异对广东省H7N9禽流感的影响

Evaluating the Effect of Virus Variation on Avian Influenza H7N9 Based on Dynamics in Guangdong Province

H7N9禽流感病毒的传播不仅会对家禽养殖业造成巨大损失,还严重威胁人类健康。在第5波疫情中,全国新增确诊人感染H7N9禽流感确诊病例暴发峰值高,确诊病例主要发生在长三角和珠三角地区。为评估第5波疫情中病毒变异对该病毒传播的影响,以广东省为研究区域,人和禽为研究对象,依据H7N9禽流感病毒的传播机理以及温度对病毒存活力的影响,建立了非自治H7N9禽流感传播动力学模型。利用最小二乘法分别对广东省2013年10月—2016年9月、2016年10月—2017年9月每月新增确诊人感染H7N9禽流感病例数进行数据拟合、参数估计,定量比较病毒变异前后环境传染系数的变化。此外,通过参数敏感性分析可知降低禽类的补充率、缩短禽类的销售时间、加强环境的清洁以及禽类因病死亡的出现可使疾病得到控制。

The avian influenza H7 N9 virus not only causes huge losses to poultry farming,but also poses a serious threat to human health. In the fifth wave of epidemic spread,the peak of newly confirmed humaninfection with avian influenza H7 N9 was high,and the confirmed cases mainly occurred in the Yangtze River Delta and the Pearl River Delta. In order to evaluate the effect of virus mutation on the transmission of avian influenza H7 N9 virus in the fifth wave,we took Guangdong province as the research area,the human and poultry as the research object,and established the nonautonomous dynamic model of avian influenza H7 N9 based on the transmission mechanism of avian influenza H7 N9 virus and the effect of temperature on the viral viability. The data fitting and parameter estimation of newly confirmed cases infected with avian influenza H7 N9 virus using the least squares method in Guangdong Province from October 2013 to September 2016 and from October 2017 to September 2016 were carried out to quantitatively compare the change of environmental contagion coefficientbefore and after virus variation. Moreover,from the parameter sensitivity analysis,we can see that the epidemic can be controlled by reducing the supplementary rate of poultry,shortening poultry sales time,strengthening the cleanliness of the environment and the emergence of the mortality rate of poultry.