Effect Of Human Infection Risk And Poultry Transportation On The Transmission Of H7N9

H7N9 avian influenza(H7N9),as one of the highly pathogenic diseases has been occured in China many times since 2013.The outbreaks of H7N9 severely damage the nationwide poultry industry,and further greatly affect the public health.It is of great significance to explore the mechanism of disease transmission and clarify the key risk factors in the process of disease transmission for controlling the recurrence of H7N9.In this thesis,dynamic models are established to investigate the impact of risk factors such as human infection risk and poultry transportation on the transmission of H7N9.Firstly,a H7N9 epidemic model is established to distinguish the high and low risk of human infection.The positive invariant set and the basic reproduction number are calculated,and then the existence of disease-free equilibrium and endemic equilibrium is proved.Furthermore,the global asymptotic stability of the equilibria is explored by Lyapunov method.Numerical simulation is applied to explore the effect of different coefficients of infected risk on the infected population.Numerical results indicate that the disease is more prevalent in high-risk groups,and the infected humans decrease with the decreasing of coefficient of infected risk.Then,a H7N9 epidemic model with irregular poultry transportation,which the poultry is transported from high-risk region to low-risk one,is established.The basic reproduction number of system is calculated,then the existence and stabilization of the equilibria are proved.Furthermore,numerical simulation shows that the poultry transportation is a key factor leading to the spread of disease.The results reveal that irregular poultry transportation lead to a further spread of H7N9,and the number of infectious humans increases as the transportation rate increases.