Dynamic Modeling And Analysis Of H7N9 Avian Influenza Infection

The emergence and spread of infectious diseases have a significant impact on the development of the country in real life.Dynamic modeling is an effective method to study the internal mechanism of the development of infectious disease.The avian influenza A(H7N9)infectious disease is a zoonosis caused by avian influenza A(H7N9)virus.According to the estimates of China authorities,as of May 2013,poultry farming industry losses caused by avian influenza A(H7N9)had exceeded 40 billion yuan.Therefore,it is very important to use mathematical models to study avian influenza A(H7N9).The dynamic analysis of the models,different factors affecting the spread of avian influenza A(H7N9)were analyzed,which provided a reliable theoretical basis for the efficient control of the spread of avian influenza A(H7N9).This paper makes the following researches:To begin with,the exposure of infected poultry is a key factor for human infection with avian influenza A(H7N9).Avian influenza A(H7N9)infectious diseases caused can quickly spread in areas such as farms,live poultry markets and wet markets.In order to analyze the impact of different groups in specific environment on the spread of avian influenza A(H7N9),we establish an avian-human coupled avian influenza A(H7N9)epidemic model.The dynamic analysis of the model is given: including the feasible region,the basic reproduction number,and the stability of the disease-free equilibrium and positive equilibria.Finally,numerical examples are given to illustrate the theoretical results.Numerical simulations show that the areas where human and poultry are easy to contact promote the spread of avian influenza A(H7N9),and the control of poultry in farms and wet markets can effectively control human infection.In addition,based on the fact that birds and poultry are the natural storage hosts of avian influenza virus,and virus in the environment plays a role in the dynamics of avian influenza A(H7N9).A nationwide poultry vaccination with H7N9 vaccine program was implemented in China in October of 2017.To analyze the effect of vaccination and environmental virus on the development of avian influenza A(H7N9),we propose an avian influenza A(H7N9)transmission model with vaccination and seasonality.The model includes birds,poultry,virus in the environment and human,and considers factors such as temperature,vaccination and high-risk population.The feasible region and the basic reproduction number for the prevalence of avian influenza are obtained.Then,the global stability of the diseasefree equilibrium and the existence of positive periodic solution are proved by the comparison theorem and the asymptotic autonomous system theorem.The theoretical results and the effectiveness of control measures are illustrated by numerical simulations.Numerical simulations show the effects of temperature and high-risk populations on the spread of disease,and show that vaccination of poultry and disinfection of the environment contribute to control the development of disease.