Study On The Dynamic Models And Control Strategy Of Tuberculosis And COVID-19 Transmission

Mathematical models are indispensable for understanding the spread of infectious diseases.This article mainly studies two types of infectious pulmonary diseases:Tuberculosis and COVID-19.After in-depth understanding of the transmission mechanism of tuberculosis and COVID-19,dynamic models were established,theoretical analysis was carried out,and specific prevention and control measures were evaluated through numerical simulation.The main research contents are as follows:(1)In order to explore the impact of bovine tuberculosis on the transmission of human pulmonary tuberculosis,according to the transmission characteristics and incidence characteristics of tuberculosis,a dynamic model of tuberculosis transmission among cattle,high-risk groups and low-risk groups was established,and the basic reproduction number R0 of the model was calculated.,And proved that in the model,the stability of the disease-free equilibrium point when R0<1,and the consistent persistence of the model when R0>1.The slaughter of sick bovine is further added to the model,and the model is fitted with the actual sick bovine data using nonlinear least squares method.It is concluded through numerical simulation that the incidence of tuberculosis in the population can be effectively reduced by controlling the transmission rate of tuberculosis from bovine to human;the impact of the slaughter rate of sick bovine on the population incidence is discussed.The higher the slaughter rate,the lower the population incidence;in addition,the proportion of the high-risk and low-risk groups will also affect the population incidence of tuberculosis.The greater the proportion of high-risk groups,the higher the population incidence.(2)In order to study the impact of measures to quarantine close contacts on the spread of the COVID-19,based on the official data and the transmission mechanism of the COVID-19,the SEIR dynamic models of the virus spread in Beijing and South Korea were established,and genetic algorithms were used to fit them.Important parameter values such as transmission rate,recovery rate and isolation rate,calculated the controlled reproduction number,discussed the impact of quarantining close contacts on the daily new cases in South Korea,simulated the highest value of daily new cases,and discussed the differences between the impact of the quarantine ratio and the number of the susceptible on daily new cases.The simulation results show that compared with more relaxing prevention and control measures,quaranting close contacts has a more striking effect in reducing the value of new cases.(3)In order to study the impact of vaccination rate and failure rate on the spread of the COVID-19,considering that the antibody level of the infected person will decline over time after recovery,a SEIR dynamic model for the spread of the COVID-19 in England was established.The basic reproduction number was calculated,and the impact of the vaccination ratio and vaccine failure rate on the daily number of new cases was discussed.The simulation results show that increasing the vaccination ratio and reducing the vaccine failure rate will reduce the number of daily new cases.