Study On The Model Of Novel Coronavirus COVID-19

The novel coronavirus has spread rapidly around the world since it was first identified in December 2019.As of March 15,2023,more than 500 million people have been infected worldwide and more than 11 million have died.The rapid spread of COVID-19 poses enormous challenges to both global health care systems and economic development,making it one of the most serious public health crises of our time.Understanding the transmission dynamics of COVID-19 is essential to develop effective public health interventions to control its spread.Mathematical modeling provides a valuable tool for studying infectious disease dynamics and predicting the impact of interventions.Based on the SEIR model,asymptomatic infected persons are introduced,this paper establishes a SEIADR model to theoretically study the impact of measures such as asymptomatic infected people and wearing masks on the prevention and control of COVID-19.Furthermore,a SEQIR model is established to study the impact of the timing and effect of the first containment measures on the spread of the epidemic.The main research contents of this paper are as follows:1.Based on the SEIR model,asymptomatic infected persons are added to establish the SEIADR model which is more in line with the actual situation,the basic reproduction number and control reproduction number are calculated and the influence of main parameter in the model on the disease transmission is theoretically studied.The results show that the proportion of asymptomatic infected people,the starting time of wearing masks and the effect of masks on the transmission of COVID-19 should not be ignored.2.Based on the SEQIR model,the development situation of the epidemic in 28 developed countries before and after the "grounding" measures were taken in the early stage of the epidemic transmission was compared.Parameter values in the model are obtained through data fitting,and sensitivity analysis of control parameters in each country is conducted to estimate the development trend of the novel coronavirus in each country.The study shows that countries must actively take control measures to contain the spread of the novel coronavirus,so that we can effectively cut off transmission routes to provide scientific basis.