Assessment On The Effect Of Control Measurements For COVID-19 Epidemic Based On The Improved SEIR Model

Since December 2019,COVID-19 has broken out globally.Thanks to the efforts of the World Health Organization and governments of various countries,many countries have controlled the spread of the epidemic effectively.The effect of different prevention and control measures between countries is a scenario that worthy of study.We use the SEIQR model(susceptible exposed infected quarantined and removed,SEIQR)to study and analyze the effect of the two main prevention and control measures which are blockade and quarantine implemented by countries in the first wave of epidemic.In addition,we establish the SEE_qAQFR model based on the epidemiological characteristics of COVID-19 and study the epidemic in Austria,Belgium and the Czech Republic.The main works of this thesis are as follows:1.Based on the SEIQR model,we adopt COVID-19 data from Johns Hopkins University and get the values of the parameters without prevention and control measures in 34 countries.Then,we evaluate the epidemic of COVID-19 according to the numerical results.What's more,the results reflect the urgency and necessity of the prevention and control measures in 34 countries.2.Using the SEIQR model,we make a comprehensive evaluation of the prevention and control measures in 34 countries(from the declaration of a health emergency to the declaration of the first phase of unblocking).Firstly,for the above-mentioned countries,the current intervention measures can reduce R₀effectively,and most of countries have achieved control of the epidemic before unblocking.Secondly,the results show that there are a large number of unreported cases in 34 countries,which puts forward higher requirements for the prevention and control of the epidemic in 34 countries.Finally,we classify the overall prevention and control effects and strategies of each country by hierarchical clustering,and we analyze the sensitivity of parameters based on the classification results.3.Using the SEIQR model and the epidemiological characteristics of COVID-19,we establish the SEE_qAQFR model that reflects the actual scenario well and get the values of the parameters in Austria,Belgium and the Czech Republic.Then we evaluate the epidemic of COVID-19 according to the numerical results.The results show that blockade and the time of prevention and control measures implemented have the greatest impact on the epidemic.