Analysis of COVID-19 Epidemic and Assessment of Prevention and Control Measures in Shanxi Province

In order to describe the incubation period, isolation period and treatment period, a kind of difference equation model with time-delay effect was established. The least square method was used to estimate the parameters and make parameter sensitivity analysis to study the development of Covid-19 epidemic in Shanxi Province. The results show that the infection rate of asymptomatic patients was not high. The latent and symptomatic patients are the main spreaders of COVID-19 in Shanxi Province. Nonetheless, the asymptomatic patients should not be ignored. If they were not infectious, the final infected patients would be reduced by 10.53%. In addition, the government's prevention and control measures have played a significant role in epidemic control. Without strict measures, the number of cases in Shanxi Province will develop to about 430 before gradually stabilizing. The time delay effect reflects the policy factors of the epidemic situation and the actual treatment situation, so that the model fits the reality, has higher fitting accuracy, and reduces the uncertainty of model analysis to a certain extent.It provides a useful theoretical support for the spread of infectious diseases. © 2021, The Press of NUC. All right reserved.