Prevention and Control Strategy for Multi-group Epidemics Based on Delay and Isolation Control

Aiming at the prevention and control of multi-group epidemics, the dynamic model of disease transmission is established, and an optimal delay and isolation strategy is proposed. The control variables in the model represent the strength of various measures taken to block and isolate contact between groups. The optimal control problem is solved by Pontryagin maximum principle and the corresponding numerical iterative algorithm is given. The results show that the delay and isolation control strategy can effectively control the epidemic of infectious diseases while minimizing the cost of infectious diseases. The outbreak of the COVID-19 in 2020 is a serious threat to people's lives and health. It is because of the timely adoption of delay and isolation control strategy of "early detection and early isolation" and "joint-prevention and joint-control", China took the lead in the fight against the epidemic situation and made an example for the whole world.