Comparative Analysis of COVID-19 Transmission Patterns in Three Chinese Regions vs. South Korea,Italy and Iran

Junyu He; Guangwei Chen; Yutong Jiang; Runjie Jin; Mingjun He; Ashton Shortridge; Jiaping Wu; George Christakos

Many models linking the evolution of susceptible, infected and removed cases have been used in 121 the study of infectious disease distributions [22] [23] [24] [25] [26] . A modified susceptible-exposed-infected-122 removed model (SEIR) was used in this study to simulate the COVID-19 spread in the six study infected, cured and dead individuals at time t. The exposed and infected individuals constitute the 129 total number of affected individuals A(t)  E(t)  I (t) . The cured and dead individuals constitute the 130 total number of removed individuals R(t)  C(t)  D(t). The time-varying parameters  1 (t) and  2 (t) 131 denote the rate of COVID-19 transmission when an individual comes in contact with infected and 132 exposed individuals, respectively, the constant  represents the probability that the exposed 133 individuals become infected, and the time-varying parameters (t) and (t) denote the 134 cure rate and death rate, respectively. The SEIR model was developed specifically for this study 135 because the COVID-19 incubation period is about 7 days, and early in this period no symptoms are 136 detected, which means the infected but asymptomatic people will unknowingly infect others before 137 they develop any symptoms.