“…The quarantine strategy, which has been widely used in the prevention of various diseases [ 24 ], is considered to be one of the most effective virus prevention measures. So, Rafiq et al established a SEIQR model to describe the propagation of COVID-19 by taking the quarantine strategy into account, and they researched not only the equilibrium points and the reproduction number, but also the local and global asymptotic stability of the equilibria [ 25 ]: where , , , , express the number of susceptible individuals, exposed individuals, infected individuals, quarantine individuals and recovered individuals at time t , respectively. The meanings of the remaining parameters in system ( 1 ) can be found in [ 25 ].…”