Effect of incubation period on epidemic spreading in complex networks

We study the effect of incubation period on epidemic spreading inthe Barabasi--Albert scale-free network and the Watts--Strogatzsmall world network by using aSuspectable-Incubated-Infected-Suspectable model. Our analyticalinvestigations show that the epidemic threshold is independent ofincubation period in both networks, which is verified by ourlarge-scale simulation results. We also investigate the effect ofincubation period on the epidemic dynamics in a supercriticalregime. It is found that with the increase of incubation period${itOmega} $, a damped oscillation evolution of $rho_T$ (theratio of persons in incubated state) appears and the time needed toreach a saturation value increases. Moreover, the steady value of$rho _T $ increases and approaches to an asymptotic constant withthe value of ${itOmega} $ increasing. As a result, the infectedratio $rho _I$ decreases with the increase of ${itOmega}$according to a power law.