Department of Physics, East China Normal University, Shanghai 200062, People's Republic of China.
State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China.
Phys Rev E. 2016 Dec;94(6-1):062318. doi: 10.1103/PhysRevE.94.062318. Epub 2016 Dec 29.
Most of the studies on epidemics so far have focused on the growing phase, such as how an epidemic spreads and what are the conditions for an epidemic to break out in a variety of cases. However, we discover from real data that on a large scale, the spread of an epidemic is in fact a recurrent event with distinctive growing and recovering phases, i.e., a hysteresis loop. We show here that the hysteresis loop can be reproduced in epidemic models provided that the infectious rate is adiabatically increased or decreased before the system reaches its stationary state. Two ways to the hysteresis loop are revealed, which is helpful in understanding the mechanics of infections in real evolution. Moreover, a theoretical analysis is presented to explain the mechanism of the hysteresis loop.
迄今为止，大多数关于流行病的研究都集中在增长阶段，例如流行病如何传播，以及在各种情况下流行病爆发的条件是什么。然而，我们从实际数据中发现，在大规模情况下，流行病的传播实际上是一个具有明显增长和恢复阶段的反复事件，即滞后环。我们在这里表明，只要在系统达到稳定状态之前，传染率被绝热地增加或减少，滞后环就可以在流行病模型中重现。揭示了通向滞后环的两种途径，这有助于理解实际进化中感染的力学。此外，还提出了一种理论分析来解释滞后环的机制。
