Asymptotic analysis of a stochastic SVEIS epidemic model using Black-Karasinski process
Lahcen Khammich, Driss Kiouach
TL;DR
The paper analyzes a stochastic SVEIS epidemic model in which transmission is perturbed by a Black-Karasinski process. Using Lyapunov-function techniques and Ito calculus, it derives two thresholds, $R_0^s$ for persistence and $R_0^e$ for extinction. It proves the existence of an ergodic stationary distribution when $R_0^s>1$ and shows exponential extinction when $R_0^e<1$, illustrating that random fluctuations can promote outbreaks. These results provide rigorous criteria for long-run disease behavior under stochastic perturbations and offer insight into noise-driven outbreak risk for public health planning.
Abstract
In this paper, we present a stochastic SVEIS epidemic model perturbed by a Black-Karasinski process. Using a Lyapunov functional approach, we derive a sufficient condition, Rs0>1 for the existence of a stationary distribution, which indicates disease persistence. Additionally, we theoretically demonstrate that the disease will die out at an exponential rate if Re0<1 . Our results show that random fluctuations will facilitate disease outbreak.
