“…Recently, stochastic differential equation models [17] , [18] , [19] , [20] , [21] , [22] have played an important role in various branches of applied sciences including infection dynamics and population dynamics, since they can provide some additional degree of realism compared to their deterministic counterparts [23] . And it is hence interesting to introduce the stochastic perturbation into the deterministic system to reveal the effect of environmental white noise on human disease [18] , [21] , [24] , [25] , [26] , [27] . For example, Gray et al.…”