ABSTRACT
In this paper, the deterministic and the stochastic models are proposed to study the interaction of the Coronavirus (COVID-19) with host cells inside the human body. In the deterministic model, the value of the basic reproduction number R0 determines the persistence or extinction of the COVID-19. If R0 < 1, one infected cell will transmit the virus to less than one cell, as a result, the person carrying the Coronavirus will get rid of the disease .If R0 > 1, the infected cell will be able to infect all cells that contain ACE receptors. The stochastic model proves that if α1 & α2 are sufficiently large then α1 & α2 maybe give us ultimate disease extinction although R0 > 1, and this facts also proved by computer simulation. © 2022 University of Baghdad. All rights reserved.
ABSTRACT
In this paper, we model the spread of coronavirus (COVID -19) by introducing stochasticity into the deterministic differential equation susceptible -infected-recovered (SIR model). The stochastic SIR dynamics are expressed using Itô's formula. We then prove that this stochastic SIR has a unique global positive solution I(t).The main aim of this article is to study the spread of coronavirus COVID-19 in Iraq from 13/8/2020 to 13/9/2020. Our results provide a new insight into this issue, showing that the introduction of stochastic noise into the deterministic model for the spread of COVID-19 can cause the disease to die out, in scenarios where deterministic models predict disease persistence. These results were also clearly illustrated by Computer simulation. © 2021 University of Baghdad-College of Science. All rights reserved.