Dynamical Analysis of Multipathways and Multidelays of General Virus Dynamics Model

2019 ◽  
Vol 29 (03) ◽  
pp. 1950031 ◽  
Author(s):  
Ángel G. Cervantes-Pérez ◽  
Eric Ávila-Vales
Keyword(s):  
Immune Response ◽  
Time Delays ◽  
Reproduction Number ◽  
Dynamical Analysis ◽  
Multiple Time Scales ◽  
Threshold Dynamics ◽  
Positive Equilibrium ◽  
Virus Dynamics ◽  
Multiple Time ◽  
Dynamics Model

This paper considers a general virus dynamics model with cell-mediated immune response and direct cell-to-cell infection modes. The model incorporates two types of intracellular distributed time delays and a discrete delay in the CTL immune response. Under certain conditions, the model exhibits a global threshold dynamics with respect to two parameters: the basic reproduction number and the reproduction number of immune response. We use suitable Lyapunov functionals and apply Lasalle’s invariance principle to establish the global asymptotic stability of the two boundary equilibria. We also perform a bifurcation analysis for the positive equilibrium to show that the time delays may lead to sustained oscillations. To determine the direction of the Hopf bifurcation and the stability of the periodic solutions, the method of multiple time scales is applied. Finally, we carry out numerical simulations to illustrate our results.

scholarly journals Threshold Dynamics of an HIV-TB Co-infection Model with Multiple Time Delays

2021 ◽  
Vol 53 ◽  
Author(s):  
M. Pitchaimani ◽  
A. Saranya Devi
Keyword(s):  
Basic Reproduction Number ◽  
Time Delays ◽  
Reproduction Number ◽  
Numerical Study ◽  
Single Infection ◽  
Infection Model ◽  
Threshold Dynamics ◽  
Multiple Time ◽  
Multiple Time Delays ◽  
The Basic Reproduction Number

In this article, a mathematical model to study the dynamics ofHIV-TB co-infection with two time delays is proposed and analyzed.We compute the basic reproduction number for each disease (HIV andTB) which acts as a threshold parameters. The disease dies out whenthe basic reproduction number of both diseases are less than unityand persists when the basic reproduction number of atleast one of thedisease is greater than unity. A numerical study on the model is alsoperformed to investigate the influence of certain key parameters on thespread of the disease. Mathematical analysis of our model shows thatswitching co-infection (HIV and TB) to single infection (HIV) can beachieved by imposing treatment for both the disease simultaneouslyas TB eradication is made possible with effective treatment.

Impact of adaptive immune response and cellular infection on delayed virus dynamics with multi-stages of infected cells

2019 ◽  
Vol 13 (01) ◽  
pp. 2050003
Author(s):  
A. M. Elaiw ◽  
N. H. AlShamrani
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Time Delays ◽  
Adaptive Immune Response ◽  
Virus Dynamics ◽  
Nonlinear Functions ◽  
Dynamics Model ◽  
Adaptive Immune ◽  
Infected Cells ◽  
Theoretical Results

In this investigation, we propose and analyze a virus dynamics model with multi-stages of infected cells. The model incorporates the effect of both humoral and cell-mediated immune responses. We consider two modes of transmissions, virus-to-cell and cell-to-cell. Multiple intracellular discrete-time delays have been integrated into the model. The incidence rate of infection as well as the generation and removal rates of all compartments are described by general nonlinear functions. We derive five threshold parameters which determine the existence of the equilibria of the model under consideration. A set of conditions on the general functions has been established which is sufficient to investigate the global stability of the five equilibria of the model. The global asymptotic stability of all equilibria is proven by utilizing Lyapunov function and LaSalle’s invariance principle. The theoretical results are illustrated by numerical simulations of the model with specific forms of the general functions.

scholarly journals Threshold dynamics and threshold analysis of HIV infection model with treatment

2020 ◽  
Vol 2020 (1) ◽  
Author(s):  
Zhimin Chen ◽  
Xiuxiang Liu ◽  
Liling Zeng
Keyword(s):  
Hiv Infection ◽  
Time Delays ◽  
Dynamical Behavior ◽  
Infection Model ◽  
Threshold Dynamics ◽  
Positive Equilibrium ◽  
Asymptotically Stable ◽  
Globally Asymptotically Stable ◽  
Immunodeficiency Virus ◽  
Hiv Infection Model

Abstract In this paper, a human immunodeficiency virus (HIV) infection model that includes a protease inhibitor (PI), two intracellular delays, and a general incidence function is derived from biologically natural assumptions. The global dynamical behavior of the model in terms of the basic reproduction number $\mathcal{R}_{0}$ R 0 is investigated by the methods of Lyapunov functional and limiting system. The infection-free equilibrium is globally asymptotically stable if $\mathcal{R}_{0}\leq 1$ R 0 ≤ 1 . If $\mathcal{R}_{0}>1$ R 0 > 1 , then the positive equilibrium is globally asymptotically stable. Finally, numerical simulations are performed to illustrate the main results and to analyze thre effects of time delays and the efficacy of the PI on $\mathcal{R}_{0}$ R 0 .

scholarly journals Analysis of a diffusive cholera model incorporating latency and bacterial hyperinfectivity

2021 ◽  
Vol 20 (11) ◽  
pp. 3921
Author(s):  
Wei Yang ◽  
Jinliang Wang
Keyword(s):  
Lyapunov Functional ◽  
Global Attractivity ◽  
Reproduction Number ◽  
Reaction Diffusion ◽  
Threshold Dynamics ◽  
Positive Equilibrium ◽  
Flux Boundary Condition ◽  
Nonlocal Reaction ◽  
Theoretical Results ◽  
The Basic Reproduction Number

<p style='text-indent:20px;'>In this paper, we are concerned with the threshold dynamics of a diffusive cholera model incorporating latency and bacterial hyperinfectivity. Our model takes the form of spatially nonlocal reaction-diffusion system associated with zero-flux boundary condition and time delay. By studying the associated eigenvalue problem, we establish the threshold dynamics that determines whether or not cholera will spread. We also confirm that the threshold dynamics can be determined by the basic reproduction number. By constructing Lyapunov functional, we address the global attractivity of the unique positive equilibrium whenever it exists. The theoretical results are still hold for the case when the constant parameters are replaced by strictly positive and spatial dependent functions.</p>

LYAPUNOV FUNCTION AND GLOBAL PROPERTIES OF VIRUS DYNAMICS WITH CTL IMMUNE RESPONSE

2008 ◽  
Vol 01 (04) ◽  
pp. 443-448 ◽  
Author(s):  
XIA WANG ◽  
YOUDE TAO
Keyword(s):  
Immune Response ◽  
Lyapunov Function ◽  
Lyapunov Functions ◽  
Disease Model ◽  
Virus Dynamics ◽  
Dynamics Model ◽  
Global Properties ◽  
The Stability ◽  
Ctl Immune Response

The stability of infections disease model with CTL immune response in vivo is considered in this paper. Explicit Lyapunov functions for our dynamics model with CTL immune response with nonlinear incidence of the form βVqTpfor the case q ≤ 1 are introduced, and global properties of the model are thereby established.

scholarly journals Global proprieties of a delayed epidemic model with partial susceptible protection

2021 ◽  
Vol 19 (1) ◽  
pp. 209-224
Author(s):  
Abdelheq Mezouaghi ◽  
◽  
Salih Djillali ◽  
Anwar Zeb ◽  
Kottakkaran Sooppy Nisar ◽  
...  
Keyword(s):  
Basic Reproduction Number ◽  
Epidemic Model ◽  
Reproduction Number ◽  
Threshold Dynamics ◽  
Positive Equilibrium ◽  
Global Dynamics ◽  
Isolation Rate ◽  
Globally Asymptotically Stable ◽  
The Government ◽  
The Basic Reproduction Number

<abstract><p>In the case of an epidemic, the government (or population itself) can use protection for reducing the epidemic. This research investigates the global dynamics of a delayed epidemic model with partial susceptible protection. A threshold dynamics is obtained in terms of the basic reproduction number, where for $ R_0 &lt; 1 $ the infection will extinct from the population. But, for $ R_0 &gt; 1 $ it has been shown that the disease will persist, and the unique positive equilibrium is globally asymptotically stable. The principal purpose of this research is to determine a relation between the isolation rate and the basic reproduction number in such a way we can eliminate the infection from the population. Moreover, we will determine the minimal protection force to eliminate the infection for the population. A comparative analysis with the classical SIR model is provided. The results are supported by some numerical illustrations with their epidemiological relevance.</p></abstract>

Dynamical behavior of a virus dynamics model with CTL immune response

2009 ◽  
Vol 213 (2) ◽  
pp. 329-347 ◽  
Author(s):  
Xueyong Zhou ◽  
Xiangyun Shi ◽  
Zhonghua Zhang ◽  
Xinyu Song
Keyword(s):  
Immune Response ◽  
Dynamical Behavior ◽  
Virus Dynamics ◽  
Dynamics Model ◽  
Ctl Immune Response
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