A Multi-Scale Model for the Spread of HIV in a Population Considering the Immune Status of People

Sol De Amor Vásquez-Quintero,Hernán Darío Toro-Zapata,Dennis Alexánder Prieto-Medellín

doi:10.3390/pr9111924

Sol De Amor Vásquez-Quintero, Hernán Darío Toro-Zapata + Show 1 more

Open Access

https://doi.org/10.3390/pr9111924

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Journal: Processes	Publication Date: Oct 27, 2021
License type: CC BY 4.0

Affiliation: University of Quindío

Abstract

A multi-scale mathematical model is proposed, seeking to describe the propagation of Human Immunodeficiency Virus (HIV) in a group of young people between 15 and 24 years of age, through unprotected sexual contact. The uses of antiretroviral therapy (ART) and therapeutic failure are considered to show how the rate of propagation and prevalence are affected. The model consists of a complex network modeling the interactions on the population scale, coupled with the immunological dynamics of each individual, which is modeled by a system of differential equations. The immunological model allows to observe some known facts from the literature, such as to control HIV infection in the immune system, it is necessary to reduce the probability of healthy CD4 T cells becoming infected or increase the probability at which cells of the specific cell response against HIV eliminate infected CD4 T cells. At the population level, it is shown that, to have a high prevalence, it is not necessary for the virus to spread rapidly at the beginning of the simulation time. Additionally, it is observed that a greater number of sexual partners induces higher HIV prevalence. Using ART in the immune system reduces the number of infected CD4 T cells and, consequently, helps to reduce the spread of infection at the population scale. An important result observed in simulations is that the average number of HIV carriers who abandon ART is greater than those who access it. The study adds to the available literature an original simulation model that describes the dynamics of HIV propagation in a population, considering the immune state of people within that population, and serves as a basis for future research involving more detailed aspects aiming for a model closest to reality.

Highlights

This paper studies a multi-scale model for Human Immunodeficiency Virus (HIV) propagation in a group of people between 15 and 24 years of age, through a cluster-type scale-free complex network, which follows a power law
The model relates the immunological scale with the population scale so that the information obtained from the immunological scale helped to model decision making on how the infection would spread in the population
It was evidenced that when the cellular immune response has a high probability of eliminating infected cells, the infection can be controlled; essentially, these results validate the model, because they correspond with known facts about the infection process and the specific cell immune response to HIV

Summary

Introduction

The Human Immunodeficiency Virus (HIV) has managed to propagate and remain in the human population for decades; it is one of the most serious public health problems globally, having no cure and each year taking new lives when the infection goes on to become an acquired immunodeficiency syndrome (AIDS) [1,2]. Once the virus enters the person’s body, it is recognized by the body’s defense system and starts the infection process. It adheres to healthy CD4 T cells, the virus introduces its genetic material and viral components into the cell nucleus that begins replication (after immunological activation) of the virus within it, goes into the bloodstream, and starts propagating throughout the body until infecting other healthy CD4 T cells [5]

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