Mathematical Analysis of Autonomous and Nonautonomous Hepatitis B Virus Transmission Models
Abdallah Alsammani
TL;DR
The paper develops an improved HBV transmission model incorporating both autonomous and nonautonomous dynamics and treatment effects, with state variables $x$, $y$, and $z$ representing target cells, infected cells, and free virus. It analyzes existence, positivity, and stability of equilibria, deriving a disease-free threshold $R_0$ and establishing local stability via the Jacobian and global stability through a Lyapunov function, linking stability to $R_0$. The nonautonomous extension replaces the constant production rate with a time-varying $\Lambda(t)$ and employs nonautonomous dynamical systems theory to show the existence of a pullback attractor and uniform contraction under suitable conditions. Numerical simulations in MATLAB illustrate stability around the disease-free and endemic equilibria and demonstrate how time-varying interventions can affect HBV dynamics, including scenarios where the autonomous model may exhibit blow-up while the nonautonomous version remains bounded.
Abstract
This study presents an improved mathematical model for Hepatitis B Virus (HBV) transmission dynamics by investigating autonomous and nonautonomous cases. The novel model incorporates the effects of medical treatment, allowing for a more comprehensive understanding of HBV transmission and potential control measures. Our analysis involves verifying unique solutions' existence, ensuring solutions' positivity over time, and conducting a stability analysis at the equilibrium points. Both local and global stability are discussed; for local stability, we use the Jacobian matrix and the basic reproduction number, $R_0$. For global stability, we construct a Lyapunov function and derive necessary and sufficient conditions for stability in our models, establishing a connection between these conditions and $R_0$. Numerical simulations substantiate our analytical findings, offering valuable insights into HBV transmission dynamics and the effectiveness of different interventions. This study advances our understanding of Hepatitis B Virus (HBV) transmission dynamics by presenting an enhanced mathematical model that considers both autonomous and nonautonomous cases.
