Effect of DAA therapy in hepatitis C treatment - an impulsive control approach

Understanding Barriers to Hepatitis C Antiviral Treatment in Low-Middle-Income Countries

Background: Direct-acting antiviral agents (DAAs) have significantly reduced Hepatitis C Virus (HCV) transmission and improved health outcomes since their FDA approval in 2011. Despite these advances, over 70 million people remain untreated globally, with a disproportionately high burden in low- and middle-income countries (LMICs). Methods: Through a structured search of open access informational sources and an informal peer-reviewed literature review, HCV treatment barriers were identified, compiled, and analyzed. Current challenges to HCV treatment were organized by themes and summarized as recommendations for LMICs. Results: Key obstacles to HCV treatment in LMICs are identified, with the underdiagnosis and undertreatment of the disease linked to inadequate funding and healthcare infrastructure for screening and testing, poor awareness among healthcare providers, and the misinformation and stigmatization of HCV disease. Discussion: Recommendations for LMICs to attenuate treatment obstacles include distributing educational media, implementing mobile clinics, and fostering international partnerships. The successful implementation of these interventions has been demonstrated in developed countries. Conclusions: To achieve the WHO's goal of eliminating HCV as a public health threat by 2030, concerted efforts are needed by LMICs to reduce gaps in care and ensure that all patients are afforded access to testing and treatment.

Local and global stability of an HCV viral dynamics model with two routes of infection and adaptive immunity

The aim of this article is to formulate and study a mathematical model describing hepatitis C virus (HCV) infection dynamics. The model includes two essential modes of infection transmission, namely, virus-to-cell and cell-to-cell. The effect of therapy and adaptive immunity are incorporated in the suggested model. The adaptive immunity is represented by its two categories, namely, the humoral and cellular immune responses. Our article begins by establishing some mathematical results through proving the model's well-posedness in terms of existence, positivity and boundedness of solutions. We present all the steady states of the problem that depend on specific reproduction numbers. It moves then to the theoretical investigation of the local and global stability analysis of the free disease equilibrium and the four disease equilibria. The local and global stability analysis of the HCV mathematical model are established via the Routh-Hurwitz criteria and Lyapunov-LaSalle invariance principle, respectively. Finally, our article presents some numerical simulations to validate the analytical study of the global stability. Numerical simulations have shown the effect of the drug therapies on the system's dynamical behavior.

Impulsive Reaction-Diffusion Delayed Models in Biology: Integral Manifolds Approach

In this paper we study an impulsive delayed reaction-diffusion model applied in biology. The introduced model generalizes existing reaction-diffusion delayed epidemic models to the impulsive case. The integral manifolds notion has been introduced to the model under consideration. This notion extends the single state notion and has important applications in the study of multi-stable systems. By means of an extension of the Lyapunov method integral manifolds' existence, results are established. Based on the Lyapunov functions technique combined with a Poincarè-type inequality qualitative criteria related to boundedness, permanence, and stability of the integral manifolds are also presented. The application of the proposed impulsive control model is closely related to a most important problems in the mathematical biology-the problem of optimal control of epidemic models. The considered impulsive effects can be used by epidemiologists as a very effective therapy control strategy. In addition, since the integral manifolds approach is relevant in various contexts, our results can be applied in the qualitative investigations of many problems in the epidemiology of diverse interest.