DYNAMICAL MODEL OF TUBERCULOSIS DISEASE TRANSMISSION WITHIN-HOST AND BETWEEN-HOST WITH AGE STRUCTURE

• Main Author: Wahyu Dewanti, Retno
• Format: Dissertations
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/83850
• Institution: Institut Teknologi Bandung

Tuberculosis (TB) is an infectious disease caused by bacteria Mycobacterium tuberculosis (Mtb) which usually attacks the lungs. TB is one of the 10 main causes of death in the world. In this research, a mathematical model was constructed to represent the dynamics of the spread of TB within and between hosts. At the between-host level, the model is built based on age structure by following the Susceptible-Exposed-Infected-Recovered (SEIR) sub-population classification. Dynamic analysis of the model shows that the existence and stability of the disease-free equilibrium point and the endemic equilibrium point depend on the basic reproduction number. The infection rate is estimated by minimizing the residual between the Bandung City TB incidence data and the model output using a Genetic Algorithm. At the within-host level, this study developed a model of Mtb interaction with immune cells in the lung to evaluate its effect on infection prevalence. Mtb population growth is influenced by bacterial replication outside macrophages (extracellular) and inside macrophages (intracellular). Qualitative analysis and numerical results show that there are two equilibrium points, namely disease-free equilibrium and endemic equilibrium which represent latent or active tuberculosis based on the number of bacteria. Analysis of model parameters showed that macrophages alone were insufficient to control the initial invasion of Mtb. The immune system involving T immune cells is needed in a more complex defense mechanism to contain Mtb infection.