This article concerns the rigorous global analysis of a class of models introduced by Nowak and Bangham that describes in a fairly successful way the initial phases of the HIV dynamics in the human body as well as some generalizations that take into account mutation. We show that the biologically meaningful positive solutions to such models are all bounded and do not display periodic orbits. Fo...

In this paper, we propose and analyze a mathematical model describing the effect of awareness programs by public media on the prevalence of Typhoid fever. A threshold quantity $R_{0}$, similar to the basic reproduction number is derived. We investigate the biologically meaningful equilibrium points and their local stability analysis. The global stability analysis has been performed with respect...

Timely prediction of the COVID-19 progression is not possible without a comprehensive understanding environmental factors that may affect infection transmissibility. Studies addressing parameters influence relied on either total numbers detected cases and similar proxies and/or small number analyzed factors, including analysis regions display narrow range these parameters. We here apply novel a...

An SEI autonomous model with logistic growth rate and its corresponding nonautonomous model are investigated. For the autonomous case, we give the attractive regions of equilibria and perform some numerical simulations. Basic demographic reproduction number R d is obtained. Moreover, only the basic reproduction number R 0 cannot ensure the existence of the positive equilibrium, which needs addi...

The basic reproduction number R0 is, by definition, the expected life time number of offspring of a newborn individual. An operationalization entails a specification of what events are considered as "reproduction" and what events are considered as "transitions from one individual-state to another". Thus, an element of choice can creep into the concretization of the definition. The aim of this n...

In this paper, a virus infection model with time delay and absorption is studied. By analyzing the corresponding characteristic equations, the local stability of each of feasible equilibria of the model is established. By using comparison arguments, it is shown that the infection free equilibrium is globally asymptotically stable when the basic reproduction ratio is less than unity. When the ba...