A Mathematical Framework for Modeling the Spread of HIV-disease within Two Different Age Classes.

In this paper, we propose a mathematical model for the spread of HIV disease within two different age classes. We define a basic reproduction number R0 that depends on the characteristics of the two age classes. We prove that if R0 < 1, then the disease is extinct in both age classes. In contrast, we prove that if R0 > 1, then the disease is endemic in both age classes. [ABSTRACT FROM AUTHOR]