Fig. 2.

A flow diagram showing the possible classes for infected individuals. The columns represent stage of disease: With subscripts 0, 1, and 2 representing early, chronic, and AIDS stages respectively. The rows represent diagnosis status, with the top row representing undiagnosed individuals, I_k, and the bottom row representing diagnosed individuals, J_k, where $k\in \{0,1,2\}$. ρ_k are per capita rates of diagnosis and γ_c are rates of disease progression. Arrows out of classes that do not flow into other classes represent the combined flow out of the infected population due to death and emigration.