Figure 4

Generic relationship between sexual risk behavior (or HIV risk ofexposure) and HIV prevalence in an HIV epidemic. Three dynamicalregions can be discerned: 1) Below the epidemic threshold (blue zone)representing the HIV dynamics among the general population outside ofsub-Saharan Africa (SSA). 2) Just above the epidemic threshold (red zone)representing the hypothesized HIV dynamics among much of the generalpopulation of SSA. 3) Well above the epidemic threshold (green zone)representing the HIV dynamics among high-risk populations globally(including SSA). These results were generated using a conventionaldeterministic HIV epidemic model [16–18].