A Fractal Model of HIV Transmission on Complex Sociogeographic Networks. Part 2: Spread from a Ghettoized ‘Core Group’ into a ‘General Population’

Study of the initial stages of HIV transmission along a ‘sociogeographic network’—a large, complex, spatially focused social network with possibly fractal geometry—is extended to include interaction between a low-dimensional ghettoized ‘core group’ within which the disease spreads very rapidly and a higher dimensional, more loosely structured ‘general population’ in which spread is relatively slow. A mathematical modeling exercise suggests that contextually modulated interaction between them can be highly nonlinear and may greatly increase the initial rate of disease transmission within the general population. This work contributes to a growing body of literature which suggests that programs to control HIV infection within the majority heterosexual population of the United States will fail spectacularly without particular focus on the coupled physical and social stabilization and rehabilitation of the urban ghettoes of marginalized populations which are the present, and rapidly expanding, disease epicenters. Evidence suggests their continued disintegration can both increase disease rates within the epicenters and increase the coupling between core groups and general populations by creating large numbers of spatially or economically displaced refugees.