An agent-based approach for modeling dynamics of sexual transmission of HIV/AIDS

Since AIDS was first discovered, mathematical models of the transmission dynamics of this disease have been developed to determine the drivers of the epidemic. It has become apparent that the most important factor in the propagation of the disease is the aggregate effects of individual behavior and perception of risk in a geographic environment. Agent-based models (ABM) allow one to simulate the social and sexual interactions which may describe the societal context in which HIV may spread easily. Using this framework, we develop an agent-based modeling approach to simulate sexual transmission of HIV/AIDS in an urban environment, as a result of individuals´ interactions in a grid context. Individuals in a closed population are explicitly represented by agents associated to places where they interact with other agents. They are endowed with mobility, allowing them to move between places within the urban environment for representing the spatial heterogeneity and the complexity involved in HIV diffusion. In order to better describe agent´s conduct, each agent has its only gender, age, sex partner, life expectancy, condom use and other attributes. In each time step, every agent may move, find sex partner, separate from his sex partner or die. The model is implemented on the Repast Simphony 1.2. The simulation results show the factors such as density of population, condom use and vision of people play significant roles in the spread of HIV/AIDS. So related departments should vigorously promote the use of condoms, pay more attention to key areas and strengthen moral education to slow down the speed of sexual transmission of HIV/AIDS when establishing measures in prevention and control the spreading of AIDS.