Multiagent-based simulation of the HIV/AIDS spatial and temporal transmission among injection drug users

In 1989, HIV was detected amongst injecting drug users (IDUs) in Yunnan province. Needle sharing drove the epidemic and HIV spread rapidly to IDUs in neighboring cities and along drug trafficking routes. By 2002, HIV was present amongst IDUs in all mainland Chinese provinces. It is believed that IDUs may have been the core source for all later sub-epidemics in China. Agent-based modeling (ABM) is the dominant paradigm in social complex network simulation which allows one to simulate the complex systems emerge from the bottom-up are composed of a multitude of heterogeneous objects called agents. This article puts forward an HIV/AIDS spatial and temporal transmission model of IDUs based on the multivalent system and geographic information systems (GIS) in an urban environment, and simulates the HIV/AIDS spatial and temporal transmission process among injection drug users during 10 years on the Repast Simphony1.2 platform. In the model, the crowd is classified into 5 types: healthy person, HIV person, AIDS person, IDU person and HIV-IDU person. Individuals represented by agents are associated to places where they interact with each other. The relationship among different agents is described with random social network. To better represent individuals in reality, each agent has its only sex, age, career, education, geographic location and other attributes. In each time step, the model defines these agents' specific behavioral rules. The model is implemented using the propagation of HIV/AIDS among injection drug users in Yunnan province southwest of China as a case study. The simulation results show that the number of initial HIV in injection drug users, the proportion of needle sharing and individual social impact have influence on the spread of HIV/AIDS in Kunming. The results also reveal the increasing HIV/AIDS transmission among injection drug users and interpret the necessity of carrying out solutions to contain the transmission of HIV/AIDS.