A dynamic scale-free agent network model for evaluating mixed HIV transmission and interventions

HIV prevalence among men who have sex with men (MSM) is rapidly increasing recently in China, The bisexual of MSM may be a bridge group to the general population for HIV transmission, and intensify the trend of the spread of HIV. The model of mixed homosexual and heterosexual HIV transmission network and intervention measures has significant effect on the spread of HIV. The paper proposes a dynamic weighted scale-free agent network model for evaluating mixed HIV transmission and interventions. Persons were divided into groups according to sexual orientation of the opposite sex, such as heterosexual, homosexual and bisexual. The bisexual people acting as a bridge people, the model of mixed homosexual and heterosexual HIV transmission network has been generated based on the configuration model. In the model agent represent males and females who interact with each other and within risk networks engaging in sexual behavior over time. The dynamics of Heterosexual network is supported through heterosexual network stable or casual partnership/links dissolution and formation. Agent describes individual high-risk behavior, course of HIV disease and social structure. Agent also defines the behavior rules for adaption to the HIV prevention interventions. Exploratory simulation results are consistent with empirical studies demonstrating that HIV spread from one network to another network through the bridge group, and the effectiveness of a combination of interventions, including voluntary counseling and HIV test, condom promotion for safe sexual behavior and initiating antiretroviral treatment.