Heterosexual behavior patterns and the spread of HIV/AIDS: the interacting effects of rate of partner change and sexual mixing.

OBJECTIVES

This study evaluates whether the influence of sexual mixing patterns on the human immunodeficiency virus (HIV) epidemic curve is sensitive to the prevailing rates of sexual partner change in a population.

STUDY DESIGN

A biobehavioral macrosimulation model is employed to assess the interacting dynamics of the rates of sexual partner change and patterns of sexual mixing between population subgroups. HIV spread is simulated under 2 rates of partner change scenarios and under various degrees of assortativeness in sexual mixing patterns.

RESULTS

With high rates of partner change, disassortativeness in sexual mixing tends to increase the overall size of the HIV epidemic. However, when relatively low rates of partner change are simulated, disassortative mixing yields a smaller epidemic. This pattern is further influenced by the underlying sexual transmission probabilities of HIV.

CONCLUSIONS

Each of the various determinants of the sexual spread of HIV must not be considered in isolation. Instead, the interactive nature of those determinants should be accounted for in discussions of HIV epidemic dynamics.