Simulating the control of a heterosexual HIV epidemic in a severely affected east African city

We compared three intervention strategies for preventing heterosexual transmission of the human immunodeficiency virus (HIV) using deterministic and stochastic models to simulate the epidemic of acquired immunodeficiency syndromes (AIDS). We estimated demographic, biological, and behavioral parameters for a severely affected east African city early in the epidemic, and used these parameter values in computing the spread of HIV under five scenarios: (1) a baseline scenario with no public health interventions; three single-intervention scenarios with strategies to (2) reduce the number and rate of change of sex partners, (3) increase condom use, or (4) improve treatment of sexually transmitted diseases (STD); and a (5) combined-intervention scenario. The rankings were the same in both models—decreasing partner change was most effective, followed by condom use and STD treatment. Combined interventions were more effective than single interventions. They interacted to produce impacts that varied with the trajectory of the epidemic at the onset of the interventions. Their timely, targeted, and sustained implementation appears critical to slow the epidemic significantly.