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 determini stic and stochastic models to simulate the epidemic of acquired immuno deficiency 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 spr ead of HIV under five scenarios: (1) a baseline scenario with no publi c health interventions; three single-intervention scenarios with strat egies 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 ranking s were the same in both models-decreasing partner change was most effe ctive, followed by condom use and STD treatment. Combined intervention s were more effective than single interventions. They interacted to pr oduce impacts that varied with the trajectory of the epidemic at the o nset of the interventions. Their timely, targeted, and sustained imple mentation appears critical to slow the epidemic significantly.