The Impact and Cost-Effectiveness of HIV Prevention Strategies in Sub-Saharan Africa: Comparative Analysis of Four Intervention Strategies in Three Randomized trials.

Background and Rationale: Resources for HIV prevention are limited, and policy makers urgently need reliable information on the impact and cost-effectiveness of alternative control strategies. Objectives: To provide information on the cost-effectiveness of alternative HIV control strategies in a range of population settings in rural Africa. Methods: Three randomized trials investigating the impact on HIV of four intervention strategies have been published or are in progress in Mwanza (Tanzania), Masaka (Uganda), and Rakai (Uganda). Cost data from the three trials are being standardized, and the cost and impact of the intervention strategies are being compared. Comparisons of impact are complicated by variations in HIV/STD prevalence and other differences between the three study populations. To address this problem, the microsimulation model STDSIM is being fitted to the extensive data from the three trials in order to predict the impact of the different control strategies within each population. Results: Preliminary modeling work investigating the impact of a single round of mass treatment (MT) in a rural African population with a low but rising HIV prevalence (Mwanza, Tanzania) predicts that MT would achieve a steep and significant decline in STD prevalence and HIV incidence. In the first 2 years of the simulated interventions MT reduced HIV incidence by 36% compared to 30% with improved syndromic treatment. Conclusions: STDSIM has been successfully applied to field data from rural Africa and used to predict the effects of intervention strategies. Further development of the model is underway to facilitate the comparative analysis of intervention studies, and work continues on the application of the model to data from the East African trials.