Mathematical estimates could reduce costs and provide faster treatment for HIV

Mathematical models could help assess the effectiveness of different HIV intervention combinations, potentially reducing the need for lengthy and costly large-scale clinical trials, according to a recent study.

Elisa Long and Robert Stavert from Yale University, who recently published the study in the Journal of General Internal Medicine, found that a combination portfolio of multiple cost-effective HIV interventions could prevent up to two-thirds of future infections in South Africa. The authors used data specific for South Africa, the home to the largest HIV epidemic in the world with approximately 5.6 million people infected with the virus.

"In the absence of multi-intervention randomized clinical or observational trials, a mathematical HIV epidemic model provides useful insights about the aggregate benefit of implementing a portfolio of biomedical, diagnostic and treatment programs," the authors said. "Allocating limited available resources for HIV control in South Africa is a key priority, and our study indicates that a multi-intervention HIV portfolio could avert nearly two-thirds of projected new HIV infections, and is a cost-effective use of resources."

The authors developed a model that accounted for mortality, morbidity, disease progression and the heterosexual transmission of HIV to forecast future trends. They estimated the cost-effectiveness and health benefits of using a combination approach of voluntary male circumcision, vaginal microbicides and oral pre-exposure prophylaxis along with current antiretroviral therapy, counseling and screening procedure. Using the model, the authors determined HIV prevalence could drop from 19 percent to 10 percent over the course of a decade using the combination approach. Without the approach, HIV rates would drop to an estimated 14 percent with the current screening and treatment process alone.

The authors also found that omitting pre-exposure prophylaxis from the combination strategy could offer 90 percent of the treatment benefits for less than 25 percent of the costs.