Reducing the high rate of mother-to-child HIV transmission in Sub-Saharan Africa through treatment with antiviral drugs can be cost-effective if drug prices are lowered, according to a new study by researchers at the University of California San Francisco AIDS Research Institute (ARI).
Study findings showed other factors combined to produce a cost-effective outcome--such as a short-course of drug therapy and a high prevalence of HIV-positive women of child-bearing age--but drug prices had the most impact. The UCSF team found drug costs need to be about 25 percent of current prices in the industrialized world.
The UCSF team conducted an economic analysis of different treatment regimens of antiviral drug combinations among women in Sub-Saharan Africa. The regimens currently are part of UNAIDS-sponsored clinical trials in Africa that are directed at determining effectiveness in preventing mother-to-child HIV transmission, which AIDS specialists also call vertical transmission.
"The goal in our research was to determine under what circumstances, if any, this might be a good investment compared with other uses of funds for HIV prevention in low-income countries," said Elliot Marseille, DrPH, MPP, UCSF senior research associate and lead investigator of the study.
"When we did this study, we had to make educated guesses about how effective this therapy is likely to be. In the meantime, results from the Centers for Disease Control and Prevention-sponsored trial in Thailand have shown that a short-course of the antiviral drug AZT alone can cut vertical transmission by about half," he added.
Glaxo Wellcome also has announced its plan to reduce AZT prices for vertical transmission prevention in low-income countries to about 25 percent of industrial world prices, according to Marseille. "These events open the way for large-scale drug interventions because we now know that these therapies can make both medical and economic sense," he said.
The research findings are reported in the May issue of AIDS. Co-investigators are James G. Kahn, MD, MPH, UCSF associate professor of health policy and epidemiology, and Joseph Saba, MD, clinical research specialist, UNAIDS. It is estimated that about 6 million women in Sub-Saharan Africa-- which includes the countries of South Africa, Uganda, and Tanzania among others--are HIV positive. The prevalence of infection among child-bearing-age women exceeds 30 percent in many urban areas and 14 percent in rural regions.
In the UCSF study, researchers evaluated the economics of combination therapy using the AIDS antiviral drugs AZT and 3TC. The team compared the results of no treatment, which is the current practice in most of the developing world, with three regimens:
- Treatment for the mother beginning at week 36 of pregnancy and continuing through childbirth, followed by treatment for both mother and infant during the first week after delivery.
- Treatment for the mother during childbirth and for mother and baby for one week after delivery.
- Treatment during childbirth only.
Among the study findings:
- If drugs prices are 25 percent of the industrialized world cost, for 100 women the total dollar amount for treatment is: $1,014 for week 36 through post-delivery; $538 during childbirth and the following week; and $254 for treatment during childbirth only.
- The cost of preventing one infant HIV infection in areas of 15 percent prevalence in pregnant women would range from $1,445 to $817 depending on which of the treatment regimens was selected.
- The relative costs and benefits of these drug treatments are in the same range as other HIV prevention programs, such as blood screening and condom promotion programs.
- The drug interventions become still more economical if it is possible to reduce the costs of counseling and testing pregnant women for HIV without compromising the quality of these services.
In previous studies in the U.S., the AIDS Clinical Trial Group of the National Institutes of Health found treatment with AZT beginning at the 28th week of pregnancy reduced vertical transmission by about two thirds, according to Diane Wara, MD, UCSF professor of pediatrics who has done extensive work in this area.
"While this protocol has great implications for efforts to stem vertical transmission, it is not practical in Sub-Saharan regions because women normally do not seek prenatal care this early in the pregnancy and this long course of therapy is too costly for the limited resources of the region," Marseille said.
According to co-investigator Kahn, the UCSF analysis "demonstrates that the interventions initially tested in the U.S. and other wealthy countries can lead to affordable public health strategies in poorer countries." But several steps must occur, he noted, for this to happen: shorter therapy and other changes to minimize resource use; careful evaluation of treatment efficacy of modified therapies; and reduction of high cost components, which in this case is drug price.
Directed by Thomas J. Coates, PhD, who also is a UCSF professor of medicine, epidemiology and biostatistics, the UCSF ARI is an institute without walls that encompasses all UCSF AIDS programs under a single umbrella. The ARI includes a dozen research institutes, a wide range of clinical, behavioral science, and policy programs, and close to 1,000 investigators.
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