Global HIV/AIDS Policy Modeling

Identifying the most effective treatment strategies for HIV infection in less developed countries
Rochelle Walensky



Optimizing HIV Treatment in Less-Developed Countries

Advances in the treatment of HIV disease have produced dramatic reductions in AIDS-related morbidity and mortality in the United States and Europe.  However, severe resource constraints in many developing countries have limited the availability of antiretroviral therapy (ART) and opportunistic infection prophylaxis.  The stark contrast in drug availability between high-income countries and low-income countries can serve to highlight more far-reaching differences in access to care; in the latter, access to care is limited by distance from health care facilities, lack of medical personnel, inadequate diagnostic capabilities, and deficiencies in medical supplies and drug availability.

Even with adequate financial resources, HIV care is a moving target in all countries.  Approaches to examining optimal antiretroviral therapy strategies depend on the availability of sophisticated laboratory studies (CD4 cell count, HIV RNA, genotypic or phenotypic resistance testing) which are continuously improving.  

In many countries, the availability of resources through the Global Fund means that less developed countries are now prioritizing the use of these funds to create national HIV treatment programs. This highlights important questions at the interface of epidemiology, clinical care, virology, and health policy: When is the optimal time to begin treatment?  What is the role of prophylaxis against opportunistic infections compared with ART?  What is the best approach to HIV testing?  Can region-specific or country-specific standards of care be developed and effectively implemented? No single observational study or clinical trial can address the innumerable possible strategies for care in a given population. By incorporating the newest available data on HIV/AIDS epidemiology, treatment efficacy, newly proposed treatment protocols, and long-term treatment-related toxicities, we use methods from decision science to identify the most advantageous patient- and population-level treatment strategies. Specific analyses include the cost-effectiveness of prophylaxis for bacterial opportunistic infections as well as ART in Cote d’Ivoire, an assessment of the value of HIV drug-resistance surveillance in resource-limited settings, identifying the optimal clinical conditions under which to initiate ART in India, a comparison of alternative treatment regimens and when to switch regimens, and the benefit of HIV testing and ART roll-out scenarios in South Africa.