HIV/AIDS
For dozens of countries around the world—including several of the most populous—the AIDS epidemic threatens every aspect of development. No other threat comes close, with the possible exceptions of use of nuclear weapons in densely populated areas or a devastating global pandemic similar to the 1917-18 influenza episode. Most governments of affected low-and middle-income countries and most providers of development assistance have only recently begun to respond more than minimally. Creation of the Global Fund to Fight AIDS, Tuberculosis, and Malaria can be viewed as an attempt of the world's top political leaders to improve on the records of existing institutions. The Global Fund's initial years have seen substantial success, but that success is potentially undermined by sharp constraints on resource availability (Bezanson 2005).
Tools to Control the Epidemic
In contrast to the initially slow programmatic movement of most national leaders and international institutions, the research and development community—public and private—has made rapid progress in developing tools to control the HIV/AIDS epidemic, although both a vaccine and a curative drug remain distant objectives. Sensitive, specific, and inexpensive diagnostics are available; means of prevention have been developed and tested; modes of transmission are well understood; and increasingly powerful drugs for controlling viral load allow radical slowing of disease progression. Tools for dealing with HIV/AIDS are thus available: As emphasized in chapter 18, a number of countries show by example that those tools can be put to effective use. Most of the high-income countries have done so, and Brazil and Mexico provide examples of upper-middle-income countries that have forestalled potentially serious epidemics. Mexico succeeded, for example, with a policy of responding both early and forcefully to the epidemic (del Rio and Sepulveda 2002). The major successes of Thailand and Uganda demonstrate that countries with fewer financial resources can also succeed—and succeed against more established epidemics that had already penetrated deeply into their populations.
Prevention and Management
Prevention underpins success. At the time the World Bank's World Development Report: Investing in Health (World Bank 1993) was being written in 1992 and 1993, the only tool for dealing with the epidemic was prevention. In collaboration with the then-Global Programme against AIDS at WHO, the World Development Report commissioned very approximate estimates of the consequence for the new infection rate of fully implementing available preventive measures (its optimistic case scenario) or of doing very little (worst case). Actual incidence numbers for 2000, unfortunately, fall very close to the worst-case projection, and chapter 18 points out that even by 2003 fewer than one in five people at high risk of infection had access to the most basic preventive services. In much of the world, little has been spent on prevention, and little has been achieved. In addition, the current U.S. administration may be partially responsible for discouraging condom use in some countries and in stigmatizing and alienating commercial sex workers who are particular priorities for prevention programs. Despite those problems, the potential for prevention is very real, and a number of successful countries have shown the possibility of using that potential well. Chapter 17 on sexually transmitted infections (STIs) and chapter 18 on AIDS discuss a broad menu of preventive measures and experiences with their implementation. Among them, treatment of STIs may be of particular salience both because the diseases are well worth treating in their own right and because the absence of STIs greatly reduces transmission of HIV.
In addition to prevention, better management of patients with AIDS could avert much misery, both by treating opportunistic infections and by ameliorating the often excruciating pain associated with many AIDS deaths. Medically inappropriate restrictions on the use of inexpensive but powerful opiates for pain control continue to deny dignity and comfort to millions of patients with AIDS and cancer in their final days (chapter 52).
Antiretroviral Treatment
Intensive research and development efforts have led in the past decade to the availability of well over a dozen antiretroviral drugs that can greatly reduce the quantity of HIV in an infected person. This reduction in viral load slows or halts progression of AIDS and can return individuals from serious illness to reasonable health. Available drugs leave a residual population of HIV in the body, however, and this population grows if the drugs are stopped. At present the drugs must be taken for life. Widespread use of these drugs in high-income (and some middle-income) countries has transformed the life prospects of HIV-infected individuals.
Early generation antiretroviral drugs suffered notable shortcomings: they were enormously costly; regimens for their use were complicated, making adherence difficult; their use generated unpleasant side effects; and rapid evolution of HIV led to resistant mutants that undermined the efficacy of therapy. In a remarkably short time, scientific advances have substantially attenuated those problems, making feasible, at least in principle, antiretroviral therapy in low-income settings. WHO's "3 by 5" program had as its objective, for example, to reach 3 million people in low- and middle-income countries with antiretroviral therapy by 2005. Although that goal was far from being met, the global effort to make treatment widely available is well under way.
Despite the indicated progress against the problems with antiretroviral drugs, challenges to their effective use in low-income environments remain formidable. The complexity of patient management is very real. Management requires high levels of human resources and other capacities in many of the countries where those capacities need to be most carefully rationed. Perhaps in consequence, achieving effective implementation has been difficult on even a limited scale. Chapter 18 reviews those problems and how they might be addressed.
Three points concerning widespread antiretroviral drug use are particularly noteworthy:
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Poor implementation (low adherence, development of resistance, interruptions in drug supplies) is likely to lead to very limited health gains, even for individuals on therapy. (This outcome is unlike that of a weak immunization program in which health gains still exist in the fraction of the population that is immunized.) Poorly implemented anti-retroviral drug delivery programs could divert substantial resources from prevention or from other high-payoff activities in the health sector. Even worse, they could lead to a false sense of complacency in affected populations: evidence from some countries suggests that treatment availability has led to riskier sexual behavior and increased HIV transmission. The injunction to "do no harm" holds particular salience.
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Unless systematic efforts are made to acquire hard knowledge about which approaches work and which do not, the likelihood exists that unsuccessful implementation efforts will be continued without the appropriate reallocation of resources to successful approaches. Learning what works will require major variations in approach and careful evaluation of effects. Failing to learn will lead to large numbers of needless deaths. Most efforts to scale up antiretroviral therapy unconscionably fail to commit the substantial resources required for evaluation of effects. Such evaluations are essential if ineffective programs are to be halted or effective ones are to receive more resources.
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Many programs rely exclusively on the cheapest possible drugs, thereby risking problems with toxicity, adherence, and drug resistance. From the outset a broader range of drug regimens needs to be tested.
