Medical News

Doubts About DOT: Antiretroviral Therapy for Resource-Poor Countries

July 8, 2003

This article is part of The Body PRO's archive. Because it contains information that may no longer be accurate, this article should only be considered a historical document.

Recent price cuts and the introduction of "off-patent" antiretroviral HIV/AIDS drugs bring new hope that antiretroviral therapy will become more widely available in the resource-poor countries where over 90 percent of HIV infections occur. There is concern, however, that poor adherence to antiretroviral therapy will accelerate widespread drug resistance in Africa, and some maintain that treatment should be delayed until adherence can be ensured. Based on concerns that the widespread, unregulated access to antiretroviral drugs in sub-Saharan Africa could lead to the rapid emergence of drug-resistant viral strains, creating havoc for individuals, curtailing future treatment options, and leading to the transmission of resistant virus, directly observed therapy programs for tuberculosis have been proposed as a model for the provision of HIV drugs in resource-poor countries.

But the authors of the current study propose that calls for such programs to provide routine HIV care are premature, as "witnessed dosing has unclear efficacy in improving adherence and reducing HIV transmission, and may paradoxically promote drug resistance. Furthermore, requiring directly observed therapy may impose substantial barriers to antiretroviral access in resource-poor countries."

The call for directly observed HIV therapy is rooted in experience with TB treatment. DOTS is a multifaceted approach to TB therapy, including observed pill-taking, community and local government commitment, case detection by sputum smear microscopy, stable drug supply, and standardized systems for case follow-up. Successful DOTS programs include all of these essential activities.

While observational studies suggest that DOTS programs achieve higher cure rates than historical controls, the impact of witnessed therapy has rarely been isolated from other components of the DOTS strategy. As has been argued elsewhere, the success of TB control programs depends more on the strength of diverse structural components, including reliable drug supply and distribution, than just on observed dosing.

Many believe that widespread poverty in resource-poor countries makes adherence a particular concern for the provision of HIV therapy. However, early data suggest that adherence to combination antiretroviral therapy is at least as good as in wealthy countries. Two recent South African studies determined that adherence ranged from 88 percent to 95 percent in clinical trial settings that included impoverished participants. Though such studies may not be representative of the larger HIV-positive population in resource-poor countries, there remains no evidence to suggest that adherence will be less in poorer countries. Studies with objective adherence measures indicate that HIV-positive patients in wealthy countries take roughly 70 percent of their medication. There is nothing to preclude equal or better adherence in resource-poor countries.

Preventing HIV transmission is the strongest rationale for making adherence interventions a requirement of therapy. However, the assumption that treatment will prevent transmission and that treatment with directly observed therapy will prevent more transmission than treatment with self-administered therapy has not yet been tested.

Because HIV is more stigmatizing than TB and requires lifelong therapy, the negative impact of directly observed HIV therapy on human rights could be potentially greater than TB. Although the prospect of access to treatment may encourage individuals to determine their HIV status, the linkage of treatment to directly observed therapy may paradoxically lower the use of counseling and testing services due to confidentiality concerns. In the United States, fears regarding HIV disclosure have led to a delay in treatment. These issues underscore the potential impact of compromising privacy by linking treatment to directly observed therapy programs.

While the authors "suggest restraint in the enthusiasm for directly observed HIV therapy as part of routine HIV care," they cannot "minimize the importance of developing effective and culturally appropriate voluntary adherence interventions to improve individual treatment outcomes globally. While the public health advantages of directly observed HIV therapy are in question, the impact on individual freedoms is not. We do not require direct observation of HIV therapy in resource-rich countries, and unless rigorous studies find important differences in adherence, there is no rationale for a different approach in resource-poor settings. We should not assume inequity with respect to people's ability to self-direct their medical care, including adherence to therapy."

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Adapted from:
06.13.03; Vol. 17; No. 9: P. 1383-1387; Cheryl A. Liechty; David R. Bangsberg

This article was provided by CDC National Prevention Information Network. It is a part of the publication CDC HIV/Hepatitis/STD/TB Prevention News Update.


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