Commentary
TB and HIV: joint problems, joint solutions?
In their article (1), Harries and his colleagues turn the spotlight on one of the major problems confronting control of tuberculosis (TB) today. Despite heroic and successful efforts to establish DOTS programmes in sub-Saharan Africa, TB continues to rise in countries with significant HIV (human immunodeficiency virus) epidemics. DOTS alone is insufficient to prevent such increases. Furthermore, HIV calls into question the global targets of 85% cure of the 70% of all smear- positive cases that should present for treatment by the year 2005. These targets were set because their achievement would, in the absence of other factors, lead to a reduction in TB incidence. Many working in Africa now believe that control of TB, especially reduction in its incidence, is dependent upon mitigating the impact of HIV. What else must we do to control TB in settings of high HIV prevalence?
From an HIV perspective, it seems probable that two things are required: a reduction in the number of HIV-infected people, i.e. a decrease in the transmission of HIV; and lessening the immunosuppression caused by HIV in those already infected. In the absence of a vaccine, we are limited to education for behaviour change, condom provision to prevent transmission, treatment of sexually transmitted diseases and, in the absence of a definitive cure, antiretroviral drugs to lessen the effects of HIV. From the TB perspective, the additional possible approaches are active case-finding and prevention of TB.
Combined approaches at the district level against TB and HIV were merged in the ProTEST initiative (2), set up by WHO and partners in the late 1990s. On the part of clients, the interventions include discovering HIV status through counselling and testing, using condoms, and modifying sexual behaviour; on the part of providers, actively looking for cases of TB among the HIV infected and the provision of isoniazid preventive therapy to those who are HIV positive, but without active TB. The impact of all this on risk behaviour and on the burden of TB awaits the final results from the initiative, expected within the year.
But a few key national managers in high HIV-prevalence countries made it clear that the international and local response to control of TB was simply inadequate to address the enormous scale of the problem. WHO and the Global Working Group on TB/HIV then considered options additional to DOTS in high HIV-prevalence settings (3). A considerable expansion of the original ProTEST work has begun in eight African countries (Ethiopia, Kenya, Malawi, Mozambique, South Africa, the United Republic of Tanzania, Uganda, and Zambia) with the Centers for Disease Control and Prevention's Global AIDS Program, the Joint United Nations Programme on HIV/AIDS, and the United States Agency for International Development as the main partners. These projects aim to establish an affordable, cost-effective package of joint measures against HIV/AIDS and TB that will reduce the burden of both diseases more efficiently than separate approaches. The interventions included are laid out in Box 3 of the paper by Harries et al. (1), who focus on the thorniest of them all, namely highly active antiretroviral therapy (HAART).
They put to one side some of the key unknowns, namely, the impact HAART will have on the transmission of both HIV and TB, and the development of resistance, and turn to the key question of how HAART should be delivered. And will the HIV community learn the hard-won lessons of the TB community?
Until just recently, the cost of antiretrovirals relieved health and development workers of having to think much about them, but the major price reductions announced last year and the establishment of mechanisms to support the purchasing of these drugs (4), have brought the issue to the forefront. There is the very real risk that the drugs will be delivered to systems ill-prepared to receive them and ill- designed to deliver them (5). Harries and his group are among the first to point to a solution. In a previous paper (6), they clearly put forward the idea of using well-performing national TB programmes to deliver not only anti-TB treatment, but also antiretrovirals. In this issue of the Bulletin, they are less absolutist and point to the necessity of a comprehensive HIV/ AIDS management strategy to which TB programmes could contribute. The central pillar of their thesis is Box 4 which extrapolates directly from the five-point policy framework for DOTS (7) to lay out the five essential elements of an antiretroviral policy package.
From experience with TB, this approach, or one very like it, would seem logically necessary for an antiretroviral delivery policy. But is it sufficient? Of course not. Full implementation of the package can only follow the strategic planning, human resource investment, and financial support required to provide and sustain the infrastructure necessary for successful delivery of HAART, and arguably would need to be the largest expansion of health services in low-income countries ever seen. Antiretroviral treatment is a lifelong undertaking. In order to assuage the doubts surrounding sustainability, HAART must be embedded in a broader developmental context such as those currently offered in the Heavily Indebted Poor Countries Initiative and the World Bank's poverty reduction strategies (8). 
Conflicts of interest: none declared.
References
1. AD Harries, NJ Hargreaves, R. Chimzizi, FM Salaniponi.. Highly active antiretroviral therapy and tuberculosis control in Africa: synergies and potential. Bulletin of the World Health Organization 2002;6:464-469.
2. First meeting of the Global Working Group on TB/HIV. Geneva: World Health Organization; 2001. Unpublished document WHO/CDS/TB/2001.293.
3. A strategic framework to decrease the burden of TB/HIV. Geneva: World Health Organization; 2002. Unpublished document WHO/CDS/TB 2002.296; WHO/HIV_AIDS/2002.2.
4. The Global Fund to fight AIDS, tuberculosis and malaria. Geneva: the Global Fund to fight AIDS, tuberculosis and malaria; 2002. Available from: URL: http://www.globalfundatm.org/index.html (accessed on 4 April 2002).
5. Hanson S. AIDS control in sub-Saharan Africa - are more drugs and money the solution? Lancet Infectious Diseases 2002;2:71-2.
6. Harries AD, Nyangulu DS, Hargreaves NJ, Kaluwa O, Salaniponi FM. Preventing antiretroviral anarchy in sub-Saharan Africa. Lancet 2001;4;358:410-4.
7. Treatment of tuberculosis: guidelines for national programmes. 2nd ed. Geneva: World Health Organization; 1997. Unpublished document WHO/TB/ 97.220.
8. Adeyi O, Hecht R, Njobvu E, Soucat A. AIDS, poverty reduction and debt relief: a toolkit for mainstreaming HIV/AIDS programs into development instruments. Washington (DC): World Bank and Joint United Nations Programme on HIV/ AIDS; 2001. Africa Region Human Development Working Paper Series.
1 Deputy Director-General and Chair, Global Working Group on TB/HIV, National Institute of Public Health and the Environment (RIVM), Bilthoven, The Netherlands.
2 Manager, TB/HIV Issues, STOP TB Department, World Health Organization, 1211 Geneva 27, Switzerland (email: nunnp@wh.int). Correspondence should be addressed to this author.
Ref. No. 02-0179