WHO has new mission in stopping TB
[Editor’s note: AIDS Alert asked officials with the World Health Organization (WHO) in Geneva to discuss the new international focus on combining TB and HIV/AIDS efforts where possible. They want the two public health camps to work together to prevent and treat both epidemics, particularly in sub-Saharan Africa, Asia, and other areas where the diseases work with synergy in creating worst epidemics than what these areas would otherwise be experiencing. Dermot Maher, BM, BCh, medical officer in the Stop TB Department of WHO; Ian Smith, MB, ChB, MPH, and Ger Steenbergen, MD, from the Stop TB Partnership offer some insight into the new focus and why it is necessary in this question-and-answer interview.]
AIDS Alert: According to a WHO abstract presented in July at the 14th International AIDS Conference, held in Barcelona, Spain, there is a need for a comprehensive response to HIV/AIDS, along with effective action against TB/HIV. Why hasn’t this response been launched previously?
Maher: Although there is long-standing recognition of the epidemiological overlap between TB and HIV, and the ways in which these two problems interact, the formulation and implementation of a joint response have lagged behind a little. On the one hand, it has taken some time for TB program to fully grasp the need for joint TB and HIV program activities to tackle the growing epidemic of HIV-related TB, and on the other hand, it has taken some time for HIV/ AIDS programs to fully grasp the need for joint activities to tackle TB as a leading cause of HIV-related illness and death. This has been partly because TB appears as one of a long list of problems on the HIV/AIDS agenda, and so there has been a tendency to say, "Well, let’s leave that to the TB people." Also, until recently, TB often didn’t appear very high on the HIV agenda, because in the course of the HIV epidemic, the emphasis was largely on HIV prevention until the mid-late 1990s. Since then, the development of highly active antiretroviral treatment (HAART) has put HIV treatment and the care of people with HIV-related diseases firmly on the agenda.
AIDS Alert: What sort of changes in international and national policy do you (and the Global Working Group on TB/HIV) advocate, and how might these be most efficiently and effectively implemented?
Maher: International policy is set out in the World Health Organization document (produced jointly by the Stop TB Department and the Department of HIV/AIDS) "Strategic Framework to Decrease the Burden of TB/HIV," which the Global Working Group on TB/HIV has endorsed. With the current huge global interest in making HAART widely available, there is more opportunity than ever before for HIV and TB programs to work closely together.
There is greater interest in, and understanding of, the need for comprehensive HIV/AIDS care, including effective diagnosis and treatment of TB as a leading cause of HIV-related illness and death. In the health sector, the international policy advocated by WHO and by the Global Working Group on TB/HIV is to promote the implementation of a strategy of expanded scope to tackle the problem of HIV-related TB.
This strategy comprises interventions directly against TB (e.g. intensified TB case finding among those most at risk, effective treatment of all TB patients, and isoniazid preventive treatment), and interventions against HIV and therefore indirectly against TB (e.g. HAART, HIV prevention measures, and prevention of common HIV-related diseases through the use, for example, of cotrimoxazole). Joint TB and HIV program activities are necessary to deliver this range of interventions.
For example, TB and HIV programs need to collaborate in ensuring that people who test positive for HIV are screened for TB, with effective TB treatment for those found to have TB and isoniazid preventive treatment for those found not to have active TB. Collaboration between TB and HIV programs is essential in the monitoring and evaluation of activities aimed at decreasing the burden of TB/HIV. The key elements of a public health program of access to HAART are similar to those for access to anti-TB treatment, namely political commitment, case detection, treatment under good case management conditions, a secure drug supply, and a system of recording cases and reporting their treatment outcomes in order to enable program evaluation.
Five key elements
The direct observational therapy strategy (DOTS) for TB control embraces these five key elements and therefore provides a possible model for delivery of HAART. This provides another fertile field for TB and HIV program collaboration.
AIDS Alert: Will this sort of international commitment require additional funding to what has already been requested by WHO and others for the long-term prevention and treatment of HIV/AIDS populations? What else is needed?
Maher: The Global Plan to Stop TB, endorsed by the Global Partnership to Stop TB, represents a good start in attempting to quantify the resources needed for a comprehensive response to TB/HIV. It remains to be seen to what extent the countries most badly affected by HIV/AIDS, TB, and malaria, and the G8 countries, will mobilize the extra resources needed to be able to achieve the targets they agreed on for tackling HIV/AIDS, TB, and malaria.
AIDS Alert: Why has it been so difficult for international scientists and health care organizations to slow the TB epidemic? Was there a possibility of this disease successfully being contained to a small percentage of the world’s population if it were not for the HIV epidemic?
Maher: Progress in slowing the TB epidemic depends on the effectiveness of the tools available (drugs, diagnostics, and vaccines) and the extent to which they are put into effect. The tools available to slow the TB epidemic actually represent quite old technology — for example, no new test has been developed, which is effective in detecting the infectious TB cases since Robert Koch pioneered diagnostic micro-scopy for TB in 1882.
Fortunately, there are now signs of increasing scientific efforts to improve the tools for TB control (drugs, diagnostics, and vaccines). Under the overall auspices of the Global Partnership to Stop TB, there are now global scientific working groups on new TB drugs, new TB diagnostics, and new TB vaccines. Despite the limitations of the currently available tools for TB control, there has been significant progress over the past decade in increasing the extent to which these tools are put into effect.
The number of countries implementing the DOTS strategy for TB control is increasing year by year, and the proportion of the world’s TB patients treated under the DOTS strategy has increased from 7% in 1994 to 27% in 2000. Increased international commitment is necessary to achieve the target of 70% global DOTS coverage by 2005.
AIDS Alert: Is it possible for a comprehensive TB plan to bring affordable TB drugs to a majority of those who need them in at least some of the areas where there is a high rate of active TB disease? If not, what should be done in place of this course of action?
Smith: Clearly a plan alone won’t do anything — it’s action on the basis of the plan that will make the difference. The Global Plan to Stop TB includes a description of the Global TB Drug Facility (GDF) — a new initiative of the Stop TB Partnership to secure access to high TB drugs in support of DOTS expansion.
Established in March 2001, the GDF already has processed applications from more than 40 countries and made grants to 24, totaling more than 1.1 million patients. Prices of TB drugs purchased through the GDF have fallen 30% compared with previous international prices, so that a full course of six to eight months’ treatment now costs less than $10. The GDF demonstrates that there are innovative ways of rapidly increasing access to affordable drugs. The Global Plan to Stop TB also emphasizes the importance of additional investments in developing health service infrastructure and strengthening human resources to ensure these drugs are used effectively and reach those who need them.
Maher: The big picture is that every country has some sort of house service and house service providers, such as nongovernmental organizations (NGOs), missions, government entities, employer health, and military policy services. We want to harness all of these to deliver DOT strategy.
We want to see the day when all other providers deliver DOT strategy, and we’re looking very hard at community groups and whether NGOs or formal groups can deliver DOTS for TB control. DOTS is only one process, and as different health service providers get involved in providing DOT strategy, we can identify people to support patients, TB treatment supports, and to provide counseling, etc. We know that very few people can manage such an arduous task of six months of TB treatment on their own, and none of us are likely to do that. So we want everyone to have a TB supporter, who can be someone on the house staff or someone in the community. This is someone who is willing to be trained and willing to be supervised and will be a buddy for the TB patient, providing emotional and psychological support and practical support.
AIDS Alert: How realistic are the goals (or even the name) of the Global Partnership to Stop TB?
Steenbergen: The goal of the Global Stop TB Partnership, to significantly reduce the burden of tuberculosis through the detection of 70% infectious cases and curing 85%, is admittedly ambitious. Peru provides a good example of a high TB burden country, which has achieved these National TB Programme targets. The broad support from the partners for the Global Plan to Stop TB brings political commitment, technical know-how, and operational expertise and experience together. This unique forum with such a wide scope of interests and expertise, guided by global principles for tuberculosis control as initiated by the World Health, has the best opportunity to tackle this disease at this point in time.
TB control is not the exclusive domain of the medical experts, but it requires input also from other disciplines. Meeting the goals of the partner-ship is realistic with these multidisciplinary and multisectoral collaborations and the synergy between the partners (including a wide representation of donor agencies).
AIDS Alert: Are there significant public health advantages to treating active TB among HIV patients when these same HIV patients will not ever have access to HIV antiretroviral treatment and will perhaps remain susceptible to TB disease?
Maher: Irrespective of HIV status, people with TB need prompt diagnosis and effective treatment with anti-TB drugs from the individual perspective (in order to be cured of TB) and from the public health perspective (in order to become noninfectious to others). There is some evidence from countries badly affected by HIV that those countries with better TB control programs have been more successful in limiting the impact of HIV on TB.
While it is the case today that a tiny proportion of people with HIV in the high HIV-prevalence countries who need HAART have access to HAART, this proportion is certain to increase as the international community is galvanized into action. With widespread HAART, the incidence of TB in the countries most badly affected by HIV is likely to fall, as HAART restores immunocompetence. The public health advantages of treating TB are likely to continue at the same time that more and more people with HIV receive HAART, for three reasons:
1. HIV will continue to fuel the TB epidemic among the people with HIV who are still waiting for access to HAART during the time that availability is increasing.
2. Even in populations where HAART is widely available, not everyone benefits from HAART (e.g. some people still do not have access to HAART even where HAART is widely available, some people do not tolerate HAART, some people do not manage to adhere to HAART) with the result that HIV-related diseases still will occur in a proportion of people with HIV.
3. HAART is not curative, so it may be that HAART postpones the occurrence of HIV-related diseases such as TB until a certain period when HAART no longer controls HIV replication and people become once more immunodeficient.
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