Tuberculosis (TB)

Introduction

The goal of this series of annual reports, published since 1997, is to chart the course of the global tuberculosis (TB) epidemic and to evaluate progress in TB control. This tenth report in the series retreads some familiar ground but also expands into new territory. The new landscape of TB control has been shaped, during 2005, by the new International standards for tuberculosis care 1 and by their incorporation, with DOTS, into the expanded Stop TB Strategy. 2 The strategy is to be implemented over the next 10 years as described in the second Global plan to stop TB (2006–2015). 3 The plan also outlines the technological developments that can be expected in the coming decade, which will almost certainly include new diagnostics and improved drug regimens by 2010.

Against this background we present, as usual, WHO’s assessment of the scale and direction of the epidemic, expressed in terms of incidence, prevalence and deaths for 22 high-burden countries (HBCs), for the six WHO regions, for selected subregions and for the world as a whole. Within the framework of the United Nations Millennium Development Goals (MDGs), the principal target for TB control is to ensure that the global incidence rate is falling by 2015. 4 5 Supplementary targets, endorsed by the Stop TB Partnership, are to halve the 1990 prevalence and death rates by 2015. The tables and annexes in this report therefore give estimates of all three key indicators and their trends, for all countries and regions in 1990 and 2004.

The principal mechanism for achieving these impact targets is the treatment of patients with active TB, following the DOTS strategy. DOTS has been central to effective TB control for more than a decade, and continues to be the primary component of the expanded Stop TB Strategy. The broader strategy makes explicit some aspects of TB control that need to be given more emphasis than they have received under DOTS. These include the management of multidrug-resistant TB (MDR-TB) and of TB associated with HIV. That HIV is among the most important risk factors for TB is now well known, but work to address the TB/HIV problem was given greater impetus when African ministers of health declared TB a continent-wide emergency in 2005.

The Stop TB Strategy also includes measures to assess TB control in the context of health system performance, to encourage the participation of all health-care providers (not just those working for government health institutions), to empower TB patients and communities that suffer from TB, and to enable and promote research. This report presents information and data on all these aspects of TB control (see, e.g., country profiles in Annex 1), except the last (because we presently have no method of collecting information on TB research). It also sets out the costs and budgets needed to implement DOTS and other components of the strategy, together with funding sources, budget gaps and expenditures.

Because DOTS remains at the heart of global TB control this report gives, like its predecessors, our best assessment of progress towards the targets for DOTS implementation; that is, to achieve 70% case detection and 85% treatment success by the end of 2005. 6 7 Case detection is traditionally expressed in terms of the diagnosis and treatment of patients with sputum smear-positive pulmonary disease, because these patients are typically more infectious and usually have more severe illness than patients with smear-negative disease. However, “definite cases” of TB are patients in whom TB has been bacteriologically confirmed, including those found to be positive by the more sensitive technique of culture. In addition, it is widely accepted that a faster, more sensitive and more specific technique is needed to replace sputum smear microscopy, and new diagnostic methods are under development. 8 For these reasons, we have continued in this report to explore other methods of evaluating case detection, comparing in particular case detection rates calculated in terms of smear and culture for countries in the European Region.

Between 1980 and 2004, 86 million TB patients were registered in national surveillance systems and reported to WHO, including 22 million notified by DOTS programmes since 1995. With each annual round of data collection, our epidemiological assessments are based on better surveillance and survey data. Planning for TB control, and reports on the process of planning and implementation, are more comprehensive and better targeted to the needs of national control programmes. The financial monitoring system has accounted for nearly US$ 6 billion spent on TB in the HBCs between 2002 and 2006, and is now beginning to show how greater investment leads to more effective TB control.

The Global TB Surveillance, Planning and Financing Project generates, in short, the information needed to make the best possible case for investing in the Stop TB Strategy. The 2006 report is a further step towards evaluating, with still greater precision, progress towards the MDGs, and ultimately towards TB elimination.


Footnotes

1 Tuberculosis Coalition for Technical Assistance (TBCTA). International standards for tuberculosis care. The Hague, TBCTA, 2005.

2 Raviglione MC, Uplekar MW. The new Stop TB Strategy of WHO. Lancet, 2006 [in press].

3 The Global plan to stop TB (2006–2015), launched by the Stop TB Partnership in January 2006, describes how the Stop TB Strategy should be implemented over the next decade, including costs and the expected epidemiological impact in seven regions of the world.

4 The MDGs are described in full at http://unstats.un.org/unsd/

5 Dye C et al. Targets for global tuberculosis control. International Journal of Tuberculosis and Lung Disease, 2006 [in press].

6 Resolution WHA44.8. Tuberculosis control programme. In: Handbook of resolutions and decisions of the World Health Assembly and the Executive Board. Volume III, 3rd ed. (1985–1992). Geneva, World Health Organization, 1993 (WHA44/1991/REC/1)

7 Stop Tuberculosis Initiative. Report by the Director-General. Fifty-third World Health Assembly. Geneva, 15–20 May 2000 (A53/5, 5 May 2000); available at www.who.int/gb/ebwha/pdf_files/WHA53/ea5.pdf

8 A range of new approaches to diagnosis is described at http://www.finddiagnostics.org/

Share