Tuberculosis (TB)

WHO report 2008
Global tuberculosis control

Chapter 1 Monitoring the TB epidemic and progress in TB control

The status of the TB epidemic and progress in control of the disease have been assessed by WHO annually since 1997. This assessment has included estimates of TB incidence, prevalence and mortality from 1990 onwards; analysis of case notification data from around 200 (of 212) countries and territories since 1995 (when reliable records began); and analysis of progress towards the global targets for case detection and treatment success established by the World Health Assembly in 1991. More recently, it has also included assessment of progress towards the newer impact targets related to incidence, prevalence and mortality that have been set within the framework of the Millennium Development Goals (MDGs) and by the Stop TB Partnership.

This chapter provides our current assessment of the state of the TB epidemic and progress towards targets, using the most recent data reported to WHO in 2007 as well as new analytical work on the broader determinants of the TB epidemic conducted in 2007. It is structured in eight major sections as follows:

  • Goals, targets and indicators for TB control. This section explains the targets and related indicators for global TB control that have been set for 2005, 2015 and 2050.

  • Data reported to WHO in 2007. This section describes the data on case notifications reported for 2006 and those for treatment outcomes reported for 2005, the years for which data were requested by WHO in 2007.

  • Incidence in 2006 and trends since 1990. This section provides estimates of the number of new cases of TB in 2006, including estimates of the number of TB cases that were HIV-positive. It also includes analysis of the trend in incidence since 1990 and its relationship with trends in HIV prevalence in the general population.

  • Case notifications. This section summarizes the total number of TB cases notified in 2006 at global as well as regional and country levels.

  • Case detection rates. Combining case notification data for 2006 with the estimates of incidence for 2006, this section presents estimates of the rates of case detection in 2006, at global and regional levels. Trends since 1995, and their implications for progress towards the global target of 70%, are discussed.

  • Treatment outcomes in DOTS programmes. This section covers results on outcomes of treatment for all new cases and re-treatment cases (2005 cohorts) and progress towards the global target of an 85% treatment success rate.

  • Progress towards targets for case detection and cure. This section reports the number of countries and regions that have met both targets, as well as the number that have reached the milestones of a 50% case detection rate and a 70% treatment success rate.

  • Progress towards impact targets included in the Millennium Development Goals. This section assesses the current status of progress towards targets for reductions in incidence, prevalence and mortality set for 2015, including a new (and still developing) analysis of the extent to which TB control efforts or broader determinants of TB epidemiology are driving the global TB epidemic.

Throughout the chapter, particular attention is given to the 22 high-burden countries (HBCs) that collectively account for around 80% of TB cases globally. This is because these countries are the focus of intensive efforts to implement the Stop TB Strategy (see also Chapter_2). However, additional data for all countries are provided in Annex 3. Further details for the HBCs are also available in Annex_1. The methods used to produce the results presented in this chapter are explained in Annex_2.