The global tuberculosis epidemic has leveled off for the first time since the World Health Organization (WHO) declared a public health emergency in 1993. According to the latest WHO report, Global Tuberculosis Control: Surveillance, Planning, Financing, roughly 60 percent of new TB cases are now detected and almost 85 percent of these cases are cured. However, over 14 million people were living with TB in 2005 and nearly 1.6 million died, indicating that significant challenges remain.

Epidemiology of Tuberculosis

Tuberculosis is a contagious, airborne disease. The tuberculosis germ, TB bacilli, currently infects over one-third of the world's population, though only 5-10 percent of those infected with TB bacilli become sick or infectious. Those with a weakened immune system, and particularly those who are HIV-positive, are most vulnerable.

The World Health Organization measures the status of the TB epidemic via three indicators:

• Incidence: total number of new cases arising in a given time period.
• Prevalence: total number of cases which exist at a given time.
• Mortality: total number of deaths due to TB.

Southeast Asia has the highest incidence and prevalence of TB due to its large population size and growth rate, accounting for 34 percent of all new cases in 2005. However, in Sub-Saharan Africa, where HIV and chronic hunger are widespread, the incidence rate (new cases per thousand of the population)is twice that of Southeast Asia and per capita mortality from tuberculosis is the highest in the world.

Source: WHO, 2007. Global Tuberculosis Control: Surveillance, Planning, Financing

Barriers to Progress

Once detected, tuberculosis is curable in 90 percent of cases for as little as $15 per treatment. However, a number of challenges remain which prevent substantial progress from being made towards eliminating TB. Those barriers described by the recent WHO report include:

• HIV/AIDS is fueling the TB epidemic, and coordination between the TB and HIV communities is lacking. HIV testing for TB patients has increased in Africa, but few people living with HIV are being screened for TB.
• The spread of extensively drug-resistant TB (XDR-TB) is a major threat to recent progress. Controlling XDR-TB will require an addition US$650 million globally, in addition to funding for more research to identify new drugs and vaccines.
• Current estimates indicate a US$31 billion gap in funding for the Global Plan to Stop TB (2006-2015). An additional 1.1 billion is needed for 2007 alone.
• In the countries where TB is most prevalent, there is a significant lack of infrastructure and capacity, including laboratory facilities and health workers.

Several regions, including the Americas, Southeast Asia and the Western Pacific, are on track to meet the Global Plan to Stop TB target of reducing by half the number of TB cases and deaths by 2015. The future of regions such as Africa will depend on the ability to overcome the obstacles listed above.

RELATED LINKS:

Millennium Development Goal 6: Combat HIV/AIDS, Malaria and Other Diseases

WHO tuberculosis website

Full Press Release

World TB Day 2007

Global Plan to Stop TB

EarthTrends

EarthTrends tuberculosis indicators

Population, Health and Human Well-Being searchable database

Data Table: Human Health 2005 (pdf)