TUBERCULOSIS

About one third of the world’s population is infected with Mycobacterium tuberculosis. While only 1 in 10 infected people with healthy immune systems will develop tuberculosis (TB) symptoms, those with weakened immune systems, such as those with HIV, are much more likely to contract TB. More than 90% of TB cases and deaths occur in the developing world, primarily among young adults.

In 2008, there were an estimated 9.4 million cases of TB globally, up from 9.3 million in 2007, as slow reductions in incidence continue to be outweighed by increases in population. Most of the cases in 2008 were in Asia (55%) and Africa (30%). In 2008, some 1.4 million (15%) of all TB cases were HIV-positive, most of them in Africa and South-East Asia.

Directly Observed Treatment Short-Course (DOTS) is the WHO-recommended TB therapy and uses a combination of antibiotics over a 6-8 month period. Patients are observed taking their medication, to ensure the continued compliance needed for complete eradication of the bacteria. Nearly 32 million TB patients have been treated under DOTS since 1995. Although a vaccine exists to prevent childhood tuberculous meningitis, a 100% effective, affordable and practical vaccine has yet to be developed against adult pulmonary TB.

Multidrug-resistant TB (MDR‑TB) affected some 440,000 people worldwide in 2008 and a third of them died. It does not respond to the standard first-line treatment and it can take up to two years or more to treat with medicines that are less potent, more toxic and more expensive. Extensively drug-resistant TB (XDR‑TB) occurs when resistance develops to the second-line drugs used to treat MDR-TB. It is virtually untreatable and cases have been confirmed in more than 57 countries, notably China and India.

The pharmaceutical industry is developing new TB medicine and vaccine candidates and supports a range of programs to increase access to TB medicines and to strengthen healthcare capacity in affected countries.

(Source: WHO Global Tuberculosis Control 2009, Epidemiology, Strategy, Financing; WHO Global Tuberculosis Control, A short update to the 2009 report; WHO Multidrug and extensively drug-resistant TB (M/XDR TB), 2010 Global Report on Surveillance and Response)