Tuberculosis

Previous feature: The stop TB strategy: building on and enhancing DOTS to meet the TB related Millennium Development Goals

Tuberculosis disproportionately affects poor people. It kills around 2 million people each year, mostly in developing countries, especially where HIV is also prevalent. It is the leading cause of death among people with HIV, and the chance of a person infected with HIV developing TB is five to ten times greater than that of someone with a healthy immune system.

TB is an airborne infectious disease caused by the TB bacillus (Mycobacterium tuberculosis) and can cause serious damage to the lungs. Modern antibiotic chemotherapy will cure up to 95 per cent of TB cases. However, the 6 - 8 month course of treatment must be fully completed or drug resistance will emerge. Treating multi-drug resistant TB is extremely expensive and puts an enormous strain on national health systems. The internationally recommended TB control strategy is DOTS (directly observed treatment, short-course). DOTS combines five elements: strong government commitment, laboratory based diagnosis, uninterrupted drug supplies, surveillance and monitoring systems, and use of effective regimes with direct observation of treatment.

World Health Organization targets are to detect 70 per cent of new infectious TB cases and to cure 85 per cent of those detected by 2005. Of these targets, the case detection rate is the most difficult to reach; in 2002, it was 37 per cent globally. The major constraints to reaching the global TB targets include a shortage of qualified staff, lack of health infrastructure, poor preparation for decentralisation of the health system, and lack of coordination with the private sector. Good TB control is reliant on a strong health system.