On the eve of World TB Day (24 March), the Bill & Melinda Gates Foundation has awarded $10 million to the UNDP/World Bank/WHO Special Programme for Research and Development in Tropical Diseases (TDR) at the World Health Organization (WHO) to facilitate the development of new tests for the diagnosis of tuberculosis (TB), a disease responsible for some 2 million deaths each year in developing countries, half a million of which occur in persons with HIV infection.

The five-year grant, supporting the Tuberculosis Diagnostic Initiative (TBDI), will speed up efforts to design new approaches to detecting TB among patients with symptoms such as cough, so that they can have access to curative treatment. Work is also under way on simple and accurate methods to detect bacterial resistance to treatment quickly and to uncover latent infection or incipient disease in persons without symptoms.

Together with the Global Alliance for TB Drug Development and the Global Drug Facility launched this week, the TB Diagnostics Initiative seeks to ensure that tuberculosis patients have access to technologies that allow prompt diagnosis and reliable therapy.

"We are 100 years behind in TB diagnostics. The diagnostic test available to most people in the world where TB is a major health problem is essentially the same as that available to Robert Koch, who discovered the bacteria in the latter 19^th century. At a time when increased funding is urgently needed both for research and control of TB, the Bill & Melinda Gates Foundation has stepped forward with a focused investment that will allow tuberculosis diagnostics activities to shift into high gear. There is now the real expectation of bringing improved techniques to the field where they are needed within the coming five years," said Dr Mark Perkins, the Manager of Diagnostics Research and Development in WHO/TDR.

Faster, simpler, diagnostics would make TB control efforts much more effective, especially in the places where patients have difficulty reaching health care: shifting populations in urban slums - isolated rural areas. More sensitive diagnostics would open the possibility of treating the less contagious cases before they infect their families and friends.

The new initiative will operate through broad partnership with public health officials, academic researchers, expert clinicians, and commercial test developers.

Dr. Carlos Morel, Director of WHO/TDR, noted that, "The global strategy for controlling tuberculosis by treating the ill and interrupting transmission depends critically on the ability to detect patients suffering from the disease. Great strides have been made in developing curative regimens and increasing patient access to good medicines, but diagnosis remains a stumbling block."

"New diagnostics for tuberculosis are desperately needed," said Dr. Gordon Perkin, Director of the Global Health Program at the Bill & Melinda Gates Foundation. "Existing diagnostic tests are slow, cumbersome and often expensive. We need tests that are low cost, with high sensitivity, and can be used in the field. We are optimistic that this program will help us take a major step forward."

TB is responsible for 5% of all deaths worldwide and 9.6% of adult deaths in the 15-59 age group. TB kills more women worldwide than all causes of maternal mortality. The disease is concentrated in low-income countries. Some 80% of all TB cases are found in 22 countries, with more than half the cases occurring in five Southeast Asian countries. Nine of 10 countries with the highest incidence rates are in Africa, where prevalent HIV infection has fuelled the epidemic and further complicated diagnosis.

The case fatality rate of TB is high, in large part because of lack of diagnosis and treatment. Approximately 50% of untreated cases die of the disease. Unless promptly diagnosed and treated, TB is contagious and is transmitted to family members and other contacts in the community. Symptoms may begin insidiously with slight cough, low-grade fever or weight loss. Untreated there is usually inexorable worsening of symptoms, with the young, the malnourished and the immunocompromised especially susceptible to rapid progression of disease.