Test kits for line probe assays. Photo / WHO

In a breakthrough which will have a major impact on curbing the spread of multidrug-resistant tuberculosis (MDR-TB) in developing countries, including South Africa, the endemic disease will in future be diagnosed within a day and not the standard two to three months, the World Health Organisation (WHO) has announced.

TB is one of the world's leading killers - second only to HIV/AIDS - with over 1.5 million deaths and nearly 9 million people falling seriously ill with the disease every year. Almost half a million people a year develop MDR-TB, a dangerous form of TB that is difficult to treat with standard drugs.

The spread of drug-resistant strains, especially the recent emergence of virtually untreatable extensively drug-resistant TB (XDR-TB), has threatened to push TB control back into a pre-antibiotic era.

In developing countries most TB patients are tested for MDR-TB only after they fail to respond to standard TB treatments.

Even then, when the health worker suspects MDR-TB, it takes two months or more to confirm the diagnosis. Patients have to wait for the test results before they can receive life-saving second-line drugs. During this period, they can spread the multidrug-resistant disease to others. Often the patients die before results are known, especially if they are HIV-infected as well.

At present it is estimated that only 2% of MDR-TB cases worldwide are being diagnosed and treated appropriately, mainly because of inadequate diagnostic services.

However, the initiative announced in Geneva yesterday (Monday) should increase that proportion at least seven-fold over the next four years, to 15% or more.

A partnership between the WHO, the Stop TB Partnership, UNITAID and the Foundation for Innovative New Diagnostics (FIND) will see the new molecular method (line probe assays) to diagnose MDR-TB, that until now was used exclusively in research settings - including South Africa, made available to 16 countries in Africa.

This was announced just one week after the WHO recommended "line probe assays" for rapid MDR-TB diagnosis worldwide. This policy change was driven by data from recent studies, including a large field trial - conducted by FIND together with South Africa's Medical Research Council and National Health Laboratory Services - which produced evidence for the reliability and feasibility of using line probe assays under routine conditions.

UNITAID, a non-profit international drug purchase facility, has provided U$26,1-million to fund the partnership.

Under the partnership Lesotho is expected to start using the new test within the next few weeks, followed by Ethiopia, Ivory Coast and Democratic Republic of Congo. A further 12 African countries will also benefit from the partnership.

South Africa will not profit from the funding partnership, but health minister Dr Manto Tshabalala-Msimang is poised to announce at a national TB conference in Durban today (Tuesday) moves to make the test widely available.

Dr Karin Weyer, team leader for laboratory services at the WHO, said South Africa was expected to start using the rapid test very shortly.

She said the cost of the test was "not yet as cheap as we want it to be", but that is was expected the price would drop as demand increased.

She pointed out that it was still 50% cheaper than the current conventional test.

Weyer said the fact that MDR would be screened within one day would accelerate the testing for XDR-TB.

South Africa has by far the worst TB prevalence rate in the world, with almost 1000 South Africans out of every 100 000 living with the disease in 2006.

The country's struggles with drug-resistant TB has been reflected in poor outcomes for TB patients being re-treated after failing to respond to earlier TB treatment. Some of South Africans die while being retreated. The cost per capita of treating TB patients is also very high as drug-resistant TB is very expensive to treat.

Despite a global slowing down in new TB cases since 2003, South Africa recorded the world's second highest rate of new cases (incidence rate) in 2006 after Swaziland, according to the Global TB report released earlier this year.

Under a second, complementary agreement with UNITAID for US$33,7-million, the Global Drug Facility will boost the supply of drugs needed to treat MDR-TB in 54 countries, including those receiving the new diagnostic tests.

This project is also expected to achieve price reductions of up to 20% for second-line anti-TB drugs by 2010. All the countries receiving this assistance have met WHO's technical standards for managing MDR-TB and already have treatment programmes in place, but many have been unable to access the second-line drugs needed to treat MDR-TB.

Some will use grants from the Global Fund against AIDS, Tuberculosis and Malaria to purchase the drugs.