Mario Raviglione, director of the WHO's Stop TB department, said the molecular test developed by Hain Lifescience and Innogenetics represented a big breakthrough in the fight against tuberculosis, a contagious respiratory ailment that kills 1.5 million people a year.

"We are capable now of making a diagnosis of MDR-TB within hours," he said, using the acronym for multi-drug resistant tuberculosis, an infection that cannot be cured with a standard course of antibiotics.

The new test can determine directly from a patient's saliva whether the tuberculosis bacteria can be treated with the two main antibiotics, isoniazid and rifampicin, making it easier to prescribe the drug to cure the disease and prevent its spread.

Previous tests required saliva samples to be incubated for as many as 60 days in order for microbacteria to grow and be tested against different antibiotic compounds.

Drug-resistant tuberculosis strains are particularly lethal for HIV/AIDS sufferers and those with weak immune systems. Errors in prescribing antibiotics can worsen drug resistance problems and lead to XDR-TB, an untreatable form that has emerged in 49 countries including the United States, France, Russia, South Africa, Brazil and Australia.

The Germany-based Hain Lifescience is also working on a test to diagnose XDR, which remains in an experimental stage, a WHO spokesman said.

Lesotho will be the first country to get the lab equipment and training to use the new diagnostics under a programme supported by the WHO's partners UNITAID and the Foundation for Innovative New Diagnostics, Raviglione told a news briefing.

The other countries due to receive support to use the new test in the next four years are: Azerbaijan, Bangladesh, Cote d'Ivoire, the Democratic Republic of Congo, Ethiopia, Georgia, Indonesia, Kazakhstan, Kyrgyzstan, Lesotho, Moldova, Myanmar, Tajikistan, Ukraine, Uzbekistan, and Vietnam.

The WHO said this deployment, as well as efforts to make second-line antibiotics more affordable, should increase to 15 percent the proportion of patients with multi-drug resistant tuberculosis who are diagnosed and treated appropriately.

At present, that rate is only 2 percent.