Beijing  - The World Health Organization (WHO) on Wednesday called for urgent action to halt an "alarming" rise in the spread of multi-drug resistant tuberculosis (MDR-TB).

"The situation is already alarming, and it is poised to grow much worse, very quickly," said WHO director-general Margaret Chan.

"If MDR-TB is not vigorously addressed, it stands to replace the mainly drug-susceptible strains currently responsible for 95 per cent of the world's TB cases," Chan said.

Chan said the world already faced a "precarious situation" in slowing the spread of drug-resistant TB, warning that it could cost up to 200 times more to treat than drug-respondent TB.

She was speaking at the start of a three-day, WHO-led ministerial meeting of some 30 countries with high levels of MDR-TB and the more serious extensively drug-resistant tuberculosis (XDR-TB).

More than 50 nations, mainly in Asia, Africa and Europe, have reported cases of XDR-TB, according to the WHO, which estimated that there were some 500,000 drug-resistant tuberculosis cases worldwide in 2007.

Improper use of drugs and poorly managed treatment regimes are the main causes of drug resistance in TB, which kills some 1.7 million people each year, the WHO said.

It said the Beijing meeting was scheduled to close on Friday with a "call for action" on drug-resistant TB to "help strengthen health agendas and ensure that urgent and necessary commitments for actions and funding are made to prevent this impending epidemic."

Officials at the meeting will also aim to "build consensus and political commitment" and "scale up the prevention and management of MDR-TB", the WHO said before the event.

China on Wednesday launched a partnership with the Gates Foundation to fight the growth of drug-resistant tuberculosis and develop a prevention model that could be used in other nations.

The partnership will be supported by a 33-million-dollar grant over five years from the Bill and Melinda Gates Foundation.

"It aims to establish an effective TB prevention model through the exploration of new diagnostic tools and methods," said Chinese Health Minister Chen Zhu.

Bill Gates said the new partnership "comes at a critical time in the world's response to tuberculosis."

"The rise of drug-resistant TB worldwide has created a new urgency to combat the disease, while scientific innovation is leading to new technologies that will help us succeed," Gates said.

The partnership aims to improve detection and treatment of the estimated 1.5 million tuberculosis cases annually in China.

The grant from the Gates Foundation will help China to develop new diagnostic tests, drug regimens, patient monitoring strategies, and health delivery approaches, Chen said.

The WHO last week said the percentage of people contracting tuberculosis globally was declining, but it warned that the world was failing to cut the death rates fast enough.

It said the Americas, the Eastern Mediterranean and South-East Asia regions will meet the goal of halving mortality rates of 1990 by 2015, but other areas, including Europe and Africa, will fail to meet the targets. (dpa)