YOKOHAMA, Japan -- The World Health Organization, or WHO, urged Asian leaders on Monday to start fighting the spread of AIDS in the region or face the prospect of millions of deaths.


Dr Michael Merson, executive director of the WHO's Global Program on AIDS told the 10th International Conference on AIDS in Yokohama that implementing basic AIDS prevention programs in Asia would cost between $750 million and $1.5 billion. But it would avoid an estimated 5 million infections by the AIDS-inducing human immunodeficiency virus, or HIV, by the year 2000.


"The economic benefit that could result from prevention on such a scale is difficult to estimate, but it is clearly massive in comparison with the investment needed," he said.


The conference was opened Sunday by Japan's Crown Prince Naruhito and Prime Minister Tomiichi Murayama.


AIDS reasearchers expressed no immediate hope for a medical breakthrough, but placed their optimism in new cocktails of virus-fighting drugs.


Michael Saag, director of the AIDS clinic at the University of Alabama, said it would be an "evolutionary process", with little chance of success within eight years.


The cocktails, known as protease inhibitors, prevent HIV developing into AIDS, by stopping its ability to get protein it nedds to multiply istelf.


This is the first time that the conference has been held in Asia, and organizers hope the location will draw attention to the epidemic in the continent, which is forecast to suffer a huge surge in AIDS cases in the next few years.


Merson said estimates showed AIDS could cause a loss of nearly $11 billion to Thailand's economy by the end of the century, with damage to Asia as a whole from $38 billion to $52 billion.


The danger for Asia is that HIV infections could explode in a short, rapid burst as is believed to have happened a decade ago in Africa, the continent worst hit by AIDS with two-thirds of the world's estimated 4 million cases.


The WHO estimates that half of the HIV infections in the 12-year epidemic in Uganda, Tanzania, Rwanda and Zambia occurred in the first three or four years. There is already evidence that Asia could be on the verge of a similar phenomenon. In south and southeast Asia, HIV infections have increased by 1 million over the past year to 2.5 million, and AIDS cases have multiplied by eight times.


Estimated HIV infections in Thailand have risen 10-fold since early 1990.


A major cause of HIV infections is probably commercial sex, said Yun-Fong Ngeow, of the University of Malaya in Malaysia.


Sex tourism took off in the 1980s, bringing in new infections from abroad. Street children in India and the Philippines sell their bodies so they can eat.


"Prostitution flourishes in Asia where there are millions of impoverished women and a social attitude that turns a blind eye to male promiscuity," she said.


However, there are hopes that the epidemic can be nipped in the bud here -- if governments act fast.


Thailand, which has run a big use-a-condom campaign and is one of the few countries putting large national resources into AIDS prevention, has got results: people have changed their sexual habits and reports of sexually transmitted diseases have declined over the past few years.


(Reuters, Newsday)