International health workers are calling on the governments of the major donor nations to support the research and development of new drugs to treat some of the deadliest, most neglected diseases in developing countries. About 150 experts are meeting in New York this week, brought together by the Paris-based "Doctors Without Borders" organization, to discuss ways to jumpstart new initiatives.

The target of this global health campaign are the big pharmaceutical companies. "Doctors Without Borders" and other global health groups argue the drug giants are focusing their research and development mostly on the afflictions of the affluent.

A new report shows there are about eight new drugs on the way for impotence, seven for obesity. But a survey of the world's leading drug companies indicates nothing new in the pipeline for tuberculosis, malaria, sleeping sickness or a series of other tropical diseases that afflict mainly the poor and underprivileged in developing regions.

Dr. Krisantha Weerasuriya from Sri Lanka works for the World Health Organization in India. He says he has waited in vain for most of his career for some breakthroughs.

"While waiting, I became very good at evaluating the 28th drug for high blood pressure, or the 45th painkiller that came along, and in case I was sleepless about this, the 68th sedative that was in the market. It is a wait of 20 years of my professional life to see a drug that would be relevant to the conditions that we have in my country, that could treat the neglected, that could treat the poor," Dr. Krisantha says.

Physicians call these neglected people the "silent sufferers." They have no voice, no strength, no political power. And for the drug companies, health workers say, there simply is no market where the number of users is huge but the potential profits are small.

International groups, therefore, are trying to pressure governments to provide leadership on the problem.

Els Torreele, a pharmacologist from Brussels, says the public sector has to step in where the private sector fails. "We believe there is more opportunity to have the public sector motivated and involved in getting this research work restarted and trying to attract the pharmaceutical industry, which has other priorities. Of course, they can be partners or we can cooperate with them, but they have no interest in doing that. There's no reason it could not be done in the public sector if you put the money and energy in it that's needed," Mr. Torreele says.

Dr. Morten Rostrup, a physician in Norway and the international president of "Doctors Without Borders," says waiting for action is no longer a viable option. "If the pharmaceutical companies are not taking care of this kind of research and development, and the public have abdicated, more or less, their responsibility, then we have to push for something, to try to provoke a change, to provoke the people, especially the governments and the public, to take their responsibility," Dr. Rostrup says.

The pharmaceutical companies argue it takes money to develop drugs and they have to keep an eye on their "bottom line." However, reports from some of the big pharmaceutical firms suggest they are spending, in some cases, less than one percent of their budgets on what health workers call the "neglected diseases."

Medical experts say prospects for the future look grim. Even with malaria and tuberculosis, where there are effective drugs on the market, new ones are needed as people develop resistance to the old medicines.

Meanwhile, physicians who work in Africa, the Middle East and Asia, continue giving testimony about the travails of people who desperately want help. They talk about sickly, frail people walking for miles through war zones, through crocodile-infested waters, through monsoons, to clinics where there may or may not be the treatment they need.

Dr. Rostrup of Doctors Without Borders says, "We are patient and as my colleague said, we've been waiting, and we have been observing what is happening, or what is not happening. And then I think we cannot tolerate this any more," he says.

Health organizations concede the solution is probably complex and it will require a lot of money. But they see the health crisis in developing countries, where the majority of people live, as a major embarrassment in a world otherwise so advanced and so prosperous.