Infectious diseases in poor countries kill more than 12 million people a year and play a significant role in keeping countries destitute. Hookworm creates anemia and learning disabilities. Malaria, by some estimates, has cut sub-Saharan Africa's economic strength in half. As President Bush and other world leaders gather in Monterrey, Mexico, this week for a meeting on how to aid the third world, they should give this issue a high priority.

The illnesses that make up 90 percent of the global disease burden get only 10 percent of the research money because they primarily affect poor countries.

Publicly funded researchers generally concentrate on basic medical discoveries. The work of bringing a promising one to market is virtually always done by pharmaceutical companies, which have little incentive to produce medicines for people who cannot pay. In recent years, drug companies have sharply increased their donations of medicines to poor countries. While this is most welcome it cannot be a long-term solution.

To stimulate research on new drugs, several groups concerned with tropical diseases are forming public-private joint ventures. One example is the Medicines for Malaria Initiative, which brings together researchers from academia and industry, financed by the Bill and Melinda Gates Foundation and others. Such projects exist or are in the works for several diseases.

While the $600 million a year that the Gates Foundation spends on poor-country illnesses is the single biggest boost in recent years to the fight against tropical disease, private generosity is not the answer. Government incentives such as the U.S. Orphan Drug Act have been crucial in stimulating the development of drugs for rare diseases in wealthy nations.

The law does not help against tropical diseases because it encourages research in part by giving companies the right to charge very high prices for their new products. But it could be tweaked to be of use to the poor.

A company that invents a treatment for a neglected disease, for example, could be given a patent extension on one of its lucrative drugs. Washington should also devote more money to research on these diseases, and could buy new drugs to give away in poor nations. A more radical alternative is to bypass pharmaceutical companies entirely.

MSF is running a pilot project to develop new drugs for sleeping sickness, chloroquine-resistant malaria and a parasite infection called leishmaniasis. The group is working with researchers in many third-world countries and plans to sell the drugs at cost to poor nations. But help from wealthy countries will still be needed to help poor governments buy these drugs.

A financial commitment along with creative ideas and public attention are needed to reverse the human and economic damage caused by neglected diseases.