Killing malaria.

• Author: Chege, Nancy

As early as the 16th century, B.C., Egyptian papyruses described symptoms like those of malaria, a disease researchers have been trying unsuccessfully to eliminate, or at least control, for hundreds of years. But for generation after generation, the parasite and the mosquito that carries it have proved resistant to drugs and pesticides.

Malaria is now the world's most prevalent disease, and one of the deadliest. At present, some 250 to 300 million people are infected with malaria parasites, and of the 110 million who develop the disease every year, about 2 million die. Half of those who die are children, often under the age of 5.

But despite this discouraging history, researchers are beginning to report progress. More than 20 years ago, Chinese scientists confirmed the antimalarial qualities of artemisinin, known in Chinese as qinghaosu (pronounced ching-how-soo). Artemisinin, a substance extracted from a fern-like plant called Artermisia annua, has been used in China as an anti-malarial drug for more than 1,500 years. Now, scientists have developed derivatives of artemisinin that can be administered either orally or by injection. Both forms of the drug are now used widely in Southeast Asia and in parts of Africa and Latin American. Injectable artemisinin has been found to act more rapidly than all other antimalarials and to be effective against multi-drug-resistant parasites. Although it is not yet approved for distribution in any developed country, the World Health Organization and some pharmaceutical companies are studying the drug's safety and effectiveness.

In another potential breakthrough, Manuel Patarroyo, a biochemist at the Immunology...