This is the VOA Special English Health Report.

Sleeping sickness is a deadly disease that infects about 60,000 people in Africa each year. Now scientists in Scotland say they may have found a new treatment. Their findings are in the journal Science.

Sleeping sickness is spread by the bite of the tsetse fly. The insect can carry a parasite that infects the central nervous system. First the infection causes fever, headache, itchy skin and weakness.

Then, when the parasite enters the brain, it causes more serious problems. People suffer seizures and thinking problems, and they sleep for extended periods. If the disease is not treated, it almost always kills the victim.

Paul Wyatt at the Drug Discovery for Tropical Diseases program at the University of Dundee led the study. He says the research identified a weakness in the parasite. The weakness is an enzyme called N-myristoyl transferase, or NMT. The parasite needs NMT to survive.

The researchers developed a mixture of chemicals that interfered with the performance of the enzyme. They tried it in test tubes containing the parasites. As a result, the parasites stopped reproducing.

The scientists also tested the treatment on laboratory mice with sleeping sickness. They gave them the chemical compound by mouth and say the infection disappeared.

Now, Paul Wyatt says a drug based on the research could be ready for testing in humans within 18 months. Currently, medicine for sleeping sickness requires a series of injections that are costly and painful. Hospital stays are also needed. And the side effects of the treatment can be serious, sometimes even causing death.

Francois Chappuis is a specialist in neglected tropical diseases with the international group Doctors Without Borders. He says a less costly, easy-to-use medicine for sleeping sickness is badly needed.

FRANCOIS CHAPPUIS: "In areas where the sleeping sickness is still very prevalent, such as remote areas of some central African countries -- which are by the way very unstable areas -- it will be also crucial to have simpler treatment and obviously oral treatment would be the best."

And that's the VOA Special English Health Report, written by Caty Weaver. Transcripts and MP3s of our reports are at voaspecialenglish.com. You can also find us on Twitter and YouTube. And you can join the community at the new VOA Learning English fan page on Facebook. We're at VOA Learning English. I'm Steve Ember.

tsetse fly: an African fly that bites humans and animals and sucks their blood and can spread a disease called sleeping sickness 舌蝇，采采蝇（叮咬人和动物吸血传染昏睡病的非洲苍蝇）

enzyme: a substance, usually produced by plants and animals, which helps a chemical change happen or happen more quickly, without being changed itself 酶

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（来源：VOA 编辑：陈丹妮）