Experts worry that the parasite that causes schistosomiasis could become resistant to an existing treatment.

This is the VOA Special English Health Report.

Scientists think they are a step closer to a new drug to treat schistosomiasis. More than two hundred million people suffer from this parasitic worm disease. Most live in developing nations in tropical climates. About ten percent of victims become seriously disabled from internal bleeding, iron loss, organ damage or other effects.

A team in the United States found that chemical compounds known as oxadiazoles can target an enzyme needed for the survival of Schistosoma. This is the group of flatworms that cause schistosomiasis.

The scientists tested oxadiazoles on laboratory mice. They found that one compound killed the parasite at every level of development