The discovery could pave the way for the development of an inexpensive and environmentally safe means of controlling the parasitic roundworms that each year destroy billions of dollars in crops, cause debilitating diseases in farm animals and pets, and now infect a quarter of the world's human population. The scientists' findings appear in the March 4 issue of the Proceedings of the National Academy of Sciences, which is making their paper available this week in its early online edition.

Major parasitic roundworm diseases in humans include ascariasis, which affects 1.5 billion people worldwide; hookworm, which infects 1.3 billion people; and elephantiasis, which affects 120 million people. Other parasitic nematodes are major agricultural pests, affecting such economically important crops as corn, soybeans, potatoes and tomatoes. They are also a problem in horses, livestock and pets.

Scientists have been increasingly concerned about parasitic nematodes developing resistance to the drugs now being used to treat or prevent their infestations. But an even larger impediment to the widespread use of those drugs is that they are costly, as any pet owner who must purchase heartworm preventative knows.

That's not the case with Bt toxins, which have played an important role in controlling insects, such as mosquitoes that carry disease, in third world countries and are now being used in genetically modified cotton, corn and other crops to control caterpillars and beetles.

"Not only are Bt toxins relatively easy to make, but they are extremely safe to humans and vertebrate animals," says Raffi V. Aroian, an assistant pr
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Contact: Kim McDonald
kimmcdonald@ucsd.edu
858-534-7572
University of California - San Diego
19-Feb-2003