Guinea Worm is an infectious disease in which yardlong worms grow under a victim's skin and then force "their way out by exuding acid under the skin."

According to this New York Times article, "Now, thanks to a relentless 20-year campaign led by former President Jimmy Carter, Guinea worm is poised to become the first disease since smallpox to be pushed into oblivion. Fewer than 12,000 cases were found last year, down from 3 million in 1986."