In Sudan, a war is waged to eradicate the 'fiery serpent'

 It started as an itch on James Madol's right ankle and festered. Two days later, the boy cried when he saw a thin white worm emerge.

"I didn't know what it was," says Madol, who was around 5 at the time.

The worm slowly slithered from his ankle, secreting toxins that felt "like fire burning." Even after the worm was removed, Madol couldn't walk for months. He stayed in his hut, able to crawl out only to relieve himself.

Now 32 and a nurse, Madol travels for miles on dirt roads through rural southern Sudan, tracking down his longtime enemy, the Guinea worm. Spanning up to 3 feet, the Guinea worm looks like an elongated spaghetti noodle. Infection with this parasite can paralyze humans, sicken entire villages and cripple economies.