Only one infectious disease has ever been eradicated: smallpox. But thanks largely to the efforts of Jimmy and Rosalynn Carter, the former president told Piers Morgan that guinea worm will soon be the second. "We found 3-and-a-half million cases of guinea worm still existing, and now we have less than a thousand cases, so we'll soon eliminate guinea worm from the face of the earth," said Carter.
After visiting more than 26,000 village in 200 countries, Carter looks forward to the end of his crusade.
"When the final case of guinea worm is resolved – it will be in South Sudan," he told Morgan. "It will be a time for celebration, not only for me and Rosalyn and everyone at the Carter Center, I think for the entire world."
Check out the web extra video above, about a cause which Rosalynn Carter says "really touches you."