TEREKEKA, South Sudan (AP) — War-torn South Sudan "should serve as an example" for other countries in the progress it is making in eradicating Guinea worm, said former United States President Jimmy Carter. Speaking to the Associated Press, Carter praised the world's youngest nation for making steady progress in ridding itself of the debilitating parasite despite the "tremendous problems." Contracted and spread by drinking infected water, Guinea worm affects some of the world's most vulnerable people. In 2006, when the Guinea worm program launched in South Sudan, the country had more than 20,500 cases in over 3,000 endemic villages.