The fiery serpents mentioned in Numbers 21 were not snakes, they were Guinea worms (Dracunculus). There are currently only a few cases a year for the last decade. The last remaining cases are in some of the most desperately poor war zones in the world (Chad and South Sudan), but once the last person is cured it will be gone forever. Jimmy Carter is the oldest living US president because he has vowed not to die until this disease is wiped out.