NPR report: the Guinea worm is almost completely eradicated:
Guinea worm is a horrific infection. First, a painful blister starts to form on the skin. Then a thin, white worm — up to 3 feet long — emerges from the blister over the course of a few weeks. It is an incredibly painful process and temporarily handicaps a person while he or she waits for the worm to come out of the skin...
People catch Guinea worm by drinking contaminated water. Simply filtering drinking water can stop transmission of the parasite. An infected person can also stop the spread of the parasite by keeping the emerging worm away from water. When the worm touches water, it releases tens of thousands of baby worms and contaminates the whole body of water.
the bad news: There is no drug to kill it. You freeze the breathing hole (or bathe the area in cold water) and the worm starts to come out, and you pull it out slowly until it is out, which takes time.
You can freeze the entire worm, and it will shrink inside. We used ethyl Chloride spray for this. But that can cause a bigger infection, so it is only used if the worm is very small... and these worms are very long.
You can also remove it surgically, but again it would be a big incision and a larger area to get infected.
thanks to Jimmy Carter who was behind the initiative to get rid of the worm.