After 22 years of fighting this horrible water-related disease, the Carter Center is within reach of eradicating it. This could be the second disease in human history to be wiped off the face of the earth.
From the Carter Center website:
How Guinea Worm is Contracted
Guinea worm disease is contracted when a person drinks stagnant water that is contaminated with microscopic water fleas carrying infective larvae. Inside a person's body, the larvae grow for a year, becoming thin thread-like worms, up to 3-feet-long. These worms create agonizingly painful blisters in the skin, through which they slowly exit the body. People with emerging worms must not bathe or step in sources of drinking water, because a worm will release hundreds of thousands of eggs, or larvae, into the water. Water fleas then eat the larvae, and people who drink unfiltered water from the pond become infected—continuing the life cycle of the parasite.