We may be close to wiping out one of the world's most horrifying parasites

Reality TV shows like Survivor are facing their first ecological crisis: It seems as though the guinea worm maybe eradicated within the next few years. This is a parasite that has to be slowly pulled out of people's legs, over the course of months. Could we really make the guinea worm the next smallpox?

In 1986, there were about 3.5 million cases of guinea worm disease across twenty-one countries. In 2011, there were just over a thousand cases, in four countries. And it looks like the entire species could be eradicated in the next few years.

We may be close to wiping out one of the world's most horrifying parasites

Guinea worms, for those of you who haven't read about them in lurid lists about human parasites or seen them on reality shows, are parasitic worms. They get into the human system when someone drinks stagnant water that hasn't been treated, and has been infested with their larvae. They live in the human system pretty quietly for about a year, and then they make a break for freedom. They come to the surface of a person's skin. This irritates the leg and forms a blister. That blister can be anything from the size of a dime to a crater in a person's flesh. The person will feel a burning sensation, and will probably dip their leg in water. At that point the blister bursts, the worm comes to the surface, and secretes more larvae into the water supply.

The parasite is most well-known for its viscerally unpleasant removal technique. It can grow to one meter in length, and tugging on one fragile end near the skin will cause the head to break off and leave the dead worm in the body. At that point, it'll rot, killing the human patient horribly. To remove the worm, humans have to tug on the head and wind it around a stick, a little at a time. Over the following weeks, the worm has to be tugged out by only a couple of centimeters per day, until the full meter is out.

The guinea worm is a parasite that's exclusive to humans, so there's little ecological impact from its eradication. It's been documented as a human parasite in ancient Egyptian texts. Health agencies are killing it off via education, telling people not to put their limbs in a common water source when they see the blister, and by offering cloth filters to strain out the larvae. There's been a big change even in the last few years — reported cases dropped 41 percent between 2010 and 2011. The Carter Center, which is one of the organizations supporting the eradication of the worm, stated that it could be killed off completely by 2015. Guinea Worm Disease will be the second human disease eliminated, after smallpox.

Images: Public Health Image Library

Via CDC and The Carter Center.