09 December 2008

Carter and the Dragonslayers

My brother, a college senior aspiring to veterinary medicine, spent four weeks this past summer working on a pair of wildlife reserves in Uganda and Kenya. He had the time of his life, as should any young man seeing the world and fulfilling a lifelong dream to boot. And he managed not to get into too much trouble while doing so. (As he put it, "I promise I was in nearly complete control of almost all of the situations I found myself in some of the time.")

However, all was not beer and skittles and charging rhinoceroses. To manage the trip, he had to put up with the threat of parasites. A particular friend to the little things that creepeth within one's flesh, my brother is not. But I guess when you get the chance to dart lions on the savannah, you deal.

Anyway, at one point he expressed concern that he might have contracted guinea worms. He didn't contract guinea worms (at least, not that we know of), he was just being momentarily paranoid.

In a few years, he might never again have to worry about contracting guinea worms. Former President Jimmy Carter announced this past Friday that cases of dracunculiasis (guinea worm disease) have hit an all-time worldwide low (AP):
Only 4,410 cases were reported worldwide during the first ten months of this year, all in six African countries. Nearly 80 percent were in Sudan, according to The Carter Center, a nonprofit founded by Carter and his wife that helps fight disease and champions voting and human rights around the world.

That total is a dramatic drop from the 3.5 million cases in 20 nations that were reported when The Carter Center's eradication campaign began in 1986. It's also less than half the 9,585 cases reported by individual nations in 2007.

"Our record on Guinea worm for the last few years has been steadily and rapidly downward," Carter said.

Health experts hope that next year may see the last reported cases of the parasitic illness, which would make it the second infection — after smallpox — to be eliminated from the world.
Mind you, there is no vaccine against guinea worms, nor is there any medicine to treat them. The eradication of this disease is being carried out via simple education and sanitation.

The only way to eradicate guinea worms is to interrupt their life cycle. The good news is, since guinea worms only infect humans, not other animals, once the disease is gone from the human population, it's gone for good. There can be no environmental reserves of the parasite.

Infection starts when a person drinks water containing copepods (itty-bitty planktonic crustaceans) infected with guinea worm larvae. Once in the person's stomach, the guinea worm larvae burrow out into the abdominal cavity, where they spend several months growing, maturing, and mating. The males die after mating. The females, now three feet long or so and almost as thick as a spaghetti noodle, need to deliver their young to a water source. To that end, they burrow down the host's leg and form an excruciating blister on the surface of the host's foot. As soon as the foot touches water, thousands of larvae are released to continue the cycle.

There are two main strategies, therefore, to preventing guinea worm disease from spreading:
1) Limit exposure by educating people about the disease and developing safe sources of drinking water (providing water filters, digging wells, etc.)
2) Prevent spread of the next cycle through good sanitation. Teach people to recognize signs of the disease, to identify it early and prevent those afflicted with emerging guinea worms from coming in contact with the water.

Dracunculiasis a devastating affliction. It cripples the host and causes incredible pain. And the only way to remove the worm is to wrap it around a stick (or, nowadays, a piece of gauze) and slowly, over the course of weeks, pull the three-foot worm out through the blister, with the afflicted having to endure burning pain all the while. Hence the worm's nickname, "the fiery serpent," and disease name dracunculiasis, Latin for "affliction with little dragons" and perhaps the most kickass of all parasite names.

Rod of AsklepiosIt is also an ancient affliction. Guinea worms have been found in calcified Egyptian mummies. The symbol of medicine, the Rod of Asklepios, is thought by many to be representative of the method of guinea worm extraction.

And now, it's almost gone. By sheer know-how and concerted effort, a disease that has plagued humans since before the time of the pharaohs is being driven to the brink of extinction.

I'm giddy. I'm eager to hear what the Carter Center has to report next year.


(Tip o' the hat to Effect Measure.)

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