Map of life expectancy at birth from Global Education Project.

Wednesday, April 27, 2011

Extinction is forever

And we generally feel bad about it. But I haven't heard anybody complain about the eradication of smallpox. Now the Carter Center says we are very close to eradicating the Guinea Worm, the parasite Dracunculus medenisis, which just 15 years ago afflicted about 3 1/2 million people in Africa and Asia. It causes severe pain and disability, and it's just about the yuckiest thing you can think of.

There's no treatment for Guinea worm infestation, but it depends on a human host to complete its life cycle. That means that it can be controlled by fairly simple physical means -- filtering and sterilizing drinking water, and making sure that the worms, when they emerge from the flesh (yep, that's what they do) are destroyed, and don't wind up back in the river where they can produce progeny. Jimmy Carter, who is a top notch ex-president, has been leading the world-wide campaign to eradicate them, and they're now very close. Last year there were fewer than 2,000 cases.

Tropical regions are inherently unhealthy because parasites and other pathogens easily thrive where there isn't any winter to kill them off. That's part of what keeps much of Africa and south Asia poor -- when sickness and disability are highly prevalent, it really holds you back. Control, and ultimately eradication of diseases such as dracunculiasis can actually give people a better chance to build more prosperous lives.

Unfortunately, malaria is a very widespread scourge which is much more challenging. But there are numerous other diseases which do not have non-human reservoirs and could be eradicated. We're also pretty close to wiping out polio, as you probably know, although the last yard is turning out to be the longest. (Technically, by the way, HIV is among them although it presents considerable difficulties because of its prolonged latency and incurability.) If we invested the money we spend on invading and bombing people, we could eliminate quite a few human diseases from the planet.

That's a great investment because once they're gone, your related expenses going forward are zero. Some people are uncomfortable with this idea, on philosophical grounds having to do with our relationship to the rest of nature. I am not -- humans have far more horrific and profound impacts on nature that we seem to accept, than the elimination of a few specific species whose only ecological niche is to exploit humans. Eliminating these diseases doesn't even cause an increase in the human population in the long run, since people ultimately have fewer children when they expect them to survive and be healthy, and when they are more prosperous.

So I say go for it.


C. Corax said...

Do you think that the current anti-vax stupidity will undo the progress that's been made re: polio, or is it (the insanity) limited enough in scope that public health efforts will succeed?

Re: wiping out Guinea worms, I'm sure another organism will quickly take their place. I do suspect that anyone who is protesting the extinction of the worms (is that for real, or someone's weird idea of a joke?) would be someone who isn't at risk of infestation.

Cervantes said...

The polio eradication program has been slowed by conspiracy theories that it is a plot to sterilize Muslims in Nigeria and other remote places, but that's obviously unrelated to Western anti-vax theories.

I'm not sure why you think another organism will take the place of the Guinea worm. These metazoan parasites are the product of millions of years of evolution. They don't emerge easily like new microbial infections.