Anopheles mosquitoes are the only kind to carry malaria, as you may or may not know. Anopheles extinct == malaria extinct, unless malaria can jump ship faster than we’ve given it credit for.
Note that only one group of mosquitoes is targeted. Other mosquitoes will fill any vacted niches except, we hope, malaria vector. So birds and frogs and such won’t starve, as the balance of mosquito populations will readjust to take up the slack. We hope.
In other words, put down the quinine, boys, we might actually have something on one of the World’s Biggest Diseases.
This does not involve any chemicals of any kind. Instead, we develop a few HEGs, or Homing Endonuclease Genes. A HEG invades the genetic structure of an organism, looks for a certain gene sequence, and replaces that gene sequence with a copy of itself. The affected animal becomes a carrier, and if it mates with another carrier, the offspring will not survive, as the HEGs have overwritten essential parts of their DNA. HEGs do not harm the hosts at all, nor do they harm the offspring of a carrier and a non-carrier except each offspring is guaranteed to carry at least one copy of the HEG. Thereby, plenty of new carriers are born.
The potentials for good are astounding. The potentials for evil are alarming. Any commentary?
Something along these lines has appeal. I would have thought a more obvious approach would be to attack the parasite rather than the critter itself - by producing an Anopheles mozzie that was resistant in the lab for example. The advantage of that is that you could do a little controlled testing before getting serious.
There are practical difficulties involved in this sort of thing. Much thought would have to be given to co-ordinated release so as to minimise the time available for mutation.
But - much as malaria is a terrible and growing scourge - this would be a leap into the unknown.
Yeah, surely it would be much easier and safer to just come up with a cure for malaria!:smack:
Probably they can’t get rid of the parasite but the mozzy itself is a bigger target, literally and scientifically.
More power to them I say, I expect that the other mosquito species will quickly fill the ecological niche, besides which it sounds like a gradual process rather than some kind of moaquitapocalypse.
Well, “we” here certainly doesn’t mean the whole world, Mooney. Smallpox still exists. You and I are just vaccinated, and are less likely to contract it if we go somewhere where the disease still exists.
Phasing out malaria sounds like a plan alright. But like others, I have to agree on preferring a method of killing the parasite rather than the carrier. It’s a bit like exterminating all the dogs on the planet in order to get rid of flees.
Smallpox was indeed eradicated. I was in Zaire during the last reported cases there, though there may have been some cases in Serbia in the late 1970s.
The reason that smallpox is a concern is that samples were retained in research and weapons laboratories and there’s a belief that terrorists may have obtained access to them and can unleash them again.
The debate over whether the samples should have been destroyed still rages in the scientific community.
Huh! I stand corrected, Mooney. I guess I thought the disease was still active because to this day, children in the Netherlands are vaccinated against it.
Also, how sure can one be about complete erradication: I recall reading a news story about a few instances of a variant of the plague ( :eek: ) a few years ago, somewhere in India (possibly Calcutta). Plus, there’s the terrorist risk you mention.
Nevertheless, you were right: smallpox was eraticated.
That’s interesting that the Netherlands are still vaccinating for it. The practice was stopped about 20 years ago in the U.S., as it’s well-known that vaccinations have a very low, but notable incidence of heart attacks or other illnesses.
WHO has tracked this one very carefully. “The New Yorker” has run a series of interesting articles over the past several years about the disease and it’s potential re-emergence from the labs (sorry that I don’t have them at hand).
IIRC, the Serbian incidents were either a final pocket of smallpox – or a virulent chicken pox strain that was closely related. In immunology circles it was used as an example of how to quickly control an infected population by targeting and isolating the early cases.
Now we can return the thread to the discussion of malaria ;=)
We can be sure it’s been eradicated (excepting the lab samples, of course) because there hasn’t been a single reported case since the 70s, and smallpox does not have any non-human hosts. It can’t be hiding anywhere else, and it’s not in humans. Bingo.
And there are a few cases of the plague every year. It still pops up. It lives in various animal vectors.
You can only eradication a disease when you destroy the origionating source of the pathogen. Small pox is relatively simple, there exists no animals that plays host to the pathogen nor is there a microenviroment where the pathogen can reside.
Plague can have some species play host without the pathogen harming them. Thus to eradicate it we have to ‘cure’ the reservoir as we cure all human cases.
Malaria is an interesting problem because it’s caused by a fully competent mircoorganism. We can either determine a way to eradicate the natural reservoirs of the parasite or we can eradicate the vector.
If we eradicate the vector we’re removing a segment of the food chain. Less food for the mosquitoe’s predators = fewer of them = other prey species flourish.
So what COULD happen is if we kill off the mosquitoes, we cause the birds that eat those mosquitoes to have less food intake and a %age of the bird population dies. This removes the negative pressure on the insect populations that the birds also controlled which in turn causes the insects to consume more food as their populations increase.
What does this mean for africa? Dunno but I wouldn’t want to be there to find out.
I say go ahead and kill the mosquitoes, as a small number of mosquito species isn’t worth the human deaths caused by malaria. The method decribed by the OP sounds gradual enough that other mosquitoe species will hopefully fill in the vacted niche, and you will have minimal impact on other species. Also, if you have some moral issue with entirly elimating a species, just try to get some people to keep Anopheles mosquitoes isolated in captivity.
The HEGs would only kill the anopheles, not any other mosquitoes. Other mosquito populations would boom to fill in the gap, thereby replacing the missing links in the food chain.
As for not targeting the parasite itself: There aren’t as many mosquitoes, and we can count them better. As the HEG depends on being pretty widespread in a population for it to work, I think we have a better chance at killing off the mosquitoe than the parasite. The researchers apparently agree with me.
