Mosquitos occur world-wide, and even flourish in many climates where rates of infection from mosquito-borne diseases are relatively low. As an example, 90% of deaths from Malaria occur in sub-Saharan Africa, and even there, the likelihood of death from infection is radically lower for western visitors than for locals.

These diseases are largely a result of poverty and poor access to healthcare, not of mosquitos.

It seems that at least some of the reason why malaria is so prevalent in sub-Sahara Africa has to do with poor housing, poor management of drainage / sewers, and poor roads.

http://www.hindawi.com/journals/jtm/2012/819563/

I'm not ruling out eliminating mosquitoes per se, but the United States and Europe managed to largely eliminate malaria in the 1930s-1940s without eliminating mosquitoes. So before I'd start advocating the elimination of entire subsets of species, I'd ask how the US and Europe were successful in their efforts, and wonder why we can't apply those lessons to the rest of the world. Maybe the money spent in targeting the elimination of mosquitoes (which cause a lot of problems) would be better spent in general health and sanitation (the lack of which also causes a lot of problems), for instance.

I'm all for releasing CRISPR on the worst species of mosquitos though. And ticks. They can't serve any function other than killing a few persons each year due to TBE.

Why does there have to be a region in permanent squalor? Why can't every place on earth where civilization exists be a decent place for humans to live, with peace, opportunity and sanitation?

But ... back down to earth. Since we can't fix that larger problem, at least maybe we can stop malaria by killing all the mosquitoes.

Seems to me that good second-world sanitation might alleviate it. But third world countries lack the sanitation and hence suffer Malaria. Seems the problem is political/social.

Coincidentally, there are quite many areas in Sweden were it is impossible to go outside in the summer without mosquito nets, and it is worsening.

Mosquitoes do exist in Europe; they don't spread malaria because it isn't there to spread, and it isn't there to spread because of effective healthcare.

(Europe isn't a great example as the mosquito population is not exactly high, which I guess is climate-related, but the above is also true of parts of the developed world where their populations are higher)

With CRISPR and gene drive, it changes from "fucking hard" to "trivial", so it is not only likely to change, it's already changed.

The kind of hubris displayed here almost certainly belies deep ignorance. Please, doctor, tell us how trivial editing DNA is.

DDT was the "perfect" mosquito killer, as well. It didn't last - resistance inevitably follows these attempts in wild populations.

So your argument is that it can't be done because no one has done it?

No one has released gene drive systems to the wild, but there is every reason to believe that it will work fine, and no credible reason to believe that it won't.

Here is the paper where they talk about the mechanism of resistance being conferred on the mosquito: http://www.pnas.org/content/109/28/E1922.abstract

The mechanism is this: "These scFvs are derived from antibodies specific to a parasite chitinase, the 25 kDa protein and the circumsporozoite protein, respectively."

So you'll spend a ton of money building a fancy CRISPR system in your mosquitoes, release them into the wild, and in a matter of months you will have parasites with on-target mutations in these proteins that will allow them to evade your resistance mechanism. I'd lay $1000 on this without blinking.

You're basically talking about curing malaria in mosquitoes. Why not, instead, just cure malaria in humans?

Second, there is no reason that a CRISPR-based system is limited to a single target. Will you also lay $1,000 against a system that targets ten species-unique sequences at once?

You're basically talking about curing malaria in mosquitoes.

Neither I nor the article is talking about that. It's a discussion of making the mosquito species itself extinct.

You're the one who brought up CRISPR and gene drive. Perhaps you should read the actual paper: http://www.pnas.org/content/112/49/E6736.full; you'll see that the proposal is entirely about giving mosquitoes resistance to the malaria parasite, not about eradication. That is, the goal is to eliminate the parasite in mosquito populations (i.e., cure malaria in mosquitoes), not to kill mosquitoes.

>Second, there is no reason that a CRISPR-based system is limited to a single target. Will you also lay $1,000 against a system that targets ten species-unique sequences at once?

Yes. On-target mutations are trivial to produce, and alleles segregate independently.

Which can be targeted to eliminate the mosquitos themselves.

"Perhaps you should read the actual paper"

The actual paper? Like there's only one? Hint: there's more than one way to use this technology, and more than one group working with it.

"On-target mutations are trivial to produce, and alleles segregate independently."

I think you're misunderstanding what "independently" means in this context.

If the probability of a mutation that will get around one targeted sequence is (say) 1 in a million, that's almost certainly going to happen, just because there are billions of mosquitos.

However, if you target (say) ten independent sequences, the probability of any one organism having resistance to all of them is going to be 1 in (1 million)^10 = 1 in 10^60 and that is basically not going to happen. It does no good in this case for one organism to be resistant with respect to one target, while another organism is resistant with respect to another target, because all of the targets will have fatal outcomes. The only way for the organism to survive would be for it to be resistant to all of them at the same time, from the beginning.

And there's no reason why you'd have to stop at 10, either.

Because plasmodium is a eukaryotic species which reproduces sexually, on-target resistance mutations to any number of mechanisms can arise independently in a bunch of different organisms and accumulate through selection + allele segregation. It's also very easy to produce these sorts of mutations, since it is trivial to change an amino acid to disrupt antibody binding/recognition without altering the function of the protein.

>Which can be targeted to eliminate the mosquitos themselves.

This is incorrect; the whole point of a gene drive is that it causes increased propagation of a trait in the mosquito population. What you're describing is a very different strategy, since a trait that kills the mosquito obviously cannot propagate. It can also be achieved much more simply by using sterile males to outcompete fertile males and reduce the population ('sterile insect' technique); however, this technique only works on small populations and almost certainly wouldn't work in Anopheles or some such.

FWIW, we could "cure" a lot of these diseases. We have, in rich parts of the world. If the option was between "we distribute cures to forgotten diseases to everyone who needs them" versus "we take a gamble and murder all the mosquitos," I might agree the former would be the better bet.

That's not the choice we're given because not enough people in the first world want to step up in a serious enough way.

In any event, learning how to control human diseases and prevent parasites from killing us seems like a very fundamental goal of medicine which should be accomplished in any eventuality. Eradicating mosquitoes need not be.

Also, regarding resistance, it is much easier to track and defeat resistance in human patients than to track and defeat resistance in wild populations of mosquitoes, which is what we'll be doing if we try eradication campaigns.

Much, much easier said than done.