Engineered Mosquitoes Could Wipe Out Dengue Fever

Christina Valencia points us to a Wired story about scientists who plan to use genetically modified mosquitoes to reduce the population of Dengue-carrying insects. The altered genes cause newly born mosquitoes to die before they are able to breed if they are not supplied with a crucial antibiotic. This is a more aggressive approach than the anti-Malaria work we discussed last year. From Wired: "Mosquitoes pass dengue fever to up to 100 million people each year, according to the Centers for Disease Control and Prevention. Up to 5 million die. If the scientists can replicate their results in real field conditions, their technology could kill half of the next generation of dengue mosquitoes, which scientists say would significantly reduce the spread of the disease. If all goes well the company envisions releasing the insects in Malaysia on a large scale in three years."

Comments

Ripple Effect

[Doc Ruby]

Those mosquitoes might suck (pun intended :P), but they're food for a lot of animals that don't suck. If we just eliminate all the mosquitoes, we probably can't tell how we'll affect the rest of the ecosystem. Eliminating the dengue fever germs will have its effect, but I'm not too worried about depriving the worms of the corpses they're used to growing fat on.

Re:Ripple Effect

[NeutronCowboy]

I'd have no hesitation in pulling the trigger if it mean eliminating every damn mosquito on earth. Sorry if that sounds unenlightened.

It's not unenlightened, it's stupid. It displays a staggering ignorance of the effect of introducing foreign species in a new environment (Northern Pike, rabbits, zebra mussel, spanish moss, etc. etc. etc.) or of removing one species from an ecosystem (grizzly bear, star fish, kelp, etc, etc, etc). Finally, you completely overestimate the redundancy and resilience of the tropical rain forests (hint: one controlled burn sets an area back about 400 years in terms of return to normal) and underestimate its complexity (hint: what's the impact of removing fire ants from the system?).

Feel free to google the terms. I've set you up with enough key terms that you can educate yourself on the impact. The basic point is that we, as a species, have optimized our behavior to the world as it is. Removing (or adding) to our system can have an impact that goes far beyond expectations, with an impact that is staggering in cost. Think Jenga on a global scale.

Re:Ripple Effect

[Doc Ruby]

Not only have I taken a walk in a tropical region, I lived in Southeast Louisiana for years, which is thousands of miles of swamp. I actually got an unidentified virus in Africa most probably from one of the many mosquitoes who bit me while I slept near the Niger River. In New Orleans, we eliminated centuries of Yellow Fever by draining the swamps, not by targeting a species with untested genetic engineering weapons. But even that action has had consequences to the rest of the ecosystem, though at the more familiar level of drainage and flooding.

Fortunately, public health decisions aren't made by one guy calling themself "Dutch Gun" who wants to just walk around pulling triggers because of their single personal benefit.

Instead, people with that kind of power typically don't make decisions with at the neural level that slaps at a sting. Instead we think of the actual costs of human intervention, and how that's different from the more integrated processes in nature eliminating species, and learning from when it's the same, and causes a ripple effect that we'd rather not be injured by.

Biology is perhaps the most complex studyable natural system. Ecosystems are the most complex interactions of biological systems. We have to consider what an apparently "simple", drastic action that destroys an entire species that other species depend on will actually do, before we do it.

Re:Ripple Effect

[Anonymous Coward]

I'm fairly certain that if someone you cared deeply for was at serious risk of catching Dengue, you really wouldn't give care quite as much how the ecology would fare without those mosquitoes.

I wish people wouldn't say stuff like this. You're basically saying, "If you only had a bunch of emotions interfering with your logic, you would change your mind." It's anti-reasoning, and it's senseless. The rest of your post was good but raw appeals to emotion like this just demean it.

Re:Ripple Effect

[Dutch Gun]

Brilliant straw-man argument there. You now have me burning down forests, killing grizzly bears, starfish, kelp, and other highly important and relevant species that would obviously have a devastating impact on the environment were they suddenly removed. And yes, I'm well aware that size alone does not necessarily dictate importance in the larger scheme of things (e.g. ocean plankton). But the notion that every single species is equally vital to the ecosystem is simply fallacious to any reasoning mind.

Yes, I'm well aware of the dangers of introducing species to new areas or making changes of any sort of an ecosystem. I just happen to think that saving so many human lives is worth the risk in this case. I'm sorry you don't feel the same way.

Re:Ripple Effect

[Dutch Gun]

In New Orleans, we eliminated centuries of Yellow Fever by draining the swamps, not by targeting a species with untested genetic engineering weapons. Call me crazy, but that sounds more devastating to the environment than the proposals we're discussing. I wish I could find a link, but I seem to recall how scientists are just now discovering that draining the swamps has a more serious impact than they figured (although I can't remember the specifics).

Fortunately, public health decisions aren't made by one guy calling themself "Dutch Gun" who wants to just walk around pulling triggers because of their single personal benefit. And thank God for that. I'm pretty sure I wouldn't want that responsibility, which is why I presented it in what I thought was a purely hypothetical context as a way to indicate my support of the scientists' efforts. Also, I'm not sure what sort of "personal benefit" I would receive from eliminating those mosquitoes, other than the warm, fuzzy feeling I'd get from saving so many lives.

Instead, people with that kind of power typically don't make decisions with at the neural level that slaps at a sting. Instead we think of the actual costs of human intervention, and how that's different from the more integrated processes in nature eliminating species, and learning from when it's the same, and causes a ripple effect that we'd rather not be injured by. All snarkiness and bravado aside, I do very much agree with you on this. Obviously, I'm neither in a position to eliminate a species from the face of the earth, nor do I have the foresight or specific education to reliably predict what the effect on the ecosystem will be with the introduction of genetically-modified mosquitoes. That being said, I feel it's equally foolish to automatically react against any sort of genetic solution to a problem because of a lot of worst-case "what-if" postulation by people who aren't remotely qualified to understand the full ramification of genetic modifications and our eco-system. I do sincerely hope, as I'm sure you do, that these decisions are made with the utmost consideration of consequences, both large and small.

But... what's the long term impact of this?

[drspliff]

I really don't know enough to speculate, but one question is: what's the long term ecological and biological impact going to be?

If these things don't breed... then they start dying off? Then what happens when the mosquito population severly reduced, will other insects take their place, or will the ones naturally immune to this grow bigger etc...

Although, a world without mosquitos would be nice :D

Re:But... what's the long term impact of this?

[Mr. Roadkill]

And what about places like Hawaii, where there were no mosquitoes until they were introduced by man? Hawaiian biota managed to do just fine before mosquitoes were introduced. Surely it wouldn't be a terrible thing to eradicate them there?

Eradicating mosquitoes in Hawaii probably wouldn't cause a major ecological disruption - unless the mosquitoes themselves had completely displaced some other organism in some niche (as either prey or predator) - but it's harder to say what would happen elsewhere. What happens to all the things that eat mosquitoes and mosquito larvae if there aren't any mosquitoes? Also, for much of the time, mosquitoes are nectar-feeders too - so if there are plants that depend primarily on mosquitoes for pollination, there could be an impact on organisms that depend on those plants. Sure, life adjusts, and a new equilibrium is established - eventually. That still doesn't mean we shouldn't be damn careful, because in the meantime there's a chance that we could do something that we'd find extremely inconvenient or unfortunate.

Whatcouldpossiblygowrong

[caller9]

Am I the only one that's noticed a ton of these "whatcouldpossiblygowrong" tags recently. Did the mad scientist class of '07 get to work quickly or what? Who is throwing all this money at applying knowledge we barely have to applications we can't imagine the repercussions of. Some of this stuff could turn out a little worse than introducing cats to Australia, if you catch my meaning.

Re:The Eco-Nut replies are telling

[Nemilar]

You're failing to take into account the big picture. People worry about the ecosystem because people are a part of the ecosystem. What affects one section of it, affects it all, including us.

It won't do people very good if, because we wipe out one creature, another creature dies out, and then another, and so on. It's called a food-chain, and an eco-system for this very reason.

Re:Are mosquitos important?

[Whiney Mac Fanboy]

I have often wondered (living in the mosquito-ridden South), if mosquitoes have any benefit to the ecosystem at all.

Bottom line is that Mosquito larvae are extremely beneficial to ecosystems (as food). Read this for a quick overview. Contains the quote:

mosquito larvae might be pictured as: "small machines that transform algae, bacteria and organic matter into compact packages of protein.

If you want to read something a little more specific to the south, try this Mosquito Virtues article.

Re:The Eco-Nut replies are telling

[Jah-Wren Ryel]

Lots of people worried about birds or "The Ecosystem". Very few seem to be worried about the millions of PEOPLE who die HORRIBLE DEATHS thanks to Dengue fever. People are part of the ecosystem too.

Fuck with "the ecosystem" and you risk secondary and tertiary effects that may produce dramatic changes for people too.

I guess it's to be expected from the "Silent Spring" crowd, who refuse to acknowledge that the REAL effect of banning DDT has been millions of deaths from malaria, against a hypothetical doomsday scenario. Sound familiar? Lol! PERFECT example of your own short-sightedness. DDT was banned because it was really fucking up PEOPLE - not the "ecosystem." It looks like DDT would be the lesser of two evils now. But are you so sure that these genetically modified mosquitoes are really the lesser of two evils? How do you know that? Are you so sure there aren't any other options?

Did you see that news article today about how partisan people are all about the emotional reaction rather than rational? Your use of term "Eco-Nut" and your simplistic framing of the discussion all point to a partisan opinion on your part.

This could make things worse

[poisoneleven]

On a bad side, if the mosquitoes adapt to reproduce prior to their sudden kill time, this could severely increase the problem as they would be able to reproduce in even smaller and shorter lasting pools of water.

*cough*killerbees

[tgd]

They've tried this before, I think...

Re:*cough*killerbees

[Phyvo]

In part, you're right. I guess. However, what happened with the Africanized bees (if I remember correctly) was that they put loads of boxes of European (I think that's the term for it) bees in the hopes of diluting the Africanized ones. This didn't work because although the two would breed together the more Africanized the bee the sooner the queen would hatch from the egg... and kill any other developing queens present. So the Europeanized offspring were wiped out before they could reproduce.

This is something altogether different. Their goal *is* population reduction, not domestication of the population... so as long as they get 50% of the females (like they have already in the lab) to waste their time producing offspring that will die, the job is done, they've just killed 50% of the next generation of mosquitoes. So I can't see a similar mistake happening.

Re:The Eco-Nut replies are telling

[jaxtherat]

Uhm, DDT was banned as it is a carcinogen, and not for the environmental impact. All Organochlorides were phased out on most developed countries for that reason.

http://www.pan-uk.org/pestnews/actives/ddt.htm

What we now use are mostly Organophosphate based pesticides (which are probably just as bad, but 'luckily' the metabolites are much harder to trace, so you can't get sued if your products poison an entire generation :roll eyes:).

http://en.wikipedia.org/wiki/Organophosphorous

Re:The Eco-Nut replies are telling

[Ramze]

So, you're saying that without malaria, the world would be even more overpopulated? I guess there's another benefit to not having toxic DDT in our environment. Not that I think dying from malaria is a fun thing and I'm playing devil's advocate for a bit... but if we're truly going to look at the big picture here, putting poisons into the water we drink and killing animals using toxins that kill or mutate animals further up the food chain is a terrible outcome from long term use of such poisons. Also, people die every day from all sorts of things. That's part of the human condition. We have to put such things into perspective. Long term, if it weren't for diseases, the world's population would be too massive for Earth's biomass to sustain it. We'd all starve from over fishing and overfarming the same land, poison ourselves with more pollution, and probably kill the planet by destroying all the rain forests and start a chain reaction killing the food chain from the bottom up until the planet is completely dead. War and murder keep the population in check somewhat, but it's still exploding. Sooner or later, people are going to have to learn to live in harmony with their environment again - and that means putting checks on how many offspring we have... and being careful about what we put into our environment so that we don't get harmful things back from it later.

Focusing on the deaths of a small portion of the human population to justify contaminating the ecosystem we ALL need to survive is short-sighted. Perhaps you value the lives of those who die from malaria more than the lives of all the human beings and other living things in the future who will have to suffer the consequences of having toxins in their environment for however long it takes for the earth to clean up the mess, but I don't. Earth is going to be here for a very, very long time and I'd like for our future generations to not curse us for the condition of the planet they inherited.

Would you honestly endorse the use of a chemical like DDT that is KNOWN to reduce bird populations because of thinning egg shells... and to be toxic to not just birds but "also highly toxic to aquatic life, including crayfish, daphnids, sea shrimp and many species of fish" and "moderately toxic to some amphibian species, especially in the larval stages." It also builds up in the food chain to toxic levels as more is accumulated and stored in the fat of animals. It's half life is long enough to where it'd easily be picked up by just about any ecosystem, build up over time, and kill the ecosystem. We don't even know what the long-term effects on humans would be. Something tells me it's going to be worse than malaria if it's use is continued and constant.
DDT Wikipedia

Having said that, these genetically engineered mosquitoes sound great. They're a biological, biodegradable, non-toxic solution to the overpopulation of mosquitoes. Sure, the drop in the mosquito population may affect birds, bats, and other animals further up the food chain, but probably not to any noticeable degree considering most animals that eat mosquitoes have other food sources. I'd say investing in mosquito netting for the areas effected would also be a good idea -- along with mosquito traps if they can afford them.

The environment arguments are one-sided

[khallow]

The thing that annoys me about the concern over certain mosquito species (some which aren't native) is that this ignores that poor people have the heaviest environmental impact. I doubt even a disruption of the local food chain is comparable. And what's one of the many ways to make lots of poor people? Sick people. Sick people miss work and incur health costs. They often get permanent disabilities. And that adds up especially when 100 million people get sick each year. And everyone that dies is someone who could have contributed to raising themselves and others out of poverty. And in case people have forgotten why poor people contribute more to environment problems, keep in mind that poor people cause more environmental damage both through lack of education, apathy, and because the small economic gain from considerable environmental damage can pay for food and such things. Further, they have a higher reproduction rate than wealthier people.

While disruption of food chains are well known, the current argument seems to be that we don't "know" what effects the proposed strategy will have on the environment. As I see it, the effects of poverty and overpopulation are well understood while the effects of food chain disruptions are also well understood. What else is there? And more importantly, if one were rational about it, how would you rank the potential for environmental damage either way? What mitigating factors can you use? As I see it, the effects of poverty and the role of disease in perpetuating that are clearly harmful in an environmental sense. The effects of food chain disruption are pretty clear as well. Keep in mind that humans have been killing mosquitos wholesale for quite some time and disrupting food chains when they do so. Finally, there seems to be unfounded concerns about the modified mosquitos with no justification given for that. Name the danger, the unintended consequence not some vague concern because humans did some unrelated and that had unintended consequences.

Re:The environment arguments are one-sided

[khallow]

I glanced at the ecological footprint methodology. It's the wrong approach since it will automatically blame the most economically active regions rather than the regions that are actually polluting. It should be calculated like GDP. Each step in the supply chain uses a certain amount of land and generates a certain amount of economic value. Then as you will see, the poorest countries will have the worst environment impact by any reasonable measure: pollution per capita, species extinctions, incident of preventable disease, and worker safety. These are more noticeable when one compares them to the GDP that the activities generate. The poorest countries are extremely inefficient when it comes to producing value. Reducing disease in these countries will have the effect of reducing the environmental impact of these countries (since as I pointed out already, richer countries have lower environmental impact).

I think it's quite important to consider where the ecological contribution to footprint comes from. Consider a shoe. A considerable portion of it is made overseas (for all but a few exceptions). If no part of the world is as poor as the bottom half of the supply chain that currently makes that shoe, then were will the pollution come from? What cheap land and labor is going to contribute inefficiently to that shoe's ecological footprint? In modern green lingo, we have "exported" the pollution to these poor countries. But what happens when the pollution no longer can be exported simply because there is no poor country to export it to? Then the supply chain for the shoe becomes more efficient and its footprint shrinks.

And that's ultimately why ecological footprint is a bad measure. Here we are disagreeing on whether becoming wealthier will reduce environmental impact. And our interpretation depends wholely on how we measure it. My take is that while it's not intuitive, ecological footprint will go down when the world gets wealthier. That's because the supply chain gets more efficient.

Re:The Eco-Nut replies are telling

[QuoteMstr]

What balance? How about the rise of oxygen-producing cyanobacteria, which single-handedly raised the concentration of oxygen to where it is today over a few million years? Keep in mind oxygen was a poison back then, and no doubt killed a lot of early life.

How about the Permian-Triassic mass extinction, which killed 96% of all marine species and a little over 70% of land species? How about the Cryogenian glaciation, also known as Snowball Earth, when glaciers reached the equator? How about the Carboniferous, when the oxygen concentration was so high that wet grass could burn? Hell, compared to the last ice age, the last ten thousand years have been wickedly hot and weird.

There is no balance in nature. There was no Garden of Eaden before we ate from the tree of science and sinned with industrialization. There was no paradise, only variable, capricious nature. The environment is valuable, but remember that we should protect it for our sake, so that we have a place to live, not because a trout or a tree is morally superior to man.

the way this evolution 'thingy' works ..

[Respawner]

well, the way it goes with diseases is,
random mutations cause some to be immune, they remain alive
the next year only the immune creatures breed and they fill the void made by the lack of breeding of the then dead ones
in 3 years time the population is back to the old level, but now the creatures have immunity for this affliction
i can't see why this wouldn't happen with an engineered disease or disorder, but then i'm no biologist either, so fee lfree to correct me
seriously, why is evolution that hard to believe for some people (religious fanatics mostly) ?

Other effects

[LoudMusic]

I'm all about saving lives, even if they're outside of my Monkeysphere. And others have mentioned issues with a mosquito replacement, or the problems with the species that eat the mosquitoes.

But what about the 5 million people per year that suddenly aren't dieing of mosquito transmitted diseases? That's a lot of new people! The people that are making all these new people are going to have to dramatically change their life style. It's no longer "make more babies and hope they life". They'll have to make fewer babies and keep them fed. We went through that in the United States a couple hundred years ago as our medications got profoundly better, but it took time for people to catch on.

The populations in the areas most effected by this big of a change are going to experience HUGE population growth, doubling in years instead of decades or more. Can their cultures support that kind of growth?

Nice pets

[Fuzzums]

And I think rabbits would make a very nice pet in Australia. Rabbits don't cause any harm, do they?

Re:Didn't we learn

[tomhudson]

"Why not breed mosquitoes that are immune to, or can't be carriers of, the Dengue virus?"

Simple answer - follow the money. Once the modified mosquito is in the wild, if it does have an advantage, it will displace regular mosquitos with no annual expenditure required.

Its the same reason nobody's looking for a real cure for the common cold - it sells more OTC (over-the-counter) "remedies" than any other disease. And the tie-in sales for kleenex, lysol "kills germs on contact", "antibacterial" soap (since when hasn't a soap been antibacterial), and you're looking at a lot of money.