Mosquitoes are deadly. Should we kill them all?

0:01It's my least favorite part of summer, and it might be yours too. You're enjoying a backyard barbecue with friends and family, and then suddenly you've been bit by the summer evening's nemesis, the mosquito. And what it's left you with is an itchy red welt that honestly can ruin your good time. But mosquitoes, they're not just a nuisance. They carry and spread lethal diseases like malaria and West Nile virus. They kill more people each year than any other animal. So when I heard that there might be a way to rid the world of mosquitoes, my immediate thought was like, well, obviously we should do it.

0:45We should kill them. We should kill them all. I was surprised by this possibility that we might actually be able to get rid of all the mosquitoes in the world that carry malaria. And I discovered this huge raging debate about whether or not we should actually try to do that.

1:03From the newsroom of The Washington Post, this is Post Reports. I'm Kolbie Echowitz. It's Thursday, July 24th. Today, I talk to climate and wildlife reporter Dino Grandoni about the science of eliminating mosquitoes and why eradicating an entire species raises complicated bioethical questions.

1:31Dino, hey, thanks for being here. Oh, thank you for having me on. To me, a world without mosquitoes, that sounds amazing. I would love to be able to sit out on a summer night and not worry about getting bit. But this is more than just like my inconveniences. There'd be some enormous worldwide benefits, right, to getting rid of mosquitoes. Yeah, mosquitoes aren't just a nuisance when, you know, we're sitting around during the summer. they spread some of the worst diseases that any person can get. It includes stuff like West Nile virus and dengue fever, and probably at the top of that list is malaria.

2:03And that kills what? It kills more than half a million people a year, mostly in Africa. I mean, that's a crazy number to think about. Yeah, and it's crazy to think that it might be in our capacity to do something about that. And isn't it actually, like, getting worse? The problem is actually getting worse, right? climate change is giving rise to even more of these mosquitoes in some of these places. Yeah, as the world gets warmer, it becomes more habitable for mosquitoes. And that's a problem for humans. Dino, I am incredibly intrigued by this idea that we could eradicate all mosquitoes. And like I said, would freaking love it.

2:40So talk me through, like, how would that work? Like, how would it work to actually get rid of all the world's mosquitoes? Well, really, you have to get deep down into mosquitoes at a cellular level where scientists have figured out a way of tinkering with the genes of the bug in order to do this. So scientists have discovered this way of altering the genetics of a mosquito so that the males, they're fine. They can fly around, they can do their thing, but the females have been rendered infertile. Basically, they've been given non-functioning ovaries. They grow these mosquitoes in the lab. And really the secret sauce that these scientists have added to this genetic change, it's called a gene drive.

3:26And basically it works like this. Under the normal rules of inheritance, a gene has about a 50-50 chance of being passed along to the next generation. But with a gene drive, scientists are able to rig that coin flip and ensure pretty much that a trait gets passed along to the next generation. So with a gene drive, scientists are able to spread this trait from one generation to the next and then out to basically every single mosquito, which will cause the population to crash because none of the females can breed. So wait, Dana, so how then does, you know, when they're doing this, how do you, I mean, how many mosquitoes are there in the world?

4:07Millions of mosquitoes? Like, how do you? Oh, there's trillions. I mean, how do you change the genes in every mosquito? Like, where does this even begin? Well, you release several hundred, let's say, or several thousand. You release some, and those mosquitoes breed with the wild mosquitoes and then are able to pass along this trait to those mosquitoes and to the next generation of wild mosquitoes and so forth until the idea goes, it would spread to the species' entire population. And really, what gene drives do is they allow us humans to be able to override the normal rules of inheritance that we learned from Charles Darwin, where you have this advantageous trait.

4:46Under the normal rules, this advantageous trait would spread across the population. But here we're actually trying to figure out a way of spreading a disadvantageous trait for the mosquitoes. So are we talking eradicating, like, all mosquitoes here? Yeah, scientists today are focusing on the types of mosquitoes that carry malaria, but there's a potential here to use this technology on all sorts of mosquitoes if we want to. I mean, besides this new technology, which is obviously a pretty extreme measure for addressing malaria-carrying mosquitoes, I mean, are there other things available to us to prevent this disease?

5:24Scientists and doctors are doing a lot right now to try to combat malaria. They're developing and deploying insecticides to try to kill the bugs. They're putting up netting to prevent the insects from biting people. They're deploying drugs to treat people who get sick with it. And there's even a vaccine that they're distributing. But a lot of this stuff is really, really hard to scale up to the level of actually eradicating the insects and the level of actually getting rid of this disease for good. But this gene drive technology, it holds that promise. Yeah, to that end, have you spoken to anyone who's excited at the prospect of this, who talks about the benefits of it?

6:02Yeah, I spoke with a man named Paul Indabale. He grew up in Zimbabwe, but he works today as a biothicist at George Washington University.

6:11Dino Grandoni:I grew up in the Zambezi Valley, an area that has got lots in terms of wildlife. Mosquitoes that carry malaria are rampant there. he's lost nephews, nieces, uncles, aunts, many extended family members to this disease. And of course, when some of the family members die from malaria, it becomes something that is, you know, traumatic. This is an awful disease that manifests in all sorts of ways, joint pain, eye fever, a sickness that can progress within days of a bite. I think maybe the scariest situation for him, though, was when his son got sick when he was about seven years old. After his son got bit, he started to hallucinate.

6:55And this is a common symptom of malaria because malaria can affect your brain. When he was in this condition, when he was hallucinating, he climbed out of a window on the ground floor in the middle of the night. And Paul and his wife were really scared. And they took him and rushed him to the hospital. Thankfully, it was in time, though, and they got him the treatment that he needed.

7:16Dino Grandoni:But I'm imagining for people who live far away from hospitals or clinics or people who live in areas where the clinics are poorly equipped, they don't have the right drugs for malaria, then that would be something else. So then what does he as a bioethicist say about the possibility that we could, you know, get rid of mosquitoes and in turn potentially free the world of malaria? Yeah, so Paul sees a lot of excitement around using some of this latest technology in communities that are affected by malaria that are hit hard by them, including in Africa. They are seeing people that are dying every day.

7:56Dino Grandoni:They are seeing people that are dying every week. And for them, they want to ensure that there are efforts to reduce the number of mosquitoes that are flying out there and at the end of the day, reduce the number of people that die as a result of malaria. So the people I've talked to who are working in Africa, they know how real malaria is. They have their own questions, of course. I've talked to people who try to combat misinformation around some of these mosquitoes, where there's some fears that being bitten by a genetically engineered mosquito will somehow affect them or render them sterile.

8:33That's not the case. Oh, fascinating. So there's a bit of misinformation that some of these scientists working in Africa have to combat, but there are a lot of people really excited on the continent for this. And with Paul, he's really excited too and interested in this idea, but he recognizes that not everyone's on board with moving forward with this sort of thing in the wild.

8:56After the break, the argument in favor of letting mosquitoes live, and whether humans should be allowed to modify Earth's entire ecosystem. We'll be right back.

9:40We'll see you next time. Ask the Post AI. Find it on WashingtonPost.com or in the app. So, you know, we just talked about, like, how absolutely devastating mosquitoes are and how many people they kill. And there seems to be, at least in my estimation, a pretty strong case for getting rid of them. But how controversial is this proposal to take out an entire species? Yeah, there are a bunch of people speaking up for the mosquito, in favor of the mosquito. So first off, there's this practical ecological concern about how much we actually know of the role mosquitoes play in the ecosystem. What happens to all the different animals like frogs that eat mosquitoes and rely on them as a source of food if we somehow got rid of that insect?

10:28There's also this question of like what might replace the mosquitoes? If we got rid of all the malaria-carrying ones, would some other insect step into that ecological niche and wreak its own havoc, spread some new disease that we don't even know about? And some scientists bring up the fact that what we were just talking about before, there are effective ways of combating malaria, netting insecticides, drugs that might do the trick without us having to wipe out an entire species. And beyond all these like practical concerns, there's this idea that species have some sort of intrinsic value that like it's not really our place as humans to try to pluck one entire species off the face of the earth.

11:11That's not our job and we should try to do it. There's some people who make that kind of ethical argument. Right. So for people like me who sees no value in a mosquito, who am I to say, right, that mosquitoes might not be here for some reason? Yeah, I mean, there's even a, we're talking about science here, but there's even like a religious argument that some people can make about God created these species. What right do we have to take them out? You know, the idea, you could look back at tradition like the story of Noah. He was asked to put every single species on earth on his boat. He wasn't, he didn't give us the space to choose which ones we did or not.

11:51Did Noah put two mosquitoes on the ark? I didn't read that in my Bible. but maybe he did, yeah. Maybe he did. I'm struck by your point, too, that, you know, maybe something could follow in its wake, that nature has this ability to kind of adapt and outsmart even our best efforts, right? And that maybe there could be some real unintended consequences beyond just kind of the ethical question of, like, we shouldn't be messing with nature. Like, how big of a concern is this with scientists? The scientific community has had long discussions about the ethics and whether we should be eliminating a species, because that's a really big deal, interfering with the natural world.

12:30So recently, Arizona State University and the Hastings Center for Bioethics, this research institute in New York State, brought together a group of bioethicists to discuss the potential pitfalls of intentionally trying to tinker with nature and render a species extinct in this way. And they came to a stance, and that was basically that full deliberate extinction might be acceptable on occasion, but it should be only done in extremely rare cases. So they were sounding a real note of caution here. I mean, one could, I would imagine, make the argument that a bug that kills as many people as a mosquito kills might be one of those kind of rare exceptions.

13:12Oh, there's plenty of people making that argument, and it's a hard one to combat, and I'm not sitting here trying to. We're talking about mosquitoes here, but really we're talking about more than that because this sort of gene drive technology can be applied to other sorts of insects and other sorts of creatures in general. And there's this question, this ethical question of a slippery slope. If we're able to do this with this one insect, can we do it with some other pests that we don't like? Is there something else that they could do to kind of alleviate the harm that mosquitoes cause that wouldn't go quite so far as fully trying to get rid of them?

13:43So there actually might be a compromise here where instead of targeting the mosquito itself, we could target the real cause of malaria. And that would be this tiny microscopic single-celled plasmodium that's inside the mosquitoes and that when transferred to us humans causes malaria. Potentially we could create a gene drive that targets that organism, that plasmodium, rather than the mosquito itself. Huh. So in that case, you wouldn't be killing, like, all the mosquitoes. You would just be killing their ability to spread malaria. So how far along is that kind of research? That's a little bit behind the research into targeting the mosquitoes themselves, but it's an option, and it's one that scientists are considering.

14:28So do you know, who would even get to decide whether or not this gene drive technology moves forward? Like, who would have to approve it? who ultimately gets the say in, okay, we're going to eradicate all mosquitoes. So yeah, that's one of the really fraught things about this. Right now, researchers with Target Malaria, which is one of the big groups doing some of this research, have approached governments in Africa, including in Uganda and Burkina Faso, about actually releasing some of these animals into the wild. But of course, animals don't know the borders that we draw on a map. And these mosquitoes could easily fly over them and do their thing in countries that perhaps haven't approved this sort of technology.

15:08So all this adds an extra layer of difficulty to this whole task. I came into this conversation thinking we should 100 % kill mosquitoes. I'm not sure that you've convinced me that we shouldn't. I still maybe think that we should. But, you know, we've asked, you know, the can we, it sounds like maybe we can. And should we? That's up for debate. Will we? Like, how likely is that this actually happens? So the scientists I've been talking to, part of this group called Target Malaria, they want to start releasing these within the next five years. So we're talking about something potentially that can happen within our lifetimes.

15:41Wow. But trying to eradicate all mosquitoes, not just the malaria-carrying ones, but the other species that don't carry malaria, that's a gigantic undertaking. There are more than 3 ,000 different species of mosquitoes, and each one of them might have to have its own particular gene drive. And even trying to get rid of one species, you know, even with the gene drive, that's still going to be really, really difficult to do.

16:07Well, Dino, thank you so much. Thank you for coming and teaching me all about this. It's fascinating. Oh, thank you so much.

16:17Dino Grandoni is a climate and wildlife reporter at The Post. That's it for Post Reports. Thanks for listening. Today's episode was produced by Tadeo Ruiz Sandoval. It was edited by Ilana Gordon with help from Ariel Plotnik and Maggie Penman. It was mixed by Sam Baer. Thanks to Marisa Belak. I'm Kolbiechowicz. We'll be back tomorrow with more stories from The Washington Post.

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