Mosquito-Borne Diseases Are Spreading As Temperatures Rise

RACHEL FELTMAN: This is Science Friday. I’m Rachel Feltman, host of Popular Science’s The Weirdest Thing I Learned This Week and Scientific American’s Science Quickly. I’m back here at SciFri today to fill in for Ira Flatow while he’s on vacation.

Later in the hour, we’ll dive into the mysterious world of eels and explore their surprising connection to crime. But first, this week, a New Hampshire man died of eastern equine encephalitis, a rare but serious mosquito-borne virus. Human cases have also been reported in Wisconsin, New Jersey, Massachusetts, and Vermont, prompting some municipalities to step up their mosquito control efforts and even advise residents to limit outdoor activities during dusk and dawn.

Joining me now to talk about this and other recent science stories is Sophie Bushwick, senior news editor at New Scientist in New York. Welcome back, Sophie.

SOPHIE BUSHWICK: Thanks for having me.

RACHEL FELTMAN: Thanks for being here. So tell me more about this virus. What is it, and how concerned should we be?

SOPHIE BUSHWICK: So the good news is eastern equine encephalitis is still very rare. It has killed five people in the US this year, but that is five people out of the whole US population. So it is definitely a concern. The problem with this disease is it has a 30% mortality rate, and it can cause permanent damage to people who fall ill with it. They can have problems for the rest of their lives. So it’s absolutely a threat that we should be taking seriously, but I don’t think that folks need to be living in fear necessarily.

RACHEL FELTMAN: Right. That makes sense. And this isn’t the only mosquito-borne disease out there, of course. In fact, last week we saw a disease specialist, Dr. Fauci, recovering from West Nile virus.

SOPHIE BUSHWICK: That’s right. A lot of these mosquito-borne diseases are actually spiking a bit alarmingly. We’ve also seen much higher cases of a disease called oropouche virus in South America– Brazil alone has had an 800% increase in the number of cases– and the mosquito-borne disease dengue as well. We’ve got almost double the cases this year compared to last year, and last year was at a record high. Dengue can cause symptoms similar to flu, but it can also in severe cases cause bad bleeding that can cause shock and then death.

RACHEL FELTMAN: Wow. And what do we know about why all of these are spreading?

SOPHIE BUSHWICK: Well, for this one, we can pretty much blame climate change. Mosquitoes love warm weather. They love wet weather. So basically if you are sweating and uncomfortable, a mosquito is going to be very happy. And climate change is not just making their season longer, it’s also making their geographic range broader, so they’re able to spread into areas where maybe they wouldn’t have been able to survive previously.

RACHEL FELTMAN: I’m unhappy. The mosquitoes are happy. Nobody’s winning.

SOPHIE BUSHWICK: I know. Yeah, mosquitoes love biting me and I hate being bitten, but it’s unfortunately the way it is.

RACHEL FELTMAN: So is there anything that people can do to protect themselves?

SOPHIE BUSHWICK: Yes. The same measures that you take to avoid getting bitten by mosquitoes will help protect you from mosquito-borne disease. So things like staying indoors during the time of day when mosquitoes are most active, which tends to be around dusk. That can help. Wearing bug spray, wearing maybe long sleeves and pants if you know you’re going to be out for a long time. Putting screens on your windows and doors is helpful and just making sure there’s no standing water around. So if you have an outdoor container that tends to get filled up with rainwater, make sure you’re emptying that out.

The other option is pesticide spraying. So we tend to be very cautious about this because DDT caused a lot of problems historically. But one option that Massachusetts is using right now is a different pesticide. It’s called Anvil 10 plus 10. And they send people a warning to stay indoors during the time when they’re spraying, which is very helpful for avoiding having problems with humans. Then they can spray the pesticide, it keeps down the mosquitoes, and it protects folks from mosquito-borne illness.

RACHEL FELTMAN: Staying loosely on the climate topic, you have a story about something people can do to help the planet while they’re behind the wheel.

SOPHIE BUSHWICK: That’s right. This is a relatively minor intervention, but it can actually make a big dent in emissions from passenger vehicles. So if you’ve ever been in a car with someone who goes up to an intersection, you know that different drivers have different styles. Some people like to slowly glide up to the intersection, and some people accelerate all the way there and then slam on the brakes. And it turns out that the gliding technique is better. If all cars glided up to intersections, then passenger vehicles could cut their total carbon emissions by 5% to 10%.

RACHEL FELTMAN: It’s funny, my brother-in-law has a hybrid and is one of those people who really pays attention to his efficiency, and he’s been gliding all this time. He already knew it. How much of a difference can this make? Is it just a thing people can do personally, or is there a way that cities or road planners could actually take advantage of this?

SOPHIE BUSHWICK: So one thing that’s cool about this is a lot of cars these days have some sort of semi-autonomous features. You might have– your car might help you stay within your lane or some people, their cars can take over when they’re driving on the highway. But it could be programmed into smart cars like this to slow down automatically when they’re approaching an intersection. It could set the pace for them.

Another thing that could happen is the traffic signal. You could put a device in the traffic signal so it’s communicating with the cars coming up and being like you’ve got five seconds or you’re at a distance where you’d have to really accelerate to make it through. So instead why don’t you slow down and glide, and that way you’ll have a less emissions heavy experience with this intersection.

RACHEL FELTMAN: Very cool. Taking a hard turn now into the world of strange physics and dark matter, I know you have a story for us about those spooky physics things.

SOPHIE BUSHWICK: Yes, I have a very wimpy story for you, wimpy as in weakly interacting massive particles or wimps. So researchers know from looking at gravitational effects that about 80% of all matter is actually dark matter. But this is a mysterious substance that doesn’t seem to even interact with light, which makes it really hard for us to detect it. And so we have a bunch of different theories about what it might be, and one of the leading ones is that it’s a wimp. It’s this– all these particles that interact very weakly with regular matter, and that’s why we’re not able to detect it.

Despite that, researchers are trying to detect it. They’ve buried this detector about a mile underground called LUX-ZEPLIN. It’s been running for about 280 days now, and it has found nothing.

RACHEL FELTMAN: Huh.

SOPHIE BUSHWICK: Yeah.

RACHEL FELTMAN: Is it that the particles aren’t doing what they expected or they’re just not looking at the right particles? What do they think is going on?

SOPHIE BUSHWICK: So what they think is happening is just that they’re– the good news is they’re able to restrict the limits of what these particles are able to do. It’s like one of the researchers compared this to searching through the ocean for a magical fish. So they’ve been searching and they’ve searched about 75% of the ocean, so they know that either this magical fish is in the final 25% and they’ve got a better idea of where to look for it or the other possibility is that the fish doesn’t exist.

RACHEL FELTMAN: Wow.

SOPHIE BUSHWICK: The [INAUDIBLE] fish.

RACHEL FELTMAN: That’s wimpy physics for you. Another mysterious thing, the brain during mating in fruit flies naturally. Tell me more.

SOPHIE BUSHWICK: Yeah. So researchers have known that when male fruit flies are going through courtship and they’re getting close to mating, they seem to be unable to visually detect threats nearby, and this isn’t great for fruit fly longevity. They need to be able to fly away from those predators. So they looked at their brains while the flies were going through courtship, and what they found was that towards the beginning of courtship, the male flies would they had a– they simulated a predator using light and shadow nearby. And the male fly would say, oh no, I’m getting out of here.

But then as the fly got closer to sealing the deal, as it got closer to the mating moment, it seemed to lose the ability to detect that threat. And they found that dopamine in the brain was increasing as the fly got closer to achieving its goal, and they think that the dopamine is just blocking some of its sensory pathways, basically forcing it to tune out all distractions as it focuses on what it wants.

RACHEL FELTMAN: Wow, I guess that is an evolutionary trade off.

SOPHIE BUSHWICK: Yes, totally.

RACHEL FELTMAN: So moving up a bit in size, researchers are now looking at how marmoset monkeys address each other.

SOPHIE BUSHWICK: Yes. Marmoset monkeys seem to use names to call each other, and this is the first non-human primates that we’ve seen this behavior in. So it’s very exciting and also very cute. I would encourage folks to look up pictures of these marmosets. They’re adorable.

RACHEL FELTMAN: Always good advice. And I know we actually have sound of this. We’re going to play some of these calls. But just a note, if you’re listening in the car as opposed to with headphones, you probably won’t hear it. It’s very high pitched. We promise there is actually a sound playing. You should go back and check it out later.

[HIGH-PITCHED NOISE]

Yeah.

Wow. So what are they saying?

SOPHIE BUSHWICK: It’s– I love that it’s almost bird-like. That’s crazy.

RACHEL FELTMAN: Yeah.

SOPHIE BUSHWICK: Yeah. These calls are called phee calls, which I think is a nice– is appropriate– an appropriate name for it. And basically the researchers recorded– took a lot of recordings like this. They took recordings of marmosets in the lab, and marmosets tend to live in these close knit, monogamous family groups. So they took marmosets from three different families, and then they paired them up in different ways and listen to their calls. And then they used AI to analyze those calls and to pick out these very subtle acoustic differences in the way the marmosets called each other, and then they played recordings of these calls for marmosets to see how they responded.

And what they found was that marmosets make tweaks to their calls depending on which monkey they’re addressing. So they’re basically encoding specific information, which we would think of as like a label or a name in it, and different monkeys from the same family group will call a monkey with the same modulation so like using the same name to refer to the same individual.

RACHEL FELTMAN: Oh, wow. So different marmosets have the same name for a specific marmoset?

SOPHIE BUSHWICK: Exactly, yes.

RACHEL FELTMAN: That’s very cool. So what does this teach us? Why do we care beyond the obvious? I care deeply. But why do scientists care?

SOPHIE BUSHWICK: Well, we think that human language didn’t just appear out of nowhere. We gained this ability. We probably developed it over time. And so by looking at animals like these marmosets or other species that seem to use name calls– so we’ve also seen this behavior in parrots, in Egyptian fruit bats, in elephants– so by looking at the way that this name use works in animals that don’t use what we would think of as human language, we can learn more about how we developed the ability to speak.

RACHEL FELTMAN: And finally another kind of communication, music, and how human brains react to it. Tell me more about this.

SOPHIE BUSHWICK: That’s right. So one of the things that makes it really fun to listen to a song is that it has distinct segments, and there’s something between the segment called a musical boundary. It’s like when you know the beat’s about to drop in a song. You’re approaching the musical boundary. So fun.

So researchers were like, well, what’s going on in the brain when this musical boundary is coming up. And to find out, they took brain scans of these subjects while they were listening to three different– very different songs. So one of them was in the genre of nuevo tango from Argentina. One of them was progressive metal from the US, and then one of them was Stravinsky so Russian ballet.

RACHEL FELTMAN: Waiting for the beat to drop in Stravinsky is underrated, and I’m not being sarcastic. That was one of the original beat drops in my opinion.

SOPHIE BUSHWICK: It’s a classic. And what they found was that when they were approaching that point, when they were approaching that musical boundary, people’s– a network in the subject’s brains lit up. And then after they pass the boundary, a different network was lighting up. So it’s like your attention is shifting between these two areas, and they actually compared it to the way that our brains change attention to understand the differences between sentences in language.

RACHEL FELTMAN: Very cool. That’s all the time we have for now. Sophie Bushwick is senior news editor at New Scientist. Sophie, thanks so much for being with me today.

SOPHIE BUSHWICK: Thank you.

Copyright © 2024 Science Friday Initiative. All rights reserved. Science Friday transcripts are produced on a tight deadline by 3Play Media. Fidelity to the original aired/published audio or video file might vary, and text might be updated or amended in the future. For the authoritative record of Science Friday’s programming, please visit the original aired/published recording. For terms of use and more information, visit our policies pages at http://www.sciencefriday.com/about/policies/