The Mosquitoes Are Winning - podcast episode cover

The Mosquitoes Are Winning

Oct 05, 202330 min
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Episode description

For decades, the world seemed to be winning the war against mosquitoes and tamping down the deadly diseases they carried. But in the past few years, progress has not only stalled, it has reversed.

Stephanie Nolen, who covers global health for The Times, explains how the mosquito has once again gained the upper hand in the fight.

Guest: Stephanie Nolen, a global health correspondent for The New York Times.

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Transcript

From New York Times, I'm Michael Barrow. This is Adali. For decades, the world seemed to be winning the war against mosquitoes and the deadly diseases that they carry. Now, we're once again losing that battle. Today, my colleague, Stephanie Nolan, explains why. It's Thursday, October 5. Stephanie, you have embarked on an entire line of coverage for the times about mosquitoes. Why? Why mosquitoes? And why now?

So I went into this really thinking about solutions. I was going to do some nerdy geeky stories because I knew there was some great new technology coming to fight mosquitoes. And, you know, there are biggest enemies, right? They're the deadliest animal. Well, just explain that. They're the deadliest animal. So they kill more humans than anything else than any other living creature. Because of the diseases that they carry. Exactly. There's West Nile, there's Dingay, there's malaria.

So I went into this planning to look at solutions. And really quickly, I realized that I hadn't really kept up with the scale of the problem. That's, yes, we have new tools, but we gave them because the problem has really gotten away from us. And I covered public health, global public health for a living, but I hadn't realized how much the kind of tide in this battle had shifted that the mosquitoes were winning. And winning how?

They're winning in terms of our ability to control mosquito-borne disease. And the place where you see that the most strikingly, I think, is with malaria, with malaria in Africa. We were doing a really good job of bringing down malaria deaths and that progress has stopped. That is genuinely surprising to me because I think of malaria as a disease that we have mostly gotten under control. So lay out for us exactly what happened and why that progress has stopped.

So if you go back, like 20 years, almost a million people were dying in malaria every year, almost all of them in Africa. So just to remind you, the way that malaria spreads is you have a mosquito who bites a person who has the parasite. The parasite reproduces in the gut of the mosquito. And then when it bites, the next person, that person gets infected. And you have the cycles of sickness that go through families. And it can be deadly, of course, especially for small children.

But it's not just about death, right? It's horrible. You get fevers that can be so severe, you get hallucinations, you get vomiting, you get this absolutely debilitating fatigue. And you don't get it once, right? You can get it four or five times in a really season. Wow. Kids are getting 10 cases in a year. And that takes like a huge toll on their families. They're spending their money on medical bills and people can't go to work because they're taking care of them. There's a huge economic cost.

And so for all of these reasons in the late 1990s, there's a decision by African governments, by some philanthropists and global public health organizations to really make an effort to wipe malaria out in Africa. We have first of all reaching out to other partners, making an alliance for a rollback malaria. And what does that look like?

It's a big investment. Microsoft founder Bill Gates is giving up daily control of his company to concentrate on his foundation, which funds health and education projects worldwide. A lot of that money comes from philanthropy, from the Bill and Melinda Gates Foundation, in particular, who make eradicating malaria a huge priority. The fact that it kills over a million children a year and yet has almost no money given to it, you know, that struck us as very strange.

And the decision is to try three strategies. We'll take the diseases of the poor, or there's no market, and we'll get the best scientists working on those diseases. One is better drugs, so there are new and better treatments for malaria, and there's a real effort to get those into primary healthcare clinics across rural Africa. There were also new and better insecticides.

So in places with a heavy malaria burden, they would spray insecticides inside people's homes, and they're long-acting, right? And so that would provide you with protection for a while. And then the last one, bed nets. The thinking was that the main mosquitoes that transmit malaria in Africa, they bite indoors and at night when people are asleep, and that's when people are getting infected.

And so you had this huge campaign to get an insecticide treated bed net in every household on every family. Mothers were sent home from clinics with them with their new babies, trucks would roll into villages and give them out. And so as these elements come together, I'm quite optimistic that we will be able to eradicate malaria. And how do these three solutions, including this quite low-tech bed net solution, actually work? Well, it works really well. Devs come way down, cases come way down.

By about 2015, deaths bottom out at about 550,000 people, which obviously is still like a horrifying number of people, but you've cut deaths in half, right? Wow. And people have really seen the difference in their lives and the economic impact on their families. And so for a while there, as you're watching that curve of infections come down, there's a belief that like, okay, if we keep investing on this and we keep going, maybe we're going to get to elimination.

So how do we get instead to where you say we are, which is not elimination, but instead mosquitoes and malaria, resurgent and winning? Well, so here's what I have found in my reporting after talking to dozens and dozens of malariaologists, parasitologists, entomologists, all kinds of people who were working in this all over Africa. The short answer is the mosquitoes adapted. Their lifespan might only be six or seven weeks, and they evolve really, really quickly.

So you get a lot of mutations within a mosquito, which means that there's lots of opportunities for a mosquito to develop a way that it can survive what we're throwing against it. And so really quickly, mosquitoes have outmaneuvered the solutions that we had in place. And one of the big changes ties directly to bed nets. So if mosquitoes were not able to feed at night, they weren't able to feed on sleepers who were under nets.

Some of those mosquitoes died out, and there was an evolutionary advantage for those who started feeding at other times in other places. Now you have mosquitoes that are feeding outdoors, feeding during the daytime. And obviously people are not wandering around all day long, wrapped in a bed net. So if you're not protected anymore at the time when those mosquitoes are biting, suddenly you have cases starting to go back up.

And that same evolutionary advantage issue comes up with the treatments, and it comes up with the insecticides. Mosquitoes are resistant at this point to almost all of the chemicals, all of the insecticides that are being used across Africa. They just don't kill them the way they did 20 years ago.

So there are three very effective solutions you mentioned that really brought down death from malaria across Africa. They create the conditions in which these mosquitoes adapt and adapt in ways that outsmart all three of these solutions. Yeah, exactly. And brace yourself for this, Michael. It gets worse. So I'm reporting on all of this, and I call up a scientist at the CDC who runs their entomology program.

And she tells me, yes, these daytime biters, these insecticide resistant mosquitoes, it's all a really big problem. But also she says that I've missed something huge. Which is what? Well, while the public health world has been focused on mosquitoes and the way that they're adapting and how to respond to malaria in rural Africa, there's a whole new mosquito. And it's an urban mosquito. It's highly adapted to live and thrive in cities.

So suddenly there's a kind of double whammy nightmare scenario being presented to you. Yeah, not only are mosquitoes out adapting all the tools that we had for rural malaria, now you have a mosquito that's bringing the disease into urban areas, and they're totally unprepared to respond. We'll be right back. Stephanie, tell us more about this second threat, this mosquito that's now posing a risk to Africa's cities.

So it's a mosquito called anopheles. Well, here's where it gets tricky. It's called anopheles steven's eye or anopheles defense eye. And the entomologist I've interviewed are kind of split right down the middle about how to pronounce it. And so in fact, a lot of them now just refer to her as Steve. Turns out these folks have a pretty good sense of humor in the face of some pretty awful information.

Yes, exactly. And Steve, but we're using she, her because mosquitoes, of course, the ones that bite us are all the females who are in search of blood for the protein to lay eggs. So Steve is, she's kind of the superhero of mosquitoes. She's unbelievably adaptable. She's great at high temperatures. She likes it when it's wet, but she's also fine when it's dry. She'll breed all year round, so you're not talking about having a malaria season anymore, like in a rainy season.

Wow. On top of all of that, she's what in the entomology world, they call a very competent vector, which means she's really good at spreading the malaria parasite. It lives well inside her, and it's very easy for her to pass it on to the next person she bites. So perhaps not a superhero, but instead like a villain.

Yeah. Is this one of the mosquitoes, Stephanie, that we think evolved across rural Africa during this period when bed nets and insecticides were being used and just has found her way into cities? Great question, but no. Steve is an immigrant. She originates in South Asia in India and Pakistan, unknown in Africa until way back in 2012. So in 2012, it was found in the tiny little country of Djibouti on the horn of Africa.

And the theory is that she was imported on container ships, maybe in old car tires. And you know, initially nobody was overly concerned about this until all of a sudden in Djibouti city, malaria cases started to creep up. Remember, malaria is not known as an urban disease, right? Like we're talking about rural disease when we talk about malaria in Africa. So it caused a lot of confusion, like what exactly is going on in Djibouti?

And then in 2022, you get an outbreak of malaria in Ethiopia's second largest city, which is a place called Dira Dawa. It's got about a half a million people. And what happens is that a Dira Dawa university, which ends up being the center of this outbreak, half of the students who live in the male dormitories fall ill. The student clinic is overflowing with cases. At first, they don't know what's wrong with these people. And then they start to realize that they've gone malaria.

And eventually more than 10,000 people are diagnosed with malaria in a city where like a half dozen people might get malaria in the course of the year. Like they've just not seen anything like this before. Fascinating. So it's very clearly the beginning of a new phase of Africa's relationship to malaria. And it sounds like that is because of Steve. Yeah, exactly. And I wanted to see what does it look like when Steven Zaynvade's a city? Why is that potentially such a problem?

And then I also wanted to see what cities, what health systems are able to do if anything when they're trying to respond. And you know, the Ethiopian government is not receptive to foreign journalists. And it took me many, many months. But finally, back in May, I got to Deeradella and went to spend time with a couple of scientists, a molecular biologist named Fitsim Tidesi,

and an entomologist named Dijeni Gatteshu. And they've been studying Steven Zaynvade and this outbreak since the moment it started. Well, tell us more about this trip. So I got to Deeradella and it's a very, very hot, very arid city in a river valley. It's very close to the border with Djibouti and Somalia. It's a very vibrant place, especially at night. It really comes alive at night because of the heat. It has lots of little narrow streets and the houses are behind high walls.

It's very dense housing actually. Little blue auto-victuas zip around in the street and you get a ribbon for a ring really brightly colored hijab and robes. And when I get there, basically, the very first thing we do is we go to the place where these scientists Fitsim and Dijeni first found Steven Zayn. Which is where? Okay, you've got the gear. I'm ready. Well, it's along the banks and little pools that have been left along the sides of the bank of the river that runs through Deeradella.

I'm ready to meet my first Steven Zaynvade. I love a little stagnant water. So we're standing in the shallow water on the edge of the river. Dane, is this one? Yeah. It's moving. Yeah, I can see them. Dijeni is scooping up water from these pools and puddles and looking at the larvae. You would say the chances are very high, Steven. It is very high. And what he's trying to do when they collect samples in a place like this is figure out how much of the mosquito population is actually Steve.

And they started doing this next to the river when the malaria outbreak began because a lot of the initial cases that were reported were in families who lived near here and near the river. So we are 100 meter radius for the larvae. 100 meter radius of everywhere you found a case. Yeah. And what they do is they go to the home of everyone who's diagnosed with malaria and they trap the mosquitoes in and around the house.

So, lo and behold, 97% of the mosquitoes they catch are an awfully students eye. Wow, so this mosquito is clearly thriving. But is it mostly contained to the river? No. So in fact, they found Steve in a lot of other places that are a lot less predictable than a river. The places this mosquito is turning up are really surprising if you think about the ways that we traditionally think of mosquitoes in Africa behaving.

Steve is so adaptable that sure, she'll breed in these pools next to the river, but she'll also breed in water tanks. And she can breed in the amount of water that you might find in an old bottle cap. She will feed on humans, yes, but she'll also feed on livestock. And that's why actually the next place that DeGene wanted to take me was into a goat shed.

So lots of families in Durodawa have these little outbuildings in their homes where they keep a couple of goats or a couple of sheep, maybe a cow. And it turns out that the mosquito will rest in there because it's cool and it's dark and it's moist during the daytime when it's really hot. And there's also, of course, a very accessible source of food, which is the goats. So I'm following along behind DeGene down these narrow alleyways, an animal shed with a low roof.

And the next thing you know, he's down on his hands and knees, crawling into these little buildings, there maybe like three or four feet tall, if crammed full of goats. And he goes and he wants to show me how this works. So in I go to... Okay, I am crawling into the goat shed. Here we go. I can see nothing. I'm gonna end up sitting on a goat. I'm too tall. I'm generally not made to be an entomologist. Hi, hi goats. There are 24 or 7 goats.

And he gets on his phone and he uses the flashlight to run it sort of really quickly over the walls. And there were mosquitoes. What would be fine? Fed mosquito. You can tell from out here. DeGene is able in the dark, in the gloom, with the goats to identify which mosquitoes they are. I can barely see them. Oh, oh, oh, angry goats. Sorry goats. He's like totally unfazed by the goats. And when you see some mosquitoes, what he does is he's got what's called an aspirator,

which is like a little glass tube with a piece of rubber piping on the end. And he puts the rubber pipe in his mouth. And he holds the end of a glass tube up against the wall where he's seen a mosquito and he gently sucks it in. Got him. So that it's alive, but trapped. And what they do is, again, like take them back to the lab where they can sort them properly and identify which species it is and then know whether he's finding Steve in these places. This is an amazing thing to envision.

Well, it's particularly amazing if you think about doing it with like a large herd of goats. So we're also very interested in what's happening and are fully attempting to participate. These goats are stiffening me. Excuse me, pardon me. Okay, all right, I'm out. Okay. So when DeGeneres had sucked all the visible mosquitoes off the walls, we crawled back out of the shed and walking through more of these narrow streets.

I'm looking at the place on a whole new way now, right? And I'm just thinking there are so many places where Steve could be. If you think that like she only needs small amounts of water to breed and she's happy with artificial sources of water, she's happy in containers in old plastic containers. I'm looking around and I'm seeing puddles under cisterns and I'm seeing water storage containers in front of people's houses.

DeRodelle is municipal water only runs a couple of days a week. So when it turns on, everybody fills up some barrels, some Jerry cans in front of their house and keeps them nearby. And they don't have reliable trash collection. So you'll get lots of these little bits of plastic around that are a place for it to breed. And when we talk about Stevens I being a threat across Africa, like that's one of the reasons why, right? Because these erratic municipal services, it's a very common problem.

So I'm looking around DeRodelle and I'm thinking Steve could be everywhere here and I'm thinking like the public health system is absolutely not in a state to respond to this. Well, what exactly is the public health infrastructure in the city like this that is now dealing with Steve and with so much malaria? So if you have been really been investing in primary care in public health, but they don't have urban malaria response, right? Remember it hasn't been an urban disease.

So there's no muscle memory in the city for responding. People don't have immunity. They get very ill and clinics don't know what they're looking at. I talked to a woman, a nurse who was pregnant when she got malaria, she got incredibly sick, but it was 10 days and you know a half dozen malaria tests before she got a confirmed diagnosis because nobody was looking for it. And this is a nurse who presumably has a lot of strong ties to the medical community.

Yeah, when you get a sudden severe malaria outbreak in a place that's not expecting it, it can really quickly start to do real things, right? And if you think that there are 600 million people who live in cities in Africa, then that's so many people who were potentially vulnerable to this mosquito. So when you start to put all of those things together, you get the scenario that keeps Ethiopian scientists awake at night that's really terrifying that CDC scientists to first told me about this.

And somewhat counterintuitively, we think of cities as places that represent progress and where healthcare is going to be better than in a rural Africa. And you're saying that it's the opposite in this case, the treatment is worse and the opportunities for the mosquitoes to grow are even greater. Yeah, look, I don't think it's hopeless, right? I don't think that there's a reason why cities can't learn to respond to this, why people can't develop this expertise, but it doesn't exist now.

Well, let's turn to the question of solutions, which is definitely the thing you set out to report on, are there any and not just solutions to Steve and African cities, but to the adaptations that are presenting such problems in rural Africa as well. What can African governments do about this beyond what they've already done? So there are some new solutions and each one of them comes with some challenges. First of all, there are improvements on the things we have.

There are new classes of insecticides being brought to market and those will hopefully kill mosquitoes more effectively. There's also some really interesting new innovative technologies. I went to Kenya to see a clinical trial of something called a spatial repellent, which is this sheet of clear plastic. It's about the size of a piece of loose leaf and it's soaked in a repellent that confuses the mosquitoes, keeps them from being able to bite.

So the early indications are that both of these things are working really well, but our mosquitoes all the time are adapting, right? And so eventually you're going to run into this question of resistance again. So all these things sound like they ultimately have a shelf life. They can't last all that long given just how quickly mosquitoes evolve and adapt. Yeah, so that's why you need to come at us from a couple of different directions, right?

And that's one of the places where I would say there's a lot of hope right now. There's a new malaria vaccine that's being rolled out in sub-Saharan Africa. You give it to small children and it should be able to provide them with a lot of protection throughout their lives. You know, vaccines like we saw with COVID, they're challenging to deliver and they can be expensive. They're coming in at about $10 per child, which maybe doesn't sound like so much.

But if you think about the fact that for example Tanzania, their whole health budget is $2 per person per year. So, to act against that, these vaccines are really going to cost a lot. So the solution situation is not where anyone wants it to be. As you've been talking, Stephanie, it's occurred to me that we've spent this whole conversation talking about Africa. But Steve seemed to come from outside of Africa to Africa.

And now as Africa's problem, I have to assume that a fear might be that as malaria becomes a bigger and bigger crisis in Africa for all the reasons we're talking about here, Africa could export its malaria problem to somewhere else in the world. Is that what the scientists you talk to fear? You know, I think I would say it's not so much about export. It's not about something that comes on a boat. It's actually, it's about something much bigger than that.

What we've been seeing with mosquito-borne disease in the last few years is a really big impact from climate change. Lots of places are becoming a better environment for mosquitoes that carry a lot of different diseases, not just malaria. I think what we're seeing is that in a very quickly changing world, mosquitoes do better move faster than we do. And for me, that's the lesson from Steve that I saw in Ethiopia.

Not that Steve's going to leave Africa and come to other parts of the world, invade other continents, but that the environmental issues that are present in a place like Africa are present elsewhere. That's the problem. That's as humans, we create lots of situations where mosquitoes can flourish. They look different in different places, cities and towns, Africa versus Latin America.

But what those places have in common is that mosquitoes are thriving and posing a threat that we're not nearly quick enough in providing solutions for. Or it sounds like from the case of Africa, prepared to deal with in real time. No, not yet. I think for me, the lesson of what I saw in Daredawa, what's happened with Steve, is really just how quickly things can go south.

You can think that you don't have the problem or you can think that you have the problem managed or that you have the tools you need. And the way mosquitoes work incredibly quickly, you can find yourself with a public health crisis. And I think as we think about the spread of mosquitoes and the threat they pose, I think that should be alarming for everybody. What's that for me? Thank you very much. We appreciate it. It's a pleasure. We'll be right back. Huge what else you need, tenor day.

My name is Ryan for President. I vow to fix our broken student loan program. Because while college degree is still the ticket to the better life, that ticket is becoming excessively expensive. On Wednesday, President Biden canceled $9 billion more in student loan debt, just as requirements to repay those loans, which have been paused for three years, have resumed. Biden's previous attempts to forgive a far larger amount of student loans were struck down by the Supreme Court.

But the latest effort is a workaround that relies on a different law. And I said at the time, I believe the court's decision to strike down my student debt relief program was wrong. But I promised I wouldn't give up. And more than 75,000 employees of the health care company Kaiser Permanente began a three day strike on Wednesday, becoming the latest group of unionized workers to walk off the job in the past few months.

The workers are demanding higher wages, which they say are necessary to end labor shortages that have plagued the company for years. The strike is being closely watched because Kaiser Permanente's health care plans cover 13 million Americans across eight states. Today's episode was produced by Alex Stern, Will Read, Rob Zipco, and Sidney Herbert. It was edited by MJ Davis Lynn, contains original music by Rowney Misto, Mary Luzano, and Dan Powell, and was engineered by Alyssa Moxley.

Our theme music is by Jim Brunberg and Ben Lanzford of Wonderly. That's it for the Daily. I'm Michael Borough. See you tomorrow.

This transcript was generated by Metacast using AI and may contain inaccuracies. Learn more about transcripts.