- 18 hours ago
The Nature Of Things S65E13
Category
📺
TVTranscript
00:14This, believe it or not, is a mosquito factory in Brazil.
00:22That's right, a mosquito factory.
00:25They breed and release 100 million mosquitoes a week.
00:30Each one of these little containers contains about 160,000 mosquitoes,
00:35which means that across this entire room, there are over 7 million.
00:42But who needs more mosquitoes?
00:48What brought me here is the fascinating story
00:52of humanity's biggest battle against our deadliest foe.
00:57Mosquitoes have actually been responsible for more human death than anything else,
01:01more than war and conflict, more than starvation or natural disasters.
01:06Mosquitoes have influenced the rise and fall of empires,
01:09from the Greek Empire of Alexander the Great to the Roman Empire.
01:14And the problem today is, they're gaining on us.
01:18And they're coming after you.
01:25But don't worry, we are not trying to ruin your summer.
01:32We might even help you outsmart them.
01:34Your first one's here.
01:35We might need to, because around the world, mosquitoes are changing fast.
01:41Mosquitoes aren't too bad, are they?
01:42Yeah.
01:43Cool.
01:44Oh.
01:46Last summer, I learned the hard way who mosquitoes like to target.
01:50A prob?
01:57How's it going?
01:58You worked up a sweat there, eh?
02:00You know it.
02:01Gang's already here.
02:03Oh yeah, sorry about the mosquitoes.
02:07Mosquitoes love the smell of sweat.
02:11Oh, hi.
02:11Hey.
02:12Come on up.
02:13I brought a cheese plate.
02:14Oh, for everyone.
02:15I appreciate it.
02:16Yeah, you can grab a seat.
02:23Oh, hey guys, how's it going?
02:25You brought beer?
02:27Yeah.
02:35Brought your appetites?
02:37Hungry?
02:37Oh yeah.
02:38Cool.
02:38Cool.
02:39They like all blood types, but may have their preferences.
02:42Oh yeah.
02:44You're welcome.
02:45Yeah.
02:45Too pretty.
02:46Yeah?
02:46Yeah.
02:52Sorry, hang on.
02:53Do you guys, like, the bugs are bad.
02:55Do you guys want to go inside?
02:56Yeah.
02:57Forget this.
02:58This is a lot.
02:59You guys go ahead.
03:00The bug spray.
03:04Got it.
03:10Here's a mosquito cheat sheet.
03:12First, there's a lot of them.
03:15Like, a lot.
03:16More than 3500 species globally.
03:19But surprisingly, most don't bite.
03:23They feed on nectar.
03:25But some species, not most, need blood to nourish their eggs.
03:30So only the females bite.
03:32They're just being good moms.
03:35Most of us like to avoid mosquitoes.
03:38But not everyone.
03:39Woohoo!
03:40Yeah.
03:42This is full of larvae.
03:43There are thousands of larvae right here.
03:46And this thing goes all the way down.
03:47There's gotta be several million mosquitoes here.
03:51Just for me.
03:53This is Bob Hancock of the Metropolitan State University in Denver, Colorado.
03:59And he's got a nickname.
04:01The Mosquito Man.
04:02Here we go.
04:04I'm pretty darn sure that I've fed purposefully over a million mosquitoes.
04:10And he's happy to demonstrate.
04:12I think you can see why.
04:13They love my ears.
04:14They love my forehead.
04:18I'm looking at extraordinary creatures that spend the beginning of their lives as aquatic worms.
04:27The scuba divers.
04:30And then they transition into these flying creatures that have to mate.
04:36They have to find nourishment.
04:38And of course, the risk that they have to take to make babies is extraordinary.
04:43They have to go and feed on a giant animal and perhaps be swatted and killed to complete their lives.
04:51I bow to their greatness every day.
04:56His enthusiasm is contagious.
04:58His students work on everything from identifying pathogens to studying mosquito love lives.
05:03Is everybody over there ready?
05:05Let's see.
05:07Undoubtedly, mosquitoes are expanding their range and that is due to changes in our climate.
05:16When I first started making an effort to film Aedes aegypti mosquitoes, they weren't in the state of California.
05:30And that was 14 years ago.
05:33Now, they're in the suburbs of San Francisco.
05:38And it doesn't take a lot.
05:41That's the crazy thing about climate.
05:43Little increments can tremendously impact a mosquito's ability to become established in a new part, in a new place.
05:53She's greedy.
05:54She's going back for more.
05:56Whether they're nectar feeders or blood feeders, Hancock thinks they're gaining on us.
06:04Biologically, if an organism's victory is based on how many individuals of a species occur in a given place at
06:14a given time or in the globe at a given time, they're winning big time.
06:20There are mosquitoes that are adapting.
06:24That's really the way.
06:26They're expanding.
06:27But they're not only expanding, they're not disappearing in places that we're working super hard to try to control.
06:36At the American Natural History Museum in New York City, Dr. Jessica Ware not only has a big job, she's
06:44got a big mosquito.
06:46So we're here at the American Museum of Natural History, and we have a big example of a larger-than
06:52-life mosquito.
06:54Mosquitoes actually have a very neat way of feeding, especially for female mosquitoes, which require a blood meal in order
07:01for her to lay her eggs.
07:02She will actually have two of her stylets that she uses to deliver something to the victim.
07:09Mosquitoes will give us something that is a pain reliever, and they also will give us an anticoagulant.
07:15And that will make the blood flow very quickly up through her stylets, into her mouth, and hopefully she can
07:20get that blood meal going before we swat it away.
07:23Dr. Ware, who is chair of the Department of Invertebrate Zoology, says the mosquito isn't trying to make us sick.
07:31Its feeding system has been hijacked.
07:34The mosquito is responsible for a lot of death, you know, the most deaths worldwide, for things like malaria.
07:41But it's not actually the mosquito that's responsible for the death.
07:45It's actually a pathogen that has kind of hijacked the feeding system of mosquitoes.
07:50So mosquitoes are sometimes called vectors because what that means is that they're taking a pathogen and they're entering it
07:57into our system.
07:58And so the pathogens, things like protozoans, little small microorganisms, they basically have their own evolutionary pathway.
08:07They've kind of hijacked the mosquito's feeding system.
08:10They travel in with the pain reliever and the anticoagulant, and that's how they invade our bodies.
08:17So it's not the mosquitoes' fault, really. They're just kind of along for the ride.
08:23You know, growing up in Canada, I spent a lot of time with my maternal grandparents up in Northern Ontario.
08:29We spent a lot of time on Lake Muskoka.
08:31And swimming and canoeing, you see insects all the time.
08:34I was just kind of fascinated by how many different insects there were.
08:39One thing that I think has become so common is this idea that you can exist as a person in
08:46your backyard in the summer in the absence of insects, and that that's a good thing.
08:50I feel like that's a real detachment with reality.
08:53Insects have been around for hundreds of millions of years before humans.
08:56We're just kind of like in their world.
08:59Often what people do is they spray, these companies will spray broad-spectrum insecticides.
09:05Not only does it kill mosquitoes and black flies, but it also will kill all the other things that are
09:10living in the soil, insects that are living in the soil, insects that are using your lawn as a natural
09:15habitat.
09:16All of these other animals are going to be impacted and affected.
09:23I've tracked down Dr. Timothy Weingard, a Canadian historian whose book on mosquitoes made it to the top of the
09:30New York Times bestseller list.
09:34This place is swarming with mosquitoes.
09:39Yeah, there's a lot of them.
09:42And at dusk, what do you think it is they like so much about this place?
09:46Dusk.
09:46If you want a crash course on mosquito warfare, this is your guy.
09:51You have called mosquitoes an apex predator.
09:55And, you know, I got to point out, you know, tigers, lions, wolves, orca whale, like there's a ton of
10:01animals.
10:02Why are mosquitoes the apex predator?
10:05Mosquitoes have killed more humans than any other animal throughout our history, by far.
10:11Humans are second and we don't even come close.
10:14There are some estimates that mosquito-borne pathogens have killed half of every human being that's ever lived.
10:20Half?
10:21Half of humanity.
10:22So, is there evidence in the historical record of the impact that mosquitoes have had on us?
10:28Oh, absolutely.
10:29Mosquitoes were certainly feeding on dinosaurs and they were transmitting parasites and pathogens to dinosaurs.
10:36Mosquitoes have not just been a problem for humans, they've been a problem for all kinds of animals then.
10:40It shadowed our own evolutions.
10:45The great apes all have malaria, reptiles have malaria, amphibians, birds.
10:50Mosquitoes have influenced the rise and fall of empires from the Greek Empire of Alexander the Great to the Roman
10:57Empire.
10:57They've decided the outcome of numerous wars, including the Greco-Persian wars, the American Revolution.
11:06General Cornwallis, for example, surrenders at Yorktown because of malaria.
11:11It's not anything George Washington and the Americans did or Lafayette did with his French forces.
11:16When Cornwallis surrenders, he says, I have 35% of my troops who can stand to post.
11:23The rest are sick, dead or dying of malaria.
11:27So, the Anopheles mosquito is a founding mother of the United States and should maybe be on Mount Rushmore
11:32in between the loving glances of Thomas Jefferson and George Washington.
11:37Well, you said half of all humans. How many humans are mosquitoes killing today, roughly?
11:42So, today it's still over a million every year.
11:45A million people.
11:46And that's who die from mosquito-borne pathogens, not who are infected or recover
11:52and go through a horrible torment and sickness, whether that's malaria or dengue or chikungunya, to name but a few.
12:01They can evolve and adapt very quickly, which is also why humanity's been battling both mosquitoes and their pathogens for
12:10eternity.
12:13I guess I never really considered the idea that mosquitoes aren't just a pest to us, right?
12:18They feed on other animals as well.
12:20They bite all animals.
12:22Most other animals have some form of mosquito-borne pathogens as well.
12:27In the Arctic of Canada, they hibernate and when there's the brief thaw in the Arctic, they're ravenous and they
12:34bite caribou at a bite rate of 9,000 per minute.
12:38And actually bleed young caribou to death.
12:42What?
12:44So imagine sitting here for one minute and getting 9,000 mosquito bites.
12:49There's not enough afterbite in the world.
12:51What are some of the best tools we've got at our disposal? Like, what's in our arsenal?
12:56So, historically, we've been trying everything. The ancient Egyptians bathed in human urine.
13:02They wore an amulet around their neck with the word abracadabra to try to ward off malaria.
13:07Wait, are you being serious right now?
13:08Yes, that's where the word...
13:09That's a real strategy?
13:10Well, it doesn't work, obviously. I don't suggest bathing in human urine.
13:15We have tried, I mean, chipmunk brain, poultices. There are so many things that we've tried to thwart, specifically malaria,
13:25but also mosquitoes.
13:27This is obviously the oldest one, is fire, smoke and fire.
13:32They don't want to be near the heat.
13:35The Americans poured tons of money and R&D into this malaria project and DDT is one of the things
13:41that came about in the Second World War.
13:50You all know her name, Anopheles Annie, the malaria mosquito.
13:57Parasitologists, entomologists, malariologists, every damnedologist in the country got on my trail.
14:07And I do mean trail.
14:11They started a cleanup.
14:16When we look at DDT, it was a miraculous mosquito killer. It's the reason we don't have malaria in Canada
14:22anymore or malaria in the United States anymore. It is DDT. It cut malaria rates in Italy by over 90%.
14:30Wow. That's amazing. That's a huge win.
14:33Yeah. DDT is banned in 1972 by the United States and other, you know, countries around the world. The ban
14:39comes about partially because of the environmental movement and the science and the degradation of the environment from DDT and
14:47cancer and everything else, but mostly because it didn't work anymore.
14:51So why doesn't it work anymore?
14:52Because whether we're talking about mosquitoes or malaria vaccines or malaria pills, whether it's chloroquine or adabrine, we do human
15:05trials with these drugs and we expose the malaria parasite to these drugs.
15:11And so by the time these drugs get approval, which takes years, the malaria parasite has already been exposed to
15:19the drug and has already adapted so they don't work anymore.
15:22Wow. They evolve that quickly?
15:24Yes.
15:25I mean, that's one reason why the mosquito is the biggest killer of humanity and has been across our existence
15:31is because it is a universal animal.
15:34There's only Antarctica, Iceland and a handful of Pacific islands across our planet that don't have mosquitoes.
15:42And just a few weeks after our camping trip, there came some unwelcome news from Iceland.
15:48Scientists have confirmed something that shouldn't have happened. The first sighting of a mosquito in Iceland. The news sent a
15:56buzz around the world.
15:57It was a surprise because it was the only country in the world that was mosquito free.
16:02The mosquito has been doing a lot of traveling lately, often on cargo ships.
16:09Then, one headline sends shockwaves around the globe.
16:26The New York Times publishes a major story by its global health reporter Stephanie Nolan.
16:32So, in 2023, I set out to write what I thought was going to be a quick story about some
16:37new innovations that were coming and how we can fight mosquitoes.
16:41And what I found pretty quickly was actually that there was a much bigger story unfolding.
16:45And that was that in the long struggle between people and mosquitoes, the mosquitoes had the upper hand. They were
16:52winning.
16:55One of the places I went reporting on this is a city called Diradawa in Ethiopia, near the border with
17:01Djibouti and Somalia.
17:03I met a nurse in a clinic who described this extraordinary phenomenon that had happened the year before,
17:09which is that she'd come into the clinic one morning and it had been packed full of sick students.
17:13And she's looking at them and she's thinking, these kids have all the symptoms of malaria.
17:18But Diradawa is not a malarial area. It's in the highlands of Ethiopia. It's never had malaria.
17:23These kids hadn't traveled anywhere. There was no way for them to have malaria.
17:29She does the malaria test anyway, and sure enough, that's what they have.
17:33Eventually, it's thousands of students and they can't figure this out.
17:38A couple of Ethiopian entomologists come to town and try to figure out what's happened,
17:43and they realize that there's a whole new species of mosquito that has been known historically in Asia,
17:50never been found in Africa, but a couple of years before had turned up in Djibouti,
17:55and now had made its way to the city and actually had been the source of this whole outbreak.
18:02It's a mosquito called Anopheles stifensi, and among some entomologists who work on this problem,
18:10it's more commonly just known as Steve.
18:14Steve is a time bomb. Malaria has been largely a rural disease, not urban.
18:21But Steve is flexible.
18:26Anopheles stifensi is very happy in a rural area, but also very happy to establish itself in an urban area.
18:34It can breed in a bottle cap.
18:36It doesn't mind if it's very, very wet, also doesn't mind very, very dry.
18:41It prefers to feed on livestock, but it'll also feed on humans.
18:45It bites during the daytime when people are moving around,
18:48and it's what we call a very competent vector of malaria.
18:52It's very good at spreading the disease, and it's resistant to every insecticide we've tried to use against it.
18:59I think what happened in Djibouti and what now seems to be happening in Ethiopia with Steve
19:05is a really good illustration of the kind of threat that mosquitoes pose
19:11in terms of how quickly they can adapt and how quickly they evolve
19:15and how quickly they can establish in places they haven't historically been
19:20and present a public health threat in ways that we haven't seen them do that before.
19:24If you look at what's happened with just this one species in this one place,
19:29it can give you an idea of the scale of the threat that we could be looking at in a
19:35lot of other places.
19:36If the mosquito gets established, it's going to present an absolutely terrifying public health problem.
19:43Over one and a half billion people live in Africa.
19:47Malaria kills over 600,000 each year, mostly children.
19:53And here in Uganda, a thousand kilometers away from the highlands of Ethiopia,
19:58entomologists like Crystal Burundji are worried that Steve will get into Africa's huge cities.
20:04If Anophilus stevensai starts to establish itself in the cities, then we face a potential huge spike in malaria cases
20:12that we're just not equipped to handle.
20:15If you consider the fact that this species survives really well in varying temperature locations,
20:22then it actually could be a danger to other continents as well that had managed to wipe out malaria.
20:27Malaria can devastate a family.
20:30Given the fact that malaria often affects young children, the children are not able to walk to the health center,
20:35so it does mean that the mother will carry these children.
20:38One mosquito can infect the entire family.
20:40So that means there will be cases where multiple children in the family are sick at once,
20:45and all these children have to be carried to the health center wherever it happens to be.
20:55While malaria is the top killer, it's not the only one.
21:00The next most common is dengue, which can easily turn deadly.
21:05Even if you survive, it won't go easy on you.
21:09Chikungunya can bring on fevers that last for months.
21:13Yellow fever was a tropical scourge that's been slowed with an effective vaccine.
21:18And recently there have been worrying episodes of Zika, West Nile, and encephalitis.
21:27An ocean away in South America, another mosquito-borne illness nears epidemic proportions.
21:34Brazil is on high alert amid a surge in cases of dengue fever.
21:39Dengue fever might not kill you, but it can definitely make you feel like you're dying.
21:47Several states have already deployed emergency measures.
21:50They're spreading larvicide in hard to reach areas to try to get rid of the mosquitoes.
21:55A story that I've been reporting on quite a bit over the past few years is an absolute explosion of
22:01dengue cases in Latin America.
22:03By the middle of this year, there had already been about 25% more cases than there were last year.
22:10We're into the millions and millions of cases, and in Brazil, Argentina, the countries that have seen the worst impact,
22:17you have health systems that are completely overloaded, the way that we saw during COVID, for example.
22:22Dengue is really painful and miserable as a thing to live through, but again, this also has an economic toll.
22:32When you have all kinds of people having to take six weeks off work because they can't get out of
22:36bed because their joints are excruciatingly painful, there's an economic cost to that as well.
22:44Daniel Peach studies mosquitoes at the Savannah River Ecology Lab at the University of Georgia, and he thinks the comparisons
22:52to COVID-19 are not a stretch.
22:56The next global pandemic very well could be carried by mosquitoes, and we have things that are ongoing right now
23:01which are sort of borderline on that already.
23:03So, for instance, dengue virus in the Americas, primarily South and Central America, there's more dengue currently than there ever
23:10has been historically.
23:12But malaria and dengue are tropical diseases.
23:16Surely the howling winds and snows of the global north are a barrier.
23:20I mean, doesn't winter kill them?
23:23There's a saying out there that winter is an excellent cure for tropical diseases, but it's not a perfect shield.
23:31So historically, even in Canada, there were cases of malaria.
23:34There were a couple of hundreds of people that got malaria during the construction of the Rideau Canal.
23:39There are historical cases from southern British Columbia around the turn of the 19th century.
23:44Mosquitoes are found all the way up into the high Arctic, the northern tip of Greenland, northern tip of Ellesmere
23:49Island.
23:49There are things that can survive that far north.
23:52The Asian tiger mosquito arrived in North America and used tires.
23:56Tires can contain water, and so these mosquitoes came in and laid their eggs in a tire with water in
24:02it.
24:02This tire was then moved from point A to B and arrived in North America.
24:07And once they filled up the water, the eggs hatched and the mosquitoes came out and established.
24:12It's not uncommon for mosquitoes to be in airplanes or in people's cars.
24:16But as our climate changes, it just makes it easier and easier for it to establish were it ever to
24:21make that jump.
24:22And the same is true for many, many pathogens out there.
24:26So, who's watching out? How do we know if an unwanted species shows up in a northern climate?
24:32You can feel them bite you.
24:34Like, they...
24:35You can't feel them until they're like, boom, their frost kiss is in and you're like, oh!
24:39Meet the Mosquito Guardians, a team of biology students and ordinary citizens who comb through the fields and swamps and
24:47forests of Nova Scotia,
24:48collecting samples and monitoring for invasive species that carry disease.
24:53So, we're going to start loading up.
24:57Across continents, scientists are comparing notes and mapping the mosquito's advance.
25:06A lot of people kind of think, well, maybe they're just gone in the winter and they come back in
25:10the spring,
25:10but I promise you they're there and waiting just in a few different ways.
25:14What happens in the fall is mom takes a blood meal, she lays her eggs, likely in vegetation or perhaps
25:21around the banks of a water body,
25:24that kind of thing, where the eggs are going to spend the winter waiting for things like snow melt,
25:29for water levels to rise in the spring, floods, those kinds of things to then initiate growing in the spring.
25:38Other mosquitoes will overwinter as adults.
25:41So, some of our Culex species, for instance, overwinter in that adult stage.
25:45Just going to take these ones, we're going to overwinter a generation that comes from these guys.
25:49And then look at length of the gonotrophic cycle at different temperatures.
25:54You'll often see mosquitoes hanging out, for instance, in people's unheated basements,
25:58or sometimes in sheds, barns, those kinds of things.
26:04There are over 3,000 species of mosquitoes across the world.
26:09And here in Canada, we have about 80 species or so.
26:13It's really something that we actually need to keep a very proactive approach towards.
26:18The West Nile virus was introduced into North America in the late 90s and spread into Canada from the United
26:25States.
26:26Largely we think through migratory birds.
26:28So that's one that we keep our eye on.
26:30We see a longer, warmer fall season.
26:34Then we see less severe temperatures through the winter.
26:37And as well, we're seeing shorter winters.
26:39So what that's doing is kind of releasing some of that pressure that used to keep some species out of
26:45our more northern latitudes and allowing new species to now move in.
26:49So these are the defenders.
26:52And there are teams like this all over the world.
26:58So the first strategy is vigilance, but the next strategy is attack.
27:05Can we eliminate the worst mosquitoes?
27:08I'm off to the front line in Brazil, where some people are trying to eliminate dengue fever.
27:17You might find this next part hard to believe.
27:20Whoa!
27:22This is amazing!
27:33Curitiba, Brazil.
27:35Home to the biggest mosquito-producing facility in the world.
27:39This is the World Mosquito Program's newest high-tech factory.
27:43Part lab, part mosquito assembly line.
27:46I'm here to see how this tiny army is being built to help stop a massive public health problem.
27:54Dengue, Zika and chikungunya are a big, huge problem.
27:57Brazil, dengue is around 40 years already in this country, but more and more we are seeing lots of outbreaks
28:05in places that we never had before.
28:08We are seeing mosquitoes moving towards the south of Brazil, even Argentina, Paraguay, other countries.
28:17And the disease is spreading like crazy.
28:19So you can transmit, because if you don't feel ill, and the mosquito bites you, you can just transfer the
28:27virus to another person.
28:29So how dangerous is it? I mean, does it kill?
28:32Last year in Brazil was the worst epidemic so far, the record.
28:37More than 10 million people had dengue.
28:40And I think it was 6,000 people died, or even more, 10,000 died of dengue.
28:47So you can have complications because of disease, and then you die.
28:54Which, I mean, considering the context makes me pretty nervous.
29:00Every week, more than 100 million mosquitoes are bred here, and infected with a naturally occurring bacterium called Wolbachia.
29:09And that simple biological twist is enough to stop mosquitoes from transmitting disease.
29:15How many mosquitoes are in this room right now?
29:18Yeah, in this room, we have about 5 million mosquitoes, adult mosquitoes, and in each of these cages, we have
29:27160,000 mosquitoes.
29:30That's incredible!
29:32The Wolbachia bacterium, which is harmless to humans, essentially takes up room in the cells of the mosquito where the
29:39dengue would be.
29:40But now, there's no room for the virus to move in.
29:45Now, when the Wolbachia mosquitoes bite someone with dengue, and then bites a healthy person, they won't transmit the disease.
29:55I love these.
29:57I love these doors.
29:57Wow!
30:00Look at this!
30:01So this is where you have our adults, right?
30:04So in every cage of this can hold up to 150,000 or 160,000 mosquitoes.
30:09150,000 mosquitoes?
30:11Yeah, exactly.
30:11That is simultaneously really cool and kind of a nightmare.
30:30I want to see if they come to my hand.
30:37Oh, yeah, they almost started to get me already.
30:43This is easily the most mosquitoes I've ever seen in my life.
30:47This is probably the same amount as I've seen across my lifetime.
30:57These have got to be eggs then, right?
30:59Exactly. So those are the eggs.
31:01Every really small black dot of this, really tiny, is one egg.
31:06You mean like the little specks of dirt? Those are eggs?
31:08Exactly. Those are the eggs, the mosquitoes eggs.
31:11Those are tiny. So then how many eggs are on this whole thing?
31:13On one strip of this, we have around 50,000 eggs.
31:1850,000 eggs?
31:19Yeah, and you can have strips with 100,000 to 100,000 eggs.
31:23It depends on how many eggs they have laid.
31:25But this is for one group.
31:27I can't believe how many eggs are there.
31:28Yeah.
31:29That's hard to believe.
31:30That's why we expect to produce 100 million eggs per week.
31:33The mosquitoes start as eggs, hatch into larvae, and then grow into pupae.
31:42Finally emerging as an adult mosquito all in about a week.
31:49I feel like I'm in the future.
31:51Hey guys, how's it going?
31:53Oh!
31:55Sure, look at that!
31:56Oh!
31:59What is this?
32:00These are the females.
32:02The females are going straight to the cages.
32:05There is a different proportion.
32:06One male for three females per cage.
32:10They use a sorting machine to divide male and female mosquito pupae.
32:18Because the males are smaller, they fall to the bottom.
32:27The female transmits to their progeny through the eggs.
32:32So that makes Wolbachia very common in nature.
32:37Around 60% of all insect species carry Wolbachia.
32:42Wow, so it's really common.
32:44Very common.
32:44And so then if I understand you properly, Wolbachia in the cells of mosquitoes
32:49means that dengue can't replicate there because they're kind of fighting?
32:53Correct.
32:54For there are some studies, scientific studies showing that there are lots of components
32:59inside the cell that the mosquitoes, the virus has to use.
33:04But Wolbachia is already using them.
33:07So there is a competition there.
33:08And Wolbachia wins this fight inside the cell.
33:12Amazing.
33:13So basically like the dengue tries to get into a hotel but there's no rooms left.
33:17Correct.
33:18Okay.
33:19That's amazing.
33:20After 10 years of collecting evidences, like scientific evidences,
33:25we showed that Wolbachia was able to block dengue.
33:29And for instance, there was a study in Indonesia showing 77% less disease happening there.
33:38Wow.
33:38And then we went to other countries.
33:40In Australia, more than 90% reduction.
33:42In Colombia, also more than 90%.
33:45And we have very positive results in Brazil too.
33:48This is amazing.
33:49This is a huge success story.
33:51After the eggs have been exposed to Wolbachia here, they're shipped to community stations
33:57around Brazil.
33:59Like these, where they're grown into adult mosquitoes.
34:10Okay.
34:12This is cool.
34:14The larvae stay in this room for seven days.
34:18Seven days?
34:19Yes.
34:19So-so.
34:21How many mosquitoes are in here?
34:24A lot of mosquitoes.
34:26So you're not just making mosquitoes for Joinville.
34:29No.
34:29You're exporting them.
34:30Yeah.
34:31For the other city near here.
34:33Wow.
34:33So there are other cities that are paying you to bring mosquitoes to them.
34:37They want more mosquitoes.
34:38Yeah.
34:40Crazy business.
34:43Okay.
34:45Here.
34:48The jars have mosquitoes.
34:52Yup.
34:52A lot.
34:53Yeah.
34:54A lot of mosquitoes.
34:55Drain.
34:56Yeah.
34:59Right.
35:00Look at that.
35:01But this is just the beginning.
35:04Next, the Wolbachia infected mosquitoes are going on the trip of a lifetime.
35:09Okay.
35:10So what's our first stop?
35:12In Gloria?
35:13Gloria.
35:14Okay.
35:15Neighborhood nearby.
35:19Okay.
35:21All right.
35:21I guess we're off.
35:23I can hop in?
35:24Yeah.
35:24Okay.
35:25Cool.
35:26Thank you so much for the tour.
35:29We're going to carry on the good work.
35:31Take care.
35:33Hi.
35:35I gotta say, a road trip with 20,000 mosquitoes?
35:39Not on my bingo card for today.
35:51We arrive in Gloria, an area hard hit by dengue.
35:56And it's time for the mosquitoes to get to work.
36:00The Wolbachia mosquitoes will breed with the wild mosquitoes so that their offspring will carry Wolbachia.
36:06And now, when these Wolbachia mosquitoes bite someone infected with dengue, and then bite a healthy person, they won't transmit
36:15the virus.
36:18World Mosquito Program releases up to 200,000 of these mosquitoes a day in the hardest hit areas.
36:24And it seems to be working.
36:29Dengue cases have fallen up to 90% in some locations.
36:40So the Wolbachia method seems promising, but it's expensive, and it only works on Aedes aegypti, the mosquito that carries
36:49dengue.
36:50It doesn't work, at least not yet, on the mosquito that carries malaria.
36:57Back in New York, Dr. Jessica Ware is watching what they're doing here, but cautiously.
37:03I mean, if I had to choose between using Wolbachia and using insecticides, I would use Wolbachia.
37:09Because insecticides have really, even the ones that we tend to think of as being very targeted for a particular
37:17order or a particular family,
37:18we often find, 10 years, 20 years down the line, that they end up having these really much more broader
37:24effects.
37:25There's another idea that scientists are testing in their labs, and it's controversial.
37:31Genetic modification. Change the mosquitoes through a gene drive.
37:36Jessica Ware worries that if we release that genie from its bottle, we'll never get it back in.
37:42But actually, we as humans have been genetically modifying things for as long as we've had agriculture.
37:47That's why our corn looks the way it does, that's why bananas look the way that they do.
37:50Inserting particular genes, that is new, and we don't exactly, what we've seen when we have had genetically modified organisms,
38:00things like crops, like corn, for example, is that it tends to spread to all of the plants in the
38:06local area.
38:08So if we're doing that with mosquitoes, the chances of those genetically modified parts or components spreading to other mosquitoes,
38:18flies, or going further out to other insects in the population, wouldn't be a surprise.
38:24And that is a concern, I think. That's the big concern that people have, is that once it's out there,
38:28it's on its own evolutionary trajectory.
38:33Once you release genetically modified mosquitoes, they're out there in a population.
38:39You can have one country that says, yes, I want to do it, and another country that says, no, I
38:42don't,
38:43but you're not going to turn those mosquitoes back at the border, right?
38:47And nothing like it has been done before.
38:49People, when you talk to them, bring up the Jurassic Park analogy all the time, right?
38:54I wouldn't say that people are, that there's a sort of homogeneously opposed opinion,
39:00but there is definitely caution and anxiety.
39:03But in Uganda, Crystal Burundji not only supports genetic modification,
39:09she works for Target Malaria, an international consortium that is actively developing it.
39:15So the biggest concern that you'll hear, environmentally, when people think about genetically modified mosquitoes,
39:21is this misconception that we're going to wipe out all the mosquitoes in the world,
39:25and then there will be an effect on the environment, and it will be terrible.
39:28But actually, genetically modified mosquitoes are very precise.
39:34Because we are targeting a fertility gene in a specific species that is spreading malaria,
39:39and only that species, and because it's spread through reproduction,
39:43and most of these species do not actually reproduce with each other,
39:47it's most likely only going to remain within the targeted species.
39:51If you look at the insecticides that we are currently using at the net,
39:54they're all aimed at reducing mosquito numbers.
39:57But unlike genetic modification, insecticides will kill everything.
40:02That is just how they work.
40:04Every insect in the area will just be annihilated, because that's how they work.
40:08But we can't stop using them, because the other side is children dying.
40:14While Crystal Burundji has high hopes for genetic solutions,
40:18Stephanie Nolan of the New York Times has seen other fronts crumbling.
40:22One of the challenges in the response to malaria and other mosquito-borne illness is that it mostly affects poor
40:30people.
40:32The recent events, the one a lot of people have been focused on,
40:36is the Trump administration's decision to end most of its foreign assistance,
40:40to shut down its Agency for International Development, USAID,
40:44and to end its participation in most big multilateral funding organizations.
40:50Since the U.S. was far and away the biggest funder of global health initiatives,
40:54that has created absolute chaos across the developing world.
40:58You know, you have all kinds of the frontline community health workers who do malaria response,
41:03who've lost their jobs.
41:04The researchers, many, many of the people that I interviewed when I was doing my project on this,
41:09have all lost their jobs, they've lost their funding, those projects have shut down.
41:14I would like to think that as a global community, we look at something like malaria deaths,
41:20we look at 650,000 children dying of a treatable, preventable illness,
41:24and we think that's not okay if I'm going to do something about it.
41:28If you're lucky enough to live in a place that doesn't have a big mosquito-borne illness problem,
41:35it might be comforting to think, well, this doesn't have anything to do with me.
41:40You might want to look at the experience of COVID, which reminded us all that pathogens and mosquitoes don't respect
41:47borders.
41:48Reality is, with a Canadian climate, we are very unlikely to see an established threat from any of the communities,
41:58the mosquito-borne illnesses that we're most familiar with right now,
42:01but mosquitoes can change the level of threat they pose quite quickly.
42:11But how can you protect yourself from being bitten?
42:15Well, for the average person, we are more commonly using something called DEET.
42:20You might use citronella, and they're all doing the same thing,
42:24making it so that mosquitoes have a harder time smelling where you are,
42:28so they have a harder time finding you.
42:31Wear thick, loose clothing.
42:36I very unfashionably tuck my pants into my socks.
42:42Obviously avoiding them by being screened in rooms.
42:45Travel with a bed net.
42:47I always have a bed net over my bed.
42:52But if they find you, they will still bite you.
43:00Well, in Canada, we are lucky.
43:04We live in a place that doesn't have a big mosquito-borne illness problem.
43:10Not yet, anyways.
43:12So you don't have to scrap your summer camping or cottage plants,
43:16but cast a grateful eye to scientists and citizens,
43:22like Laura Ferguson's team in Nova Scotia,
43:25who monitor our wetlands and forests.
43:29Because in a rapidly changing world,
43:33they also stand on guard for us.
43:36So we're going to keep them at the stage.
44:06So that's why we are here.
44:06You
Comments