Speaker 1: Hello, Hey, Yay, how's it going.
Speaker 2: It's going well.
Speaker 3: I just made it back home and I frantically prepared
Speaker 3: a gin and tonic.
Speaker 2: Gin and tonic with lemon will accept it.
Speaker 1: So for this episode, we decided to sit down with
Speaker 1: our good friend Uma to ask him about his personal
Speaker 1: experiences with malaria.
Speaker 2: I'm Umatsamji. I grew up in Nairobi, Kenya.
Speaker 4: Right now, I'm a graduate student at the University of Florida, Gainesville.
Speaker 2: And I met.
Speaker 4: Aaron and Erin in Gembo, Panama while we were doing
Speaker 4: field work at this tropical research station. I remember I
Speaker 4: had just come from a camping trip in western Kenya,
Speaker 4: and now I've been back in Nairobi, where you know,
Speaker 4: I lived and my parents lived for about two weeks.
Speaker 4: One day, I I was just feeling really lethargic and tired,
Speaker 4: and I had this lower back pain that was really memorable,
Speaker 4: like this pain in my lower back.
Speaker 2: And I went to bed and in the.
Speaker 4: Morning, you know, I was confused. I had a fever.
Speaker 4: I was really sick. My body hurt a lot. So
Speaker 4: I remember just having like really weird, wacky dreams, you know,
Speaker 4: and having these high fevers and and so I went
Speaker 4: my parents took me to the to the doctors and
Speaker 4: I got a blood test. Living in the tropics, there's
Speaker 4: a lot of different things that you could get. Of course,
Speaker 4: they did the maloria test and they didn't find malaria.
Speaker 4: But I had these very cyclical fevers. I would get
Speaker 4: really really cold, and suddenly i'd be really really hot again.
Speaker 4: And I remember when I was when I had the fever.
Speaker 3: When I was feeling really cold, I would be shivering
Speaker 3: so much that my like my muscles would contract so
Speaker 3: much that they'd be hurting. And I went for another
Speaker 3: blood test because my mom was suspicious that this actually
Speaker 3: might be malaria. And still there was no positive malaria diagnosis.
Speaker 3: But then my mom took me to the hospital at
Speaker 3: two am, and I didn't know what was happening. I
Speaker 3: didn't know why, you know, why, we were going to
Speaker 3: the hospital in the middle of the night, and I
Speaker 3: got a blood test done at that time and they
Speaker 3: diagnosed me with malaria. And I didn't learn until later
Speaker 3: that it's really common for malaria not to be in
Speaker 3: your purple bloodstream until the middle of the night.
Speaker 2: So, yeah, that was kind of an interesting experience. I
Speaker 2: feel like malaria was such a big part of life
Speaker 2: growing up in Kenya.
Speaker 3: It was I feel like it was the kind of
Speaker 3: the disease that whenever somebody had a fever or any
Speaker 3: sort of sickness, you'd always wonder like, is it malaria,
Speaker 3: because it could be. You know, it's really common there.
Speaker 3: So when you're really young, you learn about the anopolies mosquito.
Speaker 3: So like I remember in primary school growing up, we
Speaker 3: learned about anopolies and what it looked like when it
Speaker 3: was resting.
Speaker 2: It has this very unique posture when it's resting, and.
Speaker 3: You can recognize it immediately, and it's something that you know,
Speaker 3: everybody learns in school when from a really young age.
Speaker 3: When I was really young, you know how as the
Speaker 3: stereotype every like young kid hates to have the chore
Speaker 3: of doing their beds, just like any kids.
Speaker 2: I hated doing my bed but there was something else
Speaker 2: I had to do. I had to, you know, fold
Speaker 2: up and roll up my mosquito.
Speaker 4: Net every day, and every night I had to unroll
Speaker 4: it and you know, tuck it around my bed so
Speaker 4: I could go to sleep for the night.
Speaker 2: And you know, I hated doing it. It's a chore
Speaker 2: and it's this extra.
Speaker 4: Thing you have to do and I would do it
Speaker 4: badly sometimes And I remember lots of times my parents
Speaker 4: waking me up and I, you know, I had gone
Speaker 4: to sleep a rebellious.
Speaker 2: Teenager not putting my mosquito net on. I was the worst. Yeah,
Speaker 2: and you know I'll be like, okay, fine, I'll do it.
Speaker 5: That is the most beautiful introduction. Absolutely, it was like textbook.
Speaker 1: So thank you for going through that period. Yeah, so
Speaker 1: that was incredible, amazing. Thank you so much, Uhmat for
Speaker 1: sharing your story about malaria and wow.
Speaker 5: Hi and welcome to episode eight. Holy crap, holy crap
Speaker 5: of this podcast will kill you. I'm Aaron Welsh and
Speaker 5: I'm Aaron Alman Updyke.
Speaker 1: Thanks for joining us.
Speaker 5: We're very excited.
Speaker 1: This week. We're talking about malaria, yep, which is a
Speaker 1: big one. But we're gonna have a good time today.
Speaker 5: It's gonna be really fun. I'm thrilled about it.
Speaker 1: Malaria is fascinating.
Speaker 5: It's a really it's actually one of the first diseases
Speaker 5: that made me want to study disease.
Speaker 1: So I'm really excited that.
Speaker 5: Yeah, malaria is just a semiasis. Oh, they're like very
Speaker 5: close to my heart.
Speaker 1: That's so cool.
Speaker 5: Yeah, all right, I'm excited about it.
Speaker 1: Learn something new about you, all.
Speaker 5: Right, But before we jump in, we have a correction,
Speaker 5: yes to make. We always say if we get something wrong,
Speaker 5: please let us know, and this is proof that we're
Speaker 5: not lying. All of this is outside of our area
Speaker 5: of expertise.
Speaker 1: We expect to get things wrong.
Speaker 5: So in the very first episode, eight whole weeks ago
Speaker 5: at this point, oh, I know, right, we talked about
Speaker 5: influenza and I mistakenly said that influenza was a retrovirus.
Speaker 5: That is incorrect. Thank you Dustin for letting us know that.
Speaker 1: Yeah, thank you.
Speaker 5: But anyways, that's our correction. Influenza is an RNA virus,
Speaker 5: but it is not a retrovirus. So if you have
Speaker 5: a correction for us, you can go ahead and send
Speaker 5: that to this podcast Will Kill You at gmail dot com,
Speaker 5: or you can message us on any of our social
Speaker 5: media profiles as well. Yeah, that is all all right.
Speaker 1: That means that we're onto Quarantini's. Ooh, what are we
Speaker 1: drinking this week?
Speaker 5: This week is the Fever Reliever?
Speaker 1: Wonderful? And what is in the Fever Reliever?
Speaker 5: Well, since we're talking about malaria today, we're drinking basically
Speaker 5: a gin and tonic. Okay, And when I say basically,
Speaker 5: I mean it's a gin and tonic people with a line.
Speaker 1: Yes, all right, And we're going to get into why
Speaker 1: that has anything to do with malaria later on in
Speaker 1: the episode. Make sure you stay tuned.
Speaker 5: Tonic water has quinine in it.
Speaker 1: Yeah, it won't be any sort of effective dose.
Speaker 5: But no, no, no, just enough to be delicious chills
Speaker 5: chazz jaws, yes with a British accent. For many raisons
Speaker 5: chaos delicious.
Speaker 1: Gin and tonics were when I was living in Panama,
Speaker 1: they were my drink.
Speaker 5: Too bad that you weren't living in an area of
Speaker 5: Panama where malaria was a real risk factor.
Speaker 1: I don't think that's too bad, self medicare I'm pretty
Speaker 1: I'm pretty okay, you're happy with that fact.
Speaker 5: Cool.
Speaker 1: So, now that we've got our quarantines underway, we're going
Speaker 1: to delve right into the biology. Aaron, tell me about malaria.
Speaker 5: I will try my best. Malaria is a big one.
Speaker 5: And one of the things that makes malaria so interesting
Speaker 5: is the fact that it has a really complex life sitle,
Speaker 5: which means it's going to be complex to talk about today.
Speaker 1: But we're going to simplify it as much as possible.
Speaker 5: Yes, So malaria is caused by a parasite. This is
Speaker 5: the first disease that we're talking about on the show
Speaker 5: that's caused by a parasite.
Speaker 1: Can you explain to me the difference between a parasite
Speaker 1: and a pathogen.
Speaker 5: Yes, So we usually use the word pathogen to refer
Speaker 5: to viral and bacterial diseases, Okay. A parasite is usually
Speaker 5: referred to only for what are called protozoans or like
Speaker 5: parasitic worms and things.
Speaker 1: Okay, and protozoonins are not bacteria.
Speaker 5: Right, So protozoa it's not a great term, but it
Speaker 5: essentially means it's still a single celled organism, but it's
Speaker 5: much larger than a bacteria or a virus, and it's
Speaker 5: more closely related to plants and animals than it is to.
Speaker 1: Bacteria, so a little more complex, exactly.
Speaker 5: Yeah, so malaria is a protozoa all right. There are
Speaker 5: several different species of parasite that cause malaria. The one
Speaker 5: that causes the worst disease in humans and is the
Speaker 5: most widespread is called Plasmodium falciprum. This is the species
Speaker 5: that's the most common throughout most of Africa, and it
Speaker 5: replicates really quickly, so it causes a very severe form
Speaker 5: of disease. The other species are Plasmodium vivax, which is
Speaker 5: the most common species in Asia, and it, along with
Speaker 5: another species called Plasmodium o vale, have these dormant stages
Speaker 5: that kind of hang out in your liver for a
Speaker 5: long period of time where they're not really causing any
Speaker 5: active infection, not really causing any real symptoms, but they
Speaker 5: can just hang out there and then re emerge later
Speaker 5: in your life, like months or years later.
Speaker 1: Which is important also in the distribution for the mosquito
Speaker 1: and the seasonality of this, because something like falciprum has
Speaker 1: to occur where the species occurs year round, right, the
Speaker 1: pusquito species occurs year round, whereas something like vivacs can
Speaker 1: exist in a place that has more seasonality to it
Speaker 1: in terms of cold.
Speaker 5: Yeah, definitely. And then finally there's Plasmodium malaria, which is
Speaker 5: found pretty much worldwide and causes the most chronic infection
Speaker 5: if untreated. I should also note that there are other
Speaker 5: species of malaria that infect other mammals as well as birds.
Speaker 5: Avian malaria is actually really important and is a major
Speaker 5: cause of decline of native bird populations in Hawaii and
Speaker 5: other places. But unfortunately we don't have the time to
Speaker 5: talk about those today. Maybe we could have a future
Speaker 5: episode on avian malaria. Yeah, anyways, let's talk about the
Speaker 5: life cycle, shall we.
Speaker 1: Let's do it.
Speaker 5: So malaria infection starts when an infected female mosquito. Put
Speaker 5: my entomologists hat on here, because it's only female mosquitos
Speaker 5: that bite you and suck your blood. Male mosquitoes just
Speaker 5: drink nectar. They're just little beat bops. Okay, So, an
Speaker 5: infected female mosquito takes a blood meal, meaning sticks her
Speaker 5: snout into you and sucks your blood. And as she
Speaker 5: does this, the parasites which are in her salivary glands
Speaker 5: are injected into your bloodstream. These parasites, which look kind
Speaker 5: of like little spores, they're just little balls at this point,
Speaker 5: once in your blood, will infect your red blood cells,
Speaker 5: or in some cases, they'll travel through your bloodstream to
Speaker 5: your liver and infect your liver cells directly. Then, once
Speaker 5: inside of your cells, the parasites begin to replicate. They
Speaker 5: replicate and replicate and eventually explode out of your blood cells,
Speaker 5: and they'll fly freely through your bloodstream again. Uh oh,
Speaker 5: And this is what's actually causing the symptoms that we
Speaker 5: see in malaria is when these thousands of millions of
Speaker 5: parasites explode open your red blood cells and then travel
Speaker 5: through your blood to find new cells to infect. So
Speaker 5: now these parasites are free floating in your bloodstream and
Speaker 5: they can be picked up by another mosquito as it
Speaker 5: feeds on you. Then within the mosquito, the parasites have
Speaker 5: to travel through the mosquito's gut, survive through the stomach, replicate, reproduce.
Speaker 5: Then they have to exit the gut, which isn't easy
Speaker 5: to do because they're basically punching through the gut wall
Speaker 5: of this mosquito. Then they have to travel to the
Speaker 5: salivary glands where they can then get ready to start
Speaker 5: the cycle all over again.
Speaker 1: All this tells me is that I'm amazed that this
Speaker 1: is a real thing. Like, it's so cool the way
Speaker 1: it's so complex. How long it took for this to evolve, right,
Speaker 1: such a complex life cycle, it's such.
Speaker 5: This is what I love about vector borne diseases is
Speaker 5: how much more complex this becomes because you have this
Speaker 5: entire other organism and there is a part of this
Speaker 5: life cycle of this parasite that takes place only in
Speaker 5: the mosquito and is dependent on that mosquito. All players
Speaker 5: have to be there, exactly Cool. Yeah, so transmission to
Speaker 5: malaria isn't direct person a person. It happens just from
Speaker 5: the bite of this infected mosquito. Specifically, it's an anophies mosquito.
Speaker 5: There are several hundred species, but only about thirty or
Speaker 5: forty that are important in terms of human malaria transmission.
Speaker 5: And there's some evidence that once a mosquito is infected
Speaker 5: with malaria, like once these parasites are in the salivary
Speaker 5: glands and ready to infect a human, mosquitoes are more
Speaker 5: attracted to host, more persistent in their attempts to feed,
Speaker 5: and they feed on more hosts per feeding attempt, which
Speaker 5: is crazy because it's basically the malaria parasite going hey,
Speaker 5: I'm here, I'm ready to go. Better take a meal.
Speaker 5: Better take a meal, Better take a meal.
Speaker 1: That's super cool. It's host manipulation by a parasite.
Speaker 5: Yeah, it's crazy.
Speaker 1: That's one of my favorite themes, I guess, or like
Speaker 1: favorite things. And yeah, like the zombie fungus maybe we'll
Speaker 1: do an episode on cortyceps.
Speaker 5: Definitely, no question, we have to Okay, sorry to interrupt, No,
Speaker 5: you're fine. One thing I think that's really interesting about this,
Speaker 5: and I'll talk more about it later on, is just
Speaker 5: that in terms of thinking about prevention of malaria, On
Speaker 5: the one hand, it makes it a lot harder to
Speaker 5: deal with prevention when you have an entire other species
Speaker 5: that you're trying to deal with, But it also means
Speaker 5: that there's a lot of stages of the malaria parasite
Speaker 5: that you could potentially target that are outside of the
Speaker 5: human which I think is really interesting. So I'll talk
Speaker 5: more about that when we talk about the status of
Speaker 5: malaria in the world today. What else about malaria? So,
Speaker 5: the incubation period, which again is the time from when
Speaker 5: you're infected to when you show symptoms in this case,
Speaker 5: from when you're bit by a mosquito and until you
Speaker 5: have your first round of symptoms, is between seven and
Speaker 5: thirty days. And this large range depends on the species
Speaker 5: of parasite that you're infected with. Okay, so Plasmodium fauciperum,
Speaker 5: the one that's sort of the worst, has the shortest
Speaker 5: incubation period, while plasmodium malaria has the longest.
Speaker 1: That would make sense because you said falciprum replicate so
Speaker 1: quickly exactly.
Speaker 5: So in some cases, because you can have this really
Speaker 5: long incubation period, diagnosis and treatment can be somewhat harder,
Speaker 5: especially for example, if you're traveling, or you become infected
Speaker 5: while you're traveling and you come back to a country
Speaker 5: where malaria maybe isn't very common, it can be really
Speaker 5: difficult to diagnose because it might be several weeks or
Speaker 5: months until you actually have any symptoms.
Speaker 1: That makes sense, Yeah, so malaria's inside you. You've been
Speaker 1: bitten by a mosquito that has injected a bunch of parasites.
Speaker 1: What's my body gonna do?
Speaker 5: Well, First, there's something that's called classic malaria, which has
Speaker 5: a cold stage with shivering, feeling very cold, a hot
Speaker 5: stage where you have fever, headaches, vomiting, young children can
Speaker 5: have seizures, and then a sweating stage where you just
Speaker 5: sweat a lot. But I don't know why they call
Speaker 5: it classic malaria, because apparently this is a very rare presentation,
Speaker 5: like it doesn't usually happen this way. Really, Yeah, I
Speaker 5: don't know if maybe this is so maybe people have
Speaker 5: written about malaria in this way a lot, and that's
Speaker 5: why it's called classic. But realistically what happens is all
Speaker 5: at once, you have fever, chills, sweats, headaches, nausea, vomiting,
Speaker 5: body aches. You feel like absolute human garbage, human garbage.
Speaker 5: And this happens in cycles. A classic attack lasts for
Speaker 5: between six and ten hours and happens every two to
Speaker 5: three days, depending on the parasite species. So Plasmodium falciperum
Speaker 5: replicates every two days, as does vivax and ovale, whereas
Speaker 5: malaria replicates every three days. So that means that in
Speaker 5: your cells, they're basically taking two days to have a
Speaker 5: full cycle of replication and then they're bursting out of
Speaker 5: your cells, okay, And so that is how you end
Speaker 5: up with these fever and headaches, is all of these
Speaker 5: parasites all at once are bursting out of your cells
Speaker 5: and into your bloodstream.
Speaker 1: So each time you have this intense spike and all
Speaker 1: these symptoms, it's in response to the parasite reproducing exactly.
Speaker 5: And that is also when you're going to be most
Speaker 5: effective for mosquitoes, because that's when these stages that are
Speaker 5: effective to the mosquito are free floating in your bloodstream
Speaker 5: as well.
Speaker 1: Okay, that makes sense.
Speaker 5: Yeah, so that's most of what you need to know.
Speaker 5: I think about malaria biology. One thing that makes it
Speaker 5: difficult to control also is that diagnosis is really difficult.
Speaker 5: So typically it's done by microscopy. So you need a
Speaker 5: person who's very highly trained to actually take a smear
Speaker 5: of your blood on a microscope slide and look through it.
Speaker 5: And it's effective. But you have to have people that
Speaker 5: are very well trained and even very well trained people
Speaker 5: because you have these cycles. If you just take blood
Speaker 5: at the wrong time, you might not see them, or
Speaker 5: you might see things that look like malaria but aren't
Speaker 5: actually malaria. So basically microscopy is imperfect. There are other
Speaker 5: molecular methods that you can use for detection of malaria,
Speaker 5: but they're also not perfect, and in many cases they're
Speaker 5: expensive and sometimes cost prohibitive. But yeah, I think that's
Speaker 5: it for malaria biology. Okay, so do you want to
Speaker 5: hear about the history of malaria.
Speaker 6: Oh, I'm really excited about it.
Speaker 1: It's spans eons, eons, oh millions and millions of years.
Speaker 5: What that's got to be that's the first time We've
Speaker 5: talked about millions of years on this episode.
Speaker 1: Probably is malaria's history is Yeah, it's enormous, and we're
Speaker 1: going to get through it all.
Speaker 5: Yes, in the next ten minutes.
Speaker 1: No, uh, well, first we're going to go back to
Speaker 1: the Dinosaursky and malaria's evolutionary origins. Then I'm going to
Speaker 1: talk malaria before treatments were discovered, then Panama Canal time, yes,
Speaker 1: just a little bit, and the failed eradication campaigns the
Speaker 1: twentieth century.
Speaker 5: I'm thrilled, let's do this. Gave it to me.
Speaker 1: Malaria is an ancient, ancient disease, definitely prehistoric. Some researchers
Speaker 1: think that the parasite evolved from a free living plant species.
Speaker 1: A plant species, yeah, like algae or something. Yeah. So
Speaker 1: it has a bunch of genetic fragments that are similar
Speaker 1: to those used to make chlorophyll.
Speaker 2: What.
Speaker 5: Yeah, that's so cool. I never knew that.
Speaker 1: It's very it's very strange.
Speaker 5: I just assume that everything is like an animal because
Speaker 5: I'm oh, what does Matt call it? I have plant blindness?
Speaker 1: Yeah, you do, I think we both do. Yeah, a
Speaker 1: lot of disease ecologists have plant blindness. Definitely, Okay, anyway,
Speaker 1: so in prehistoric times, I'm talking like time of the dinosaurs, prehistoric,
Speaker 1: the ancestor of malaria made the jump from plant species
Speaker 1: to parasite. Scientists have found the DNA of a malaria
Speaker 1: species in a biting midge, which is an insect preserved
Speaker 1: an amber from one hundred million years ago.
Speaker 5: Stop.
Speaker 1: Yeah, that's thrilling, like Jurassic Park style.
Speaker 5: That's really Jurassic Yeah. Oh yeah, that's so cool.
Speaker 1: So long, long, long before malaria became a parasite of humans,
Speaker 1: it was probably a parasite of dinosaurs, which makes sense
Speaker 1: considering that there are malaria parasites in so many different
Speaker 1: groups of animals today, including birds and reptiles. Okay, but
Speaker 1: we know that modern malaria is transmitted by mosquitoes, not
Speaker 1: biting midges. So when did that happen? Probably around thirty
Speaker 1: million years ago. Eventually it became a parasite of humans
Speaker 1: maybe eight million years ago, wow, or ancestors of humans
Speaker 1: maybe fifteen thousand years ago. I mean, there's a lot
Speaker 1: of debate.
Speaker 5: Everyone in the U and I study plus or.
Speaker 1: Minus eight million years. In any case, once it was
Speaker 1: in humans, it never really left ever since malaria emerged
Speaker 1: as a human parasite. It has infected and killed billions.
Speaker 1: That's with a bee. That's what a be of people
Speaker 1: throughout history. Oh man, it doesn't really have the same
Speaker 1: wham like epidemic storyline that some of these other diseases
Speaker 1: that we've talked about have.
Speaker 5: Dinosaurs are a pretty big wham though.
Speaker 1: Oh yeah, absolutely, But like you know, in terms of
Speaker 1: a pandemic or an epidemic. But the numbers are still
Speaker 1: absolutely staggering, both an ancient and in modern times. Are
Speaker 1: you ready for the body count? Malaria probably killed half
Speaker 1: fifty percent of all of the humans who have ever lived.
Speaker 1: What about one hundred and eight billion people have existed
Speaker 1: at some point or another throughout history. That means that
Speaker 1: malaria has probably killed about fifty four billion of them.
Speaker 5: What on earth? Does that? Even?
Speaker 1: You can't even?
Speaker 5: I can't. I literally.
Speaker 1: Okay, no, we were millennials before, you know now. But
Speaker 1: also that number seemed really outrageous. Also, it's just too
Speaker 1: it's too much, it's you can't wrap your brain around it.
Speaker 1: All those things. Yeah, but I was like, all right,
Speaker 1: that seems wait, let's hold on a second. Let's take
Speaker 1: a step back.
Speaker 5: Exaggerating I saw.
Speaker 1: That and I was like, I really want to put
Speaker 1: that in the podcast. And I was like, I don't know.
Speaker 1: That seems a little bit bogus. I looked into it,
Speaker 1: and it may be on the upper end of things,
Speaker 1: but it seems certainly possible. There's obviously, yeah, there's well,
Speaker 1: I don't know if you can make a confidence interval
Speaker 1: with this type of you know, back of the cuff calculation,
Speaker 1: but it is possible. Wow, it's insane.
Speaker 5: That is really a cool statistic. Now, that's the kind
Speaker 5: of thing you want to whip out at a party.
Speaker 1: Yes, only without statistics.
Speaker 5: This is why I have so many friends.
Speaker 1: Okay, So I don't really have estimate for when malaria
Speaker 1: first popped up in humans. The reality is that malaria
Speaker 1: has been with us throughout our evolutionary history and actually
Speaker 1: plays a pretty big role in it. As we all know,
Speaker 1: the cradle of human evolution is in Africa, so it's
Speaker 1: also likely that that is also where malaria evolved. As
Speaker 1: you mentioned I did, Malaria is caused by several different
Speaker 1: species of organisms. I'm going to focus on just two
Speaker 1: of them because they probably made the biggest impact on
Speaker 1: human history.
Speaker 5: Cool.
Speaker 1: All right, so we've got plasmodium vivax and plasmodium falciprium,
Speaker 1: which I'm just going to call vivax and falciprium from
Speaker 1: here on.
Speaker 5: That's good.
Speaker 1: Vivax is the less severe and more ancient one. Falciprium
Speaker 1: is more deadly and more recent.
Speaker 5: Interesting, I didn't know that that falciprium was more recent.
Speaker 1: Mm hmm. Vivax probably showed up in hunter gatherer groups
Speaker 1: many thousands of years ago and caused sporadic but deadly outbreaks.
Speaker 1: And we know this because of something called the Duffy antigen,
Speaker 1: which prevents vivax from entering the blood like the red
Speaker 1: blood cell. What so, if you are a person with
Speaker 1: the Duffy blood type, then you are protected from vivax malaria.
Speaker 5: That is really cool.
Speaker 1: And because vivax was probably so severe in those early
Speaker 1: years and this mutation was so beneficial, the Duffy antigens
Speaker 1: spread like wildfire throughout much of Africa, and by around
Speaker 1: five thousand years ago, nearly every person born on the
Speaker 1: African continent had the Duffy blood type.
Speaker 5: And so is that why you basically don't see vivax
Speaker 5: in Africa exactly? That is exactly awesome.
Speaker 1: Yeah, cool. And today the proportion of black individuals from
Speaker 1: Africa with this blood type is between ninety and one
Speaker 1: hundred percent.
Speaker 5: Wow, so it's persisted. Oh absolutely, man, that is very advantageous.
Speaker 1: And despite the Duffy mutation, Africa would not remain malaria
Speaker 1: free for long. Another malaria parasite was about to take
Speaker 1: Vivax's place, enter Falciprium. Falciprium probably made its appearance when
Speaker 1: people began to farm in or near rainforest in central Africa,
Speaker 1: So there a new malaria parasite emerged, taking advantage of
Speaker 1: settled groups so more stable where it could actually persist
Speaker 1: in a community, whereas Vivax was able to survive prior
Speaker 1: to like large settled groups because of the dormancy.
Speaker 5: Ah, that makes sense, super cool.
Speaker 1: Yeah, and then there was also a more efficient mosquito
Speaker 1: for falciprium disease transmission. Falciprium when it first popped up
Speaker 1: would have been really devastating, so devastating in fact, that
Speaker 1: when yet another mutation, this one protecting against falciprium malaria appeared,
Speaker 1: it rapidly spread through the African continent. This one you
Speaker 1: may have heard of, sickle cell. I'm not going to
Speaker 1: delve too deeply into the biology or the genetics of
Speaker 1: this one. But basically, people with one copy of the
Speaker 1: sickle cell allele have blood cells. Actually, people with one
Speaker 1: or two copies of the sickle c allele have blood
Speaker 1: cells that have a shape that prevents the falcipum parasite
Speaker 1: from entering them.
Speaker 5: They're sickle shaped.
Speaker 1: Yes.
Speaker 5: Yeah.
Speaker 1: There are other mutations with a pretty high prevalence that
Speaker 1: are linked to malaria, such as G six PD deficiency thallacemia,
Speaker 1: and about one in fourteen people on Earth has one
Speaker 1: of these mutations.
Speaker 5: Wow.
Speaker 1: Yeah, Anyway, with these two very protective mutations, malaria should
Speaker 1: have been history, right right.
Speaker 5: Yeah, not so much, too sneaky.
Speaker 1: By the time that pretty much everyone in Africa was
Speaker 1: protected against vivax malaria, it had escaped to Europe and Asia,
Speaker 1: and falciprium would continue and continues to wreak havoc on
Speaker 1: the African continent. Malaria doesn't leave any traces on skeletons,
Speaker 1: but we can track its history through human genetics, like
Speaker 1: I just talked about, through examining mummies and through ancient writings.
Speaker 5: What can we see in mummies?
Speaker 1: Yeah, I was just going to say this is so cool.
Speaker 1: Malaria antigens were found in five thousand year old Egyptian
Speaker 1: and Nubian mummies. No dang, what tested their tissues? God?
Speaker 5: Mummies? Science science.
Speaker 1: And there are mentions of a cyclic fever probably malaria
Speaker 1: in ancient Chinese, Greek, Roman, Sumerian writings. Wow, in Rome,
Speaker 1: vivacs probably contributed to the fall of the Roman Empire. YadA, YadA, YadA.
Speaker 1: Like every stinking week I say something about the fall
Speaker 1: of the Roman.
Speaker 5: Yeah, it's not, it's not. This podcast will kill you
Speaker 5: if we don't mention ancient Rome.
Speaker 1: Ebola might be another story. But that's okay.
Speaker 5: Maybe I'll find a way.
Speaker 1: Uh yeah, So, but I gotta tell you. I'm not
Speaker 1: going to go talk about the Roman Empire, but I
Speaker 1: do want to tell you about some of these Roman
Speaker 1: cures for malaria, because what were they thinking? All right,
Speaker 1: So you're a citizen of ancient Rome.
Speaker 5: I have my toga on and I'm holding someone who's
Speaker 5: holding grapes that I'm eating exactly. Yeah, my gosh, I'm
Speaker 5: so perfect.
Speaker 1: I'm your doctor. You probably shouldn't trust me, don't you
Speaker 1: have no choice?
Speaker 5: I do?
Speaker 2: Oh?
Speaker 1: Wow, you have recurrent fever and chills. Well, that sounds
Speaker 1: like malaria. I could prescribe you some honeysuckle dissolved in wine.
Speaker 5: Oh, it sounds delicious, right, it sounds pretty nice.
Speaker 1: Or I could instruct you to consume the liver of
Speaker 1: a seven year old mouse.
Speaker 5: How are you even gonna find a seven year old mouse?
Speaker 5: For God's sake?
Speaker 1: I assume it's killed and then preserved for seven years.
Speaker 5: Oh that's even worse than just a really old creaky
Speaker 5: mouse running around.
Speaker 1: Well, I could also tell you about my famous meal
Speaker 1: combo of bed bugs, eggs and wine. Okay, what not
Speaker 1: bed bug eggs, but bed bugs and eggs? Yeah? Why
Speaker 1: I don't have those answers?
Speaker 5: How do you prepare the eggs?
Speaker 1: Again? I assume over easy?
Speaker 5: Oh my god, this sounds to try. I want to
Speaker 5: leave rome.
Speaker 1: Well, whichever one of those you choose, honeysuckle, duh. Sorry,
Speaker 1: but I'm gonna prescribe you whatever I think is best.
Speaker 1: And I'm also going to prescribe you a piece of
Speaker 1: papyrus that you're gonna wear around your neck with the
Speaker 1: powerful word abracadabra on it. Not yes, no, abercadabra. That
Speaker 1: is where abercadabra comes from stop it right malaria. It
Speaker 1: was to prevent malaria and ancient Romans.
Speaker 5: Stop it right now.
Speaker 1: It took everything I had to hold this factoid from you.
Speaker 1: So I wanted maximum impact.
Speaker 5: Abra cadabra means go away malaria.
Speaker 1: H oh, well, I don't know if it necessarily means.
Speaker 1: I looked at the etymology and it seems like nonsense
Speaker 1: away malaria.
Speaker 5: Yeah, oh my god, that is the best news I've
Speaker 5: ever heard.
Speaker 1: Yep. Okay, So we got abracadabra, we got some mouth,
Speaker 1: we got some bed bugs. We're done with ancient Rome.
Speaker 1: There's nothing more I can say.
Speaker 5: I need to leave this place.
Speaker 1: I'm gonna talk a little bit about more modern Rome.
Speaker 1: I guess, like not modern day, but it's important because Rome,
Speaker 1: in like the fifteen hundreds, I think, is probably where
Speaker 1: malaria actually got its name. Oh so malaria mal meaning
Speaker 1: bad and aria or area whatever meaning air bad air,
Speaker 1: bad air. So remember the theory of miasthmatism. I do
Speaker 1: the idea that disease is caused by foul smelling air
Speaker 1: and certain weather patterns. That is what was at play
Speaker 1: here when malaria was coined.
Speaker 5: Right, it's just the bad air that you're breathing in right.
Speaker 1: People. Notice that it occurred more frequently in the summer
Speaker 1: and in low lying marshy areas, which also happened to
Speaker 1: be when and where mosquitoes are most abundant.
Speaker 5: Great mosquito habitat in those marshes.
Speaker 1: But the root of transmission wouldn't be figured out for
Speaker 1: a while. Yeah, and we'll get there, But first, let's
Speaker 1: head to the New World.
Speaker 5: Let's go on the boat.
Speaker 1: Before Columbus and the European invasion of North and South America,
Speaker 1: the western hemisphere was free of malaria.
Speaker 5: What mm hmm, I don't think I even knew that.
Speaker 5: That's embarrassing.
Speaker 1: That's why you're here. But I'm here too. Yeah. So,
Speaker 1: both vivax and falciprum were brought over by Europeans, particularly
Speaker 1: during the slave trade. In fact, some historians suggest that
Speaker 1: the slave trade was so massive because two things. One,
Speaker 1: wide scale colonization of Africa by Europeans hadn't been successful
Speaker 1: because falciprium, the more deadly malaria, would kill so many
Speaker 1: of the European invaders, while Africans had been exposed to
Speaker 1: the disease as kids and were more protected. Yeah, so
Speaker 1: there was more emphasis on invasion and colonization of North
Speaker 1: and South America instead where all of the indigenous people
Speaker 1: were killed by the invading diseases as well, right.
Speaker 5: Like smallpox and then malaria. You know, I guess I
Speaker 5: actually did know that about the slave trade malaria, So
Speaker 5: I'm not that stupid, Okay.
Speaker 1: But there's the second reason that the slave trade might
Speaker 1: have been so massive because of malaria.
Speaker 5: Wow.
Speaker 1: So, as we've heard in other episodes, Europeans brought with
Speaker 1: them a bunch of diseases that wiped out up to
Speaker 1: ninety percent of the Native American population in the first
Speaker 1: few decades of colonization see episode three, which the Europeans
Speaker 1: saw as wiping out their potential workforce slash slaves, so
Speaker 1: they turned to Africa and ramped up the slave trade
Speaker 1: to compensate.
Speaker 5: Cool.
Speaker 1: Although malaria was new to the Western Hemisphere, there was
Speaker 1: a secret there hidden in the forested hills of the Andes,
Speaker 1: the Sincona tree. The bark of this tree contains a
Speaker 1: chemical called quinine, which, when ingested, reduces the symptoms of
Speaker 1: malaria and basically cures you. The Quetchewa people of Peru, Bolivia, Venezuela,
Speaker 1: and Ecuador had been using bark from the sincone tree
Speaker 1: for ages prior to the European invasion, but when malaria
Speaker 1: started popping up, they saw that it was also an
Speaker 1: effective treatment for that illness. Some Jesuits from Spain noticed
Speaker 1: this catchewan practice of treating malaria with this bark and
Speaker 1: co opted it, bringing the powdered bark back to Spain,
Speaker 1: announcing it as a miracle cure, which it really was,
Speaker 1: and calling it Jesuits bark, claiming that they had discovered
Speaker 1: it in its practice.
Speaker 5: Pretty typical.
Speaker 1: Uh huh, it's like, come on, guys. Really, Europe was
Speaker 1: still very much malarious I think that's a word at
Speaker 1: this time, which is like the mid sixteen hundreds, and
Speaker 1: when the news spread about this miraculous fever tree, the
Speaker 1: race was on to find these trees, get their bark,
Speaker 1: and most importantly, control their production. There were many missions,
Speaker 1: failed and successful to harvest saplings, collect seeds, and bring
Speaker 1: them back to Europe to be planted. It became a
Speaker 1: huge commercial venture with a lot of political turmoil. The
Speaker 1: Sincune tree was almost harvested to extinction.
Speaker 5: Wow.
Speaker 1: Exporting these trees out of Peru and selling the seeds
Speaker 1: was quickly outlawed, but that didn't stop it from happening,
Speaker 1: and the Dutch maintained some pretty huge sincone plantations in Indonesia,
Speaker 1: while the British had some in India. Of course, only
Speaker 1: wealthy people could afford to purchase the treatment, which kind
Speaker 1: of set the precedent for malaria being a disease of poverty.
Speaker 1: The other thing that sincon Bark did was to enable
Speaker 1: the colonization of parts of the world that had previously
Speaker 1: resisted because of the amount of malaria there. Now Europeans
Speaker 1: could travel to and invade these places, such as India,
Speaker 1: such as parts of Africa, as long as they took
Speaker 1: with them a suitcase full of sincne bark. I mean,
Speaker 1: so I'm kind of speculating over here, but I don't
Speaker 1: think it's necessarily a coincidence that the whole manifest destiny
Speaker 1: British imperialism movement really hit its stride as soon or
Speaker 1: soon after access to a malaria treatment was possible and
Speaker 1: fairly easy.
Speaker 5: Oh, definitely not.
Speaker 1: I mean, British officers in India invented tonic water as
Speaker 1: a malaria preventative because quinine on its own was too bitter,
Speaker 1: so those of you who are drinking along with us,
Speaker 1: or have ever had tonic water, you have ingested quinine.
Speaker 1: Aaron is guzzling the rest of ours. Yep, you heard it.
Speaker 5: That was That was the last last sip, holding my glass,
Speaker 5: waiting for the moment in which I could so.
Speaker 1: Quinine is a really bitter, bitter tasting. Apparently it has
Speaker 1: some really nasty side effects, and so in order to
Speaker 1: take it and not vomit immediately afterwards.
Speaker 5: I would make it within gin sugar.
Speaker 1: Tonic water contains a lot of sugar, yeah, and so
Speaker 1: if yeah, so it's an all tonic water. Even though
Speaker 1: by the late sixteen hundreds there was an available treatment
Speaker 1: for malaria, people didn't discover the cause or transmission root
Speaker 1: of malaria until the late eighteen hundreds. In eighteen eighty,
Speaker 1: a French surgeon named I don't mean to do it him. Okay,
Speaker 1: I'm gonna. I'm gonna give you. I'm gonna prompt yous, Lavon,
Speaker 1: thank you. It was beautiful.
Speaker 5: That means you're welcome.
Speaker 1: Clearly, I know zero French. Okay. So this guy, Lavaron
Speaker 1: Lon glanced into a microscope at a smear of blood
Speaker 1: from a malaria patient and saw something wriggling in the
Speaker 1: blood cells. He knew that this was not a bacterium.
Speaker 1: It was something new, something he had never seen before, wriggling,
Speaker 1: uh huh. And he figured that it was the causative
Speaker 1: agent of malaria. And he presented his findingschool yeah, which
Speaker 1: were met with scorn by the leading bacteriologists of the day,
Speaker 1: who had already decided that malaria was caused by an
Speaker 1: airborne bacterium, thus supporting the whole miasthmatism theory.
Speaker 5: I just love it.
Speaker 1: They completely shut him down, but Leon didn't back down. Instead,
Speaker 1: he doubled down, also claiming that malaria was transmitted by mosquitos,
Speaker 1: even if he didn't have any evidence to back that up.
Speaker 5: He just was like, I've decided.
Speaker 1: Yeah, so the role of the mosquito in philariasis had
Speaker 1: recently been discovered, and so he was like just jumping
Speaker 1: on that train.
Speaker 5: Well, I mean that makes sense.
Speaker 1: Oh yeah, I mean he clearly had a good wriggling thing.
Speaker 5: And you're like, that doesn't look so different from what
Speaker 5: causes this. It's gotta be a mosquito. Yeah, seems like
Speaker 5: a smart eye to me.
Speaker 1: I think he eventually did get a Nobel price cool,
Speaker 1: but all of his findings at the time more or
Speaker 1: less fell on deaf ears. Eventually he would be proven
Speaker 1: right about both, but that would take a couple of decades.
Speaker 5: Wow.
Speaker 1: In the meantime, the French had decided to build a
Speaker 1: canal through the little land mass connecting North and South America. Oh,
Speaker 1: you know, Panama.
Speaker 5: Such nostalgia.
Speaker 1: We both did our field work in Panama, the entirety.
Speaker 5: We spent months, many months, especially in your case.
Speaker 1: Yeah, I spent years, literally years literally. Panama had been
Speaker 1: the bane of Europe's existence for a while, since it
Speaker 1: inconveniently blocked easy transport from the Atlantic to the Pacific oceans.
Speaker 1: How rude of it, I cannot believe it. At its narrowest,
Speaker 1: Panama is about fifty miles or eighty kilometers across. It's
Speaker 1: actually a little bit less than that.
Speaker 5: So small, it's very small.
Speaker 1: And the Spanish had previously built a trail, Actually, the
Speaker 1: Spanish had their slaves built a trail known as the
Speaker 1: Communo da Cruzes to link these two oceans. But the
Speaker 1: forests were full of malaria and yellow fever, and in
Speaker 1: the rainy season, huge parts of this trail would be
Speaker 1: washed away and I should know because I used to
Speaker 1: walk along what remains of this trail every week during
Speaker 1: my field work.
Speaker 5: Didn't you find a lot of really cool old bottles
Speaker 5: and junks? Yeah on that trail? Yeah, so cool.
Speaker 1: It was my favorite thing in the world. Anyway. Fresh
Speaker 1: off the success of the Suez Canal, well, the French
Speaker 1: engineer Ferdinand de Lesseps was hired to cut into Panama.
Speaker 1: Construction began, but progress wasn't really made. Workers were dying
Speaker 1: by the thousands from malaria and yellow fever. In eight years,
Speaker 1: over twenty two thousand workers died in the construction. Wow,
Speaker 1: eight years eight is twenty two thousand lives lost.
Speaker 5: That's half the students at this university.
Speaker 1: It was a complete disaster.
Speaker 5: That is awful.
Speaker 1: So the French after this, they were like, Okay, this
Speaker 1: isn't working. Yeah, so the whole project was abandoned for
Speaker 1: a number of years.
Speaker 5: Oh my god.
Speaker 1: A few years after the canal was canceled, a couple
Speaker 1: of researchers finally showed conclusively that malaria was transmitted through
Speaker 1: the bite of a mosquito. And this finding, though, would
Speaker 1: come too late for the thousands of workers who died
Speaker 1: during the first canal efforts, but not for the second
Speaker 1: successful attempt to build a canal. When the US took
Speaker 1: over canal construction, they hired a guy named William Crawford
Speaker 1: Gorgis to act as medical specialists. Gorgas one of the
Speaker 1: first things that he did was to start a full
Speaker 1: on war against the mosquito. He put in screens, drained swamps,
Speaker 1: oiled puddles, and fumigated buildings in the area known as
Speaker 1: the canal zone. As a result, malaria was more or
Speaker 1: less driven from that part of Panama, but not outside.
Speaker 1: It only in those areas that he directly targeted, which
Speaker 1: of course were the areas where the Americans were living.
Speaker 5: Just a bunch of white people mm hmm.
Speaker 1: And also, since living quarters were segregated by race, only
Speaker 1: the buildings for white people received screens or were treated
Speaker 1: with pesticides.
Speaker 5: Oh my god.
Speaker 2: Yep.
Speaker 1: It was really typical and crappy of them, horrible of
Speaker 1: them anyway, but it was enough to get the canal built.
Speaker 1: It's funny because Gorgas is hailed by so many as
Speaker 1: the man who conquered the Mosquito, but he was very
Speaker 1: specific right. The only reason that it persisted that malaria
Speaker 1: control persisted in the canal zone is because Americans stayed
Speaker 1: in the canal zone right until like the nineteen seventies,
Speaker 1: so they.
Speaker 5: Kept up with that, yes, type of control exactly right.
Speaker 1: Once it became widely known that the mosquito was responsible
Speaker 1: for malaria, many countries took the same approach as gorgas,
Speaker 1: control the mosquito and you control malaria. This is when
Speaker 1: we see DDT and other pesticides make a big appearance.
Speaker 1: DDT spraying campaigns were going so well in the first
Speaker 1: half of the twentieth century that people started to talk
Speaker 1: about eradication. Yeah, let us spray, let us spray, was
Speaker 1: their motto. And let us spray, let us spray. I
Speaker 1: love that malaria was completely eliminated from areas that had
Speaker 1: been so badly afflicted before, until a new case popped
Speaker 1: up here and there, which was confusing since there shouldn't
Speaker 1: be any mosquitos left.
Speaker 5: Yeah, that's right.
Speaker 1: Pesticide resistant mosquitoes bad news, bad bad, bad news. Malaria
Speaker 1: infected mosquitoes quickly re established themselves and caused disease, which
Speaker 1: was so much worse because people didn't have the past
Speaker 1: exposure to gain a bit of immunity to protect themselves.
Speaker 1: The death tolls were super high, and the spraying campaign stopped,
Speaker 1: both because of resistance evolution, but both because of the
Speaker 1: evolution of resistance, but also because of the devastating effects
Speaker 1: of these pesticides on wildlife.
Speaker 5: Yeah ddts with.
Speaker 1: The racial Carson silent spring, right, it's really gnarly Okay.
Speaker 1: Public health professionals were like, well, I guess we'll just
Speaker 1: have to try another approach. This time they targeted the
Speaker 1: parasite rather than the mosquito with drugs. Again, huge numbers
Speaker 1: of people were mobilized to administer newly developed powerful drugs
Speaker 1: to treat and prevent malaria. Again it worked, but again
Speaker 1: only for a while before the first drug resistance cases
Speaker 1: popped up. Efforts were soon abandoned, and by the nineteen
Speaker 1: seventies and eighties a lot of the funding from malaria
Speaker 1: had dried up. There was a huge upsurge in cases
Speaker 1: around this time, but no real focused efforts to relieve
Speaker 1: the malaria burden in those areas most impacted because a
Speaker 1: lot of the early twentieth century campaigns focused on wealthier countries,
Speaker 1: So the Southern US, I mean malaria was endemic in
Speaker 1: a lot of the United States, the southeast United States,
Speaker 1: it went up the East Coast, it was in Europe.
Speaker 1: So once those areas which were first targeted for eradication,
Speaker 1: once those were cleared, it was kind of like.
Speaker 5: Well, I mean, you know, the white people are safe,
Speaker 5: so hey, we've done our job. Yeah.
Speaker 1: My story kind of ends around then with the sad
Speaker 1: facts that the incidence of malaria really increased following this
Speaker 1: decline in funding and sort of the shutdown of all
Speaker 1: of these spraying and drug campaigns. So tell me what
Speaker 1: you got for today.
Speaker 5: Yeah, that's that's where I should step in. Then you
Speaker 5: got it. So, first of all, as of twenty sixteen,
Speaker 5: nearly half of the world's population lives at risk of malaria.
Speaker 5: Half half, So that's like three and a half billion
Speaker 5: people or so. Putting that on the table right away,
Speaker 5: it's literally over three billion people live in areas that
Speaker 5: have malaria transmission in ninety one different countries. Wow, there's
Speaker 5: a lot of countries.
Speaker 1: It's a lot of people at risk of malaria, a
Speaker 1: lot of people probably getting malaria.
Speaker 5: Right, And the money that you're talking about that dried
Speaker 5: up back in the sixties, seventies, eighties, didn't really start
Speaker 5: flowing back towards malaria research and prevention until two thousand WHOA, Yeah,
Speaker 5: I know, I thought that had to be wrong. But
Speaker 5: the other thing that's really important to keep in mind
Speaker 5: when we're talking about malaria is that when you look
Speaker 5: up these numbers of cases and numbers of deaths, they're
Speaker 5: basically guesses. They're educated guesses. They're guesses that are based
Speaker 5: on some surveillance and a lot of statistical and mathematical modeling,
Speaker 5: but there's still just guesses. And depending on who you
Speaker 5: talk to or whose paper you read, they're either really
Speaker 5: great guesses or they're maybe not that great of guesses.
Speaker 5: And this is especially important because the guess work in
Speaker 5: this case extends not just to guessing how many cases
Speaker 5: and deaths there are, but how effective the interventions have
Speaker 5: been in reducing those cases and deaths.
Speaker 1: It would have to be like a massive reduction to
Speaker 1: detect any sort of.
Speaker 5: Kind of yeah, and just to really understand how big
Speaker 5: of an impact is this intervention having versus that intervention.
Speaker 1: Right, So any sort of evaluation is it's it's really difficult.
Speaker 5: Yeah. So in two thousand and six, who estimated that
Speaker 5: there were two hundred and sixteen million cases of malaria
Speaker 5: worldwide and four hundred and fifty five thousand deaths. That
Speaker 5: was last year. Let me just say that again.
Speaker 1: Yeah, I need to repeat that last repeating.
Speaker 5: Last year, there were two hundred and sixteen million cases
Speaker 5: of malaria and four hundred and forty five thousand deaths.
Speaker 5: Estimated two hundred and eighty five thousand of those deaths
Speaker 5: this is larger than the population of the town I
Speaker 5: grew up in. Were children under the age of five.
Speaker 1: For a disease that has a cure and prevention are
Speaker 1: preventative drugs.
Speaker 5: Yeah, that is.
Speaker 1: Horrifying.
Speaker 5: Yeah. Almost ninety percent of these cases and ninety one
Speaker 5: percent of the deaths happen in Africa.
Speaker 2: Yeah.
Speaker 5: So one study that I read, and so this is
Speaker 5: where we'll start to talk about the interventions and the
Speaker 5: fact that, believe it or not, these numbers are better
Speaker 5: than they were.
Speaker 1: Wow, that's really hard to believe.
Speaker 5: I know. So this one paper that I read estimated
Speaker 5: that in two thousand, in Africa alone, there were three
Speaker 5: hundred and twenty one million cases of Plasmodium falciprum the
Speaker 5: bad one, the bad one, and by twenty fifteen that
Speaker 5: number had dropped to one hundred and eighty seven million,
Speaker 5: So that's a forty percent reduction, and it took fifteen
Speaker 5: years for that forty percent decline.
Speaker 1: And since this is so much guesswork, I mean, do
Speaker 1: we think that that's do you want to know that
Speaker 1: that's a real decline.
Speaker 5: Well, it seems like it's a real decline. So this
Speaker 5: study specifically could detect that about sixty eight percent of
Speaker 5: this reduction could likely be explained by the use of
Speaker 5: insecticide treated nets. So bednets treated with long acting in
Speaker 5: second decide long lasting insecticide are one of the main
Speaker 5: intervention methods that people use to control malaria. To prevent malaria,
Speaker 5: they're quite effective, they're cheap to make, but they haven't
Speaker 5: always been available cheaply to people.
Speaker 1: Right, I saw somewhere that said five dollars a bednet
Speaker 1: in an area where the average daily income was less
Speaker 1: than one dollar.
Speaker 5: Yeah, it wasn't until very recently in the two thousands
Speaker 5: that the who made it one of their main goals
Speaker 5: to get these insecticide treated nets to every household, especially
Speaker 5: in Africa. And so I think, I don't know, I
Speaker 5: hope that that number on five dollars per net came
Speaker 5: from prior to that time.
Speaker 1: Yes, it did.
Speaker 5: The other things that are commonly used to control malaria
Speaker 5: besides bednets is something called indoor residual spraying, which essentially
Speaker 5: means instead of like the massive DDT campaigns of the past,
Speaker 5: where we just spray DDT throughout the whole air and
Speaker 5: all over everything, this is just spraying the inside walls
Speaker 5: of your house because what mosquitoes do. This is fun.
Speaker 1: She's very excited.
Speaker 5: Yeah, after a mosquito takes a blood meal, it's all
Speaker 5: fat and full of blood, and it's like, I'm tired.
Speaker 1: It's hard to fly.
Speaker 5: So she goes, I'm sleepy. So ridiculous. Anyways, so she
Speaker 5: flies off and she takes a rest, and she usually
Speaker 5: lands on a wall to take that rest, a vertical surface.
Speaker 1: Oh yeah, sorry, I jumped the gun. I think I
Speaker 1: know you're going with this.
Speaker 5: Yeah, the walls kill the mosquitoes. So there are several
Speaker 5: problems with this. One is that you kind of have
Speaker 5: to spray at least eighty percent of the houses for
Speaker 5: this to be effective, which is a hell of a
Speaker 5: lot of work.
Speaker 1: Yeah, that's going to be really hard, right.
Speaker 5: The second is it only lasts for about three to
Speaker 5: six months, so you have to do this every three
Speaker 5: to six months. And lastly, do you want to take.
Speaker 1: A guess resistance resistance?
Speaker 5: Oh yeah, So insecticide resistance is already happening. It's been
Speaker 5: happening right in many parts of Africa and in many
Speaker 5: parts of the rest of the world where malaria is
Speaker 5: to landemic. You have resistance to all four classes of
Speaker 5: insecticide that are used.
Speaker 1: Uh oh yeah, I mean that's four doesn't really quite
Speaker 1: cover it.
Speaker 5: There's like four different main entire classes of insecticide that
Speaker 5: act in totally different ways on totally different systems, and
Speaker 5: some species of mosquito have shown resistance to all four
Speaker 5: of those classes. We don't have a lot of options
Speaker 5: left because of this physiological resistance, potential behavioral resistance. Indoor
Speaker 5: residual spraying, while it can be effective, might not be
Speaker 5: that effective. The other scary thing that you talked about
Speaker 5: already is this drug resistance. Because the other main way
Speaker 5: of malaria control is combination therapy at least two different
Speaker 5: types of drug. The problem is that this pair site
Speaker 5: is already resistant to the main drug that's used, and
Speaker 5: in a lot of countries, in a lot of places
Speaker 5: it's developing resistance to some of the secondary drugs that
Speaker 5: are used as well. Yeah, so that's pretty scary. Another
Speaker 5: thing I don't know is climate change.
Speaker 1: Oh yeah, this is my sweet spot.
Speaker 5: It is. It's like your favorite thing. Yeah, well, I
Speaker 5: mean to talk about intellectually, Well, no.
Speaker 1: I would say that that's more in my wheelhouse in
Speaker 1: terms of my dissertation.
Speaker 5: Definitely, there's a lot of conflicting opinions out there on
Speaker 5: what the effects of climate change are going to be
Speaker 5: on vector borne diseases. Yes, and at this point, what
Speaker 5: we know for sure is that things are likely going
Speaker 5: to change.
Speaker 1: That seems very reasonable.
Speaker 5: We don't necessarily know the exact direction of these changes.
Speaker 5: We don't necessarily know if things are going to get
Speaker 5: better in some areas and worse in other areas, or
Speaker 5: if they're just going to get worse or better overall.
Speaker 5: But it seems pretty clear, is that.
Speaker 1: In talking about infectious diseases right in Talctor.
Speaker 5: Born and talking specifically about vector borne.
Speaker 1: Diseases right it is, it's going to be very location specific.
Speaker 5: Exactly. So, some studies have shown, with math modeling and
Speaker 5: things like that that it's very possible that the distribution
Speaker 5: of malaria could change going forward because of climate change.
Speaker 5: So we might see these mosquitos, and in some cases
Speaker 5: we already are seeing these mosquitoes move up to higher
Speaker 5: altitudes where they were never previously able to live because
Speaker 5: it would get too cold. Right. We could also see
Speaker 5: a shift from coastal regions to more inland regions, and
Speaker 5: so all of this could very dramatically affect the malaria
Speaker 5: burden that we actually see in humans. So then the
Speaker 5: question becomes what do we do moving forward.
Speaker 1: It's a really tricky question.
Speaker 5: Yeah, it's there's not a clean answer for this. So
Speaker 5: I just want to talk about something that I'm into. Okay,
Speaker 5: because I can. Let's do it our podcast.
Speaker 1: Again.
Speaker 5: Why we're here, right, So one thing that I am
Speaker 5: super interested in is the possibility of transgenic mosquitoes. Oh yeah,
Speaker 5: I know people are gonna hate me for it. Maybe
Speaker 5: we'll get our first hate mail for this gm I
Speaker 5: would love it if we hail yeah GMMs, if we
Speaker 5: got some yeah, I mean kind of, I'd be thrilling.
Speaker 5: I don't want hate mail, Okay, don't send us hate mail.
Speaker 5: So there's a lot of really cool research that's being
Speaker 5: done on how to make these mosquitoes less permissive to
Speaker 5: malaria infection.
Speaker 1: What does that mean?
Speaker 5: So it basically means that instead of focusing on stopping
Speaker 5: these mosquitos from biting you, or curing everyone with the parasite,
Speaker 5: or removing mosquitos from the ecosystem, this looks at blocking
Speaker 5: the cycle of reproduction of the malaria parasite within the mosquito. Okay,
Speaker 5: so there's a few different groups and a few different
Speaker 5: ways that people are looking to do this. Actually, what
Speaker 5: I think is cool is there were two different groups
Speaker 5: that published two different papers in the same issue of
Speaker 5: Science in September of this year that we're looking at
Speaker 5: two different strategies to do this.
Speaker 1: Oh a man, I bet that they were racing to
Speaker 1: both get it ready by tepe, I'm sure that Science
Speaker 1: was like, Okay, guys, we're gonna do this on purpose.
Speaker 5: I just put them both in what I just hope
Speaker 5: that these two groups are more less like Sulk and
Speaker 5: Saban and more like Arin and erin get it like
Speaker 5: they worked together.
Speaker 1: Collaborative.
Speaker 5: Cool hilarious. Anyways, So, one of these groups was looking
Speaker 5: at using a genetically modified bacteria that's found in the
Speaker 5: gut of mosquitoes that can help to fight off the
Speaker 5: Plasmodium infection. WHOA, yeah, So it's this bacteria that's normally
Speaker 5: present in the gut of all mosquitoes, but it they
Speaker 5: basically genetically modified it to produce more compounds that would
Speaker 5: help the mosquito fight off this infection. Because don't forget
Speaker 5: that this plasmoi, this malaria parasite is bursting through the
Speaker 5: gut wall of these mosquitoes and traveling through their body
Speaker 5: to get to the salivary glands. So the mosquitoes generally
Speaker 5: have some sort of immune response to this. It's not
Speaker 5: it's not like a totally benign infection necessarily in the mosquito.
Speaker 1: So you can kind of jump on that train with
Speaker 1: this bacteria, yeah, to try to stop the infection overall, exactly.
Speaker 5: And the other study was looking at genetically modifying the
Speaker 5: mosquitos themselves to basically produce more immune compounds to fight
Speaker 5: off the infection itself. That's cool, it's very cool. And
Speaker 5: that study was really interesting because they actually found that
Speaker 5: genetically modified males were more likely to mate with unmodified females,
Speaker 5: So basically they were good at sending this gene forward,
Speaker 5: which is one of the big challenges of genetically modifying
Speaker 5: mosquitoes is how do we get this gene into the
Speaker 5: population of mosquitos that already exists. I love this stuff.
Speaker 1: So is that the state of malaria today?
Speaker 5: That's the state of malaria today. That is a.
Speaker 1: It's depressing, it's depressing. It's a little bit uplifting because
Speaker 1: it seems like there's work being done, but it's really
Speaker 1: disheartening that there are still so many over two hundred
Speaker 1: million people infected every.
Speaker 5: Year every year.
Speaker 1: Wow.
Speaker 5: Yeah, and it was actually a little higher in twenty
Speaker 5: sixteen than it was in twenty fifteen. We are definitely
Speaker 5: not seeing the declines that we have seen in other
Speaker 5: diseases that we've talked about.
Speaker 1: So yeah, all right, well, sources, sources, not right, Okay.
Speaker 1: I read a few books. One is called The Fever
Speaker 1: by Sonya Shaw, and this is a really great overview.
Speaker 1: It's really written, well, it's interesting. I really liked it.
Speaker 1: Take a look. She's a great science writer. The other
Speaker 1: is called The Making of a Tropical Disease by Randall Packard,
Speaker 1: and that's a more it's a less accessible take on
Speaker 1: the history of malaria, and it focuses largely on the
Speaker 1: role that agricultural practices have played in the transmission of malaria,
Speaker 1: and I wish that I had more time to talk
Speaker 1: about it because it was really interesting to see how
Speaker 1: small scale farming versus large scale farming, et cetera. Anyway,
Speaker 1: take a look if you're interested in The final one
Speaker 1: is called the Fever Trail by Mark honing'sbamb and it
Speaker 1: was interesting. I don't necessarily highly recommend it it just
Speaker 1: because the readability was a little bit less, but it
Speaker 1: was very cool. It mostly focuses on quinine and the
Speaker 1: discovery of the Sincoona tree.
Speaker 5: I've got several papers I want to site today. I
Speaker 5: always cite the WHO, but at least three other papers today.
Speaker 5: So one was by bot at all in Nature published
Speaker 5: in twenty fifteen, and that was the paper on the
Speaker 5: effect of malaria control on P. Foul Ciprum in Africa
Speaker 5: between twenty twenty fifteen. And then the other two were
Speaker 5: the two papers about genetically modified anoplies and genetically modified bacteria.
Speaker 5: Those were both published in the September twenty seventeen issue
Speaker 5: of Science, so you can find those. The first one
Speaker 5: is by Wang and the second one is by Pike
Speaker 5: hot Off. The presses hot off the press September twenty seventeen.
Speaker 5: There was a bunch of others, So if you're interested
Speaker 5: in any specific aspects of malaria, shoot us a message
Speaker 5: or something.
Speaker 1: And also just as a reminder, we do have a
Speaker 1: good Reads list which has all of these books, and
Speaker 1: we're working on getting a Google Docs up for the
Speaker 1: different articles that Aaron mentioned, so you can take a
Speaker 1: look at those. Yeah, if you're interested in reading further.
Speaker 5: Yeah, well, I.
Speaker 1: Think that that about wraps up our episode today. It does.
Speaker 1: Thanks again to Umat for providing his first hand account
Speaker 1: of malaria super interesting, and also thank you again to
Speaker 1: Bloodmobile for providing the music in this episode. And for
Speaker 1: all of you bird people out there, one of the
Speaker 1: songs features a bird native to the Andies, So see
Speaker 1: if you can pick it.
Speaker 5: Out, rate, review, and subscribe.
Speaker 1: Please please follow us on social media and thanks for listening.
Speaker 5: Thanks so much. Now wash your hands, you have filthy animals.