When I was a young boy, I had two uncles. Both were heavily infected with guinea worms, and back then, no one here knew how guinea worm was transmitted. People would become infected and we just kept wondering why. During those years, we had some communal fighting, fighting between communities
amid South Sudan struggle for independence. One day, fighting erupted in the evening, so everyone in my village ran away, but my uncles could not run, so they crawled to the garden to hide because no one could carry them. My mom could not carry them, and I had lost my dad during the struggle, so we had to leave them. There weren't any options. We just cried. So warfare comes and fighters raid our cows and kill some people and
then go back where they came from. After that, when the people came back, we found that my uncles were gone. They had been killed. If it were not for guinea worm, they would have just joined us and treked away from the danger. So I say that it was guinea worm that killed them indirectly. When I was young, I could not understand how the guinea worm killed my uncles, But as time goes on, I have come to know this
is our story. Later, we were living at a refugee camp and we were given pipe filters from the Carter Center. I didn't know why people were given pipe filters, so I refused to use mine. My mom is educated and she told me these were for guinea worm. And now she began to tell me this story, and I finally could see the connection between the guinea worm and the loss of my uncles. I said, okay, there are people that are working for this, and that was when I
committed to working for guinea worm eradication. Because guinea worm had done something bad to me, and even if it had not been me, what of the rest of the community. That's what inspired me to work for the eradication of guinea worm. So I went away to school and when I came back, I looked for this work. When I found the man who would be my director, I told him I will never let you and my country down. I just need to relate to my community and see
how this guinea worm is cruel to my community. I want my community to be free, and that's why you see I am doing this work. It is very difficult. If you want to work for guinea worm, you need to leave the good things in your life behind and become part of the community. That way, you come to understand the dynamic of how to help the community to
eliminate the guinea worm. And that's been very effective. I've been there and I've worked, and I've seen how the guinea worm can go to nothing, and I have hope that one day we will be free and able to say that guinea worm is gone. It will be a very great achievement. I thank the Carter Center for helping us achieve it.
Wow. That was that was Wow? That was an amazing story. Yeah.
Yeah, so that was from Daniel deng Uh and he wrote that story called guinea Worm Killed My Uncle's which we found on the Carter Center blog. So that's who that was from. Yeah. Hi, I'm Aaron Welsh and I'm Erin Allman Updyke.
And this is this podcast will Kill.
You And if you haven't guessed, today we're talking about guinea.
Worm, guinea worm tricculasis. I am really excited for this episode, which I know we say that every episode.
Episode, but we're always excited, So it's always always excited.
If you like, it's been a while since we've done a parasitic disease, so that's always interesting, you know. And the other reason that I'm super excited for this episode is that we have an incredible guest.
Yes, we were.
Fortunate enough to interview Sarah Urian, who is the senior Associate director of the guinea worm eradication program at the Carter Center.
How amazing, I know.
So we got to talk.
With her a bit about her experiences on the ground as well as some of the more like, you know, the logistical finer points of how eradication is actually achieved.
So keep an ear out for that later in the episode.
Yeah, we're really excited about it. But first, oh, what what time is it?
I think it's I think it.
It must be quarantininey time. If I'm not mistaken, you're right.
I just it's quarantine time. I checked my watch and everything.
Well, Aaron, what are we drinking this week?
We're drinking the Littlest Dragon.
I love this name, so but it does require maybe a bit of explanation. Just so, the species name for guinea worm is Dracunculus medinensis, and dracunculus means little dragon, and so it's like the littlest dragons.
The Tiniest Little Dragon.
A cute name for a not so cute worm. I have to admit it's not the cutest of worms.
You know. Are there cute worms out there?
Absolutely?
Oh?
Okay, yeah, I don't know anybody, but I'm sure I'm sure that there are.
Like oceanic worms. Actually, there's some cute ones in the ocean.
Yeah, yeah, okay.
Anyway, the Littlest Dragon. The Littlest Dragon is actually quite a delicious cocktail. So it has blue currosow, it has a rum pineapple juice cream of coconut, and the most crucial part is that you garnish it with a toothpick with a sour gummy worm wrapped around the toothpick for reasons that will become clearer later in the episode.
Yes, and we'll post the full recipe for that quarantini as well as our non alcoholic plusy Brita on our website This podcast will Kill You dot com and all of our social media channels as well.
Yes, so, I think we have a couple other pieces of business to take care of.
We do so.
First of all, I finally checked our po box after months of not going to the post office because of Corona and I'm thrilled for we got a couple of really really kind presents that we wanted to say thank you for. So First, I want to say thank you so much to Kira, who sent us not only the most adorable sweet just the sweetest letter, but also a handmade like Matt coaster for our quarantinies that looks like the coronavirus.
Oh my gosh, it is incredible. Kira, Thank you so much. It's so sweet of you. And yeah, that letter made us like, oh, it's just like we're like, we.
Don't deserve this.
This is too nice.
And also, thank you so much to Melanie who made us handmade masks with little germs on them.
Oh my gosh, they're so cool. Thank you so much Kira and Melanie. We appreciate It's so very much, so.
Much, really amazing.
Well, I think the only other business is that we've got, you know, merch as per usual. Good to this podcast We'll kill you dot com and click on the merch tab.
Shout out to Abigail Irvin Penner, who designed all of our new merch. We love it so much.
Oh my gosh, I'm I mean, I'm obsessed seriously, and we also have a Bookshop affiliate account, so you can find all of the books that we talk about on our podcast there and also good Reads list, so check those out.
You can find all of those things on our website.
Awesome, is that all? I think that's all excellent. Shall we dive right into the biology of this little worm? Let's do it right after this break. Guinea worm or as you mentioned aaron, Dracunculus medinensis, right.
I think that's how you say it.
I even googled how to make sure I pronounced dracunculus properly because I've never been able to pronounce it. But everyone knows I have issues with pronunciation.
What do you mean? Cough cough.
Anyways, Dracunculus medinensis is a nematode or a roundworm. So this is the same phylum as hookworm. This is our second nematoad. Gotta love them, Gotta love them, that's their tagline. So okay, because this is a complex parasite, we obviously have to start with the life cycle.
Okay, excellent.
We're gonna start with the first stage, larva, so that when we end this cycle will end with the human part of the life cycle. Okay, Okay, So the first stage larva, if dracunculus are tiny dragons. These are the tiniest dragons, the babies. They're found in water sources, fresh water or brackish water sources. They swim and they thrash about in this water the way that worms like to do. And then they find tiny little copa pods. Okay. A copa pod is a little crustacean think plankton from SpongeBob.
They're really cute, really cute.
Yeah, they're very adorable. These copa pods swallow this first stage larva of the guinea worm, and then within the body of the copa pod, the larva kind of burst out of their stomach and begin to develop and grow.
Question.
Yes, I know, it's starting early. Okay, So the first stage larva it is ingested by the copapod. Does it have any movement towards the copa pod, like you know what I mean? Does it have any directional movement?
They have certainly movement. I don't know if they have directional movement towards copapods. I didn't see anything about that in the literature that I read. But that's a really interesting question. Okay, gotcha Okay, so now they've molted, they've grown inside of this copa pod, and then a human comes along and fills up their water container from the well or the pond or whatever that this copa pod has been living in, and they've been walking for a while.
So they take a big old swig of that water and they swallow these tiny little plankton copa pods, and then inside our stomach, the human stomach, the copopods die because of all of the acid, and they're obliterated, and the larva come forth, burst free, survive somehow in our stomach, travel down into our small intestine, and then burrow their way out of the small intestine and into the wall of our abdomen.
What it's terrifying. It is truly like the movie Ali, Yes, but just a little much smaller scale.
The tiniest dragon of scale.
Which is actually really funny because there's a documentary I watched which is narrated by a Sigourney Weaver about guinea worm.
Yeah, oh my gosh, that's phenomenal. Okay, so now these tiny larval worms are in basically like the connective tissue layers of your abdominal wall, your belly wall, and there is where they will begin to mature into fully adult worms. And these worms have male worms and female worms, and they will mate and then the females will grow and grow and grow and become all full of millions of eggs. And this is a process that takes many, many months.
And then over the course of these months, as her eggs mature into embryos, she will then travel down through our connective tissue, down and down and down to the lower limbs like your leg, usually your ankle or your foot, although she could travel anywhere because she's basically just under your skin, just like in the fatty tissue underneath your skin. And these little worms are migrating through down into your
lower extremities. And then ten to fourteen months after somebody drinks these copapods, this fully engorged female worm, which is now seventy to one hundred centimeters long, that's up to a meter long.
Very long.
It's just very long.
It started in like microscopic and now it's a meter long. Okay. Then they come all the way forth to the surface of your skin, and in doing so it produces a blister. And this blister is incredibly incredibly itchy, like unbearably itchy, and it's burning, and it's really uncomfortable, so much so that the only thing you want to do to try and stop the itch is submerge your foot in cool,
cool water. So you find a pond and you do that, and as soon as your foot enters the pond, that worm contracts and she pushes up, and she bursts forth and literally pushes open part of her gravit uterus out of the blister, bursts open and expels upwards of five hundred thousand larval worms into the water, thus completing her life cycle.
It's incredible, It is incredible. So seems like otherworldly. Absolutely seems like this is everything about it.
Is mind blowing. It's it really is. Nematodes in general, I think are absolutely mind blowing creatures.
Like I genuinely am fascinated by them.
Same So I said that she bursts forth and releases all these larval worms, that's not the end of her story. That's just what happens the very first time that she comes into contact with water. But now she is partially freed from your skin. Literally part of this female worm
is sticking out of you. And then every time that she's submerged in water, she'll release more larva, and the part that's outside of your body will kind of just shrivel up and die, and then a little bit more of her will emerge every day, every day, every day, until finally she is completely gone and has released I don't know, more than like three million larval worms into the environment.
Whoa mm hm.
It's a journey.
Yeah, it's a real journey.
Okay.
So number one, what happens to the male? Ooh, great question, because he's just floating around in there somewhere.
Pretty much just floating around. Yeah, you can sometimes get like a small inflammatory response from wherever he ends up, but usually he just sort of your body will just sort of calcify him, and then you'll just have a little like boop of calcium some deposit somewhere in your body.
Nothing much does the where he ends up dying? Can that be problematic in terms of like if he ends up in a joint?
Oh, Aaron, you are getting so far ahead. Okay, we'll just put a pin in it all right.
My next question is how does the female know where to go?
No? Idea, great question, I don't. It is the weirdest it is the weirdest thing, and all of the things that I read were She's just like, yeah, most of the time it's from the lower limbs, but it could be anywhere. I think that there's some thought that they
travel in part along like lymphatic routes. So if they just get on the right lymphatic tract in your abdomen, a lot of your lymphatics are going to be draining down to your legs, or like your lymphacts from your legs are going to be draining up towards your abdomen. So it kind of makes sense they're if they're in your lower abdomen already that they just sort of end up going down to your legs. Gotcha, gotcha?
Okay, And my other question pertains to the longevity of these worms. So good ten to twelve months, and that's typically just in correspondence with like a rainy, dry season in the places where these are most abundant.
Probably good question, very good question. Yeah, So there is definitely seasonal dynamics in terms of transmission, but whether people are more likely to get infected in the wet or the dry season depends on where they live and what region.
So in some parts of the world, transmission is highest during the rainy season if it's areas where people are primarily using ponds as their water sources that are otherwise dry during the dry season, right okay, But in other places that are maybe more wet in general, where you have step wells or other types of cisterns, then transmission tends to be highest in the dry season or right before the rainy season starts, at the very end of the dry season, because at that time the water quality
supports higher numbers of copapods. The water is less turbid, and there's not as many streams washing things away, so the copapods aren't as dilute as they would be during the rainy season when water levels are high.
That makes sense, isn't that ecology?
There?
You go? So cool, it's very interesting.
Okay, but that didn't answer your question. So the worms live a long time?
Yeah, yeah, I guess I'm thinking like other species of nematodes, they mature a lot more quickly, right, yeah, than that, And so I wonder whether it does seem to be more in correspondence with like the timing of the dry and the rainy season.
Yeah, yeah, that makes sense because pretty much across the board, even though in some places it's the wet season and in some places it's the dry season. Either way, we definitely see seasonal trends, so that does make sense. Yeah, cool, yeah, all right, okay, so that was that was just the worm, right, right, that was just the life cycle of the worm. We're missing like the human part of it, right, These are humans that are being infected, So what the heck is
going on in you? Let's find out tell me, okay. So for some people, the first sign of infection might be noticing the worm itself, right, just kind of beneath the skin, a few days before it emerges, kind of as it's traveling down. For others, and very commonly, it's kind of a more generalized kind of allergic type symptoms, so maybe hives, maybe a bit of a fever, some swelling under your eyes, kind of like you might think I have an allergy to something.
But all of this would be still around the time of its emergence.
Of its emergence, right, not of when you get infected. Pretty much, there's basically no symptoms when you first get infected. So this is a year after you drink the larvae. Okay, But for most people, the very first indication of infection is the blister. And like we said, already, eighty to ninety percent of the time, it's on the legs or the feet, and it usually starts pretty small, but it grows fairly rapidly. It can grow over a number of
hours or over a couple of days. And the blister before it opens is sterile, So it's not filled with like puss and bacteria like a pimple kind of blister.
Right, it's just clear.
It's clear liquid, it's inflammatory fluid, and it's filled filled with larva worm. So the female starts to release larval worms underneath your skin as part of the formation of the blister.
So we're not quite sterile, is it.
Well, yeah, it doesn't grow bacteria, is what we mean by sterile. And what's so interesting is that it's not entirely clear, like pathologically what causes the formation of the blister, like whether it's the adult worm releasing enzymes that cause tissue death, or whether it's the embryos the larva themselves that are causing the tissue damage, which I think is really interesting that we still just don't quite understand.
Well. I also think you know to jumping ahead a little bit, but that there's probably a lot that we don't know about the biology or the ecology of this simply because it's not directly relevant to the control right of the parasite exactly.
I think there is so much of this that we just don't know because it hasn't been studied because we didn't technically need to quote unquote to get it under control. Right, Yeah, okay, So now you have this blister, and then it'll start to open. So very often it opens at first in contact with water, because that does produce in the female worm this intense contraction where she pushes herself forth. But it is possible to have the blister break open even
if you don't put your feet in water. So now you have this female worm half sticking out of a wound in your foot, and basically the only way to get her out is to slowly pull her out in a process that can take usually at least a month, where you slowly twist the worm around a small stick yep And that's why we have a gummy worm in our quarantini.
It is indeed, if anyone still even wants to make it after that, after the script.
Of a worm coming out of your foot that you're wrapping around a stick slowly over the course of a month, Okay, And that is the best case scenario, right, That's not what always happens. More than fifty percent of the time, the wound itself is complicated by a secondary bacterial infection. And there's a whole bunch of different ways that this can happen. Okay. So when the worm is happily living under the surface of your skin, in your subcutaneous tissue,
it's in this little worm house, Okay. So it forms like this little fibrous worm sheath around itself, and that's how it can move without getting stuck to your tissues, like because of our inflammatory response. Okay, whoa, Yeah, it's that really cool, which I think is probably part of why it takes so long to travel down, right, It's not just like swimming through. It's like slowly moving its little sheath within its sheath.
Oh my god.
Okay wow. Yeah, But once it starts to emerge and it breaks through our skin, then our inflammatory response can really start to kick in and it can form adhesions to the worm itself rather than the sheath, which can complicate the removal and make it harder because it's stuck
to our tissues. So if the worm gets broken during the extraction process, because it's quite a fragile little worm, then what's left of the worm in your body kind of withdraws back into its little sleeping bag and it brings with it all the bacteria from the outside of your skin, so stapf oureus e, coal like anything living there. So then you can get deep tissue infections because of that.
But you also could get an infection even if you don't break off the worm right, just because you have this open wound and it's on a place like your foot or your ankle that's in contact with like the environment, right right. Tetanus is also a very real and very common complication, so secondary infection with a Claustridium species that produces tetanus toxin and then you end up with tetanus because of this. So that's kind of the most common
complication of guinea worm infection. But it's also possible, like you mentioned aarin in your jumping ahead, for the worm to get a little bit lost on its way to try and emerge, So whether that means it makes it to your skin, but for some reason can't quite penetrate
through your skin, which can happen. Then what will happen there is the worm just kind of becomesied with our own immune response, which wouldn't be a problem if it's just like say, in the subcutaneous tissue of your abdomen or your arm, but if it's in an important organ like your pancreas or your heart, or like you mentioned, aaron in your joint space, then you could end up
with arthritis. It can also lead to deep abscesses. So even though I said that this blister is sterile, quote unquote, quote unquote, if the worm begins to release the embryos or the larva in your deep tissue, it will cause a really dramatic inflammatory response, and that will lead to a serious abscess where you would find a lot of puss and white blood cells and things like that. You still wouldn't find bacterial infection, but it would be full
of larva. Right, And so overall, the reported period of kind of incapacitation due to this infection on average is eight and a half weeks, but that range is from two to sixteen weeks or even longer, and it really depends on how many worms you're infected with or whether you get a secondary infection and things like that, because ps getting infected with one worm doesn't prevent you from getting infected with multiple worms.
Right, there's no immunity, Yeah, exactly.
So usually most of the time people get infected with like one to three worms that emerge at a time, but some reports have found up to forty worms emerging from one person at a time, which just sounds unimaginably awful.
Yeah.
Yeah, yeah, because yeah, even like I said, in the best case scenario where you have a worm that emerges without any complications or infection, this is.
A very painful process. You're slowly winding a worm, a living worm, out of your tissue in your leg. There's nerve pain, there's itching, there's burning, it's it's extremely painful.
Yeah, just even getting around, like even not just the process of pulling the worm.
Out, but like walking.
Yeah, it's really painful and challengery painful. Yep, that's it, Aaron, that's biology. Okay, do you have any other questions for me?
I don't think so.
Well. Good, So, Aaron, where did this worm come from? Why? Why? I didn't mention this? But it only infects humans for the most part. Why how did it find us? Where did it come from? What are we doing about it?
What?
Tell me everything?
I can't wait to right after this break? All right, it's kind of funny that you ask me where does it come from? And why does it only infect humans and etc. Because, to be honest, I couldn't find a ton on the evolutionary history of it, except for just like, here's the phylogeny of these worms, and so, you know, to answer those questions, I don't really know.
I know that it's been with humans.
For a very very long time, and it actually does seem to infect other animals, maybe not as readily as it does humans, but the infection in dogs seems to be a problem that's contributing to some of the difficulties in the complete eradication. So yes, yeah, yeah, I don't know. Anyway, I'm sorry, I wish I had more. If anyone has any great evolution Dracunculus Menaden says, evolution papers, please send them our way.
I'd like to know.
Yeah, okay, So, but the history of guinea worm has got all of the other usual suspects mummies, fun etymology, imperialism, and more and it's maybe the most classic disease quote unquote that we've had in a while. Yeah, So if you're playing tpwky bingo, get your cards ready.
I love it all Right, let's begin ancient Realm to.
Rome, to ancient Rome. Actually, let's go back even earlier erin because this this worm seems to have been known to humans for basically all of written history.
And it makes an appearance in you might guess the.
Ebers Papyrus Ebers for virus. They go there, we go Bengo number one. That's from around fifteen fifty BCE, by the way, so it's.
Very old, very old.
And so researchers think that the rare and obscure verb dqr, which is just like all one word together, refers to the pulling and spinning of the worm for its removal.
Huh yeah, just like they had a specific verb that meant.
That, right, And so like researchers were like, well, it kind of looks like it's referred to with like a spindle against one's leg, but it's also meant to something beneath the surface, and so they think it refers to the removal of the guinea worm. Using that method, huh.
And there's also evidence to support this, or to support at least the fact that guinea worm was present in ancient Egypt, because a calcified worm was found in a mummy of a thirteen year old female from one thousand BCE roughly who had died shortly after her lower legs had been amputated, oh right, which some researchers have speculated was done to try to save her from the secondary infections that you mentioned.
Oh my cause by the worms.
Wow.
Yeah.
And then of course there's the Biblical mention. So in the Old Testament in numbers twenty one to six, which is thought to have been written around the eighth century BCE, there's this line, then the Lord sent fiery serpents among the people, and they bit the people, so that many people of Israel died. And so this is where the worm gets its fiery serpent nickname that you've probably come.
Across, so that they think is Dracunculus worm. Fascinating, uh huh.
Yeah.
And the Ebers Papyrus and the Bible aren't the only ancient texts to mention guinea worm. There's also talk of the worm in ancient Greece and ancient Rome. For instance, there's this from around forty six to one twenty CE quote, the people who live near the Red Sea are tormented by an extraordinary and hitherto unheard of disease. Small worms issue from their bodies in the form of serpents, which
gnaw their arms and legs. When these creatures are touched, they withdraw themselves and insinuating themselves between the muscles give rise to horrible sufferings.
One hundred percent guinea worm.
One hundred percent.
And it was Galen who gave the infestation its first name, dracontiasis. And one more thing.
So you're getting to my favorite part yet, I think it might be right now, Okay, good, this might be it.
I'm sure you've heard it said before that the staff of Esculpius had Asclepius, which is that symbol that you often see associated with medicine and medical things. It's basically a singular snake winding around a rod. It's been said that the snake actually represents a guinea worm.
Some people hypothesize.
That's my favorite. It's my absolute favorite. It's so much better than it being like just a random snake like it has to be guinea worm. Of course it's guinea worm.
Well, there are there are other hypotheses, so before I get to those, the WHO logo actually has the staff of Asclepias on it, and side note a lot of the times you'll see and I was always confused that the caducius, which is like two snakes and the wings, that's actually something.
Else, that's Hermes.
That's Hermes, right, and so that refers to more like messaging or trade or commerce, information flow, et cetera. But the other thing that I think is really interesting about the staff of Asclepias or the rod of Asclepias is that Asclepias was this Greek god that was associated with medicine and healing, and so some people hypothesize that the snake was like part of the healing process is shedding of the skin and becoming like that renewal, and so
that's why they think the snake might represent. Besides ginea worm.
I don't like it as much.
I'm just you don't have to like it.
You're just the messenger.
I'm just the hermes of Okay. So whether or not the rot of Asclepias truly represents guinea worm, it does. From all of these ancient references to the parasite, we can at least tell that it was pretty prevalent across the tropical and parts of the subtropical regions of the
Old World. And while most of these ancient folks seem to recognize it as a parasite so as like an animal, a creature that has somehow invaded your body and is now causing you harm, others, including the famous Avicenna, weren't as convinced, instead claiming it was actually a vein gone awry.
Interesting m hm. Yeah.
He did give it a name that would stick with the worm until present day, though, the Medina sickness or the Medina vein, because apparently it was quite prevalent in Medina, which is a city in western Saudi Arabia.
Like that funky called Medina.
The funky worm from Medina. Oh okay anyway, So the scientific name of guinea worm, which was given by Linnaeus in the mid seventeen hundreds, is Dracunculus medinensis. So, as we mentioned, from the Latin draco meaning dragon or serpent and medenensis meaning from funky cold Medina.
Wait, Draco means serpent like Draco Malfoyd meant literally serpent or dragon.
Yeah.
I never knew that, Okay, sorry.
Yeah, no, I didn't know that either. Yeah.
So basically its scientific name means little dragon from Medina.
Okay, it's kind of cute. Yeah.
As travel and trade expanded throughout the sixteenth and seventeenth centuries, reports of the worm became more numerous, as did hypotheses about its nature. Was it an animal or was it just part of your body? Its life cycle, and how a person became infected in the first place. And it was also during this time that it was first called guinea worm, as it was seen in super high numbers
along the west coast of Africa. The Transatlantic slave trade also led to the introduction of the worm in parts of North, central and South America, but it doesn't seem that local transmission was sustained for very long after that mid eighteen hundreds, possibly because of environmental conditions, possibly because
the right copopod species weren't there. I don't really know for sure, Okay, But throughout the eighteen hundreds and early nineteen hundreds, the rapid expansion of travel and in particular, colonization, led to a heightened interest in the parasite in India and parts of Africa, for instance, British officers reported seeing cases of infestation among the military serving there, and so as you might expect, this led to calls for doing
something about this guinea worm problem. Although the association between the parasite and water had long been recognized, especially in places where it had been prevalent for basically all of human history, there still wasn't a very clear understanding of how exactly they were connected and whether there were any other players in the game. In the eighteen seventies, a Russian parasitologist named Alexei Faedchenko getting his start just as
the field of parasitology was taking off. What an exciting time. We would never have been allowed to pursue this career. So Fedchenko was encouraged by leading hell mythologist Rudolph Lukart to look at the possibility that infected copa pods might be harboring the larvae of the worm in eighteen what now erin eighteen seventies they were.
Like, hmm, pretty sure it's a copa pod.
What well, So this guy, Rudolph Lukart, he had he had either discovered this or learned about this in another species of worm. Isn't that using copopods as an intermediate host? Yeah, it's yeah.
Like I know that we've talked about like early discoveries like this before, but it is still blows my mind that people could figure out a life cycle as complex as this. Oh just you wait, oh gosh, okay, just you wait. Okay.
So so yeah, So Fedchenko looked and sure enough, within some species of Cyclops copapods that he had found in contaminated drinking water, he found larval worms that he thought might be the intermediate stage of guinea worm.
There you go, incredible.
And then he was like, all right, you know what, Humans probably become infected when they drink water containing these infested copopods.
Because that's logical.
Yeah, And he was like, I'm going to try to show this experimentally, So I'm going to give some infected copapods to cats and dogs. But they never developed the infection.
Mm, they didn't.
And so his hypothesis just kind of sat there quietly in the parasitology journals for a couple of decades, while others argued that it infected humans by boring into their skin directly kind of like you know, a La hookworm, a La hookworm. Meanwhile, in Britain's colonies in Africa, guinea worm continued to pose a threat to productivity and political stability.
Oh gosh.
And so the Committee of the London School of Tropical Medicine asked, fresh out of medical school with basically no research training, twenty four year old parasitologist Robert Leiper, whom you may remember from Marcs to Semius this episode, I don't that's okay. I just remember the name and that's it. And now I'm wondering did I pronounce it differently in that episode? So anyway, they asked Leper to head to Accra and Ghana to learn more about the parasite so
that it could be controlled. And he entered this field of conflicting hypotheses and big egos and made frankly incredible progress towards understanding the key components of the parasite that would allow for its dramatic to cline in prevalence over the next one hundred years. Wow, most of that decline was concentrated in the last couple decades. But anyway, first of all, he demonstrated that no the larval worms do
not burrow into your flesh. He fed a monkey bananas that contained infested copa pods, and then he waited six months and carried out a post mortem that showed that, yes, indeed, there were some Dracunculus medinensis in the monkey. Next, are you laughing at the banana?
Yeah, the banana. I don't know why that's so funny.
I don't know either. I don't know either, Like.
You can't just put it in his water, like, you've got to add it to the banana.
That's what That's what made me include that that detail. I was like, it's not just feeding them infested copa pods, it's the banana.
The banana.
Well, And then next Leper ruled out that it was any other intermediate host besides copopods. He then decided to do a series of experiments showing under what environmental conditions the larvae can live, the timeline of their maturation, and he mimicked conditions of the human stomach. He made an acidic solution to show how the copopods are killed, allowing the larvae to burst forth and then continue their passage through the human body. He did this in what year now,
nineteen oh five what on earth? And so From all of this, he concluded that quote, the young larvae must be discharged directly into fresh water soon after the parent worm has succeeded in creating a break in the overlying skin, and before the wound has become markedly septic. The embryos must find a cyclops Within.
A few days.
They must moreover, succeed in entering its body cavity. Five weeks later, they will have developed into mature larvae. They must therefore be taken into a human stomach, and, having been set free from their host by the gastric juice, reached the connective tissues by penetrating the gut wall.
Wow, I mean everything. I described everything.
And so basically, within two years of his arrival, the twenty four year old had essentially laid out in impressive detail the life cycle of this parasite.
Also, he didn't stop there.
They never do never.
Lbird took this information and made recommendations for its control, basically, clean the water to eliminate the worm. He also stressed the importance of knowing the seasonality of infection, timing of dry seasons and wet seasons, and where people get water as crucial in knowing where and when water supplies are most likely to be infested.
Oh my goodness.
Uh huh.
He also recommended filling in surface water and shallow wells, getting rid of step wells where people have to descend to get water, and instead using draw wells, artesian wells, or pipes from rapidly flowing streams.
Wow.
And finally, just the cherry on top, he suggested that certain fish species might be a great way to naturally control the copa pods and hence the disease.
Oh my gracious, uh huh. Wow.
And so all of this he did in a couple of years, and then he like wrote a couple of papers and then didn't do anything with guinea worm ever.
Again He's like, I did it all. I'm done, guys, I solved it. Just do it.
I mean, kind if.
I mean he was wrong.
Yeah, And so after that he just went to hookworms and shisto and wow, that was it.
And yeah.
So I think that's That's one thing that I find so fascinating about guinea worm is that so much of the information that we use today to control guinea worm is literally ancient, or at the very least like old knowledge, right like in over one hundred years old, over one hundred years old, sometimes over three thousand years old. Wow.
Yeah.
In the early.
Nineteen hundreds, the development of certain arsenical treatments for other worm we parasites led to some researchers trying them out on guinea worm, but none worked very well or they caused greater problems because then the worm would die in a joint or something, and then, as you mentioned, all of the horrible effects that can come from that right
like on its way down. And then even if those side effects weren't an issue, there was the aspect of getting access to any potential treatments and the financial aspect of that as well. The method described in the Ebers Papyrus from fifteen fifty BCE of winding the worm around a stick to remove it, that's what we use today twenty twenty, twenty twenty. I mean, that's incredible to me.
Yeah. Yeah.
The connection between water and the parasite was long known in the areas where the parasite has been historically most abundant, even while Western researchers were fighting amongst themselves over whether it was from water or from the grass or from this or that, and the larger scale control efforts that we use still follow the same principles that Robert Leiper laid out in nineteen oh seven, which brings me to the last part of the history, yes, the eradication campaign.
Although by the early nineteen hundreds the information needed to make serious progress towards controlling guinea worm was there, the disease remained neglected for almost seven decades, receiving little to no priority in national or international health campaigns for many reasons. Certainly part of it was that the populations that were most affected were often poverty stricken in rural, hard.
To reach areas.
But another aspect is that there were or are often many other diseases that had higher mortality rates or prevalence or both, so this was just lower on a priority chain. Yeah, there were some regional eradication efforts made during those seventy years, and other places made larger infrastructural changes to the water supply that essentially eliminated guinea worm, even if that was
not one of the primary intended goals. But it was only in nineteen eighty one when the United Nations added guinea worm to the United Nations International Drinking water supply
in sanitation decade. It was only in that year that the pair site was featured in an international elimination plan HUH, and so the Carter Center was founded a year after this was added to this elimination plan in nineteen eighty two, and one of its goals was the eradication of guinea worm, a cause that former President Jimmy Carter became very interested in after a trip to West Africa in their early nineteen eighties in which he witnessed some of the devastating
effects of the infection. With the Carter Center's involvement, in nineteen eighty six, the WHO added support to the campaign to eradicate the infection, but one of the biggest challenges in this plan was the lack of accurate surveillance data. A survey in nineteen eighty six revealed that the disease was endemic in twenty countries, most of which were in Africa, and there were an estimated three point five million cases.
The economic strain caused by the infection, as well as the relatively inexpensive methods of control, led to both continued support of the initiative as well as rapid progress in
the control of the parasite. Still setbacks occurred in the shape of logistical difficulties, political instability, financial or technological shortcomings, but despite these, within four years, the number of estimated cases fell from three point five million in nineteen eighty six to eight hundred and ninety two thousand in nineteen ninety and then in twenty fifteen, twenty two.
Oh oh m hmm, okay, yeah, I know.
There's more to There's no more to that story which you're going to pick up one. But and so, although you know twenty fifteen it sounds pretty great to only have twenty two cases, and each year seems to bring an article with the headline guinea worm radication.
Could it be this year?
But complete elimination has remained just out of grasp. And so Aaron, yeah, that's where I'll leave off and leave it to you, okay, to tell us.
What's going on with guinea worm today?
Right after this break so Erin, you asked for me to tell you what's going on with guinea worm today, but I'm not going to do that because, as we mentioned in our intro, we were fortunate enough to talk with Sarah Urian, the senior associate director for the Guinea worm eradication program at the Carterson who obviously knows a lot more than I do about what's going on today. So I am thrilled to introduce her and we'll let her tell us all what's been going on. Awesome.
My name is Feri Urian and I am the senior Associate director for the Guinea worm eradication program at the Carter Center. And I started this job about a year ago following six years working with the Carter Center and the Guinea room eradication program in South Sudan, a few years as a technical advisor in the field and then my last three years in South Sudan as the country
representative for the program in South Sudan. And so now here at headquarters work with the team here to provide support to the country programs in the remaining endemic countries, which is Chad, South Sudan, Ethiopia, Molly and now Angola.
Awesome.
Thank you so very much for taking the time to chat with us.
We really appreciate it.
So could you start us off by telling us a little bit about the history of the Guinea worm or radication program and sort of what kind of work was being done in the early days there in terms of systems that were put into place for surveillance or direct care and field work, those sorts of things.
So guinea worm, though it's not a deadly disease, it does cause debilitating pain when it's emerging from the body and then also during the healing process, and particularly if there has been a secondary infection associated with the emergence of that worm. And so this disease is something that was devastating communities and there were even parts of West Africa where it was called the disease of the empty granary.
And so with simultaneously we're having the success of the smallpox eradication campaign and the nineteen seventies, the global community was looking for what might be next. And so now you have guinea worm disease which is devastating communities, and it's also a disease that potentially meets the criteria for eradications.
And also, you know, there was an assessment done by the World Bank where they determined that actually the cost of the eradication campaign would be less than the costs that are associated with the socioeconomic impact of not eradicating
guinea worm. And I think that's a critically important part of that consideration, and there was also sufficient funding and sustained political will, and so with all of that factors and the devastating impact of guinea worm on communities, that's how it was taken on as the next disease to try to eradicate. When we talk about setting up a surveillance system to address guinea worm, we're talking about kind
of two phases of guinea worm eradication. The first is breaking transmission and then the second is certifying a country as guinea worm free. And so currently, you know, we have gone from over twenty one endemic countries in Africa and Asia in the nineteen eighties to five. Now we have South Sudan, Molly, Ethiopia, Chad, and Angola that remain endemic for guinea worm and they are still working to
break transmission. And so endemic countries have to establish active community based surveillance and the foundation of this community based surveillance structure is the village volunteer. So in every endemic village, the volunteer actually walks house to house on a daily basis, searching for possible cases of guinea worm and providing health education to the community residents. And then treating any potential
cases of guinea worm that are detected. And these volunteers are also ported by a hierarchy of other health workers who support their work and the implementation of a package of interventions to stop transmission. But at this point we know now that we have a suite of interventions that, when applied together, can be successful in stopping transmission. And that includes searching for cases and treating them. And also, you know, another intervention is health education to the communities
on transmission and prevention of guinea worm. We also distribute nylon filters so that the communities can filter their drinking water, and we've also over the years have developed a pipe or a straw filter and finally treating water sources with
a chemical that's safe for drinking water. But that reduces the presence of cyclops in the water and therefore the population of effective guinea worm larvae in the water is about behavior change, and that requires a constant presence from program staff in affected villages, and it requires building trust and that's something that takes time and it's not going to be able to be bought with any amount of money.
And so, you know, I think the success of this campaign is really credited to the endemic communities themselves and the actions that they've taken to stop guinea worm in their communities. And so after transmission is broken, the second kind of phase of the eradication campaign takes place in
a country. And so after they've reported zero, they go three years without reporting another case of guinea worm, and then they can apply for certification as guinea worm free from the ic CD, which is the International Commission for the Certification of the Kunkliasis Eradication.
Gotcha awesome? So, you know, one thing I wanted to ask was about how there are these certain large scale infrastructural changes that would make not only guinea worm eradication more possible, but would also greatly reduce the prevalence of other diseases, particularly waterborne infectious diseases.
So how do you strike.
That balance between investing in the underlying infrastructure, such as like a consistently clean water supply versus a more targeted approach like the use of those filters that you mentioned that prevent guinea worm transmission but not of other waterborne pathogens.
So two things here. One, you know, the guinea worm, as you've said, the guina worm program has to remain targeted on guinea worm disease in order to be able
to demonstrate success. But at the same time, the program is training and developing a group of volunteers and health workers who will be prepared to provide other health services once guinea worm is eliminated in that country And in some countries we've seen that these health workers and volunteers have gone on to be involved in programs such as river blindness or tracoma control, and in some places they've even been absorbed into the national Ministry of Health system
once guinea worm is gone. So I think that's one good example of some of the effects of the campaign
that are beyond just the targeted disease eradication. And the other thing is guinea worm because it was as a water born disease, the presence of guinea worm or endemic guinea worm endemic communities has been an opportunity to leverage access to safe water, and so the guinea worm program in many countries has been able to work with ministries of Water and UNICEF and others to prioritize certain villages
or locations for provision of safe water. Because guinea worm is an indicator that safe water is not present in that location.
Gotcha, Okay, yeah, that makes a lot of sense. So throughout the history of the program, there has been an absolutely incredible amount of progress made towards eradication, So for millions of cases in the nineteen eighties to just like you know, dozens in the last few years. So can you bring us up to speed a bit with the latest numbers and especially the biggest hurdles that remain.
So, as you've said, since the nineteen eighties, we've seen a ninety nine percent reduction in cases, which is phenomenal. So we've had twenty one cases so far in twenty twenty, which is a fifty six percent reduction compared to the same period in twenty nineteen. And at this point in the campaign, really our biggest challenge is transmission in animals
and mostly in domestic dogs in Chad. And just to give you a sense of the numbers, in twenty nineteen, we had almost two thousand infected dogs that were detected globally and only eleven that were detected outside of Chad. You know, we've talked about guinea worm being transmitted through drinking infected water but we also have some evidence that dogs in particular could be getting infected by eating aquatic
animals or aquatic animal waste that contains effective larva. And so as we're tackling the problem with dogs, we've had to kind of think outside the box a little bit and try to tailor some of our interventions to better
target dog infections. And so the program is also working with the communities to kind of figure out what works best in each location, but to provide supplemental food to the household so that to feed the dog with and then also access to veterinary care and good access for the dogs to exercise, and so far, you know, this is something that has been a very recent intervention, but we are encouraged by the twenty six percent reduction and dog infections in Chad that we've seen so far in
twenty twenty. And so while we may not have all of the answers or a perfect intervention or a silver bullet just yet, we are excited about some evidence that these new interventions to target dogs might be working.
It's yeah, it's it's fascinating.
I think there's there's a lot to uncover there, which is really cool. And so the last question that I want to ask is about you. So how did you get involved with the Guinea worm or medication program? And I was wondering whether you could share with us any memorable experiences that you've had while working with the Carter Center.
When I was doing my master's and public health at the Rolling School of Public Health University, there was a professor Stan Foster who had been a big part of the smallpox eradication campaign. And one day I was in his office. We were talking about something else, and he said, you know, I think you could do it. I said, do what he said, I think you could be a
technical advisor for Guinea worm. And so a few months later I found myself signing up for a six month contract with the Guinea ram eradication program working in South Sudan. That turned into six years working with the program there and then now in this role here, a total of seven years later. And I think for me, you know, initially going into this, what interested me was that this really seemed like an opportunity to apply field at the gemiology.
You know, you're collecting data and making decisions in real time, and it's really an honor and it's really a privilege to be part of a program and to work in places where the community has invited the program to work there with them, and the governments themselves indeed have invited the support of Carter Center and other partners in their national eradication campaigns. And so I think that level of discipline and diligence that's required from everyone in the program is really incredible.
And to just.
Imagine how many tens of thousands of volunteers and help workers around the world that have all displayed that level of commitment to support their communities to get rid of guinea worm is I think truly remarkable. And for me, as I said, has been a real privilege to be part of that.
That was so great.
Thank you so much, Sarah for taking the time to chat with me about guinea worm.
It was great. I loved it.
Oh, it was so great. It's how amazing that we get to interview people who have actual experience working on these things like that's incredible.
It blows my mind.
Thank you so much for taking the time.
Yeah, it's kind of nice that we get to end this episode on a happy note. Yeah, it's not often that we get to do that when we discuss diseases, particularly neglect of tropical diseases.
Yeah, it's a really thing. And do you know, we could actually make this episode even a little happier if we wanted to. We of course, did an episode on polio way back in was it twenty seventeen? I think it was, yeah, our first season. And there's been some new news on the polio eradication front that is absolutely thrilling. So we now are even closer to polio eradication because as of twenty twenty, the World Health Organization African Region
has been declared free of wild polio. They haven't had a single case of wild polio on the continent in the last four years.
That is remarkable.
I mean, I know, to hear that it is on the verge of eradication is absolutely incredible.
There's only two countries left in the entire world that are still left to be eradicated, Pakistan and Afghanistan. So incredible. Like, we're so close, We're so close.
Oh that's very cool.
Yeah, awesome.
So is that should we dive right into sources?
I think we ought to?
Yes, okay, cool. So I read a few things. One was a couple chapters in a book called a History of Human Heal Anthology by David Grove. And then a few papers that I found super helpful were DQR Spinning in Treatment of Guinea Worm by Miller in nineteen eighty nine and by Taya at All twenty seventeen Guinea Worm
from Robert Leiper to Eradication. And then I also wanted to shout out a couple of really interesting papers by Amy Moore and Thomas, one titled a Salvage Ethnography of the Guinea Worm and another called the Creation of Emergency and Afterlife of Intervention, and these I thought were very interesting discussions on sort of the merit of targeted approaches to disease eradication or elimination versus like a more integrative, bigger scale infrastructure approaches.
Very very interesting papers.
I feel like those are really sort of important discussions to have in the context of these kind of eradication campaigns. So AB definitely shout out those papers awesome. I have a number of papers for the biology as well. We'll post the full list of all of our sources for this episode and every episode on our website This podcast will Kill You dot Com. Just click on the episode's tab and you can find all of our sources there.
Thanks again to Sarah for taking the time to chat with us about guinea worm, and also thank you to Emily for helping set that up.
Yeah, that was really incredible. And thank you to Bloodmobile for providing the music for this episode and all of our episodes.
And thank you to you listeners for still tuning in and listening to us talk about disease.
We really appreciate it.
We hope this could be like a small little ray of sunshine in your September twenty twenty.
Yeah.
Yeah, well okay, until next time, wash your hands.
You filled the animals a