The smart Alex scientists were not satisfied to declare our cow's stumbling symbols of certain death. They declared that hookworms were literally gnawing us into the grave. We had never heard of Charles Wardour Styles, who had headed a commission to eradicate the hookworm, or the writer Walter Hines Page, who promoted his efforts, or the Saint Gothard Tunnel in Italy, where the dread parasites had caused the death of so many of the workers. The crusade against our unseen enemy
was sprung on us suddenly. In August nineteen twelve, the Winston County Journal ran a blood curdling illustration of a greatly enlarged female hookworm that resembled a diamond rattlesnake more than a worm. We were told the worm had laid three thousand eggs a day, but without an explanation of who counted them. Alongside the illustration of the voracious monster was that of an emaciated boy teetering on the brink
of the grave. The journal listed times and places when a representative of the Rockefeller Sanitary Commission and the Mississippi Department of Health would be on hand to gather fecal specimens for hookworm tests. I became so frightened at the prospect that I was constipated for a week. In the end, my test proved negative and I could look forward to a healthy existence, provided the scientist did not discover some other deadly menace.
Oh that was really great.
Isn't that joyous?
Yeah?
I love it.
So terrified I was consummated for a week. I feel like I can relate to that.
I know.
So that was. That was from a book called My Century in History Memoirs by Thomas D. Clark. Hello everyone, I'm Aaron.
Welsh and I'm Erin Almond Updyke and.
This is this podcast will kill you today.
We're talking about.
Worm, which is so exciting.
It's thrilling. This is our first macro parasite.
It is. I was thinking like, did we do did we know? No, this is it.
I did the same thing. I was like, well, we didn't know. We haven't done any worms.
And I love worms.
I know you do. I know they're one of your little loves.
They are one of my little loves, one of my many little loves. Okay, So to celebrate the hookworm, the glorious hookworm. What are we drinking today?
Our quarantine today is do poison.
Oh dw. And it's called that because.
That was one of its common names. Is that correct?
It's because you would walk through corning dew, Yeah, and then the little larval hookworms would burrow their way into you so lovely. So what's in do poison?
So we've of course got whiskey, preferably bourbon, but you could use rye chocolate liqueur, hazelnuts syrup or hazelnut liqueur up to you gonuts. Top it with whipped cream, and of course dirt in the form of chocolate cookies, and the all important vodka soaked gummy worm.
Yes, booze soaked.
But don't forget that. We'll post the full recipe for our quarantini as well as our non alcoholic Placey Brita, on all of our social media channels as well as our website.
That's right cool. Well, now that we've got that really delicious, licking drink in our hands, can you tell me about hookworms? Tell me all about the biology.
Absolutely, we'll take a quick break before we get started.
Just before we dive into the episode, we want to let you know that we have a very special treat waiting for you at the end. It's a song specifically dedicated to parasites, and you're going to love it. So if you usually tune out right as we start listing our sources, do yourself a favor and keep listening until the very end.
Let's get into the biology. So hookworm. The way that you get infected with a hookworm is when, like you said, the baby larvae drill their way into your skin.
It's so cool, it's so cool.
And this most commonly happens when you're walking barefoot across soil or grass or leaf litter that's just teeming with tiny baby larval worms. Although it is possible to get infected in other parts of your body. So if you're digging in the soil, you can get infected in your hands, taking a nap in the grass. Why not anywhere in your body? Why not? And there are two main species of hookworm that infect humans, Nicator americanis and ant Cyclostoma duadinale.
In the case of ant cyclostoma, you can also get infected by ingesting the worms, eating.
Them, ingesting the larval Yes, the.
Larval worms, right, yeah, weird, right, But that's all I'm gonna say about that, because like, no one talks about it. It's just a thing that exists. Okay, So let's go over the life cycle of how these worms get to the point where they're going to infect you, because it's so cool, it's nice.
So much, but it's one of my favorites.
Okay. So it all starts, of course, as it almost always does, with an egg, just a little unassuming egg chillin' in some soil. About twenty four hours after it pops into the soil, it'll hatch into a tiny, little L one larval worm, which will just scoot along its way for like a week until it grows big enough to molt again. Now we call it L two. It's not gonna hurt anyone. It's just a worm in the soil
doing wormy things. But then once that gets big and strong enough, it'll molt one more time into an L three larva. This is strong enough to slither? Do you say slither for a worm? Sure to slither its way up to the top of some grass or some leaf litter, and wait for your foot.
How big is this L three?
Very very small? I know how big the adults are, and this is smaller than the adult.
Oh, like, could you see it?
Yes, you can see it.
Is it like bigger or smaller than a nymphle tick?
Bigger?
Okay? Yeah?
So the adults are between five and thirteen millimeters. Okay, So I don't know exactly how much smaller the L three larva are. I didn't see that in my research, but I presume they're smaller but definitely still visible as far as I can tell.
How are they growing? Where are they getting the energy to grow?
So they eat microbes in the soil. Oh yeah, so when they hatch out of an egg, they'll eat little microbes, but they're not hurting anybody. They're just like chill and eating microbes, like living in the soil like normal worms. But then once they get to this L three stage, they're like, now I'm ready for the big kid meal, and that is human flesh and blood. So this L
three larva waiting on top of the grass for you. You come along, I don't know, Just out for a walk in the woods without your shoes on, because of course why not. The grass feels great between your toes, and this little larva burrows its way into your foot, goes straight for your blood stream, travels through your blood stream back to your heart where all your blood goes out
of your heart and into your lungs. Yep. Once it's once it's in the capillaries of your lungs, it'll bust its way out into your alveoli, which are the air sacks where gas exchange actually happens. So it literally bursts out of your blood vessels into the air sacks of your lungs, and then it swims its way up your bronchials, through your bronchi all the way to your trachea, to the top of your trachea, which is called the epiglottis. That's the flap that normally makes it so you don't
swallow your food into your lungs. Maybe gives you a little tickle right there and maybe you just a little and then it's gonna pop up and over that epiglottis and down back into your esophagus. It's gonna travel all the way down your esophagus, through your stomach and into your small intestine.
And it's like, hmm, I'm home.
I'm finally home. It'll molt into an adult worm at this stage and then it attaches do you want to know how it does this.
Yeah, it has.
These two hook things, that's why they're called hookworms, and they basically gouge their way into your mucosa or in some cases, all the way through to your submucosa, which is like through an entire layer of flesh inside of your intestine, and they attach in there and they mate, So you have to do you do have to have at least two worms for them to be successful. They mate and then they start laying eggs, and then you poop out those eggs. They find their way back to
the soil and the beautiful cycle of hookworm life begins. Anew, isn't that gorgeous?
It's just I still still even after reading about this cycle and being amazed. I'm amazed every single time that it will go up through your heart into your lungs. You cough it up, you swall, I can't. It's incredible.
It's so complicated, it's inspiring. Yeah, you should all seek to have a what is journey?
You succeed in a journey such as that.
So that whole process from initial penetration of your foot until egg laying adult takes between five and nine weeks, so it's a pretty long process. Okay, so let's talk about what's happening in your body. Do you even know you're infected? You already mentioned one of the first symptoms that you might get, which is groundedge, and so that's something that can happen at that initial site of penetration
where you just have kind of an allergic reaction. You get itching, you get redness right from where the site where the worm's burrowed in. That's your first hint that something might be a miss.
Okay, anytime that any of you have an itchy foot.
But it's probably it's probably not a hook.
But that's what you're all thinking, isn't it.
It could also be totally asymptomatic, and in a lot of cases, hookworm infection is almost entirely asymptomatic, and we'll talk about when it is versus when it isn't. So, once you get past the grounditch, the worm is just swimming through your circulatory system and it makes its way to your lungs and since it's bursting out of your capillaries and busting its way into your LVLI, you can
imagine that might cause some damage in your lungs. Yeah, so you might get some cough, you might get numinitis, which just means inflammation in your lungs, and that's just a result of mostly a result directly of the worm's causing damage, but it also can be from the immune response that you mount in response to the damage that the worms cause. And then as they make their way into your gut, you might have some minor diarrhea, some
intestinal upset. But if you just have a few worms, you might not ever know it because just a few worms, these are small, They're not doing a ton of damage.
NBD. The last one happens to die and you poop it out and you see it in your poop.
Well, I mean, is that that's going to do you some psychological damage? Maybe? You mean?
Sure? It's sort of like if you see one cockroach, you know that there are thousands more in your walls.
Yeah.
Is it the same with hookworms and intestinal walls?
Uh? No, I think if you had thousands of hookworms in your walls, you'd know it.
They'd be tens what's the scale at which which we start to see infestation?
Because let's talk about it. So the problem here is that because the worms in your gut can produce if we're talking about nicatamorus nine to ten thousand eggs a day. If we're talking about an Cyclostoma duodenale, we're up to thirty thousand eggs per day.
So it's incredible.
It's incredible. And these worms are not reproducing in your body, so you're not going to get multiple worms from just two worms. They're not going to reproduce adult worms in your body. However, if you're being constantly exposed to soil that's contaminated with human feces and humans are pooping out nine to thirty thousand eggs per day, you can end
up with an extremely high parasite burden. And the reason that that's problematic is because when the adult worms use their little hooks and they cut their way into your mucosa, they use negative pressure, they contract their esophagus to suck out your blood, and they use both their physical sucking and biting as well as hydrolytic enzymes to burst open your capillaries and arterials, suck out a plug of your tissue into their open mouth, anti coagulate the crap out
of you so that you don't stop bleeding, and then they're drinking your blood.
Oh, boy so, and there are species differences between the amount of blood that they take as well.
Yeah, so the smaller worms which are in the cater americanas take between like, they take much less blood than ant Cyclostoma do adon alle. Even a douadon alley would only take a maximum of about zero point three milliliters of blood per day, which isn't a lot, right, that's point three mills. That's basically nothing. However, I did some math, because you know, whenever we start talking numbers, I'm going to do some math. The human body has five liters
of blood. Okay, on average, your red blood cells reproduce in one hundred and twenty days, So we can assume that your blood volume replaces itself every one hundred and twenty days. So if you back calculate, you're making on average, about forty five milliliters of blood every day. That's how much new blood your body is producing every day. So if you have just one worm and you're losing zero point three mills of blood per day, no big deal. But once you get to let's say one hundred worms,
that's thirty mils of blood loss per day. Wow, that's almost that's more than half of the blood that you're able to make every day.
That's only one hundred worms. And that's only one hundred worms, right, extreme.
Yeah, it's not. And so your body, if you are losing blood, your body will start to upregulate red blood cell production. That's that's what your body does. If something happens, it will respond. That's why if you give blood and you lose a pint, you don't die immediately. Your body's like, no problem, We'll use our iron stores and will make
new red blood cells faster than we normally would. But if you're constantly losing thirty or more mills of blood per day, eventually those iron stores run out and you can't make new blood. You just can't. You don't have the materials in your body to actually do it. So the biggest thing that we see in people who have
high worm burdens is iron deficiency anemia. So that's the kind of hallmark sign and so much of the sort of downstream effects that we see are all due to this iron deficiency anemia that just results from blood law itself.
Wow. Yeah, And you.
Can start to see this especially depending on who you're talking about. So women, if you are a woman of reproductive age who has a uterus, you're probably losing blood every month, which means that you're already more susceptible to iron deficiency anemia. If you are a child, you don't have a full five liters of blood, which means you're already more susceptible to iron deficiency anemia because you don't have as much blood and you don't have as much
iron stores. You're just a smaller human. It's actually adults who have the highest burden of hookworm, which is totally the opposite of most other soil transmitted helmets, where you see the highest burden in children. And it's thought that this is because hookworms are really good at evating our immune system, so while other worms you get a high burden and then you can eventually clear them with your
immune system. Not so. So it's just a linear trend where you're exposed over your whole life, and the older you get, the more worms you have.
Oh I see, isn't that crazy?
Yeah huh so, yeah, that's how you end up with iron deficiency anemia. That's the biggest issue with hookworm infection, and children especially are at really high risk because when children suffer from high burdens of hookworm, and they end up with iron deficiency anemia. They can also have growth retardation and cognitive impairments which are life long, and so overall, you can start to see the effects of iron deficiency anemia with as few as forty to one hundred and
sixty worms. That's the range that I found, and it's not uncommon to find people with much much higher worm burdens than forty two one hundred and sixty worms.
Yeah, so.
That's that's hookworm in a nutshell. The good news about it is that it is quite treatable. It usually only takes a few doses over a few days of anti holme ethics albendazol or another benzimittazol if you're interested in what you treat it with, and you can pretty much get rid of all of them. However, the biggest problem is that if you don't address the sanitation issues that often are the cause of hookworm infection, then reinfection is almost inevitable.
Right, So, I have a question that's a little bit out there. Okay, you mentioned that hookworms are really good at evading your immune system. Do they suppress your immune system? That's not my out there question.
So I don't know if they suppress your immune system directly. They do, and there's a lot of interesting evidence that they modulate your immune system, so they do have big effects on changing the way that your immune system responds to them. The interconnectedness between the human immune system and parasitic worms is so amazing. It's so cool.
It is because there are ancient enemies and friends at the same time. It's incredible, it's so so interesting. But so my out there question is, I remember during my masters I ran into many different studies on people self treating with hookworms, to treat MS, to treat crones, to treat ibs and other sort of autoimmune disorders. What's going on there?
So I was I had all of this in the current events section, but we can talk about it.
Now, Okay. I wasn't sure if I was jumping the gun.
Yeah, so yeah, So this all stems from this idea of what's called the hygiene hypothesis, which I think we've talked about before on this I don't remember.
Let's do a refresher anyway, Okay, So a quick refresher.
The hygiene hypothesis, which is also sometimes called the old friends hypothesis, is this idea that the reason that we see such high rates of allergies and autoimmune diseases in a lot of wealthy nations is because cause we have eliminated all of the diseases that we normally are exposed to, especially parasitic worms, which our immune system essentially evolved under constant attack in in conjunction with like constantly being exposed
to things like parasitic worms. And so it's the idea that our immune system evolved to respond at a baseline level assuming that we were always going to be infected with something. When you take all of that away, your immune system's like, well, what the heck am I going to do? Guess I'll start attacking myself. That's the very
simplified hygiene hypothesis. So people have suggested purposefully infecting people with helmets such as hookworms can help to control autoimmune diseases, especially gastrointestinal autoimmune diseases like alterative colitis crones celiac disease, and also to help control allergies and other autoimmune diseases like you said, like MS. So the basic idea is
that if you give patients a few worms. Not a high burden, because we know that's terrible, but just a few they'll attach to the gut like they would normally, and it induces a certain amount of inflammation, but it also modulates your immune system in ways we don't fully understand, and this will then reduce the symptoms of these other hyper inflammatory autoimmune type diseases.
And it seems anecdotally to sometimes work, but what are the stats on that.
So there's a really interesting review article. It came out, I believe in twenty fifteen. I'll definitely post it on our website. It's very mixed results, leaning towards it doesn't seem to be working. Okay, So in animal studies it definitely works, but in clinical trials it hasn't been successful.
And so one of the ideas is that maybe you need to have been expos to worms before the onset of this hyper inflammatory state, which I thought that's super interesting that like maybe once you already have crones you cannot heal it with a worm, but maybe if you had had worms you would be less likely to get
crones or something like that. So at this point, there isn't really a lot of clinical evidence that it works at all, but it is still a cool concept and there is definitely still research that's being done on it, so ah cool. Yeah. So that's pretty much the biology and a little bit of the current research just for fun. So, Aaron, how do you get to this point? Where did these guys come from? Okay, I'll tell you right after we sell you more things.
Though there have been exceptions, like with leprosy and tuberculosis, we've mostly been dealing with pathogens that leave no physical trace of infection on bones or in fossil form, so our search of the history of a pathogen can't really extend much beyond the earliest writings. Of course, we can make guesses based on the evolutionary history and current geographic distribution, but we mostly can't rely on physical specimens to confirm
those guesses. But here, in dealing with our first lovely wormy parasite, suddenly we can start saying words like archaeoparasitologist and paleo parasitologist, and my favorite, copro lite, which means fossilized poop.
Oh my gosh, I never thought about how cool that is that we'd have so much more evidence because the worm eggs are there.
The worm eggs are there, you can do paleo epidemiology. Oh, I got chills. How cool?
That is amazing?
Yes, yeah, so these worms they sometimes sometimes rarely, but they do sometimes have what it takes to survive the extensive fossilization or mummification process. Researchers paleo parasitologists have found evidence of fossilized hookworms dating back as far as seventy two hundred years before present, so about five thousand BC, and there have been other more recent archaeological findings of hookworm eggs and fossilized poop or in at least one case,
adult hookworms in the intestine of a mummy. Whoa, which is the species Anceelostoma duadin.
Alley, which, of course I pronounced wrong. That's cool.
I don't know how you pronounce it.
You know what, It's fine.
It's fine. Someone will let us know maybe. But I'm guessing that it's probably not that surprising to you that we have this ancient evidence of hookworms. You probably would expect this relationship between hookworms and humans to be quite ancient. But here's the kicker. Oh, most of these findings come from the New World aka North and South America.
Huh, why is that the kicker, because that's weird.
Well, it's probably not that it's the majority that is found there. That could just be sampling bias. It's that they're found there at all.
That means that people they came over with them, They came over and infected exactly.
But how did that happen? So let's talk for a minute about the peopling of the Americas. There are still many, many open questions about when in North and South America were settled and how people got there. There are a
couple of things, though, that are generally accepted. One is that the people probably came from Asia, and they probably arrived over ten thousand years ago, probably even longer like fourteen thousand, and you probably learned like I did that The most commonly accepted route is overland migration via Boringia, which is that piece of land that connected eastern Siberia and western Alaska where there's now water, the Bearing Strait. Once over the land bridge, they dispersed throughout the two
continents fairly rapidly. I don't know exactly how rapidly, Not like over the course of months, but over the course of three weeks.
Yeah, shoveled all the way down to the tip.
Okay, but where do hookworms fit into this? Like I said, fossilized hookworm egs and mummified hookworm bodies have been found in archaeological sites in North and South America pre Columbian, indicating that during these early migrations, they brought the parasites with them. Right, But this poses a pretty substantial problem for hookworms, which require time outside the host in a suitable environment in order to develop into larvae and infect something new.
And there they're kind of finicky too.
Yeah. They're generally restricted to the tropical and temperate zones of the earth between I think thirty six degrees north and thirty degrees south. Nice latitude.
That's some deep knowledge there.
It's the hookworm belt. So they can't establish these more northern areas because the climate is too harsh. So how then could hookworms have been brought over the Baringia land Bridge.
Because they're in your body forever, dude.
Okay, yes, they can live for five to ten years, but it's not like this migration took place over five to ten years.
That's true.
It probably took one hundred of years for people to migrate up, over and down, and this would have also required that the people who migrated would have had hookroom infection in the first place, which if they were living far enough north, would not be likely. Basically, this discovery of pre Columbian hook rooms and the New World, if that is what they are, strongly points towards an alternative migration route, such as along the Pacific coast, which is
not a new hypothesis, stop it. Yeah so, I do need to point out that these findings and their implications were debated are debated amongst some researchers. In fact, I haven't seen so much sniping and shade and just straight up insults in scientific articles for a long time. Oh it was. I was like, oh, Mike, when's the next response coming? Response to fuller response.
To even more than than the dilution effect debate, A.
Wait it fell It felt more personal. So but yeah, so. The one of the primary opponents of these conclusions doubts that the fossils belong to hookworms in the first place, since evidence is scarce. There are only a few eggs, sometimes one egg in one location, and it's hard to tell tiny ova apart when they're in fossilized poop.
That's true, it's almost impossible.
And some of these archaeological sites are in locations that are inhospitable for hookworm development. So for instance, in a very arid region of Peru where there really aren't hookworms now, and because the hookworms couldn't live in the very arid sand.
Could they be animal hookworms.
So that would point towards the dog hookworm would be the most likely. That's the only that's one of the only other ones that can infect humans, but it doesn't often complete its life cycle.
I've got stories on those. If you want to talk about doghookworm in humans.
Sure, but I don't know. I think that the point is it would require a pretty substantial burden in order to be established in a population. And this person also doubts that the dating was done correctly and all these other things this person also says are also doubts that a heavily infested person could have gone on or survived
an overwater transpecific migration. So ancient DNA analysis could of course address all of these or some of these at the very least, but these samples are quite precious, and the researchers maybe rightly don't want to destroy them for a procedure that might not work. Ancient DNA analysis, from what I understand, is really hard as low success rates.
Sometimes it's probably getting better. But however, there's also the fact that studies of more modern hookworm distributions somewhat lends support to the pre Columbian presence of hookworms in the New World as well. So a study of the intestinal parasites of an indigenous group and Paraguay found a much higher ratio of Antelostoma dwaden alley to Nicator americanus, which is the opposite of what was found in settlers of European origin and also is the same species that was
found in the mummy from Peru Okay. So this to me is extremely thrilling. Like I find this to be mind blowing that you could look at a piece of fossilized poop or at a mummy's intestine and say, oh, you know what, Humans settled in North America in a completely different way than what we have been thinking the whole time, or maybe it was an additional route. But I also don't know how this is perceived in the anthropology community. So if there are any anthropologists or paleontologists
out there, please let me know. I tried to find some current status on on these and like updated articles, and I just maybe didn't have the right search terms. But yeah, didn't find anything that.
Is just so so interesting though.
Isn't that amazing? I love it? Okay, moving on, Okay, it wouldn't be an episode of this podcast will kill You if I didn't mention ancient ancient Egypt or Greece.
Yeah, some ancient civilization.
Pola, ancient something that, yeah, hookroom appears to get a shout out in that Ebers Papyrus, which is a collection of medical and herbal knowledge from ancient Egypt around fifteen fifty BCE. I've mentioned it before on this podcast a few times. I don't remember on what In this papyrus, there is something called ah ah ah or AAA disease that could be describing hook romanemia but might also be
shist a semiasis. Yeah, And Hippocrates described a condition that included the combination of dirt eating geophagi, intestinal distress, and a yellowish complexion that could be hookroom infection.
Yeah.
There are also a few other random reports from the Mediterranean Basin in ancient and early medieval periods that are thought to refer to hookroom infection. In any case, we can assume that hookworms were not only present throughout human history, but most likely pretty abundant. Despite this, and despite their size and visibility, I mean, you can see them. Human hookworms weren't described until eighteen thirty eight.
Wow.
Animal hookwrooms had been known to occur for decades, but it wasn't until eighteen thirty eight that an Italian physician named Angelo Dubini was dissecting a young cadaver and noticed some worms attached to the intestinal wall. He checked them out under the scope and realized they were different from roundworms, and they had these plates in their mouth end. It has a mouth and a butt end. Oh of course, okay, that seemed to hook onto the intestinal wall, so he
named it hookworm. So clever ancleiostoma is how it was spelled back then. I yeah, who knows. Other cadavers he looked at also appeared to be infested with this hookworm, but he didn't believe that they were the cause of death in any of these cases. In fact, the hookroom didn't outwardly appear to have harmed its human host at all except for some inflammation at the site of attachment.
After this announcement of hookworm discovery, people started finding it everywhere, and a few decades after this new parasite was described, a trio of Italian scientists connected the adult hookworm to the eggs it produceds which appeared in the stool of infected people. So then if you had a microscope and a willing donor, you could check for hookworm infection to.
Lock in their poop.
Yeah, but there was still a lot about hookworms left discover like transmission route treatment other species, and linking the infestation with disease symptoms because hookworms were discovered sort of incidentally, like Dubini wasn't exactly on a quest to find hookworms, he just sort of found them. The modern description of symptoms came after the discovery of the infectious agent, which is not what you're used to seeing what we're used
to seeing. And one of the tricky things about hookworm is that the intensity of symptoms can depend on the intensity of infestation, so it can make linking the parasite to the disease a little bit more difficult. Anemia, for instance, was tentatively linked to hookworm infection early after its discovery. But there are a lot of things that could cause anemia, one being just poor nutrition, and so it would take a substantial event to make that link, and that would
occur in Italy, which again Italy. I didn't know how how much of hookworm history is linked to Italy. In eighteen eighty, during an outbreak of anemia and a bunch of miners who were working on the Saint Goddard Tunnel in the Alps stool inspections of hundreds of miners, which aren't you glad you don't have that job. I would love that job just looking at poop all.
Day or not. I bet they were full of full of things.
I'm sure that they were, But you wouldn't get sick of looking at poop after a bit. I don't know in the smell.
I mean, it's just a few hundred miners. Just a few hundred sounds like a small research study, seems manageable.
Well, you, if you had been one of these researchers, you would have found rampant hookworm infestation. So fun in one miner who actually died, over fifteen hundred hookworms were found. Oh my gracious, Yeah, fifteen hundred, So I don't know the math on that. Wow, in terms of blood.
Loss, and these are antelostoma, Yeah, okay, so we can for the more higher rates of blood loss. Yeah, that's three hundred and seventy five mills a day or more.
Dang dude, that's amazing.
Wow.
So the physician who who counted those fifteen hundred hookworm basically it was like, Okay, guys, I'm pretty sure that hopeworm causes an ethiath, so maybe we should do something about this.
I've got a pretty strong feeling on this one.
It's kind of a hunch, but it's also pretty pretty certain. And so the next year, actually a successful treatment was developed, which is super fast. One year later, one year after this outbreak. Wow, so the treatment thim al could be extremely dangerous. But still that's less than fifty years after the first human hookroom infection was described.
Wow.
Yeah. But still the question of transmission route remained, and I honestly don't know whether it was suspected that hookworm and other intestinal worms were transmitted through feces in some manner at that time, but the exact details of hookworm transmission were uncovered by someone named Arthur Loose. One day he was working in the lab and accidentally spilled a beaker of water containing hookworm larvae on his hands, like
you do. Yeah, And he noticed that the spot where he had spilled the water burned and turned red and was very itchy. So he was like, hmm, I'm gonna bet that's hookworm larvae and started checking his poop for signs of hookworm eggs, which he found a couple of months later.
Yeah, five to nine weeks.
Five to nine weeks. And he started telling people about this, and people did.
Not buy it.
I'm sorry you did what.
Imagining this guy being like, no, seriously, check my poop.
I've got these eggs.
I know it came from when I spilled that water on my hand.
Yeah.
Oh, this poor guy man, I know, right, poor Arthur Arty Artie.
Yeah. I don't know why. People didn't quite buy it, but you know, poor guy. But eventually they had to because more testing confirmed not only this percutaneous route, but all of the nitty gritty of the entire migratory path of that parasite. By the late eighteen hundreds and into the early nineteen hundreds, there had been substantial progress made on getting a sense of the global distribution of hookworm, and on understanding various aspects of hookworm ecology, biology, and pathology.
But much of the research and awareness was limited to Europe and parts of North Africa. The America's really lagged behind, and the pair site was largely unknown until well after the first treatment was developed. It would take Charles Wardell Styles, the discoverer of hookworm in North America, to change that. Originally from New York, Styles left the US in the
late eighteen hundreds to study zoology in Europe. While he was there, he spent much of his time in Germany learning from the leading medical zoologists and parasitologists of the day, and he developed a passion for worms.
Of course he did, who wouldn't I know.
Right after he got his doctorate at the age of twenty three, oh stop, he returned to the US to work at the Department of Agriculture to find ways to increase production by decreasing disease. As a European educated scientist, he was in super high demand, not only at his
official job, but also as a part time lecturer. He was shocked by how few physicians had ever heard of hookworm period He spent a chunk of his lectures describing the worm, showing slides of its life stages, and then suggesting that if the future doctors at these lectures ever come across anemic patients in the tropics or in the South, to suspect hookworm. One future doctor that was present at one of these lectures, Bailey Ashford, would move to Puerto
Rico shortly after graduation as an Army surgeon. While there, he noticed that a huge number of people, especially among the more impoverished agricultural workers, seemed to be anemic, and that anemia was a commonly accepted cause of death. He was like, what's going on here? What is causing this? He tried a protein rich diet and that didn't help. Malaria didn't seem to be present in the blood. But what about the poop?
What about the poop?
The eternal question. Sure enough, he found hookworm eggs in their stool. He made his announcement of discovering the cause of widespread anemia and Puerto Rico and sent off some adult worm specimens, which he assumed to be Antelostoma duadnale to styles as a gesture of professional courtesy, though Ashford later claimed to have noticed that these worms looked a
bit different. It was Styles who would formally describe them as a new species of human hookworm, giving it the name Nicatur Americanus to indicate that it was a new world hookworm. Despite this name, the species was found to be widespread in Africa, India, and Australia, and probably made its way to the Americas during the import of slaves
from Africa. Seeing how rampant and detrimental hookworm caused anemia was in Puerto Rico, Ashford was able to wrestle up some funds to start the Anemia Commission of Puerto Rico in nineteen oh three, which at that time was the first and largest anti hookworm campaign in the world. Who and poor Ashford because it seems like everything he did was overshadowed by Styles. Both of them deserve credit for raising awareness and promoting treatment of hookworm, but Styles gets
most of the acclaim slash notoriety. Styles really was the one who discovered that hookworm was incredibly widespread in the Americans house. He was sent there to hunt for hookworm, specifically to see how many people were infected and what soil or environmental or living conditions seemed most linked with infection. In many of the places he went, more than he expected, he saw the characteristic symptoms of hookworm infection geophagi, fatigue, and a yellowish or greenish hue.
Do you want to know why people are eating dirt?
Is it because they're trying they have pika for like iron deficiency?
Yeah, I just thought listeners might like to know that if they didn't know that.
Oh yeah, yeah, Well, and I know that it's not necessarily linked to hookworms, Like you can have PIKA without having hookworms.
It's a really common symptom of iron deficiency anemia.
Not only was hookworm present in the American South, it appeared to be one of the most prevalent diseases there.
In his nineteen oh two report, which was made public, he announced quote, there is not the slightest room for doubt that unsnariasis is one of the most important diseases of the South, especially on farms and plantations in sandy districts, and that much of the troubles popularly attributed to dirt eating and even some of the proverbial laziness of the poorer classes of white populations are manifestations of unsnariasis.
Unscenariasis is an interesting word for it.
Yeah yeah. Styles's conclusion was picked up by a journalist who wrote the headline that would give hookworm a catchy nickname and breed justified resentment across the South quote germ of laziness found question mark. Oh yeah, oohh. Immediately the story and the phrase spread, leading to many jokes and cartoons and poems and satires all about how laziness was
all because of this worm. Obviously, this was not well received by people in the South who were being targeted by these jokes and articles and were being told that not only are you lazy, right, but you are also filthy and riddled with parasites.
So terrible.
And there was also the implication that don't worry, those parasites are the cause of your laziness, and we all knowing doctors know how to get rid of it for you so you can be a productive member of society again, because you aren't right now right, the hookworm was being blamed for the South remaining separate distinct from the rest of the US, rather than racism, poverty, and a lack
of access to education. Hookworm was this easy fix and was viewed as a worthy social cause, whereas the more entrenched issues such as racism and education were much more controversial and would need an entire shift in the way things were done for anything to be to become better. These headlines and articles painted this picture of the South as a filthy, backwards place full of uneducated, lazy people. It was hugely damaging, and the stereotype and myth remained
long after hookworm had disappeared from these places. For all of the negative feeling the term germ of laziness fostered, it did do one positive thing. It put hookworm on the map. People were talking, writing, thinking about this parasite that until then had pretty much not been known. And so when Styles teamed up with Surgeon General Wyman to begin a campaign against hookworms in the South, people at least already knew what hookworms were, so they could shut
the door in Styles's face that much faster. Apparently he wasn't the most easy to get along with guy, and I would go as far as to say that he was often downright condescending and insulting towards rural Southerners.
Shocking.
Also, he was pro child labor cool. So great guy overall, great guy. I mean he did do a lot by way of treatment and promotion, but he was I think he just said I know better than you. Anyway. His and Wyman's campaign had a too pronged approach. Improved sanitary conditions, especially privies, and spread the word about hookworm and offer treatment. They weren't super successful with either, but Styles would not
let the issue drop. He talked on and on about hookworm to anyone that would listen, and eventually someone did pay attention. And that someone was Frederick T. Gates, who was John D. Rockef you know, Mega rich Man, principal philanthropic advisor. In nineteen oh nine, with a one million dollar budget, the Rockefeller Sanitation Commission began its goal of eradicating hookworm disease in the South.
One million dollars in nineteen oh nine. Yes, that's so much. I don't even know how much money that is.
Yeah, I don't know what the let's look up what the.
Inflation version is. Yeah, let's see. Wow.
Okay, so now it's worth twenty seven million, five hundred and ninety four thousand, one hundred and seventy five. So twenty seven and a half million dollars billion dollars.
Goodness, gracious, good gravy. Good gravy is right.
So they had this goal to eradicate hookworm, and Styles was like, Uh, that's not going to be possible. You have no idea how rampant hookworm is. That's not possible. But they tried anyway, and their approach was similar to Styles and Wymans. So one aspect was immediate treatment and the other was education primarily focus on how you can prevent getting hookworm infection. And this was a massive undertaking that required the involvement of hundreds of people on the ground.
The first step was getting a sense of just how enormous their task was going to be by conducting prevalence surveys were Rockefeller in Styles and the like, blowing it out of proportion, probably not. Surveys from the first couple of years showed that over ninety percent of counties surveyed had hookworm infections, and overall prevalence hovered around forty three percent, with some areas experiencing ninety or one hundred percent prevalence
of Wow, yeah, it was very, very, very prevalent. While the states involved in the sanitation Commission never truly accepted Rockefeller's support. Eventually, most did come around to accept that hookroom was a big problem and that treatment and infrastructure
changes should be made. And a big part of the shift was because the Commission worked directly with state health departments, which at that time were pretty dinky and unorganized, and so this really kind of helped spur them into motion, to have a direction and a focus and to see how things worked at different levels. The Commission also hired Southern doctors as inspectors and field workers, which also helped
inspire a level of trust. Interestingly, women played quite a large role in the lab side of things, where they were hired over medical students to process samples aka look at poop. Women were quoted as doing better work, doing it faster, and more satisfactory in every way, which included costing half as much as the male med students that they replaced. Of course, I was like.
Where is the catch here? Like, what is the real reason they're cheaper?
The money can stretch so far?
Excellent.
Kentucky started the trend of hiring women, and apparently Kentucky women were so amazing at looking at poop and doing their jobs that they were lent out to other states.
Kentucky women, you need a shirt now, that says Kentucky woman.
Well, I was just about to say, if we had the rights, I would play Neil Diamonds Kentucky woman right now. Momentum up for the commission grew, and doctors would travel to towns all over the South, carrying with them their microscope, glass jars containing hookworm specimens, and plenty of pamphlets. These
hookworm dispensaries were like old tent revivals. Almost the whole town would show up and they some people would bring fried chicken, biscuits, boiled eggs, poundcake, peaches, and this is those are like I'm quoting that directly from someone who was at one of these dispensaries, and they would bring a blanket and just spend their whole day watching these
displays of hookworms. There was also this traveling train car that was sort of this interactive exhibit on hookworm where you could go and you could do the same sort of thing, but it would travel all throughout on the railroads of the South.
That is so cool, Oh cool.
I don't know if that exists in a museum format today, but I would I would love to see that. Yeah. Even though the Sanitation Commission had the broad goal of eradicating hookworm in the South, what that meant in practice
was treating white communities for hookworm infection. Many people, including politicians and scientists, blamed black people for bringing the parasite to the South via slave trade, and most of the very few campaigns that did actually focus on black communities were motivated more by the fear that they were spreading
hookworm to white communities. The Risevelt Sanitation Commission lasted five years only, nineteen oh nine to nineteen fourteen, over which time seven hundred thousand people were treated for hookworm infection, which is quite a feat, but barely any long term changes were made that would have any lasting impact on the prevalence of hookworm in the South. The Commission had failed in its stated goal, even though they wouldn't admit that.
They stopped after that time because I think in part Gates, who was the head of the philanthropy division, got bored with the issue and recognized that not enough true progress was being made. Prevalence was forty three percent at the beginning and thirty nine percent at the end, but that number would climb up immediately once the Commission left great After withdrawing from the South, the Rockefeller Foundation went global and they set up programs in China, South and Central America,
Northern Africa, and many other countries and places. And again, even though the dispensaries were popular and many thousands or millions of people were treated, there was no permanent change in hookworm prevalence because the underlying causes were still there.
In the southern US, hookworm did eventually mostly disappeared due to things like indoor plumbing, cheap and healthy foods, mechanized agriculture, but it was still prevalent well into the sixties and seventies, and in so many other places of the world it hasn't shrunk one bit. And I focused only on the US because the story of the Rockefeller Foundation is so important in terms of the development of global health initiatives
and programs. But while that was going on, while people were being treated in the American South, many people all around the world had still had hookroom infection and it was still prevalent. Hookrooms are not germs of laziness, but they do perpetuate the cycle of poverty, which is only possible to break by changing infrastructure to promote access to
clean water and improve sanitation. Erin, I know you've probably got some jaw dropping numbers for the EPI, So tell me where do we stand with hookroom today.
I can't wait to do that after a quick break. You're so right Erin, I have some jaw dropping numbers for you.
Good.
So it's actually a little bit hard to get numbers directly from the World Health Organization on hookworm itself, and that's because the World Health Organization addresses hookworm in combination with several other diseases which all share this heading of soil transmitted helminth infections. So if you look at all soil transmitted helmets, we are talking about an estimated one point five billion people currently infected.
That is twenty percent twenty percent.
Yeah, and again this is all soil transmitted helmets, and for most other soil transmitted helminth infections, soil transmitted worms. That's what helminth means. It's primarily a disease of children, not so with hookworm. Hookworm infections just seem to get worse as you get older, and actually adult males tend to have the highest of infection, and that's likely due to occupational exposures. So especially in certain occupations like you
said miners, miners are still at really high risk. Also, people who work in the tea industry, so picking tea or in other agricultural industries are at They tend to
have the highest burdens of hookworm infection. So the World Health Organization has a lot of initiatives to help deal with soil transmitted helmets, but they mostly focus on the periodic treatment of preschool and school aged children, and they say also women of child bearing age and adults in certain high risk professions in endemic areas, they recommend periodic deworming treatment once a year if the baseline prevalence in that community is over twenty percent, and twice a year
if the baseline prevalence is over fifty percent. The problem, which we've already talked about, is that you have to combine these deworming treatments with both health and hygiene education, but mostly with sanitation infrastructure, right, and the sanitation infrastructure is the most difficult part to accomplish, and it's most often not accomplished. So while they have done tons of
deworming every year for a number of years. In twenty sixteen, they treated over three hundred and eighty five million school aged children with anti helminth thicks. That's sixty eight percent of all children who are at risk sixty eight percent. So that's pretty good. Is treatment free?
Yes?
So treatment is donated by WHO to the health ministries in each of these countries, and then they're administered through the health ministries.
Okay.
Their current goal is to quote eliminate morbidity due to soil transmitted helmets in children by twenty twenty, so they're one year out. I have a feeling they're not going to make it.
Just to to clarify the distinction between morbidity and mortality and what exactly a dally.
Yeah, So I actually have some better numbers from a twenty sixteen review that's about hookworm specifically. So it's estimated that if we're just talking about hookworm, probably almost five hundred million people are infected, and hookworm infection likely accounts for over four million disability adjusted life years, which is the measure of disease burden that takes into account the number of years lost due to poor health, disability, or
early death. So we're not only looking at mortality, but we're also looking at just the number of years that you lose because you're so sick essentially.
Which it's very easy to look at things like plague and smallpox and tuberculosis and go, okay, those are those big mortality numbers. But these, with the number of people that are infected did this is hugely impactful and I think in a way that seems to be more invisible, but it shouldn't be.
Right, it's really problematic. It's also estimated that it causes an economic burden of one hundred and thirty nine billion dollars every year.
Wow, what about a vaccine? I know that there was some Peter Hotez vaccine initiative.
Yeah, yeah, that still exists. From what I can tell, it doesn't seem to be moving along all that rapidly. In twenty thirteen and again in twenty fifteen when they published updates, they were still in phase one trials. So
that's the most that I found about it. If you're interested in the specific areas where hookeworm infection is the biggest problem and where soil transmitted helmets in general are at their highest burden, there's a really cool interactive map that the who has that, I'll post on our website where you can look at every country and you can at least get an idea of the number of school age children that they estimate need to be receiving preventive therapy.
So it's not a perfect estimate because it doesn't include adults at all, but I do think it's interesting.
That's very cool an interactive map.
Yeah, it's really cool. It's it's very interesting. But in twenty seventeen, a paper came out that got some popular press that it's a very very small sample size, but they did a survey in Alabama in a county that is one of the poorest in the entire state, that has over thirty percent of the population live under the poverty line, and in many of the homes, they do not have access to sanitation, so waste from their houses are going either through ditches or pipes just directly away
from the residents with no actual sanitation system aka primo grounds for helminth infections, and in stool samp of fifty five people, again very small sample size, fifty five people in this county, they found thirty percent of them infected with hookworm. Yeah, so this idea that hookworm does not exist anymore in the US is not.
True, not at all.
So that's something I think that's important to keep in mind. We in the US really liked to pretend that things are over there and our problems that don't affect anyone back here at home. But that's just plain not true.
Yeah, even in nineteen thirty nine. So the Rockefeller Sanitation Commission ended in nineteen fourteen, and in nineteen thirty nine, I think they published this report that said human hookworm infection all but gone in the southern US. At that time, forty percent of people were still infected.
It's interesting because when this article came out, which again i'll post this on the website, the popular press that I read that referenced it, they started hookworm was once eradicated in the US, thought to be gone, but now it's back, And I'm like, it was never gone, it was just nobody cared.
No, it's still in some in certain populations, extremely prevalent.
Yeah, hookworm, it's still around. It's a huge problem worldwide. Do you want to ask me how scared we should be?
How scared should we be? I think you.
Should be very concerned. How about that?
Can you say more about that.
I think that hookworm is like many neglected tropical diseases. It's something that just perpetuates this cycle of poverty, and I think that if you are a human, that should be really concerning to you.
Yes, well, in the fact that we have the technology, the resources, the personnel to make this a disease of the past, and yet it's not happening because there's no money in it. And there are tons of people doing great work on fighting that, on fighting these, you know, hookworm and other neglectrotropical diseases, including who, including Bill and Melinda Gates Foundation, including Peter Hotez, who is like his superstar, and lots of lots of other people. Is yeah, but yeah,
there is concern five hundred million people. Five hundred million people are infected.
Yep.
If you walk away with from this episode with any number, let it be that one.
Yeah, So sources, sources.
I'll post a bunch of articles on this. Paleoparasitology early pre Columbian evidence of hookworm infection. Cool. But a few things that I do want to shout out. The first and foremost is this book called The Germ of Laziness by John Ettling, And there was this great article on the PBS website called how a worm gave the South a bad Name by Rachel Newer. And in that article there was a link to a YouTube channel called gross Science from Nova, which I have never heard of, but
it's full of shortish videos like under five minutes. I think that are just about one many, many, many different things. But among these there's a whole section on like parasites and pathogens and so in one of the episodes, the focus was hookworms. It was so well presented and so fun. So seriously, if you guys want some multimedia, check that channel out Gross Science.
That sounds awesome. I have a bunch of really cool articles. We will post all of them on our website. This podcast will Kill You dot com. You can find all of our sources from every single episode there.
Thank you to Bloodmobile for providing the music for this episode and all of our episodes.
And thank you for listening to us ramble, and for writing us and emailing us and tweeting at us and following us on Instagrams, like this is really cool that we get to do this.
It is also you really need to check out the song called Hookworm blues by someone named blind Blake came out in nineteen twenty nine. It's a blues song about hookworm. What could be cooler?
It's fantastic.
We'll post it.
Yeah.
Until next time, wash your hands, you filthy animals, and now listen to this fantastic song by our good friend Merrimack Valley Girl. It's called Parasite Love Song, and it's basically the most perfect song for this podcast ever. You can find more of her music and gigs on Merrimackvalleygirl dot com and her instagram Merrimack Valley Girl. So that's spelled m E r amec. Valley Girl will include the links in the show notes and on our social media pages. Here is Parasite Love Song.
I cannot live without you, not even for a day. Please don't try to push me out, Please just let me stay. It's a miracle I've found you. Introductions were not forced. They'd brought us together. Let nature take her course. You tried to avoid me, but my instincts were too good. Your defense is now arising, but I knew that they would. I never want to hurt you. I don't want to make you. Please do you understand me? Do you know that I have needs. Have you ever felt so wanted?
I may be a fluke, our support may not be mutual, but please do not rebuke your giver. I'm a taker, but relations can evolve. I'll adapt to stay with you. Our problems can be solved.
Oh what do I.
Love about you? You're such a lovely host, your beautiful and rich inside where it counts the most. I promise I.
Won't cheat on you. Please just let me stay.
I cannot live without you, not even for a day. I want you out. You make me sick.
I want you out. You make me sick.
I want you out, your magne sick. Oh, you're lousy and your magne sick.