As The Toast searches for its one true Gal Scientist, we will be running a ton of wonderful one-off pieces by female scientists of all shapes and sizes and fields and education levels, which we are sure you will enjoy. They’ll live here, so you can always find them. Most recently: Mansplaining Physics. Today’s column is sponsored by the lovely Sarah Redmond, so blame her for your nightmares.
Parasites make for great conversation starters at any social occasion. Tales of parasitic diseases are like ghost stories: people are creeped out, but they can’t help asking what happens next. Sometimes they say things more along the lines of “ew, that’s disgusting” or “please, I just want to eat my sandwich in peace,” but trust me, they really do want you to keep talking. Even if they don’t show genuine curiosity, comfort yourself in the fact that you are helping people protect themselves against the scourges of mankind.
To help you choose the right story for the right occasion, I have listed a few examples of situations where it might be particularly appreciated. It’s safe to say that any of these are perfectly appropriate for preschool graduations, gender reveal parties, or your ex-boyfriend’s wedding.
Plasmodium — Malaria
The next time you get together with your friends for a night out, pour yourselves a gin and tonic and toast to the British Empire for popularizing the drink. Your hangover the next morning will remind you that you were protected from malaria, if not alcohol-induced dehydration.
Malaria is one of the most notorious parasitic diseases and it definitely deserves its bad reputation. Over 200 million people suffer from malaria, and more than 500,000 die each year. Malaria is caused by protozoans of the genus Plasmodium that are carried by mosquitoes and cause flu-like symptoms. Untreated, the disease can progress to the brain, lungs, kidneys, and liver. Fatality rates can reach as high as 20%.
There are several anti-malarial medicines in use now, but the oldest and best known is quinine. Unfortunately, quinine, an alkaloid from the bark of the cinchona tree, tastes awful. It is terribly bitter and must be consumed daily to ensure Plasmodium is killed. The soldiers of the British Empire who went conquer India, understandably, did not want to take their daily quinine. However, it is difficult to conquer if your soldiers keep dropping dead of disease. Adding soda and a hint of sugar to quinine to masks the bitter taste and makes a refreshing drink: tonic water. Even now, if you buy a can of Schweppes to make your G&Ts at home, you’ll see a label in small font: “Contains Quinine.” British officers found it was more pleasant to add gin to make it a medicinal afternoon drink. It’s like an adult version of Mary Poppins’ “A Spoonful of Sugar.” Just a shot (or two) or gin makes the quinine go down.
The perfect story for: bachelorette parties in tropical locales, trying out a fake British accent, telling your spouse “it’s medicinal” if they question the number of G&Ts you are consuming.
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Schistosoma — Schistosomiasis
Chances are you’ve never even heard of schistosomiasis before, but it actually affects 200 million people worldwide. It’s the second most prevalent parasitic disease after malaria, and has plagued humans for thousands of years. The ancient Egyptians actually had a hieroglyphic symbol for it. Technically the symbol meant “blood in urine,” but the point stands: schistosomiasis is one of the deadliest diseases you’ve never heard of.
Schistosoma worms spend half their life in fresh water and infect snails. They grow and mature inside the snail until light causes the larva to swim out of the snail and into the surrounding water. If you are the unlucky human nearby, they will pass directly through your skin and into your blood vessels. You won’t notice their entry; they are less than a millimeter in size and have special enzymatic secretions that break down your skin. Are you scared yet?
Once inside your body, the worms settle down inside blood vessels to eat red blood cells and mate. As with most parasites, the females are significantly larger. The smaller male sits enveloped by the female, which produces between 300 and 3,000 eggs per day. The eggs find their way into your bowels or bladder, depending on the species of worm. As you contaminate other fresh water sources with your urine or stool, the Schistosoma life cycle continues. The worms, meanwhile, stay inside you as long as they please. There have been documented cases where the worms have lived for several decades inside their hosts.
So what do these worms do inside you besides constantly eat and mate? Not a whole lot, actually, but it’s the eating and mating that makes you sick. For one thing, you need all those red blood cells they’re devouring. Anemia is always the first sign that something bad is happening inside you. Iron is a very limited resource; parasites, bacteria, and even tumor cells do everything they can to get more of it. Anemia leads to muscle weakness, poor cognitive function in children, and stunted growth.
Most of the long-term problems are not caused by the worms but by their eggs. The worms are able to slip past your immune system through a number of tricks, but the eggs cannot. Your body, understandably, tries to fight, but only makes things worse by causing inflammation. Long-term inflammation leads to severe damage in the liver, kidneys, or bowels and a predisposition to cancer in these areas. Inflammation can even cause sores, in the case of Schistosoma haematobium, in the female uro-genital region. Sores facilitate the entrance of HIV, so in parts of the world where both diseases are endemic the parasite unwittingly helps a virus that will eventually kill its host.
This is the part that most people overlook when they think of parasites: most parasites don’t want to kill you, but they make it a lot easier for you to die.
The perfect story for: romantic dinners featuring escargot, winning a point at pub trivia, justifying your hatred of snails
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Trypanosoma cruzi — Chagas disease
If you have donated blood recently, you may have noticed a question near the end of the form that asks “have you ever been diagnosed with Chagas disease?” Chagas disease, caused by the protozoan Trypanasoma cruzi, infects over ten million people, mostly the poor in Latin America, South America, and the Caribbean. Some researchers are actually calling it “the new HIV/AIDS.”
Trypanosomes spend part of their lives inside blood sucking insects called “kissing bugs” that like to bite humans near their lips. After sucking out some of your blood, the beetle turns around and defecates next to its bite. You wake up, itchy, and scratch your face, inadvertently introducing T. cruzi into your blood stream. Like the HIV virus, T. cruzi can be spread through blood transfusions and organ donations (hence the question on the blood donation form), and from mother to fetus. Unlike HIV, it can be transmitted in food. If you are making yourself some delicious sugarcane juice and there happen to be kissing bugs hiding on the stalks, you end up with a glass full of trypanosomes once you’ve crushed everything to a pulp. A bunch of Brazilian children were infected with very high parasite loads this way.
Now that you’re terrified to itch your face or drink juice, you should know why T. cruzi is so dangerous. While there is a treatment for the “acute phase” of infection (the first few weeks after the parasite enters you), there is no treatment for the chronic phase, which ultimately kills 20-40% of those infected. In the chronic stage, trypanosomes settle down to make their home inside of you, especially in your heart. Chagas can affect the digestive and nervous systems, but usually it’s the damage to the circulatory system that kills. Over time, trypanosomes slowly devour your heart, causing inflammation that enlarges and weakens the muscle. Chagas disease is the leading cause of heart failure in Latin America.
If you remember nothing else about these parasites, remember that they will make an excellent metaphor for your ex-boyfriend in any terrible poetry you will write. You were my trypanosome/ living inside me/ consuming my heart.
The perfect story for: connecting with sullen teenagers, Valentine’s Day, getting people on juice cleanses to stop talking to you
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Naegleria fowleria — Primary Amoebic Meningoencephalitis
If you lack a paranoid coworker to send you terrible news stories on Facebook, perhaps you did not hear about the two high-profile cases of a brain-eating amoeba that infected two children in the United States last summer. Naegleria fowleria is a deadly protozoan: it kills more than 99% of the people it infects.
Parasites do not usually kill their hosts quickly. Why bite the hand that feeds you when you can slowly nibble on it for years? N. fowleria is an accidental parasite. It can live out its entire life cycle in freshwater, dividing and propagating in warm ponds and poorly chlorinated pools. They don’t need a human host to live, but if they go up your nose when you jump into the pool, they will keep going about their business. Only now their business is inside your nose, and the amoebas go into attack mode.
Your nose is the first victim. N. fowleria kills your olfactory bulbs and eats them; one of the major early symptoms of the disease is losing the ability to smell. After dining on your nasal cavity, N. fowleria travels along the neurons connected to your brain. It takes between three to seven days for the amoebas to make the journey, but once they’ve reached the brain you are pretty much screwed. Amoebas feast on your brain in earnest, causing you to suffer from hallucinations and seizures. Soon, the rest of the brain will begin swell until you fall into a coma. Within two weeks, amoebas are eating your brain stem, and the brain can no longer tell the lungs to breathe; respiratory failure is the ultimate cause of death.
If you were ever teased as a child for being a wimp and plugging your nose when you jumped off the diving board, take comfort in the fact that you were protecting yourself from N. fowleria. Then impress everyone by doing a cannonball in the pool (just make sure it’s full of chlorine first).
The perfect story for: children’s birthday parties, visiting water parks, skinny-dipping during camping trips
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Dracunculus medinensis (Guinea Worm) — Drancunculiasis
Guinea worms are some of the least prevalent human parasites, but they are definitely one of the most disgusting. Guinea worms are only found in four countries with 96% of all cases found in South Sudan. Reported cases have dropped 99.98% since 1989, with only 97 infected in 2013 as of August. If you know what guinea worms are, that’s 97 cases too many.
Guinea worm larvae live inside water fleas. When you drink contaminated water, the water fleas die in your stomach, but the worm larvae escape into your body and mature into adults. After the adults mate, the male worms die while the females burrow into connective tissue. They particularly like the space next to leg bones, which allows them to grow unperturbed. While adult males are only an inch long, female worms will grow up to two to three feet in length. That’s right, there’s a worm two to three feet long inside of you, and it’s as thick as a cooked spaghetti noodle.
A year passes before the female worm makes its move. A blister forms on your leg or foot, and within three days the blister pops, revealing the end of the worm. The blister is extremely painful and, seeking relief, you soak your foot in cold water. The worm uses this chance to release her eggs, contaminating the water. All the while, there is a three-foot worm sticking out of your foot.
Extracting the guinea worm is as horrifying as you might imagine. The main method has been used since the time of the ancient Egyptians: slowly and gently wrapping the worm around a stick. The blistered area stings like crazy and you must take great care not to break the worm. If the worm snaps in two, the part left in the body with either rot or, worse, petrify. Some worms like to wrap around joints, and having a petrified worm in your knee is obviously a problem. The slow extraction can take anywhere from hours to months. As you can imagine, this is pretty disruptive to people’s daily lives. It’s hard to be a productive member of society if you have a giant worm slowly coming out of you for months at a time.
The good news is Guinea worms, while painful, do not kill their hosts. The downside is there’s a giant worm coming out of your leg.
The perfect story for: spaghetti dinners, adorning the Christmas tree with tinsel, inducing vomiting after eating too much on Thanksgiving
Tags: gal science, louise goupil, parasites, science
Y’all, I had a pretty bad parasitic infection when I was doing an international medicine rotation in Ecuador, and as soon as my bowels were back in order, I could not stop talking about it. I thought it was the most fascinating thing ever, because I was (am) a total weirdo. I got home just in time for my mother’s giant Memorial Day house party, and by the end of the week no one even wanted to sit next to me for the fireworks display because they were so grossed out/tired of hearing about my parasites.
What I’m saying is that this article is the greatest, and now I’m terrified I have Chagas.
I LOVED this post. I am a big fan of disgusting parasite stories, and also springbok benches. How do you feel about those, Louise?
Yeah, but if you tell the quinine story, some asshole* is going to explain how many gin and tonics** you’d actually need to consume for a therapeutic dose.
*That asshole will be me.
**Not just a swaggery “Heh heh–challenge accepted!” number. A really unreasonable and gross number.
How many how many?
Follow-up question: did the British in fact consume that gross and unreasonable number of gin & tonics? Wash down quinine pills with a g&t chaser? Just tell themselves it helped while actually getting a whole bunch of malaria anyway?
For some reason I’ve always assumed that the British officers were drinking ridiculously potent tonic, and that contemporary commercial tonic water was a diluted and sissified form of the original medicinal-ish drink. My baseless assumption was incorrect, huh?
No, your baseless assumption is exactly correct (although I like to believe that colonial gin & tonics were super gross) (because: colonialism)! But to get a mid-range dose of quinine from modern tonic water, you would have to drink two liters of it a day, so at a minimum figure a liter of gin? and I’m pretty sure you would die, or wish you had.
But I kind of like the idea of a quinine shooter…
Oh god. I’d definitely be dead.
I’m glad we share the fantasy that the colonialists were at least suffering in a beverage-sense! I also imagine that they were getting a bunch of itchy mosquito bites even though they weren’t malarial, and sweating, and growing to shudder at the sight of khaki.
My gf snapped her Achille’s tendon and had her leg in a cast for several months – when she got a cramp and wasn’t able to stretch it out we went to A&E and the attending doctor prescribed g&t’s! Gotta love the NHS.
I love this and will be found curled up in a corner, twitching occasionally, for the rest of the day.
This was really ordered well to transition me from a small smile upon learning the origin of gin and tonic to a complete lack of facial expression as the muscles have melted off my face in horror.
Yeah, I didn’t read the Guinea Worm one, because I already knew about those, and I just can’t. *shudders*
*screams forever*
*silently screaming everywhere*
I’m not much of a G&T fan, but I always get one when I’m at a bar with black lights*, because the quinine’s fluorescence delights me so.
*the probability of this is mercifully infrequent, but still nonzero
We used to have black light parties with G&Ts in college just for that reason. Any (lame) excuse to drink…
Brb, taking a Silkwood shower forever.
P.S. I was scratching my face as I read the line about introducing T. cruzi into the bloodstream and now I’m dead.
OH MAN DO BOTFLIES NEXT
NO PLEASE DON’T. It’s boy fly season for the horses and every year I’m paranoid enough that one of the eggs I’ve picked off the horse has stuck under my fingernail and I’ve somehow eaten it.
I had no idea Guinea worms were so rare! They seem to be a favourite of undergraduate biology professors and they always gave the impression that Africa was FULLof Guinea worms.
Here’s a story about the efforts to eradicate the guinea worm:
http://www.newyorker.com/online/blogs/elements/20…
Be warned, there is a photo of a child with a guinea worm in her leg.
They aren’t parasites, but face mites do the the poop-on-face thing too: http://blogs.discovermagazine.com/notrocketscienc…
Parasites, man. One of the few things that make me think I should’ve studied biology.
WELL, THAT WILL HELP CUT DOWN ON TRAVEL EXPENSES.
As in never leaving the bed. Ever.
Oh my god the Guinea worm nooooooooooooooooooooooo D:
I met a dude with that once! He had to wear socks all the time.
Eeeeeeeeeeuuuuuuuugh. While the writing was fantastic and fun, the content made for a truly horrifying reading experience. (Ghost story metaphor: apt.)
BUT. How much do I love the first three images? So, so much.
A family member once got pinworms and all I learned from that was don’t bite your fingernails after you’ve been handling dirt or sand. Is that right? And something about scotch tape used in the diagnosis but I am not going to write that out, you can google it for yourself.
Not biting your fingernails after handling dirt or sand is a good practice in general, but the main parasites of concern would be roundworm or hookworm larvae (from soil or sand contaminated by cat, dog, or raccoon poop). Humans aren’t the normal host for these species, so the larvae in your GI tract get all confused and start wandering around to places they shouldn’t be, like under your skin or, more significantly, into your eyeball or brain. I believe I remember learning that ocular larva migrans (meaning, “larvae wandering around in your eye”) is a leading cause of blindness for young children in some parts of the world. The main thing I remember about pinworms is that dogs and cats don’t get them, so if your kid has them, don’t blame it on the dog. That, and the test with the scotch tape and the flashlight–can’t say I know anyone who’s tried that, though!
I’m sure I speak for many when I say WHY DID I READ THE WHOLE THING.
The first conversation my husband and I had was about tapeworms. At a fondue party. We had a blast – some of the other guest were not so amused.
My 9th grade (age 14) biology teacher had written her masters thesis on parasites, so we had a six-week (!) unit on them in class, right before Christmas. On Christmas Day, we went to my grandma’s for dinner and had a pork roast. I asked her if she’d cooked it enough, to kill all the trichinosis. I don’t think she ever fully forgave me. In my own defense, I’d been studying All the Disgusting Things for six weeks and was completely traumatized.
“This is the part that most people overlook when they think of parasites: most parasites don’t want to kill you, but they make it a lot easier for you to die.”
Well put! I love this post. Can it be a recurring series, pretty please?
This was a fine, fine article. Can we also talk about how neglected parasitic diseases like the ones above affect over half a billion kids in the developing world today? and how there are effective treatments in existence and a lot of them could be prevented/treated for like 50 cents per patient per year? Learned about this for the first time at an alumnae talk with a Smith professor last year. http://www.end7.org/ is an organization doing good work if you’re so inclined.
I have heard that the American symbol for medicine with the stick and the snakes is a demonstration of removal of Guinea Worm. When I was at school I made friends with a new student who had just arrived from Ghana and was infected with a Guinea Worm so I got to hear aaaaaaaaaaaaaall the details.
Am so, so itchy now. This is horribly fascinating. Genuine thanks!
I loved this! I mean, Im never going outside again, but I really loved this.
D: D: D:
What about the Amazon urethra bugs?? The most horrifying parasites of all? Are they even real?
Dioctophyma renale! It’s a three foot-long worm that lives in your kidney. The look on people’s faces when I tell them about it almost makes up for the cost of vet school.
LOUISE I am currently writing a book about nightmare creatures (a book for grown-ups but in the style of a children’s pop-up book) and this type of thing is EXACTLY what I’m looking for. Ten points for Gryffindor.
Those are real! They're actually fish (Candiru fish) and they're not really parasites because they aren't normally found inside humans. They are attracted by the urea and mistakenly swim up the urethra and get stuck because they can't turn around and swim back out. I'm not sure how common they are, but pretty much every medical TV show has had them, which leads me to believe that only like 5 people a year have this problem.
That sounds AWESOME! Who doesn't love pop-up books?
Aaaah I am biking through Cuba in February and was very much looking forward to downing large amounts of fresh sugar cane juice! But now I am too scared of Chagas disease.
*runs to look up prevalence of these kissing bugs in Cuba*
I scanned this article the same way I peer through my fingers at scary movies.
That being said, who needs to go to exotic locales when I can pick up Lyme disease right in my own neighborhood?
Aaaaaaaaaaahhhhhh. D: D: D: I had to take a class on parasites in college and dear god I did not stop itching. Now I just cringe in terror at the tv show “Help! I caught it abroad!” which has convinced me never, ever to leave the country again.
I had a professor who, as a way of keeping up with the literature, would give everyone in his class a water-borne disease/parasite at the beginning of the semester and tell us to find out as much as was known about it. I had Naegleria fowleri, and I have never been able to open my mouth in the shower again, and I try to keep my nose as safe as possible.
Technically those are parasitoids, if you are talking about the things that inject their eggs into other things and when the eggs hatch they eat those things (alive or otherwise). Like, gall wasps are parasites, but the wasps that find the galls and inject their own eggs into the developing larvae inside the galls are parasitoids.
In one of my Portuguese classes, there was an ongoing one upmanship game going on between two students who had worked in Lusophone Africa. They were constantly comparing ghastly tropical diseases and parasites.
One of them finally pulled out the story of the time she was with a canoe that flipped over, and her partner got eaten alive by a crocodile. The other student stared at her in shock, then high fived her. End of contest. (Thank God.)
LOL at “they [parasites] don’t really want to kill you…they just make it easier for your to die”.
Thanks for the chuckle.
Relevant! http://phenomena.nationalgeographic.com/2013/12/0…