Stories tagged parasites


Dead zombie bee: Up to 80 percent of bee hives along the West Coast may be impacted by the "zombie bee" phenomenon. Parasite flies plants inside the bees, like this one, that ultimately kill them.
Dead zombie bee: Up to 80 percent of bee hives along the West Coast may be impacted by the "zombie bee" phenomenon. Parasite flies plants inside the bees, like this one, that ultimately kill them.Courtesy wintersixfour
Zombies are all the rage these days, and not just on cable TV shows or at pub crawls.

There's a growing trend in "zombie bees" working its way around the West Coast. Just this week beekeepers in Washington state report finding evidence of "zombification" of their bees.

The impacted bees get their name for their changing behaviors once they host the parasitic flies that cause the trouble. While most bees spend their nights nestled snuggling in a comb, these "zombie bees" actually go out flying in very erratic patterns. Like many other night bugs, the zombie bees fly to light and usually die quite soon.

What's really at play is that the tiny parasitic flies plant eggs into the host bee. Those eggs grow into maggots that eat the inside of the host bee that ultimately cause its demise.

Evidence of zombie bees was first found in 2008 near Sacramento, Calif., and beekeepers around the west coast have seeing the spread of the problem in the years since.

Researchers are trying to figure out if this parasite problem is a factor in the bee population declines that have been going on nationwide. One researcher has set up a website – – to allow amateur beekeepers to share information about zombie bees they are finding around their hives. It is also looking for people who want to step forward to be "zombee hunters."

There has been one isolated report of zombie bees in South Dakota. So far, two investigations in Minnesota have turned up no evidence of zombie bees.


This could be you: (Again, only if you were a snail.)
This could be you: (Again, only if you were a snail.)Courtesy Thomas Hahmann
I'm not going to get into the full parasite extravaganza here, because Wired Magazine already laid it out pretty well, but here's the general idea:

What if some worm eggs snuck into your body through something you ate (something gross)? What if one of them lodged itself in your liver, and, after a little while, started producing embryos of its own? What if it packed those embryos into giant, pulsating egg sacks that flopped out of your eye sockets and hung from your head? And what if those pulsating egg sacks looked so delicious to birds that they would flap down and eat them (and your eyes)?

It can all happen. I mean, you'd have to be a snail for it to happen to you, but still... Leucochloridium paradoxum is out there.


What is it?: It's... ah... you know, whatever.
What is it?: It's... ah... you know, whatever.Courtesy Reytan
Roll up your sleeves and prepare a glass of filtered water, Buzzketeers, because it’s time to learn about the Guinea worm. It’s time to learn about the Guinea worm… hard!

In case the title of this post didn’t spoil it for you already, or if your mother printed out the page but cut off the title, or in case your eyes just don’t read letters that big, the Guinea worm grows to be up to three feet long. Inside you. And even though everything that enters my body must first pass through flame, it still freaks me out.

The parasitic guinea worm, or dracunculiasis (which means “afflicted with little dragons”—you’ll see why in a second), was once found in 20 countries across Asia and Africa, but improved sanitary conditions have reduced its range to just 4 countries in Sub-Saharan Africa. Which is cool, because the Guinea worm is super gross and bad, but not good enough, because the Guinea worm is super gross and bad.

The worm works like this: little worm larvae swim around in puddles and ponds until they get eaten by teeny, tiny crustaceans called copepods (sort of like little shrimp). They live and grow inside the copepods until the copepods get swallowed by people drinking unfiltered water. (Just to be clear, this isn’t just any unfiltered water. If you’ve got electricity to power a computer to read this, there’s pretty much zero chance that there are any worm-carrying copepods in your water. If it came from a tap and not a puddle, you’re probably cool. And even if it came from a puddle, you’re probably still cool.) The copepods get dissolved in the drinkers’ stomach acid, but not the baby worms, which then move from the stomach to the abdominal cavity. There, the worms mate. The male worms die and get absorbed, but the female worms wriggle their way deeper into the body, and grow. And grow and grow. Until they’re about three feet long. They live inside their human host for a year, and then they form a blister somewhere on the surface of the person’s body. When the blister bursts, the female worm emerges just a little bit. The worm releases chemicals that cause the blister to have a very painful burning sensation, and when the host puts the affected area in water to cool it, the worm releases hundreds of thousands of worm larvae into the water, where the cycle can begin again.

As if that whole experience weren’t uncomfortable enough, the treatment isn’t a whole lot better. Because there’s no medicine for Guinea worm infection, the adult worm itself must be removed. The way to do that is to grab the exposed bit of the worm and wrap it around a twig or a piece of cloth, and then twisting the twig. But it has to be done slooooowly so as to not break the worm while it’s still inside your muscles—the process, which is said to be extremely painful, can take up to a month before the worm is fully removed. It’s thought that the ancient symbol for medicine, a snake wrapped around a rod may have been inspired by this procedure.

So, you know… ouch, blech, ouch.

Becoming infected once confers no protection from getting infected again, so people can get Guinea worms over and over again, and in addition to being painful, the blister the worm creates can make the sufferer vulnerable to more dangerous infections.

The good news is that preventing infection is relatively simple; infected people shouldn’t wash in water that will be used for drinking, and simple filters can keep people from ingesting the copepods that carry the worm larvae.

President Jimmy “Billy who?” Carter’s non-profit organization, The Carter Center, has been working for the last 20 years to eradicate the parasite. Despite some pretty significant barriers, it is expected that dracunculialisis will be the second disease, after smallpox, to be completely eradicated through human efforts. (Here’s a recent article on that.)

From what I’ve read (and what the Carter Center says), it looks like humans are the Guinea worm’s only host. So it seems to me that eradicating the infection would cause the extinction of the species. Think about that for a second. Usually sciencey types are pretty much completely against driving other organisms to extinction. But it seems like this one… considering how it pretty much only makes life worse for people who are already dealing with some serious challenges… should maybe… maybe… go extinct? I mean, obviously, right? But try that one on for size; I bet you haven’t often said to yourself that you’re cool with something going extinct. It’s a strange experience.

(If you just can’t deal with it, Here’s a website devoted to saving the Guinea worm. It’s satire, but subtle enough that you could probably play along. But, um, remember that sometimes the Guinea worm emerges from the eyes or genitals of its host. Just saying.)


Tens of thousands of childhood nightmares: wrapped up in one little package.
Tens of thousands of childhood nightmares: wrapped up in one little package.Courtesy bug_girl_mi
Remember stumbling through the world as a stupid little kid? You touched bugs. You dug holes. You explored mud. And then… then you heard about killer bees. Killer bees and flesh-eating diseases. Killer bees, flesh-eating diseases, and tiny eggs that could come off a picnic table, get into your body, and hatch into something that would eat your brain.

It wasn’t the end of your childhood, it just gave you something to think about all the time. No, you’re childhood didn’t end until you were able to convince yourself that these things—killer bees, flesh-eating bacteria, brain eggs—were harmless… if they even exist at all.

Well guess what: they do. They exist, and they are dangerous! Your childhood is long gone, and now so is your adulthood. Welcome to the next stage in your life: The childhood nightmare spotlight!

Today’s feature: raccoon poop brain parasites! They’re real, and they’re all up in your brains!

So, what’s nice about raccoon poop brain parasites as a childhood nightmare—as opposed to childhood nightmares like killer bees, or one of those little fish that will swim up your urethra—is that even we fancy city-folk are vulnerable to it.

See, there is, in this world, a thing called Baylisascaris procyonis. B. procyonis is a species of roundworm. It is a parasitic species of roundworm, in fact, known to infest the guts of raccoons. Should procyonis eggs find their way into a human (and more on ust how they might do that in a minute), there’s no need to worry about them turning into worms and going crazy in the intestines—the parasite really only wants to do that to raccoons. Instead, the eggs hatch into larvae, and enter the blood stream, traveling about the body to wherever suits them. I think that whoever wrote the wikipedia article on them puts what happens next rather well:

A great deal of damage occurs wherever the larva tries to make a home. In response to the attack, the body attempts to destroy it by walling it off or killing it. The larva moves rapidly to escape, seeking out the liver, eyes, spinal cord or brain. Occasionally they can be found in the heart, lungs, and other organs.

This can lead to a whole range of symptoms from skin irritation to blindness to brain damage (and what doctors call “craziness”) to death.

So how do they get in you? You have to eat poorly cooked raccoon, or uncooked raccoon feces.

I know what you’re thinking. You’re thinking, “Phew! It’s been years since I’ve had undercooked raccoon, and I almost never put raccoon feces in my mouth anymore. Not since college! I don’t even know where to get raccoon feces these days!”

Shows what you know. Raccoons are everywhere, even in your precious, safe cities. And when they pick a spot to relieve themselves, they really go for it. Raccoons, as it happens, us communal “latrines.” That means that multiple raccoons will pick a spot in, say, your back yard, to all go to the bathroom on. Each gram of raccoon feces can contain up to 20,000 worm eggs, so when you’ve got a latrine full of raccoon mess, you’ve got plenty of potential brain parasites. Especially if you’re in the habit of putting everything in your mouth, or of cleaning your yard with a leaf-blower. (The leaf blower would fill the air—and possibly your mouth—with tiny particles of raccoon feces and brain parasite eggs.)

Not many people get the disease (only 14 in the last 30 years, says this article, or possibly 25 in the last 6 years, like this article says) but getting it is bad enough that you might want to give it a little thought. Or lots of though, late at night. Don’t believe me? Read this article again.

The best way to avoid it is to keep that raccoon feces out of your mouth. And to follow the simple tips on cleaning up raccoon latrines offered in this article (which you already looked at). My favorite anti-raccoon latrine tip? “Flame” the latrine with a propane torch! It’s like Aliens!

At any rate, you’re probably safe. Possibly safe. Safe-ish.

You really could have raccoon poop brain parasites, you know. There were probably some on your deck, and you didn’t even think about it when you were eating that watermelon.

You probably have a headache right now.


A leg. With elephantiasis.: Or lymphatic filariasis, if you will.
A leg. With elephantiasis.: Or lymphatic filariasis, if you will.Courtesy otisarchives1
Y’all know about elephantitis, right? Sever thickening of the tissue in the legs and genitals, to the point of developing massive, lumpy appendages (like and elephant, I suppose). Not a condition you’d want to develop, right?

Well don’t sweat it, kids and adults—elephatitis doesn’t actually exist. There’s a big weight off your back (and legs and genitals).

Unfortunately, this silver cloud has a rainy lining: while elephantitis isn’t a real thing, elephantiasis is. And elephantiasis is pretty much exactly what I described above, only it’s often mispronounced as “elephantitis.” Oh, fudge.

Elephantiasis, basically, results the body’s own response to some foreign agent—sometimes irritants in the soil, but usually parasitic worms cause the massive inflammation. And maybe the worms sometimes prevent it too… (for more on that, take a look at this Buzz post from last month)

When you get tight down to it, elephantiasis isn’t great to have. It hurts, and it makes life more difficult. Millions of people around the world have the disease, and about 1.3 billion people (a fifth of the world’s population) are considered “at risk” for contracting the disease that causes elephantiasis.

However, the World Health Organization is making a push to distribute a cheap and simple cure for the disease to all at risk areas (the effort was described in a BBC piece today). It’s estimated that the project has prevented 6.6 million children from developing the condition, and halted its progression in another 9.5 million people.

The treatment is based on a couple different drugs, neither of which are mentioned in the BBC article, but I’m guessing that it’s referring to albendazole and ivermectin. These drugs are anti-parasitic, attacking the worms that cause elephantiasis. Getting rid of your worms is generally a good thing, and it should prevent the development of elephantiasis, but I bet that—as the article implies—it won’t eliminate elephantiasis once it’s in its severe form. So, you know, catch it early.

The WHO program hopes to more or less eliminate elephantiasis by 2020. Although there are no known cases of elephantitis, I’m afraid that one may stick around a little longer.


Eat up!: Technically, these aren't the right kind of parasitic worms. But it couldn't hurt to have a few, right?
Eat up!: Technically, these aren't the right kind of parasitic worms. But it couldn't hurt to have a few, right?Courtesy Teseum
Finally, folks, we have yet another reason to get infected with parasitic worms!

Don’t get me wrong—there are already reasons that you should look into getting worms, plenty of reasons. The company, for one; you’re never alone when you’ve got worms, after all. And the excuse that you’re eating for two (or two hundred) is always useful at big dinners. And the day that “Hey, I have worms! Let’s kiss!” stops being an effective icebreaker at parties is the day I’m not interested in living any more.

And yet there will always be naysayers. Killjoys and health nuts, for whom no pro-worm argument seems to be adequate. Hey, worm-haters, guess who had worms. Your great grandparents, probably, and were they bad people?

In any case, the obstinate will soon have an even harder time ignoring the cold, hard face of reason.

It has been observed that in tropical regions where infection by a particular type of parasitic worm is common, auto-immune diseases—like rheumatoid arthritis, multiple sclerosis, and type-1 diabetes—are particularly uncommon. Scientsts, clever devils that they are, have figured out why this is.

Certains type of parasitic nematodes (nematodes are round worms) are capable of causing filariasis in their hosts. Among other things, filariasis causes elephantiasis. Elephantiasis for those of you blocking out memories, elephantiasis (often misheard as “elephantitis”) is characterized by severe “thickening of the skin and underlying tissues,” occurring most often in the legs and genitals. And it’s pretty gross.

It isn’t in the worm’s interest, as it were, to have this massive inflammatory response in its host, so it secretes a large molecule called “ES-62.” ES-62, according to researchers, seems to act like a “thermostat” for inflammation. With no known adverse health effects, ES-62 reduces the inflammatory immune response that causes elephantiasis, as well as rheumatoid arthritis, while leaving intact the immune system’s other mechanisms for fighting infections.

Similar research has been done on parasitic schistosomes (blood flukes). Populations with high infection rates of certain schistosomes have a greatly reduced incidence of allergies and asthma, and the thought is that the blood flukes are also able to regulate their host’s immune response so that it ignores some irritants (like the flukes) but still doesn’t allow the body to become too sick.

Wild, huh?

So get yourself some worms, y’all. Foxy boys and girls can tell when you’re sneezing and limping (not attractive), but they can’t see the worms and blood flukes teeming through your system. So you decide.


A tapeworm: like a friend that will always be with you. A friend that's taller than you are. Living in your intestines.
A tapeworm: like a friend that will always be with you. A friend that's taller than you are. Living in your intestines.Courtesy Savadorjo
I just came across this tasty little item on A Chicago man recently passed a nine-foot-long tapeworm, which he believes to have gotten from undercooked salmon.

I’m not sure of the best way to express my feelings on this subject, so let’s just talk about tapeworms.

Tapeworms are, of course, parasitic flatworms. Humans can become infected with tapeworms by consuming food or water contaminated with the eggs or larvae of the worm. You might not think it, but whether one is infested with eggs or larva can make a big difference. If you accidentally eat the eggs, the larvae that hatch from them may migrate out of your intestines, and make little cystic homes in other parts of your body, like your lungs or liver. These cysts are both super gross, and super dangerous—you can die from them, and treatment is difficult. If, on the other hand, you unwittingly eat tapeworm larvae, it’s much more likely that the baby worm will snuggle up in your guts, and eat what you eat. This is super gross, and still pretty bad for you, and it’s best if you avoid it.

If you do get a tapeworm living in your intestines, as the man in the story did, you may suffer from nausea, diarrhea, abdominal pain, weakness, and loss of weight. Or you might not demonstrate any symptoms at all. But you’ll still have a huge worm living inside you.

There are a variety of tapeworm types that might infect you, including the beef tapeworm, the pork tapeworm, the dwarf tapeworm, and the fish tapeworm. Some tapeworms go through their whole lifecycle inside one host, developing from egg to larva to adult, while others attach themselves to the lining of the intestine, and others still allow themselves to be passed (into the toilet).

According to the Mayo clinic’s page on tapeworms, adult worms can grow up to fifty feet inside their hosts. So, all things considered, the Chicago guy should feel lucky.

Tapeworm eggs can be passed from one person to another via… stool… so be sure to wash your hands. Constantly.


It's probably not the worst day in this caterpillar's life: But it's the worst day it will remember.
It's probably not the worst day in this caterpillar's life: But it's the worst day it will remember.Courtesy The Agricultural Research Service
That’s a lie, really—If I suddenly discovered that I had the ability to lay eggs inside a living caterpillar, I would probably have myself sealed in a basement. An eternity of being bricked off in an alcove is probably preferable to an all-encompassing desire to stab an ovipositor into moth larvae.

Unless you’re a wasp. It seems that the world, in its unceasing attempts to gross us out, has come up with something new: a wasp that lays eggs in a caterpillar. That, obviously, is nothing remarkable—all sorts of things stick their offspring in other things. This wasp, however, turns the caterpillar into a zombie guardian of the wasp larvae as they hatch and crawl out of its body. Oh, man! What a trick!

So, the wasp larvae hatch (again, inside the body of the caterpillar), and then chew their way out of its body. Once they’re out, and doing…whatever it is parasitic wasp larvae do (Sega Genesis?), the caterpillar stops eating, remains close to the larvae, and uses its head as a club, thrashing its body to beat away any predators.

I’m sure that all the other little wasplings are super jealous of those who have huge zombie bodyguards, but, more than that, research has shown that zombie caterpillar bodyguards increase chances of larvae survival by 200%.

So, to refine my earlier statement, if I could turn caterpillars into zombie servants, I would. But not if it meant that I had to lay little JGordon eggs in them. Yuck. I don’t think that’s how I was born (although my mother has always been pretty vague on the subject, and my father always refused to discuss it at all).


A harmless bot fly: kind of cute, really.
A harmless bot fly: kind of cute, really.Courtesy Wikimedia Commons
Have you thrown up yet today?

Oh, you haven’t? That’s fine if you haven’t. Not even an issue, really.

Forget that. Let’s go and learn about science!

Have y’all heard of the bot fly? They’re a little gray fly, native to the Americas, and they’ve got the most fascinating life-cycle.

Just a second—it feels like there’s a tiny person with diarrhea camping out in my stomach. Sorry, that was totally unrelated.

Anyway, the bot fly has a remarkable life cycle, especially the bot fly species dermatobia hominis. Pupating in the soil, the adult d. hominis emerges after about a week, and sets out looking for a mate and a mosquito. Once the bot fly finds and catches a mosquito, surprisingly, it doesn’t hurt the captured insect at all. The fly just attaches its own eggs to the mosquito’s body.

Now, I know what you’re thinking—you’re thinking that this is going to be one of those bugs that lays its eggs in another insect and leaves it alive so that when the eggs hatch the new larva can eat the living host. Get that thought out of your head right now; it’s simply not the case.

Oh, man, I feel like I’m salivating a lot. And burping.

Anyway, now we have this mosquito giving bot fly eggs a friendly lift. The mosquito goes about its life, looking for a blood meal. When the mosquito finds a mammal to drink from (usually a monkey or a person in the case of d. hominis), the eggs hatch, and the itty-bitty bot fly larva drop off the mosquito on to its host. The larvas then crawl into the tiny hole conveniently provided by the mosquito, and make a little home for themselves. For the next eight weeks, they feed off the tissue under the skin of their host until they grow into a large grub, about three quarters of an inch long, ringed with strong, hooked barbs, which make extracting the larva quite difficult and painful. Once the eight weeks are up, they chew their way out of the skin, and drop to the ground, where they burrow into the dirt. And about a week later…an adult fly is born once again! Isn’t nature a miracle?

Wait! Don’t leave yet! I have something else for you: a video I like to call The miracle of (bot fly) birth. I can’t make you watch it, but you probably should.

Now I think I have to go lie down and take some deep breaths