Skip to comments.Hidden Epidemic:
Tapeworms Living Inside People's Brains
Posted on 05/19/2012 5:44:54 PM PDT by LibWhacker
A human brain overrun with cysts from Taenia solium, a tapeworm that normally inhabits the muscles of pigs.
Courtesy of Theodore E. Nash , M.D.
Theodore Nash sees only a few dozen patients a year in his clinic at the National Institutes of Health in Bethesda, Maryland. Thats pretty small as medical practices go, but what his patients lack in number they make up for in the intensity of their symptoms. Some fall into comas. Some are paralyzed down one side of their body. Others cant walk a straight line. Still others come to Nash partially blind, or with so much fluid in their brain that they need shunts implanted to relieve the pressure. Some lose the ability to speak; many fall into violent seizures.
Underneath this panoply of symptoms is the same cause, captured in the MRI scans that Nash takes of his patients brains. Each brain contains one or more whitish blobs. You might guess that these are tumors. But Nash knows the blobs are not made of the patients own cells. They are tapeworms. Aliens.
A blob in the brain is not the image most people have when someone mentions tapeworms. These parasitic worms are best known in their adult stage, when they live in peoples intestines and their ribbon-shaped bodies can grow as long as 21 feet. But thats just one stage in the animals life cycle. Before they become adults, tapeworms spend time as larvae in large cysts. And those cysts can end up in peoples brains, causing a disease known as neurocysticercosis.
Nobody knows exactly how many people there are with it in the United States, says Nash, who is the chief of the Gastrointestinal Parasites Section at NIH. His best estimate is 1,500 to 2,000. Worldwide, the numbers are vastly higher, though estimates on a global scale are even harder to make because neurocysticercosis is most common in poor places that lack good public-health systems. Minimally there are 5 million cases of epilepsy from neurocysticercosis, Nash says.
He puts a heavy emphasis on minimally. Even in developed nations, figuring out just how many people have the illness is difficult because it is easy to mistake the effects of a tapeworm for a variety of brain disorders. The clearest proof is the ghostly image of a cyst in a brain scan, along with the presence of antibodies against tapeworms.
The closer scientists look at the epidemiology of the disease, the worse it becomes. Nash and other neurocysticercosis experts have been traveling through Latin America with CT scanners and blood tests to survey populations. In one study in Peru, researchers found 37 percent of people showed signs of having been infected at some point. Earlier this spring, Nash and colleagues published a review of the scientific literature and concluded that somewhere between 11 million and 29 million people have neurocysticercosis in Latin America alone. Tapeworms are also common in other regions of the world, such as Africa and Asia. Neurocysticercosis is a very important disease worldwide, Nash says.
The alarming illness occurs when tapeworm larvae lose their way. Normally, Taenia solium has a life cycle that takes it from pigs to humans and back to pigs again. Adult tapeworms, living in the intestines of humans, produce up to 50,000 eggs apiece. The eggs are shed in the infected persons feces. Pigs swallow these eggs accidentally as they rummage for food on the ground. When the parasite eggs reach a pigs stomach, larvae hatch and burrow their way into the animals bloodstream. Eventually they end up lodged in small blood vessels, typically in the animals muscles. There they form cysts and wait until their host is eaten by a human. (Pork has to be undercooked for the tapeworms to complete their journey.)
But sometimes tapeworms take a wrong turn. Instead of going into a pig, the eggs end up in a human. This can occur if someone shedding tapeworm eggs contaminates food that other people then eat. When the egg hatches, the confused larva does not develop into an adult in the humans intestines. Instead, it acts as it would inside a pig. It burrows into the persons bloodstream and gets swept through the body. Often those parasites end up in the brain, where they form cysts.
The tapeworm larvae often get stuck in ventricles, or fluid-filled cavities, in the brain, sprouting grapelike extensions. In this way the worm actively cloaks itself from immune cells. Protected and well fed, its cysts can thrive there for years.
As a tapeworm cyst grows, it may push against a region of the brain and disrupt its function. It may get stuck in a passageway, damming the flow of cerebrospinal fluid. This impasse can cause hydrocephalus, or water on the brain, along with dangerously high pressure. A resulting brain hernia can result in stupor, coma, or death.
If a tapeworm cyst doesnt cause big troubles, it may go unnoticed for its entire life. Eventually a tapeworm cyst that cant move on to its adult stage will die; this signals the hosts immune system, eliciting a powerful attack and bringing its covert deception to an end. In many cases, the immune cells swiftly annihilate the revealed cyst, but often damage occurs. The immune systems attack on the cyst can cause the surrounding brain tissue to swell with inflammation. For reasons unknown, a calcified cyst can keep triggering these immune reactions for years after the parasites death.
Although any cyst in a susceptible area of the brain can cause seizures, those lodged near regions that issue commands to muscles can trigger violent convulsions. One of Nashs patients suffered from tapeworm cysts that twisted around his brain stem. After the tapeworms died, the inflammation that followed was so severe it put the man in a coma.
Thirty or 40 years ago, these patients just died. Surgeons would go in and see this mess and couldnt do much, Nash says. Fortunately, the situation is improving. Even his comatose patient woke up and, after a few years of off-and-on treatment, completely recovered. Now the guy is doing quite well.
Breaking the Cycle
A great step forward came in the mid-1980s when praziquantel, the first drug able to kill tapeworm larvae in the brain, became widely available. But praziquantel proved too effective. It not only kills tapeworms but also triggers an immune reaction that causes brain swelling. Paradoxically, we produce the disease we want to treat, Nash says.
Over the years Nash and others refined the treatment by combining praziquantel with other drugs that tamp down the immune system. It is far from a perfect solution, though. Sometimes the immune system still overreacts, requiring years of care for seizures and other symptoms. And immune-suppressant drugs like steroids have side effects of their own.
The hunt for better drugs to fight neurocysticercosis is not an easy process. The best way to test potential medicines on tapeworms is to get living cysts out of infected pigs. Nash and his colleagues recently set up a lab in Peru, where infected pigs are abundant, to do just that.
Although finding a better cure is important, Nash is more interested in preventing tapeworms from getting into human brains in the first place by breaking their life cycle. A favored strategy is identifying people who have adult tapeworms in their bodies and giving them drugs to kill the parasites. It is also possible to vaccinate pigs so that they destroy tapeworm eggs as soon as they ingest them.
None of this is rocket sciencewhich makes Nash all the more frustrated that so little is being done. I see this as a disease that can be treated and prevented, he says. But there are precious few resources available for treatment and little recognition of the problem. All of this seems to be very feasible, but nobody wants to do anything about it.
(In Before The Zombie Jokes)
Awesome. The perfect dinner-time post!
Is it prevalent in Congresspersons?
Geez, a hypochondriac’s nightmare, I should know
1,500-2,000 in the US?
It is amazing when they look for the rarest medical problems and label them ‘epidemics’.
There's a clue that even House could believe.
Tell the cook you want that pork chop cooked to a crisp!
Praziquantel? Wasn’t he in the NBA?
I’m so glad my brain doesn’t look like that. And, yes, I know what my brain looks like.
Dont eat pig meat people...they are also big carriers of MRSA...
Mmmmmm... Pork is worth the risk!
You’re thinking of Quetzal Coatl. Played for the Knicks.
They even have his statue in San Jose:
1,500 to 2,000 cases in the USA is hardly an Epidemic
monsters inside me
Yeah, I’m going to quit eating bacon because your opinion means so much to me.
Thanks for telling me what to do.
I’m feeling a sudden urge to chug some veterinary de-wormer.
Common in Kenya, it would appear.
Pork, it’s the meat of kings!
That’s why Obamacare was invented. Liberals are eaten up with brain worms.
I’ll have mine with a side order of tapeworm kill.
Curley: I'll have burnt toast and a rotten egg.
Moe: Why are you ordering burnt toast and a rotten egg?
Curley: It serves my tape worm right!
That was my decision years ago. In fact I stopped eating ALL mammals.
Makes me very, very thankful that I’ve been a vegetarian for more than 40 years and never, ever eat out.
Ever since I saw tapeworms in formaldehyde in 10th grade biology class I’ve hated to eat pigs.
I'm feeling queasy.
Ditto. In reality, all we need to do is make sure pork is cooked thoroughly.
Arggh! Don’t say that. You know what we had tonight? Takeout tacos from this Mexican joint down the street. I don’t know where he gets his pork, but it doesn’t look like anything we can get from Safeway.
I just had pork chops for dinner, ewwwww.
Red Cross says I cant donate blood any more because I lived in Germany for 3 years and possibly came in contact with Mad Cow.
In my cynicism I throw back that I was only addicted to the Jagerschitzel.
Now this??!!?? Im a goner fer sure!
Yeah but that stray cat problem you had a few years back has worked itself out nicely.
Lev 11:7 and the swine, though it divides the hoof, having cloven hooves, yet does not chew the cud, is unclean to you.
Lev 11:8 Their flesh you shall not eat, and their carcasses you shall not touch. They are unclean to you.
I don’t know about you, but I’m eyeing that bottle of mezcal in the liquor cabinet.
“There’s a clue that even House could believe.”
Good call. The pilot episode of House was... tapeworm cysts in the brain.
Lol! Wow, was that seizure I just had caused by the worms or your spider?
I was just thinking of that very same joke; I think I first heard it in the late 1960s. About when did you first hear it from your dad?
Lol, nicely captures the parasite’s mind.
I thought so too,just cook pork thoroughly
Re post #25.
Say hello to my lil friend.
Ive been hankerin for some snakebite, my own self, for a few days now.
“Is it prevalent in Congresspersons?”
Now, we have full explanation for the idiocies of Harry Reid, Nancy Pelosi, Bawney Fwank, Babwa Boxer, and of course, the Obamaloon.
Looks like a giant coprolite created by a creature with a very high fiber diet.
What’s it supposed to actually be, a coiled snake?
Indeed it is - but I now feel a bit like those wolves in that old Far Side cartoon, as they surveyed the pig pen and proclaimed: "I say we do it, and trichinosis be damned!"
Vincent: Want some bacon?
Jules: No man, I don’t eat pork.
Vincent: Are you Jewish?
Jules: Nah, I ain’t Jewish, I just don’t dig on swine, that’s all.
Vincent: Why not?
Jules: Pigs are filthy animals. I don’t eat filthy animals.
Vincent: Bacon tastes gooood. Pork chops taste gooood.
Jules: Hey, sewer rat may taste like pumpkin pie, but I’d never know ‘cause I wouldn’t eat the filthy ....... Pigs sleep and root in s.... That’s a filthy animal. I ain’t eat nothin’ that ain’t got sense enough to disregard its own feces.
Vincent: How about a dog? Dogs eats its own feces.
Jules: I don’t eat dog either.
Vincent: Yeah, but do you consider a dog to be a filthy animal?
Jules: I wouldn’t go so far as to call a dog filthy but they’re definitely dirty. But, a dog’s got personality. Personality goes a long way.
Vincent: Ah, so by that rationale, if a pig had a better personality, he would cease to be a filthy animal. Is that true?
Jules: Well we’d have to be talkin’ about one charming .... pig. I mean he’d have to be ten times more charmin’ than that Arnold on Green Acres, you know what I’m sayin’?
Absolutely. And the illegals bring those tapeworms here to this country.
What is interesting is tapeworms lay eggs that get into the bloodstream. Those eggs travel to the brain and get encapsulated and present as a brain tumor.
Guess who is paying for the neurosurgery.