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.
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. That’s 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 can’t 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 patient’s 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 people’s intestines and their ribbon-shaped bodies can grow as long as 21 feet. But that’s just one stage in the animal’s life cycle. Before they become adults, tapeworms spend time as larvae in large cysts. And those cysts can end up in people’s 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.
Cyst Attack
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 person’s feces. Pigs swallow these eggs accidentally as they rummage for food on the ground. When the parasite eggs reach a pig’s stomach, larvae hatch and burrow their way into the animal’s bloodstream. Eventually they end up lodged in small blood vessels, typically in the animal’s 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 human’s intestines. Instead, it acts as it would inside a pig. It burrows into the person’s 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 doesn’t cause big troubles, it may go unnoticed for its entire life. Eventually a tapeworm cyst that can’t move on to its adult stage will die; this signals the host’s 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 system’s 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 parasite’s 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 Nash’s 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 couldn’t 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 science—which 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.”
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.
Scary
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.
We’ve had numerous brain damaged Democrats who retained their seats in office (and perks) for years.
Now this?
This is alarming..
Have another plate of pork.
Wow! Now we know what ‘Lunch box’ Joe Biden’s problem is.
Ben Day’s unwanted passenger
Warning: This story contains graphic details
Individual NRC rankings leader Ben Day never intended to contest the overall win the SRAM Tour of the Gila. Instead, the Aussie hoped to help Fly V Australia teammates Phil Zajicek and Jai Crawford test themselves against world-class climbers such as Levi Leipheimer and Tom Danielson. But Day hoped that in the process he could post some strong results, particularly in Friday’s stage-3 time trial.
Day’s ambitions for Gila changed, however, last Saturday after he extracted a four-foot tapeworm from his anus while on the toilet. Following the extrication, which he described as “an out of body experience,” Day suffered vomiting and diarrhea for several days, nearly knocking him out of Gila altogether. He started the race in hopes of adding a few points to his NRC lead, but discovered quickly on the opening stage that he hadn’t yet recovered from severe dehydration.
Day claims he had no clue he was hosting a parasite until he went to the toilet last Saturday prior to a training ride and had diarrhea.
“I had a dangler,” Day said. “I had to pull it out. It was three or four feet long, at least. It was white and flat, like a ribbon. I just told myself not to think about it, just do it, just get it done. I honestly don’t know if I got it all or it just snapped off. The thought of it still makes me cringe.”
After the extrication Day headed out on a training ride. When he returned, he didn’t feel like eating, he said. Instead, slumped on the couch, nausea kicked in, and soon he was “throwing up everything I had for breakfast.” Fever followed as Day spent the night on the toilet, dripping with sweat.
Day put in a call with his team doctor, and is now taking a pair of medications — Albendazole, which starves the parasite, and Praziquantel, which attempts to kill the parasite immediately. He was told that, judging from the size of the tapeworm, it had probably taken residency in his intestinal tract for “at least a few years,” meaning he won the overall at this year’s San Dimas and Redlands Classic stage races while infested.
“Apparently tapeworms don’t commonly cause any noticeable symptoms,” Day said. “They just attach themselves to your stomach lining and absorb the nutrients you are trying to eat. I can remember a few times when things didn’t feel right, but nothing substantial. It never seemed to bother me until last Saturday.”
Though he estimated that he went to the toilet “10-15 times a day” between Saturday and Thursday, Day decided to give it a go at Gila, which started Wednesday. Day finished Wednesday’s stage 15 minutes behind Leipheimer.
“Whenever I would eat food I felt like I was going to have diarrhea and throw up at the same time, just massive nausea,” Day said. “But I was feeling so good from the previous week, I knew I had good form, I had good training, all the (power data) was great. I was just hoping it was something I could get on top of, and get over. I didn’t realize until halfway through Wednesday’s stage that I really wasn’t that good.”
Day has spent the rest of the race taking it easy, helping the team as he can. He finished 61st on the time trial, 4:30 off the winning time. Zajicek, his teammate, sat fourth on GC heading into Saturday’s criterium.
“There’s no point in trying to hurt myself now, it’s best just to recover a bit and get ready for the Joe Martin Stage Race,” Day said, adding that he doesn’t know how he should expect to wait for a full recovery. “I’ve read that some people have to take medication for up to six months. We’re being aggressive by taking both of these medications at the same time. I’m hoping it’s out of my system really quickly.”
True to his laidback Aussie personality, Day has kept a lighthearted attitude about the experience, disclosing graphic details about the experience and even dubbing the parasite “William the Worm.”
“He was a big part of my life for a few years, apparently,” Day said.
This sounds like it should be easy to treat, but that it is not being detected.
How does the tapeworm inhabit the brain in the first place? Eating meat that it not thouroughly cooked?
LOL!
You and me, both. Besides, pork ain’t kosher.
8-track or cassette?
Thanks LibWhacker.
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