Human Culture Shaped by Cat Parasite?

I saw a blurb somewhere on this the other day, and it kept nagging at the corner of my mind until I went and tracked down the story today. I'm curious if there is anything concrete to it, or if it is out in the realm of science fiction.

Mind Control by Parasites

Half of the world's human population is infected with Toxoplasma, parasites in the body—and the brain. Remember that.

Toxoplasma gondii is a common parasite found in the guts of cats; it sheds eggs that are picked up by rats and other animals that are eaten by cats. Toxoplasma forms cysts in the bodies of the intermediate rat hosts, including in the brain.

Dr. E. Fuller Torrey (Associate Director for Laboratory Research at the Stanley Medical Research Institute) noticed links between Toxoplasma and schizophrenia in human beings, approximately three billion of whom are infected with T. gondii:

Toxoplasma infection is associated with damage to astrocytes, glial cells which surround and support neurons. Schizophrenia is also associated with damage to astrocytes.
Pregnant women with high levels of antibodies to Toxoplasma are more likely to give birth to children who will develop schizophrenia.
Human cells raised in petri dishes, and infected with Toxoplasma, will respond to drugs like haloperidol; the growth of the parasite stops. Haloperidol is an antipsychotic, used to treat schizophrenia.

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Half the world's population infected with a parasite that causes schizophrenia? That would explain alot, especially these days. There is another article on the same website that takes things even further, postulating that human history may have been shaped by interactions between such parasites and their human hosts.

A parasitic microbe commonly found in cats might have helped shape entire human cultures by manipulating the personalities of infected individuals, according to a new study.

Infection by a Toxoplasma gondii could make some individuals more prone to some forms of neuroticism and could lead to differences among cultures if enough people are infected, says Kevin Lafferty, a U.S. Geological Survey scientist at the University of California, Santa Barbara.

In a survey of different countries, Lafferty found that people living in those with higher rates of T. gondii infection scored higher on average for neuroticism, defined as an emotional or mental disorder characterized by high levels of anxiety, insecurity or depression.

His finding is detailed in the Aug. 2 issue of the journal for Proceedings of the Royal Society, Biology.

Other studies have also found links between the parasite and schizophrenia. T. gondii infection is known to damage astrocytes, support cells in the brain that are also affected during schizophrenia. Pregnant women with high levels of antibodies to the parasite are also more likely to give birth to children who will develop the disorder.

In light of such studies, Lafferty wondered whether high rates of T. gondii infection in a culture could shift the average personality of its individuals.

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I've often wondered if the alien invasion was internal, with the human race, rather than the earth, as host. Schistosomes and other weird worms with multiple life stages give me the creeps. Is this thing some kind of biological implant, a nanotech device from the ancient past? Worms and spiders and snails, inside!

Get me some Praziquantil, quick! For me and my cat.

Reminds me of everyone's favorite sexually transmitted disease: syphilis. I am totally ripping off my favorite movie of all time, "The Hunt for Red October," when I say:

Syphilis, Icarus Rising, an STD. A bacterium that knows a hell of a lot more about the human nervous system, then you do. - Me

Anyway, the idea that an alien invasion would be more subtle than a full invasion is at least as old as the X-Files. My take on it has always been that the only viable way to spread our genetic seed over the universe is in the form of specially crafted viruses. The end goal would be a forced million-year evolutionary cycle resulting in intelligent life similar to their human ancestors. In their minds would be mysterious arcane knowledge in the form of genetic memory; a mass delusion of a common history the evolved species never themselves experienced.

Jon

A whale, Seaman Beaumont, a whale. A marine mammal that knows a hell of a lot more about sonar, then you do. -Seaman Jones

[edit on 8.6.2006 by Voxel]

The only flaw with this idea is that half the world's population isn't infected with toxoplasma gondii. It seems that in several studies, only 30% of the population tested showed antibodies, which means they had AT ONE TIME been infected or were at that time infected. So if half of those testing positive for antibodies were infected, that's only 15% of the population.

Mariella

I didn't see a link or anything else but your word for the claim that the infection rate is only 15%. Maybe you could provide a little more background.

Perhaps this cat-borne mind alterning parasite answers a few mysteries...especially the question of who first came up with the concept of the 'cat-flap', and why we believe that 8 out of 10 cats are capable of expressing a preference in marketing surveys

First, I never said the infection rate was exactly 15%. I said that less than 30% of people tested showed antibodies, which means not all of them had an active infection, I just guesstimated with 15%. Either way, no where NEAR 50% of people have an active infection. Here are some sources:

www.cdc.gov...
www.ncbi.nlm.nih.gov...
www.sma.org.sg...

I'm going to go out on a limb and say that since several medical studies showed the same results, that is, roughly 15-20% infection rates rather than 50% as you suggested, it's actually 15-20%.

Mariella

Regardless of whether a person has an active infection or not, they could still have the cyst activity and be serving as a host for the organism. All I did was ask you to provide a link to back up your claim on infection rates, and I used the 15% figure you quoted without any substantiation on your part whatsoever.

If you look closely at my opening post you will see that I am not claiming the article as fact, but presenting the information for discussion and review.

I believe it may be in the medical establishment's vested interest to underreport these statistics so they can call these cysts cancerous and/or do more research at patient and taxpayer expense.

If you have a toxiplasmotic cyst, you will show an elevated eosinophil count. This is basic medicine. Come now, do some research before putting on your tinfoil hat.

Mariella

So again, we are back at the 30% number of those who may have been infected at one time. Throwing unsupported statistics around and talking down to other members is not the way to increase your credibility.

Even at a 30% rate of once and current infection, we are talking about roughly 2 billion people, and with concentrations specific to regions with high rates of feline domesticity, that could be a significant portion of a given culture, possibly enough, given the propensity of carriers to exhibit symptoms of schizophrenia, to sway cultural behavior norms significantly.

Originally posted by Icarus Rising
So again, we are back at the 30% number of those who may have been infected at one time. Throwing unsupported statistics around and talking down to other members is not the way to increase your credibility.

Even at a 30% rate of once and current infection, we are talking about roughly 2 billion people, and with concentrations specific to regions with high rates of feline domesticity, that could be a significant portion of a given culture, possibly enough, given the propensity of carriers to exhibit symptoms of schizophrenia, to sway cultural behavior norms significantly.

No, we are not at the 30% number. The CREDIBLE stats I provided show 15-20%. Also, I think it's hard to prove "regions of high feline domesticity" are a link, considering feral cats also spread this parasite. I highly doubt you could draw a conclusive link between cat owners and schizophrenia. Can you just admit that it was an interesting though that didn't work out in reality and take off your tinfoil hat? Not everything is a conspiracy, you know. Stuff like this is why very few people are taken seriously when they bring forward well supported conspiracies.

Mariella

Dr Joanne Webster from Imperial College London, and lead researcher said: "Although we are certainly not saying that exposure to this parasite does definitely lead to the development of schizophrenia, this and previous studies do show there may be a link in a few individuals, providing new clues for how we treat toxoplasmosis and schizophrenia."

Previous epidemiological and neuropathological studies have indicated some cases of schizophrenia may be associated with environmental factors, such as exposure to the parasite T. gondii. At the same time several of the medications used to treat schizophrenia have been shown to posess anti-parasitic and in particular anti-T.gondii properties. This led the authors to suspect that the anti-psychotic activity of these medications may be due to their inhibition of these parasites.

link

In truth, it is blind allegiance to preformed opinions that is more of an impediment to the advancement of knowledge than any half-baked theory I could come up with on my own.

To test his hypothesis, Lafferty looked at published data on cultural dimensions and average personalities for different countries. The countries examined also kept records of the prevalence of T. gondii antibodies in women of childbearing age. Countries with high prevalence of T. gondii infection also had higher average neuroticism scores.

"There could be a lot more to this story," Lafferty said. "Different responses to the parasite by men and women could lead to many additional cultural effects that are, as yet, difficult to analyze."

Remember, I am saying maybe, you are saying definitively not.

No where in those articles does it suggest that 50% of people in the world are infected, nor does it suggest that people who own cats or live near domestic cats are at a higher risk. What it DOES say, however, it that women of childbearing age show a higher prevalence, which can be explained easily: women who are pregnant or have just completed a pregnancy have a lapse in adaptive immunological cells. This is due to the fact that their bodies were compensating for the infants lack of adpative cells. This would most certainly allow a less common parasite to infect them. Again, though, the articles you present stated they tested positive serologically, which means antibodies, and suggests that they AT ONE TIME had an infection, not necessarily an active, current one. It could have been 5 years ago, and the parasite has since been flushed out, but they will always test positive on antibody tests. This is due to memory B cells.

Please, please PLEASE for the love of god and everything holy, read your own articles and do some research before suggesting doctors are purposely hiding the "real cause" of schizophrenia. You do that, and I will take a nicer tone with you. I'm just fed up with people who work themselves into a frenzy all because they don't understand the most basic of concepts regarding the "research" they found.

Mariella

Here is a question to clear something up.

What percentage of the population is believed to have schitzophrenia?

From www.schizophrenia.com :

As far as current scientific understanding goes, the symptoms of schizophrenia seem to be the result of multiple genetic and environmental factors. Within the general population, an individual has a 1% chance of developing schizophrenia. For siblings of people diagnosed with schizophrenia, the risk increases to about 9%.

www.schizophrenia.com...

Emphasis my own.

Mariella

Please, please PLEASE for the love of god and everything holy,

I have seen this statement from you ad nauseum, and it does nothing to add to the content or correctness of your posts.

Go ahead, keep stroking yourself, and have a jolly good time at it.

Half of the world's human population is infected with Toxoplasma, parasites in the body—and the brain. Remember that.

Dr. E. Fuller Torrey (Associate Director for Laboratory Research at the Stanley Medical Research Institute) noticed links between Toxoplasma and schizophrenia in human beings, approximately three billion of whom are infected with T. gondii:

Scientists estimate that the parasite has infected about 3 billion people, or about half of the human population.

The tone you take reflects much more on you than it does on me, and trying to blackmail me into retracting speculation by offering to take a nicer tone is par for your haughty course.

Careful reading will show this study focuses not only on schizophrenia, but neuroticism in general, something our good resident doctor may have failed to take into acount.

In a survey of different countries, Lafferty found that people living in those with higher rates of T. gondii infection scored higher on average for neuroticism, defined as an emotional or mental disorder characterized by high levels of anxiety, insecurity or depression.

Saying a parasite is the cause of neurotocism, which is a general term for pretty much any emotional/personality effecting neurological condition, ranging from massive blunt trauma to genetic alterations, is the same as saying standing next to someone with the flu is the cause of all flu cases. It may cause a small portion, sure, but is most certainly not the most prevalent cause.

Mariella

Actually, the connection between cats and schizophrenia has been floating around for at least twenty years. I'm not sure, but I think Fuller Torrey first postulated this theory.

Schizovirus

Cats and Schizophrenia

Originally posted by GradyPhilpott
Actually, the connection between cats and schizophrenia has been floating around for at least twenty years. I'm not sure, but I think Fuller Torrey first postulated this theory.

Schizovirus

Cats and Schizophrenia

Yes, the CONNECTION has, but Icarus' idea that areas with high "domestic cat" rations, has not, unfortunately.

The truth of the matter is, less than 1% of the population has schizophrenia, and more than 1% owns cats. It's much more likely that feral cats are carriers, I would imagine, anyways.

Mariella

T. gondii infects both wild and domestic cats, but it is carried by many warm-blooded mammals.

I'm not sure how much human contact feral cats have, being feral and all, but cats that are adopted (or in my case, just took up residence) from who knows where, may be a factor.

Still not sure that parasites can manipulate the behavior of host organisms? Consider these other cases:

The lancet fluke Dicrocoelium dendriticum forces its ant host to attach to the tips of grass blades, the easier to be eaten. The fluke needs to get into the gut of a grazing animal to complete its life cycle.

The fluke Euhaplorchis californiensis causes fish to shimmy and jump so wading birds will grab them and eat them, for the same reason.

Hairworms, which live inside grasshoppers, sabotage the grasshopper's central nervous system, forcing them to jump into pools of water, drowning themselves. Hairworms then swim away from their hapless hosts to continue their life cycle.

This isn't my idea, it is my speculation based on the two articles I am attempting to discuss here.

"There could be a lot more to this story," Lafferty said. "Different responses to the parasite by men and women could lead to many additional cultural effects that are, as yet, difficult to analyze."

Lafferty thinks that climate could be an important factor in determining which human populations are infected by T. gondii. The parasite's eggs can survive longer in humid, low-altitude regions, especially at mid latitudes that have infrequent freezing and thawing.

Other factors could also influence infection rates, including how a culture's attitudes about having cats as pets and the hygiene practices of its people.

Peace to you, Mariella, and my apologies for any affront to you from my comment about doctors hiding root causes of schizophrenia.