Human host manipulation

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  • Thread starter Evo
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  • #1
Evo
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I've been reading about parasitic host manipulation and was amused by the section on T. gondii (cat poop parasite) and it's effects on human behavior, especially on women.

Look what the cat dragged in: do parasites contribute to
human cultural diversity?

Kevin D. Lafferty∗

In stark contrast, infected women are more likely to
score themselves as warm-hearted, easy-going, con-
scientious, persistent, insecure and moralistic (Flegr et
al., 2000). Infected women are also more likely to have
many friends and romantic partners and like to shop for
clothes.
Both men and women are more prone to guilt
when infected. Personality changes are greater in indi-
viduals that have had infections for a long time, helping
to discredit the hypothesis that personality determines
exposure risk. Perhaps the most dangerous thing about
latent T. gondii is that it slightly reduces the ability to
focus on a task (Havlicek et al., 2001). This may ex-
plain why infected people are nearly three times more
likely to crash their cars (Flegr et al., 2002).
page 280

http://www.lifesci.ucsb.edu/eemb/labs/kuris/pubs/Lafferty_05_BP.pdf

I want to add more to this for discussion, but wanted to get this out to see if anyone else has an interest.
 

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  • #2
lisab
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Holy cat crap, that's really amazing :surprised:! Really makes me wonder how many other parasites are influencing human behavior.
 
  • #3
DaveC426913
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There's a Leno punchline in here...
 
  • #4
rhody
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Infected women are also more likely to have
many friends and romantic partners and like to shop for
clothes. Both men and women are more prone to guilt
when infected. Personality changes are greater in individuals
that have had infections for a long time, helping
to discredit the hypothesis that personality determines
exposure risk. Perhaps the most dangerous thing about
latent T. gondii is that it slightly reduces the ability to
focus on a task (Havlicek et al., 2001). This may explain
why infected people are nearly three times more
likely to crash their cars (Flegr et al., 2002).
Modern pharmaceuticals provide a range of popular
I have a nagging question, is there a scientific test you can take to confirm diagnosis, and if positive, what can you do to rid yourself of the little buggers.

I am having a DaveC moment, second guessing myself, the paper says this is more prevalent in the Northeast, and second, I regularly scoop and place in plastic cat doo doo, and wash hands well after I do. It gives one pause. Sorry Dave, I had too, lol.

Rhody...
 
  • #5
Evo
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I have a nagging question, is there a scientific test you can take to confirm diagnosis, and if positive, what can you do to rid yourself of the little buggers.

I am having a DaveC moment, second guessing myself, the paper says this is more prevalent in the Northeast, and second, I regularly scoop and place in plastic cat doo doo, and wash hands well after I do. It gives one pause. Sorry Dave, I had too, lol.

Rhody...
Yes, there is a test to confirm it. I have a feeling I have it. I grew up in Houston, TX (moist warm), had cats all of my life.

Seems T. gondii may also trigger schizophrenia. http://www.cdc.gov/ncidod/eid/vol9no11/03-0143.htm
 
  • #6
rhody
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Yes, there is a test to confirm it. I have a feeling I have it. I grew up in Houston, TX (moist warm), had cats all of my life.

Seems T. gondii may also trigger schizophrenia. http://www.cdc.gov/ncidod/eid/vol9no11/03-0143.htm
clinical trials are under way of antimicrobial drugs with anti-Toxoplasma activity, such as trimethoprim-sulfamethoxazole and azithromycin, as adjunctive treatment for persons with schizophrenia in double-blind trials. These studies may lead to new methods for the treatment of schizophrenia and other psychiatric disorders that may be associated with Toxoplasma and related organisms.
Evo,

From your link, funny, my Mom, who passed this July, had schizophrenia, and had multiple failures in delivering children, the main way infection occurs is from exposure to undercooked meat, and cat feces. We will never know in my Mom's case, rest her soul, but it certainly could have been one of a number of possibilities that triggered it.

How did you come across this insight in the first place ?

Rhody...
 
  • #7
Evo
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Evo,

From your link, funny, my Mom, who passed this July, had schizophrenia, and had multiple failures in delivering children, the main way infection occurs is from exposure to undercooked meat, and cat feces. We will never know in my Mom's case, rest her soul, but it certainly could have been one of a number of possibilities that triggered it.

How did you come across this insight in the first place ?

Rhody...
I'm reading "Survival of the Sickest" by Sharon Moalem, he has doctorates in neurogenetics, human physiology, and evolutionary medicine. Very easy read, Now I need more.

https://www.amazon.com/dp/0060889659/?tag=pfamazon01-20&tag=pfamazon01-20
 
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  • #8
rhody
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I'm reading "Survival of the Sickest" by Sharon Moalem, he has doctorates in neurogenetics, human physiology, and evolutionary medicine. Very easy read, Now I need more.

https://www.amazon.com/dp/0060889659/?tag=pfamazon01-20&tag=pfamazon01-20
Evo,

I hope you get to the root cause of it, if and when you do, and I have no doubt you eventually will, it will be a personal triumph for you. You deserve the credit for it. You may help others afflicted in the process as well.

Rhody...
 
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  • #9
Was watching National geographic channel the other night and heard about it. I have a stray with f.i.v. that's attached to my hip and was all worried.

Maybe I need to fetch an Idol of Bast for safe measure.
 
  • #10
lisab
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I wonder if the research compared cat owners who are infected with cat owners who are not infected. Otherwise, there would be a huge bias in the data, since I bet most people who are infected are cat owners. Then we'd just be seeing the difference between cat people and non-cat people.

God knows cat people are a bit different from the rest of the herd, due to the loving influence of our fe-lion masters.
 
  • #12
Q_Goest
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I take it this parasite doesn't affect the DNA in neurons? Just wondering if someone can confirm that.

Also,
i watched a video of Sapolsky talking about this parasite recently. it's really fascinating, especially the consideration about its impact on free will.

http://www.edge.org/3rd_culture/sapolsky09/sapolsky09_index.html
Thanks Proton Soup, nice find! Sapolsky says:
So what about humans? A small literature is coming out now reporting neuropsychological testing on men who are Toxo-infected, showing that they get a little bit impulsive. Women less so,
which seems to contradict the original article:
Infected women are also more likely to have many ... romantic partners and like to shop for clothes.
It seems to me, having many romantic partners and shoping for cloths are impulsive things that women are reportedly less likely to do when infected. I wonder how these two statements can be reconciled?
 
  • #13
Evo
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Perhaps this paper goes into more detail.

Decreased level of psychobiological factor novelty seeking and lower intelligence in men latently infected with the protozoan parasite Toxoplasma gondii Dopamine, a missing link between schizophrenia and toxoplasmosis?


Abstract

Toxoplasma gondii, a parasitic protozoan, infects about 30-60% of people worldwide. The latent toxoplasmosis, i.e. life-long presence of cysts in the brain and muscular tissues, has no effect on human health. However, infected subjects score worse in psychomotor performance tests and have different personality profiles than Toxoplasma-negative subjects. The mechanism of this effect is unknown; however, it is supposed that presence of parasites' cysts in the brain induces an increase of the concentration of dopamine. Here we search for the existence of differences in personality profile between Toxoplasma-positive and Toxoplasma-negative subjects by testing 857 military conscripts using a modern psychobiological questionnaire, namely with Cloninger's Temperament and Character Inventory (TCI). ANCOVA showed that Toxoplasma-positive subjects had lower Novelty seeking (NS) scores (P=0.035) and lower scores for three of its four subscales, namely Impulsiveness (P=0.049), Extravagance (P=0.056) and Disorderliness (P=0.006) than the Toxoplasma-negative subjects. Differences between Toxoplasma-negative and positive subjects in NS was inversely correlated with duration of toxoplasmosis estimated on the basis of concentration anti-Toxoplasma antibodies (P=0.031). Unexpectedly, the infected subjects had also lower IQ (P(2)=0.003) and lower probability of achieving a higher education (P(2)<0.0000). Decrease of NS suggests that the increase of dopamine in brain of infected subjects can represent a missing link between toxoplasmosis and schizophrenia.
http://www.ncbi.nlm.nih.gov/pubmed/12853170

For women

Changes in the personality profile of young women with latent toxoplasmosis.
Flegr J, Havlícek J.

Department of Parasitology, Faculty of Science, Charles University, Prague, Czech Republic. flegr@beba.cesnet.cz

Abstract
Latent toxoplasmosis is the most widespread parasite infection in developed and developing countries. The prevalence of Toxoplasma gondii infection varies mostly between 20 to 80% in different territories. This form of toxoplasmosis is generally considered to be asymptomatic. Recently published results, however, suggest that the personality profiles of infected subjects differ from those of uninfected controls. These results, however, were obtained on non-standard populations (biologists or former acute toxoplasmosis patients). Here we studied the personality profiles of 191 young women tested for anti-Toxoplasma immunity during gravidity. The results showed that the differences between Toxoplasma-negative and Toxoplasma-positive subjects exits also in this sample of healthy women. The subjects with latent toxoplasmosis had higher intelligence, lower guilt proneness, and possibly also higher ergic tension. The difference in several other factors (desurgency/surgency, alaxia/protension, naiveté/shrewdness, and self-sentiment integration) concerned changes in the variances, rather than the mean values of the factors.
http://www.ncbi.nlm.nih.gov/pubmed/10353191
 
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  • #14
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I've been reading about parasitic host manipulation and was amused by the section on T. gondii (cat poop parasite) and it's effects on human behavior, especially on women.

Look what the cat dragged in: do parasites contribute to
human cultural diversity?

Kevin D. Lafferty∗



page 280

http://www.lifesci.ucsb.edu/eemb/labs/kuris/pubs/Lafferty_05_BP.pdf

I want to add more to this for discussion, but wanted to get this out to see if anyone else has an interest.

3 words. Dawkin's extended phenotype.

It worths to read his book.
 
  • #15
rhody
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Evo ,

From this http://www.google.com/webhp?tab=mw#...&aql=&oq=&gs_rfai=&pbx=1&fp=573da4ec7e15bdf2":

I did a little digging and found, from this:http://www.medsci.org/v06p0135.htm" [Broken]
Toxoplasma gondii is an obligate intracellular protozoan responsible for infections throughout the world in a wide range of hosts including humans. Primary infection is usually subclinical but in some patients cervical lymphadenopathy or ocular disease can be present [1]. Infection acquired during pregnancy may cause severe damage to the fetus. In immunocompromised patients, reactivation of latent infection can cause life-threatening encephalitis [1]. T. gondii infection can be diagnosed indirectly with serological methods and directly by Polymerase Chain Reaction (PCR), hybridisation, isolation, and histology. Whereas indirect serological methods are widely used in immunocompetent patients, definitive diagnosis in immunocompromised people is mostly undertaken by direct detection of the parasite [1].

In our laboratory the diagnosis of infection by T. gondii is carried out by the detection of specific anti-Toxoplasma immunoglobulin (IgM and IgG) and to discriminate chronic from reactivated infection IgG avidity is also determined with VIDAS instrument (bioMerieux, France) [2]; moreover, the diagnosis of toxoplasmosis using bioptic tissue samples, blood, and urine is done detecting T. gondii DNA by a Real-Time PCR Fluorescence Resonance Energy Transfer (FRET), targeting T. gondii 529 bp repeated region [3]. The extraction of DNA is performed from samples by the MagNA Pure LC instrument (Roche Diagnostics, Mannheim, Germany), according to the manufacturer's specifications. For FRET PCR, we used the LightCycler Fast-StartDNA MasterPLUS Hybridization Probes Kit (Roche Diagnostics), as previously described [3].
The three cited articles at the top of the search list are for people who present with serious symptoms, and who are not asymptomatic as hopefully you are.

Finally: http://www.otterproject.org/atf/cf/{1032ABCB-19F9-4CB6-8364-2F74F73B3013}/23528.pdf"

This is nine pages and I will give it a close look tomorrow. A cursory scan indicates plenty of research scientists are on top of this from animal and human perspective.

Good hunting...

Rhody...
 
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  • #16
Evo
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Thanks Rhody, I read that up to 90% of the population of France may be infected. There's actually speculation that levels of infection within a population might explain the "oddities" of certain countries. Quite interesting.

http://emedicine.medscape.com/article/1204441-overview
 
  • #17
rhody
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http://fullmal.hgc.jp/tg/docs/toxoplasma.html" [Broken]

Here is another link I found and a couple of thumbnails from it.

The link I posted yesterday is very good, gives a 100 year history, and lists the tests for and symptoms, it appears a common thread is enlarged lymph nodes, and that depending where these little buggers take roost decide what type of symptoms the host will exhibit. I think it is wise to change the litter in Luna's litter box with disposable gloves from now on, then wash just to be safe.

This reminds me of lyme disease, we have a friend of the family whose daughter at 41 committed suicide from dealing with the symptoms of lyme for over a decade, which for some unknown reason were particularly intense in her case.

Rhody...

P.S. For some folks snakes, spiders give them the heebie jeebies. I don't mind saying these little buggers do, I guess it must be their insidious nature depending on what type of tissue they invade.

Edit P.P.S. Weird, I just noticed that Evo and I lasted posted exactly 12:00 hours apart, 11:06 pm and 11:06 am, how weird is that !! :uhh:
 

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  • #18
cobalt124
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Not qualified to contribute here, but thread is subscribed to because I need to know if my life and future happiness is dependent on the contents of my cats tray.
 
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  • #19
lisab
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Not qualified to contribute here, but thread is subscribed to because I need to know if my life and future happiness is dependent on the contents of my cats tray.
Not just you...at the rates of infection that are being reported, it looks like kitty poop can affect all of humanity! So, no fear, it's practically painless - come join us...:wink:
 
  • #20
Math Is Hard
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One of us... one of us.. one of us...
 
  • #21
cobalt124
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Probably happened years ago and it was so subtle I didn't realise. I've been cleaning up after cats on and off since I was a kid. Our two cats do seem to have been running the show for years, the human members of my family have been powerless to do anything about it. We recently got a dog and he seemed to be able to break the hold for a while. I don't know much about dog behaviour but over time his behaviour has become more cat like, and not alpha cat. It all seemed to change that day I found a funny pod in the greenhouse......
 
  • #22
DaveC426913
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You know, this reminds me very strongly of a sci-fi story I read long ago by Larry Niven.

I think it was called something like The Giving Disease.

The virus' effect on the host was to make them more altruistic. The virus' primary transmission vector was via blood donations.
 
  • #23
Evo
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The reason this affects humans is supposedly the similarity of human and rat brains. Makes you wonder about what is possible.

LOL @ cobalt124. We always kind of knew cats could control humans, now it's confirmed. (ok, it's a parasite, but cats are behind it)
 
  • #24
bobze
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This was from another topic about what could create "zombie humans" I posted on. I've been rather fascinated with toxo since I got involved in clinical microbiology.

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.

Since cats don't want to eat dead, decaying prey, Toxoplasma takes the evolutionarily sound course of being a "good" parasite, leaving the rats perfectly healthy. Or are they?

Oxford scientists discovered that the minds of the infected rats have been subtly altered. In a series of experiments, they demonstrated that healthy rats will prudently avoid areas that have been doused with cat urine. In fact, when scientists test anti-anxiety drugs on rats, they use a whiff of cat urine to induce neurochemical panic.

However, it turns out that Toxoplasma-ridden rats show no such reaction. In fact, some of the infected rats actually seek out the cat urine-marked areas again and again. The parasite alters the mind (and thus the behavior) of the rat for its own benefit.

If the parasite can alter rat behavior, does it have any effect on humans?
"[URL [Broken]
LiveScience Link[/URL]

Once in the rat, Toxo's goal is to then be eaten by a cat so it can be fruitful and multiply, but as I mentioned, this can only take place in the cat's gut. Toxo's goal is to get the rat eaten by a cat. Toxo could get the desired effect through a whole sort of seemingly obvious ways; e.g., Make the rat hard to run so it is easier for a cat to catch it. Instead it takes a far more interesting approach: Toxo generates cysts in the brain of the rat. These cysts take over the fear center of the brain, but specifically the fear of predators. Common fear sources for rodents (e.g., bright lights, open spaces, etc.) still operate perfectly well in an infected rat, but now they are no longer afraid of cat piss. That alone would be cool enough, but Toxo takes it one step further. When Toxo is going about futzing with the fear center of the brain it also goes into the sexual excitement part of the brain. It hijacks the incoming Fear of Cat Piss™ and instead diverts the signal to the Barry White™ center of the brain.

"Somehow, this damn parasite knows how to make cat urine smell sexually arousing to rodents, and they go and check it out. Totally amazing.
-Dr. Sapolsky
 
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  • #25
rhody
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Dave,

Here is another book in addition to the one you mentioned from the link: bobze provided:
Are parasites like Toxoplasma subtly altering human behavior? As it turns out, science fiction writers have been thinking about whether or not parasites could alter a human being's behavior, or even take control of a person. In his 1951 novel The Puppet Masters, Robert Heinlein wrote about alien parasites the size of dinner plates that took control of the minds of their hosts, flooding their brains with neurochemicals. In this excerpt, a volunteer strapped to a chair allows a parasite to be introduced; the parasite rides him, taking over his mind. Under these conditions, it is possible to interview the parasite; however, it refuses to answer until zapped with a cattle prod.
and more cases of parasites causing their hosts to be more vulnerable to other hosts, amazing...
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.
also
Half of the world's human population is infected with Toxoplasma, parasites in the body—and the brain. Remember that.
If this is true, why isn't the NIH taking notice, applying money time and research to study, educate the public and develop treatment for those infected ?

Rhody... :eek:

P.S. This stuff is creepy, makes me think that natural selection should expanded to include a sub category: intelligent natural selection, or insidious natural selection, or "I'll be back" natural selection.
 

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