Science > Political Ponerology: Macrosocial Evil
Return of the Puppet Masters
Laura:
Thought this one deserved its own thread.
Here is the post I wrote in "Ultra-terrestrials" which, I think, is very useful in terms of Ponerology as well.
--- Quote ---I found a strange article today that is going up on the Signs page which is so odd (IMO) that I thought I would share it here first:
--- Quote ---http://www.corante.com/loom/archives/20 … asters.php
by Carl Zimmer
Are brain parasites altering the personalities of three billion people? The question emerged a few years ago, and it shows no signs of going away.
I first encountered this idea while working on my book Parasite Rex. I was investigating the remarkable ability parasites have to manipulate the behavior of their hosts. The lancet fluke Dicrocoelium dendriticum, for example, forces its ant host to clamp itself to the tip of grass blades, where a grazing mammal might eat it. It's in the fluke's interest to get eaten, because only by getting into the gut of a sheep or some other grazer can it complete its life cycle. Another fluke, Euhaplorchis californiensis, causes infected fish to shimmy and jump, greatly increasing the chance that wading birds will grab them.
Those parasites were weird enough, but then I got to know Toxoplasma gondii. This single-celled parasite lives in the guts of cats, sheddding eggs that can be picked up by rats and other animals that can just so happen be eaten by cats. Toxoplasma forms cysts throughout its intermediate host's body, including the brain. And yet a Toxoplasma-ridden rat is perfectly healthy. That makes good sense for the parasite, since a cat would not be particularly interested in eating a dead rat. But scientists at Oxford discovered that the parasite changes the rats in one subtle but vital way.
The scientists studied the rats in a six-foot by six-foot outdoor enclosure. They used bricks to turn it into a maze of paths and cells. In each corner of the enclosure they put a nest box along with a bowl of food and water. On each the nests they added a few drops of a particular odor. On one they added the scent of fresh straw bedding, on another the bedding from a rat's nests, on another the scent of rabbit urine, on another, the urine of a cat. When they set healthy rats loose in the enclosure, the animals rooted around curiously and investigated the nests. But when they came across the cat odor, they shied away and never returned to that corner. This was no surprise: the odor of a cat triggers a sudden shift in the chemistry of rat brains that brings on intense anxiety. (When researchers test anti-anxiety drugs on rats, they use a whiff of cat urine to make them panic.) The anxiety attack made the healthy rats shy away from the odor and in general makes them leery of investigating new things. Better to lie low and stay alive.
Then the researchers put Toxoplasma-carrying rats in the enclosure. Rats carrying the parasite are for the most part indistinguishable from healthy ones. They can compete for mates just as well and have no trouble feeding themselves. The only difference, the researchers found, is that they are more likely to get themselves killed. The scent of a cat in the enclosure didn't make them anxious, and they went about their business as if nothing was bothering them. They would explore around the odor at least as often as they did anywhere else in the enclosure. In some cases, they even took a special interest in the spot and came back to it over and over again.
The scientists speculated that Toxoplasma was secreted some substance that was altering the patterns of brain activity in the rats. This manipulation likely evolved through natural selection, since parasites that were more likely to end up in cats would leave more offpsring.
The Oxford scientists knew that humans can be hosts to Toxoplasma, too. People can become infected by its eggs by handling soil or kitty litter. For most people, the infection causes no harm. Only if a person's immune system is weak does Toxoplasma grow uncontrollably. That's why pregnant women are advised not to handle kitty litter, and why toxoplasmosis is a serious risk for people with AIDS. Otherwise, the parasite lives quietly in people's bodies (and brains). It's estimated that about half of all people on Earth are infected with Toxoplasma.
Given that human and rat brains have a lot of similarities (they share the same basic anatomy and use the same neurotransmitters), a question naturally arose: if Toxoplasma can alter the behavior of a rat, could it alter a human? Obviously, this manipulation would not do the parasite any good as an adaptation, since it's pretty rare for a human to be devoured by a cat. But it could still have an effect.
Some scientists believe that Toxoplasma changes the personality of its human hosts, bringing different shifts to men and women. Parasitologist Jaroslav Flegr of Charles University in Prague administered psychological questionnaires to people infected with Toxoplasma and controls. Those infected, he found, show a small, but statistically significant, tendency to be more self-reproaching and insecure. Paradoxically, infected women, on average, tend to be more outgoing and warmhearted than controls, while infected men tend to be more jealous and suspicious.
It's controversial work, disputed by many. But it attracted the attention of E. Fuller Torrey of the Stanley Medical Research Institute in Bethesda, Maryland. Torrey and his colleagues had noticed some intriguing links between Toxoplasma and schizophrenia. Infection with the parasite has been associated with damage to a certain class of neurons (astrocytes). So has schizophrenia. Pregnant women with high levels of Toxoplasma antibodies in their blood were more likely to give birth to children who would later develop schizophrenia. Torrey lays out more links in this 2003 paper. While none is a smoking gun, they are certainly food for thought. It's conceivable that exposure to Toxoplasma causes subtle changes in most people's personality, but in a small minority, it has more devastating effects.
A year later, Torrey and his colleagues discovered one more fascinating link. They raised human cells in Petri dishes and infected them with Toxoplasma. Then they dosed the cells with a variety of drugs used to treat schizophrenia. Several of the drugs--most notably haloperidol--blocked the growth of the parasite.
So Fuller and the Oxford scientists joined forces to find an answer to the next logical question: can drugs used to treat schizophrenia help a parasite-crazed rat? They now report their results in the Proceedings of the Royal Society of London (press release). They ran the original tests on 49 more rats. Once again, parasitized rats lost their healthy fear of cats. Then the researchers treated the rats with haloperidol and several other anti-psychotic drugs. They found that the drugs made the rats more scared. They also found that the antipsychotics were as effective as pyrimethamine, a drug that is specifically used to eliminate Toxoplasma.
There's plenty left to do to turn these results into a full-blown explanation of parasites and personalities. For example, what is Toxoplasma releasing into brains to manipulate its hosts? And how does that substance give rise to schizophrenia in some humans? And even if the hypothesis does hold up, it would only account for some cases of schizophrenia, while the cause of others would remain undiscovered. But still...the idea that parasites are tinkering with humanity's personality--perhaps even giving rise to cultural diversity--is taking over my head like a bad case of Toxoplasma.
--- End quote ---
With the article, I have included a snippet of C's transcripts but here, I am going to include more of that particular session than I put on the news page:
--- Quote ---9 August 1997
Q: Next question: is there any relationship between the fact that Roger de Mortimer, the carrier of the last of the line of the Welsh kings, was the lover of Isabella of France, who was the daugther of Philip the Fair, the destroyer of the Templars, and the murder of Edward II, the first of the English Prince of Wales?
A: Templars are a setup, insofar as persecution is concerned. Remember your "historical records" can be distorted, in order to throw off future inquiries, such as your own.
Q: I know that. I have already figured that one out! But, it seems that no one else has made this connection. I mean, the bloodlines that converge in the Percys and the Mortimers are incredible!
A: You should know that these bloodlines become parasitically infected, harrassed and tinkered with whenever a quantum leap of awareness is imminent.
Q: Whenever a quantum leap...
A: Such as "now."
--- End quote ---
Now this last item above is the part that struck me. I had never figured that remark out at all in the 9 years since it was made and then, today, there is this strange article where I noticed (with a chill down my spine, I should add)
Given that human and rat brains have a lot of similarities (they share the same basic anatomy and use the same neurotransmitters), a question naturally arose: if Toxoplasma can alter the behavior of a rat, could it alter a human? Obviously, this manipulation would not do the parasite any good as an adaptation, since it's pretty rare for a human to be devoured by a cat. But it could still have an effect.
But, if the C's are correct, it may not be rare for humans to be eaten by "something" else. Which reminds me of a more recent item from the C's. The context was that we were discussing an individual who announced that she was dropping out of QFG because she had become "infected" psychically, you might say:
--- Quote ---6 August 2005
Q: (L) What's the deal with this K***** in the group?
A: Some people are born to serve, others are born to be served...
--- End quote ---
Thing is, if this article is correct, there may not be a lot of difference between being "infected" physically AND psychically!
But, I digress. In the first excerpt above, where the C's just casually dropped that comment about people being parasitically infected at times of potential quantum jumps in awareness, they then immediately introduced what was obviously a direct follow up. Now, notice, the C's don't very often voluteer stuff so when they do, I really pay attention. So here is the rest of that transcript:
--- Quote ---C's: Here is something for you to digest: Why is it that your scientists have overlooked the obvious when they insist that alien beings cannot travel to earth from a distant system???
Q: And what is this obvious thing?
A: Even if speed of light travel, or "faster," were not possible, and it is, of course, there is no reason why an alien race could not construct a space "ark," living for many generations on it. They could travel great distances through time and space, looking for a suitable world for conquest. Upon finding such, they could then install this ark in a distant orbit, build bases upon various solid planes in that solar system, and proceed to patiently manipulate the chosen civilizations to develop a suitable technological infrastructure. And then, after the instituting of a long, slow, and grand mind programming project, simply step in and take it over once the situation was suitable.
Q: Is this, in fact, what has happened, or is happening?
A: It could well be, and maybe now it is the time for you to learn about the details.
Q: Well, would such a race be 3rd or 4th density in orientation?
A: Why not elements of both?
Q: What is the most likely place that such a race would have originated from?
A: Oh, maybe Orion, for example?
Q: Okay. If such a race did, in fact, travel to this location in space/time, how many generations have come and gone on their space ark during this period of travel, assuming, of course, that such a thing has happened?
A: Maybe 12.
Q: Okay, that implies that they have rather extended life spans...
A: Yes...
Q: Assuming this to be the case, what are their lifespans?
A: 2,000 of your years. ... When in space, that is...
Q: And what is the span when on terra firma?
A: 800 years.
Q: Well, has it not occurred to them that staying in space might not be better?
A: No. Planets are much more "comfortable."
Q: Okay... imagining that such a group has traveled here...
A: We told you of upcoming conflicts... Maybe we meant the same as your Bible, and other references. Speak of... The "final" battle between "good and evil..." Sounds a bit cosmic, when you think of it, does it not?
Q: Does this mean that there is more than one group that has traveled here in their space arks?
A: Could well be another approaching, as well as "reinforcements" for either/or, as well as non-involved, but interested observers of various types who appreciate history from the sidelines.
Q: Well, SWELL! There goes my peaceful life!
A: You never had one!
Q: Well, I was planning on one! ...Any other comment?
A: You chose to be incarnated now, with some foreknowledge of what was to come. Reference your dreams of space attack.
Q: Okay, what racial types are we talking about relating to these hypothetical aliens?
A: Three basic constructs. Nordic, Reptilian, and Greys. Many variations of type 3, and 3 variations of type 1 and 2.
Q: Well, what racial types are the 'good guys?'
A: Nordics, in affiliation with 6th density "guides."
Q: And that's the only good guys?
A: That's all you need.
Q: Wonderful! So, if it is a Grey or Lizzie, you know they aren't the nice guys. But, if it is tall and blond, you need to ask questions!
A: All is subjective when it comes to nice and not nice. Some on 2nd density would think of you as "not nice," to say the least!!!
Q: That's for sure! Especially the roaches! Maybe we ought to get in touch with some of these good guys...
A: When the "time" is right.
Q: Speaking of time - any further comments?
A: Just pay attention to the signs, please! It is not helpful to place yourself in a vacuum of awareness.
Q: I don't think I am in a vacuum of awareness. Now, this Jason Dunlap is printing a lot of stuff that reminds me of the Hale Bopp incident. There is a lot being said about the sightings out in the SouthWest area. They are saying that this is the 'new' imminent invasion or mass landing. Can you comment on this activity?
A: Prelude to the biggest "flap" ever.
Q: And where will this flap be located?
A: Earth.
Q: When is it going to begin?
A: Starting already.
Q: Is this biggest flap going to be just a flap, or is it going to be an invasion?
A: Not yet.
Q: Not an invasion?
A: Yes.
Q: So, it will just be inciting people to frenzies of speculation...
A: Invasion happens when programming is complete...
Q: What programming?
A: See Bible, "Lucid" book, Matrix Material, "Bringers of the Dawn," and many other sources, then cross reference...
Q: Well, if something is fairly imminent, we are not gonna hae time to do all the things you have suggested that we do!
A: Yes you will, most likely.
Q: Well, we are supposed to build a pool, a maze, a psychomantium, to build a database, get a Nobel Prize... a LOT of things in the works here.... This just sort of takes the heart right out of me!
A: Not so!
--- End quote ---
[Note: our idea of WHY one would want a Nobel Prize has nothing to do with money, though we could sure use it, but rather with the fact that it helps one to advance their ideas with less resistance. Of course, we were thinking this back in 1997. We later became aware of what happened to Nobel Prize Winner Brian Josephson. He was accused of losing his mind or having a nervous breakdown when he wanted to address these topics seriously. So, since that event, we no longer think that getting a Nobel would make a hill of beans difference other than helping us pay for a few other researchers to collaborate and really make some progress!]
--- Quote ---Q: Well, are we going to have time to do all these things?
A: All these things were suggested for this reason, among others.
Q: So, all the things you have suggested are to get us ready for this event?
A: Yes.
Q: Well, we better get moving! We don't have time to mess around!
A: You will proceed as needed, you cannot force these events or alter the Grand Destiny.
Q: I do NOT like the sound of that! I want to go home!
A: The alternative is less appetising.
Q: Sure! I don't want to be lunch!
A: Reincarnation on a 3rd density earth as a "cave person" amidst rubble and a glowing red sky, as the perpetual cold wind whistles...
Q: Why is the sky glowing red?
A: Contemplate.
Q: Of course! Comet dust! Sure, everybody knows THAT! Wonderful!!! Anything further?
A: Stay tuned for all pertinent information.
--- End quote ---
I had to smile when re-reading this because of the reference to "being lunch." It really makes sense now...
Well, we don't know if any of this is true. As I've said many times, I've never seen what I would call an Ultraterrestrial except in a state that I wouldn't trust 100%. But the C's do have a really good record and we are daily witnessing the reality they predicted back in the early and mid 90s, right on up to the later 90s. I would also like to point out that Zimmer says:
--- Quote ---The question emerged a few years ago, and it shows no signs of going away.
--- End quote ---
That means that it is entirely possible that the C's were talking about such a possibility before it was ever looked at seriously by science.
But that doesn't mean that it is quite that simple as people being just physical food. It is also possible that such a parasitic infection could make a person just psychically susceptible to manipulation and control. Also notice the possible connection to shizophrenia. If this guy is right, half the population of this plane is infected. Those aren't very good odds. It will obviously take a lot of effort to overcome such a "frequency fence." Which brings me to another recent bit of transcript. Once again, we were discussing a particular individual and situation that was somewhat perilous.
--- Quote ---23 October 2004
Q: (H) When you referred to the manipulations with S****, what kind of manipulations were you referring to: internal or external?
A: Both but mostly external as in not directly perceivable in the environment.
Q: (L) Does that mean that if someone believes an illusion, that it leaves a hole in their defences?
A: More or less.
Q: (H) What is the major problem facing the group at the moment?
A: Stalling frequency waves.
Q: What can we do to help?
A: Requires will and knowledge. You share, they find will if it is there to find.
Q: (A) What kind of knowledge do we need to share?
A: That their lack of ability to see and do is due to deliberate stalling.
Q: (H) Can you elaborate?
A: They are in a frequency fence being stored for later food.
Q: (A) Are we also in a fence? Or is there a difference?
A: Quite.
Q: We are quite different?
A: Yes.
Q: What makes us different?
A: Seeing and doing.
Q: (L) Well, if we have a network, different people are doing different things. They are at different levels. Shouldn't we consider it in this light?
A: You were in as bad condition before leaving the USA, remember?
Q: (H) Can they overcome the stalling?
A: If they wish.
--- End quote ---
In short, it's not going to be easy. We see that from the fact that the people of the world are sleepwalking to disaster. But it CAN be done.
--- End quote ---
As to HOW overcoming the stalling frequency can be done, and that includes the paralysis and "anchoring" of psychophagic concepts in the mind of the normal person, Lobaczewski offers some helpful information:
--- Quote ---If a person with a normal instinctive substratum and basic intelligence has already heard and read about such a system of ruthless autocratic rule “based on a fanatical ideology”, he feels he has already formed an opinion on the subject. However, direct confrontation with the phenomenon causes him to feel intellectually helpless. All his prior imaginings prove to be virtually useless; they explain next to nothing. This provokes a nagging sensation that he and the society in which he was educated were quite naive.
Anyone capable of accepting this bitter void with an awareness of his own nescience, which would do a philosopher proud, can also find an orientation path within this deviant world. However, egotistically protecting his world-view habits from disintegrative disillusionment and attempting to combine them with observations from this new divergent reality only reaps mental chaos. The latter has produced unnecessary conflicts and disillusionment with the new rulership in some people; others have subordinated themselves to the pathological reality. One of the differences observed between a normally resistant person and somebody who has undergone a transpersonification is that the former is better able to survive this disintegrating cognitive void, whereas the latter fills the void with the pathologic propaganda material, and without sufficient controls. ....
--- End quote ---
Notice here that Lobaczewski mentions that there are people who attempt to combine their observations of psychopathy with their own world view, such as attempting to impose their "everyone has a soul and we just have to figure out what is wrong with these people and save them" shtick, only end up being in chaos. It could be said that the same chaotic state is common to those people who have been in a state of internal conflict and discomfort when dealing with psychophages and keep trying to blame themselves or try to "fix" things.
What is important is that those who have this problem of internal confusion and chaos are those who probably have the WILL to resist and that is what the confusion and chaos is about: the instinctive substratum is screaming: "PREDATOR" and the conscious mind's programming is saying "It's not a predator, it is a human being and I just need to figure out how to fix him/her." This conflict is what produces the "extremely unpleasant psychological states" that Lobaczewski has described: the freezing, the loss of ability to think, the mental catatonia, followed by the "anchoring" of psychopathic material.
Notice also that he mentions those that undergo what he calls "transpersonification." These are the people in whom the psychopathic material "anchors" and because they have never been able to fully accept the reality of what we can plainly call "evil personified," because they can't let go of the idea that "all are one" and "we only need love" or "let's just all get along and play nice" or "I can fix it" or they have some emotional investment in preserving the status quo, then that void is not filled with the TRUTH of the situation based on FACTS. And so, with a void inside, they are subject to having that void filled with pathologic material. They have no controls.
But, getting back to the people who do have a big conflict and who are capable of the will to resist being "assimilated, (probably because they have the WILL in there in the first place), even if they are weary and scarred from battle, there is much hope because by dealing with the phenomenon directly, they seem to be "inoculated." As Lobaczewski describes it:
--- Quote ---Only once these unbelievably unpleasant psychological states have passed, thanks to rest in benevolent company, is it possible to reflect, always a difficult and painful process, or to become aware that one’s mind and common sense have been fooled by something which cannot fit into the normal human imagination.
--- End quote ---
He also taoks a bit about the value of individuals who have been "inoculated" by first hand experience:
--- Quote ---The specific role of certain individuals during such times is worth pointing out; they participated in the discovery of the nature of this new reality and helped others find the right path.
They had a normal nature but an unfortunate childhood, being subjected very early to the domination of individuals with various psychological deviations, including pathological egotism and methods of terrorizing others.
The new rulership system struck such people as a large-scale societal multiplication of what they knew from individual experience. From the very outset, they therefore saw this reality much more prosaically, immediately treating the ideology in accordance with the paralogistic stories well known to them, whose purpose was to cloak bitter reality of their youth experiences. They soon reached the truth, since the genesis and nature of evil are analogous irrespective of the social scale in which it appears.
Such people are rarely understood in happy societies, but there they became useful; their explanations and advice proved accurate and were transmitted to others joining the network of this apperceptive heritage. However, their own suffering was doubled, since this was too much of a similar kind of abuse for one life to handle. ...
Finally, society sees the appearance of individuals who have collected exceptional intuitive perception and practical knowledge in the area of how pathocrats think and such a system of rule operates.
--- End quote ---
That is what we hope to do here. It seems to me that this is the most important thing to do at this time. As Lobaczewski writes:
--- Quote ---Man and society stands at the beginning of a long road of unknown experiences which, after much trial and error, finally leads to a certain hermetic knowledge of what the qualities of the phenomenon are and how best to build up psychological resistance thereto. ....
We shall thereupon observe psychological phenomena, knowledge, immunization, and adaptation such as could not have been predicted before and which cannot be understood in the world remaining under the rule of normal man’s systems.
A normal person, however, can never completely adapt to a pathological system; it is easy to be pessimistic about the final results of this.
Such experiences are exchanged during evening discussions among a circle of friends, thereby creating within people’s minds a kind of cognitive conglomeration which is initially incoherent and contains factual deficiencies. ...
Moral and religious values, as well as a nation’s centuries-old cultural heritage, furnish most societies with support for the long road of both individual and collective searching through the jungle of strange phenomena. However, this apperceptive capacity possessed by people within the framework of the natural world-view contains a deficiency which hides the nucleus of the phenomenon for many years. Under such conditions, both instinct and feelings, and the resulting basic intelligence, play instrumental roles, stimulating man to make selections which are to a great extent subconscious.
Under the conditions created by imposed pathocratic rule in particular, where the just described psychological deficiencies are decisive in joining the activities of such a system, our natural human instinctive substratum is an instrumental factor in joining the opposition. Similarly, the environmental, economic, and ideological motivations which influenced the formation of an individual personality, including those political attitudes which were assumed earlier, play the role of modifying factors which are not as enduring in time. The activity of these latter factors, albeit relatively clear with relation to individuals, disappear within the statistical approach and diminish through the years of pathocratic rule.
The decisions and the way selections made for the side of the society of normal people are once again finally decided by factors usually inherited by biological means, and thus not the product of the person’s option, and predominantly in subconscious processes.
Man’s general intelligence, especially its intellectual level, play a relatively limited role in this process of selecting a path of action, as expressed by statistically significant but low correlation (-0.16). The higher a person’s general level of talent, the harder it usually is for him to reconcile himself with this different reality and to find a modus vivendi within it.
At the same time, gifted and talented people join the pathocracy, and harsh words of contempt for the system can be heard on the part of simple, uneducated people.
Only those people with the highest degree of intelligence, which, as mentioned, does not accompany psychopathies, are unable to find the meaning of life within such a system. They are sometimes able to take advantage of their superior mentality in order to find exceptional ways in which to be useful to others. Wasting the best talents spells eventual catastrophe for any social system.
Since those factors subject to the laws of genetics have proven decisive, society becomes divided by means of criteria not known before into the adherents of the new rule, the new middle class mentioned twice above, and the majority opposition. Since the properties which cause this new division appear in more or less equal proportions within any old social group or level, this new division cuts right through these traditional layers of society. If we treat the former stratification, whose formation was decisively influenced by the talent factor, as horizontal, the new one should be referred to as vertical. The most instrumental factor in the latter is good basic intelligence which, as we already know, is widely distributed throughout all social groups.
Even those people who were the object of social injustice in the former system and then bestowed with another system, which allegedly protected them, slowly start criticizing the latter. Even though they were forced to join the pathocratic party, most of the former prewar Communists in the author’s homeland later gradually became critical, using the most emphatic of language. They were first to deny that the ruling system was Communist in nature, persuasively pointing out the actual differences between ideology and reality. They tried to inform their comrades in still independent countries of this by letters. Worried about this “treason”, these comrades transmitted such letters to their local party, from where these were returned to the security police of the country of origin. The authors of the letters paid with their lives or with years of prison; no other social group was finally subjected to such stringent police surveillance as were they.
--- End quote ---
So the task before us is clear. It isn't easy, but it is possible.
Laura:
A paper found on the web thanks to a link from Keit:
http://www.natur.cuni.cz/%7Eflegr/Tehul3.htm
(I am omitting the tables since they did not format properly for the forum here.)
Folia Parasitologica, 1999, 46: 22-28
Changes in the personality profile of young women with latent toxoplasmosis
Jaroslav Flegr and Jan Havlíček
Department of Parasitology, Faculty of Science, Charles University, Vini?ná 7, 128 44 Prague, Czech Republic
Running head: Induction of personality changes by toxoplasmosis
Key words: Toxoplasma gondii, behavior, Cattell's questionnaire, manipulation hypothesis, permutation test.
Author for correspondence:
Jaroslav Flegr, Department of Parasitology, Charles University, Vini?ná 7, Prague 128 44, Czech Republic
telephone +4202-21953289, fax 004202-299713, email: 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 B 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 nonstandard 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, naivete/shrewdness, and self sentiment integration) concerned changes in the variances, rather then the mean values of the factors.
One of the most widespread parasites in the Czech Republic is the protozoon Toxoplasma gondii. The longtime prevalence in normal population of this parasite is about 30%, while the prevalence in higher age categories and within some risk groups increases above 50% (Nemec et al. 1988, Sengbusch and Sengbusch 1978, Yamaoka and Konishi 1993). Four distinct forms of toxoplasmosis exist. The most serious form is the congenital toxoplasmosis which often leads to serious malformations including hydrocephaly, intra-cerebral calcification and microcephaly (Koppe and Rothova 1989). The second form is the acquired acute toxoplasmosis. It is characteristic by the presence of T. gondii tachyzoites in a blood and in other tissues of infected people and by a complex of clinical symptoms which varies from fever and headache to serious neurological and psychiatric malfunctions (Kramer 1966). In the most cases, however, the acute toxoplasmosis is only a mild disease which is often misdiagnosed as a common bacterial or viral infection. Infrequently the acute toxoplasmosis evolves into chronic disease in which the clinical symptoms as well as high titres of specific antibodies persist for many years. Mostly, all symptoms of acute diseases quickly fall away, the antibody titres decrease and the toxoplasmosis evolves into the latent form of the infection. During the latent toxoplasmosis the parasite survives in the dormant form of bradyzoites mostly in the neural and muscular tissue of the host. The latent toxoplasmosis probably last for the whole life of infected person (Remington and Krahenbuhl 1982) and it can turn into acute toxoplasmosis only after serious violence of integrity of immune systems (AIDS, treatment with immunosupressive drugs etc. (Heitman and Irizarry 1997, Mocsny 1992)).
Latent toxoplasmosis is considered to be asymptomatic. Most of the infected people never learn to have met T. gondii in the past and carry the dormant stages of the parasite for the rest of their life. Recently, however, significant differences in personality profiles of men and women with latent toxoplasmosis and normal controls were reported to exist (Flegr and Hrdý 1994, Flegr et al. 1996). Toxoplasma-positive subjects differ by mean value of some psychologic factors measured by 16 PF Cattell=s personality questionnaire. The differences in some of these factors increase with the duration of latent toxoplasmosis (Flegr et al. 1996). This suggests that the changes were induced by the toxoplasmosis rather than the personality factor shift influencing the probability of being infected with T. gondii. Under natural conditions the intermediate hosts of Toxoplasma are small rodents and the final host is a cat. Therefore, the changes in the human personality can be a product of manipulation activity of the parasite which is primarily aimed to increase the probability of transmission from intermediate to a definitive host by predation. Such manipulation activity of T. gondii was observed in many experimental systems (Hutchison et al. 1980, Webster et al. 1994, Berdoy et al. 1995, Hutchison et al. 1980, Webster 1994, Arnott et al. 1990). The mechanism of manipulation activity of Toxoplasma gondii is not known. However, it can probably include the synthesis (or induction of synthesis) of some neuromodulator (Stibbs 1985) or of other biologically active substance (Varela et al. 1956, Varela et al. 1957). In the aberrant host (man) such activity of the parasite is of course nonproductive. However, it can manifest its presence by nonspecific (from the point of view of a manipulation hypothesis) changes in human personality.
In the previous studies the personality changes were studied either on population of biologists or on subjects previously diagnosed for acute toxoplasmosis (Flegr and Hrdý 1994, Flegr et al. 1996). Neither of the experimental sets represents a typical population. Therefore, it is difficult to guess whether the obtained results can by generalized for normal population. Moreover, in both cases the subjects were informed that the aim of the research is to reveal possible influence of toxoplasmosis on human personality. Such information could influence the subject=s responses on the questionnaire (at least in the second study in which the subjects were aware to be infected be Toxoplasma gondii before the questionnaire testing).
The aim of the present study was to find out whether the differences in personality profiles can be detected also in a random sample of normal women tested for toxoplasmosis during pregnancies. For ethical reasons (a possible fear of young mothers of congenital toxoplasmosis) the women could not be informed that the research concerns the toxoplasmosis. The absence of a priori knowledge about the subject of the research helped to eliminate possible intentional or unintentional data distortion by the experimental subjects. The results showed that personality profiles of women with latent toxoplasmosis significantly differed from those of women without the infection. The character and the amount of these personality changes were similar to those observed in the previous studies.
MATERIAL AND METHODS
Experimental subjects. The experimental set (young women) consisted of 191 women 18-39 years old who were serologically tested for toxoplasmosis during pregnancy. Among these women 146 tested negative and 55 have the titers of anti-Toxoplasma antibodies between 1 : 8 and 1 : 64 which indicates latent toxoplasmosis. According to the levels of IgG and IgM antibodies no woman involved suffered acute toxoplasmosis. All subjects (824) received the personality questionnaire 6-7 month after the serological examination, mostly 2-5 months after the childbirth. In the cover letter they were only asked to voluntarily participate in an unspecified research project (to avoid a possible fear of young mothers of congenital toxoplasmosis). The return rate was approximately 23.2%.
Personality tests. Cattell's sixteen factor questionnaire (form A) (Cattell 1970) was used for characterization of personality profiles. This questionnaire is still widely used for personality studies in many countries, including the Czech Republic. It covers sixteen personality factors (Tab. 1). The main advantage of this traditional is that it contains only one hundred and eighty-seven (187) questions. Therefore, it can be completed by most subjects within forty minutes. All subjects obtained the questionnaire by mail and were asked to voluntarily participate in an unspecified research project.
Immunological tests for toxoplasmosis.
The latent toxoplasmosis in pregnant women was diagnosed with complement-fixation test (CFT), (Warren and Sabin 1942), in the National Diagnostic Laboratory for Toxoplasmosis, National Institute of Public Health, Prague, Czech Republic. The titre of anti-Toxoplasma antibodies in sera was measured in dilutions between 1 : 8 and 1 : 1024. All subjects with the titres from 1 : 8 to 1 : 64 were considered latent toxoplasmosis positive, the subject with titre lower then 1 : 8 latent toxoplasmosis negative. No subjects with titres equal or higher than 1 : 128 (the indication of recent acute toxoplasmosis) were involved in our study.
Statistical tests.
The computation of standard residuals by linear regression (for elimination of the effect of age), the t-tests and the Levene tests were performed by the program package Statistica7. The program TREEPT (originally called PTPT, (Flegr and Záboj 1997)) was used for all permutation tests including the permutation tests with elimination of false negative cases. This freeware Windows program for various permutation tail probability tests is available on the address http://www.natur.cuni.cz/~flegr/programs. The rationale of the permutation test is described in the legend of the Table 3. Differences in variances of personality factors between Toxoplasma negative and positive subjects were tested by the same permutation tests, however, the absolute values of age-standardized factors instead of age-standardized factors were entered into the program. The rationale of this approach was based on our previous observation that for certain personality factors both minimal and maximal extremes were absent in Toxoplasma positive subjects.
RESULTS
We obtained the personality data from 136 Toxoplasma-negative and 55 Toxoplasma-positive women. Effect of the age was eliminated be computation of standard residual of linear regression between the age and raw personality factors. The effect of latent toxoplasmosis was tested by t-test and the Levene's test for the homogeneity of variances. The results (Tab. 2) suggest that no differences in mean values of Cattell=s factors exist between Toxoplasma-negative and Toxoplasma-positive women.
The diagnosis of latent toxoplasmosis was performed by complement fixation test. This simple serological test is very useful for rapid screening for acute toxoplasmosis. However, it often provides false negative results for subjects with low titers of antibodies, for example for subjects with very old T. gondii infections. Therefore, our subset of Toxoplasma-negative women must be contaminated by an unknown percentage of Toxoplasma-positive women. Such women with old infections (and consequently with low levels of specific antibodies) are known to have the highest amount of the personality factor shift (Flegr and Hrdý 1994, Flegr et al. 1996). Therefore, their presence in the Toxoplasma-negative subsets can flatten out any possible difference between the two subsets. The effects of such kind of data contamination can be revealed and eliminated by a permutation test with data reassignment. For this kind of tests we used the program TREEPT which can perform permutation tests analogical to t-test or ANOVA with reassignment of a particular fraction of cases from one group to the other (in this case from the subset of Toxoplasma-negative women to the Toxoplasma-positive subset). The results of this analysis are shown in the Table 3.
The results of permutation tests showed that the Toxoplasma-positive women had higher factor B (intelligence), factor O (guilt proneness) and possibly also Q4 (high ergic tension) and Q1 (radicalism). The differences between Toxoplasma-negative and Toxoplasma-positive women in the factors L and Q3, and possibly also F and N demonstrated its existence by changes in the character of distribution, rather then changes in the mean values of the factors. The histograms of standardised factors (not shown) suggest, that the distribution of values of these factors in Toxoplasma-positive women have lower kurtosis and can be approximated by the rectangular while that of Toxoplasma-negative women by the normal distribution.
DISCUSSION
Our results suggest that the personality profiles of women with latent toxoplasmosis differ in certain factors from those of women without toxoplasmosis. Toxoplasma-positive women have higher intelligence, guilt proneness (are more apprehensive, self-reproaching, insecure), possibly also higher ergic tension and radicalism. The changes in other personality factors were manifested by difference in distribution of values of the factor rather than in differences in the mean values of the factor.
These changes, however, cannot be observed directly when the women are sorted into the Toxoplasma-negative and positive groups on the basis of routine serological tests (like CFT). These tests are optimised for early diagnosis of acute toxoplasmosis. They are able to prove the existence of high titres of specific anti-Toxoplasma antibodies which are characteristic for patients with an acute phase of acquired toxoplasmosis. In most of clinical laboratories the samples of sera are either measured from the titre 1 : 8 or the subjects with the titres less then 1 : 8 are considered as Toxoplasma-negative (and are excluded from further analysis by more specific tests, for example by IgM ELISA). The women in our experimental set were screened for toxoplasmosis during routine clinical examination in pregnancy. Their sera were tested by complement fixation test (Warren and Sabin 1942) and the subjects without positive reaction in 1 :8 dilution were considered as Toxoplasma-negative. The clinical records as well as the comparison of results of CFT and IgG ELISA tests suggests, that the titres of specific antibodies estimated by CFR can decrease below 1 : 8 within a few years after the end of acute toxoplasmosis. Therefore, our group of 136 Toxoplasma-negative women must be contaminated by an unknown percentage of women with old Toxoplasma gondii infection. The results of our observation of toxoplasmosis patients during the interval 13 years after infection (Flegr et al. 1996) showed that at least some of the Toxoplasma gondii induced personality changes are very slow. Therefore, the personality of subjects with longest infections (who might be often missdiagnosted as Toxoplasma-negative) can express the most prominent changes in our experimental set. Even a small percentage of such subjects in the Toxoplasma-negative set can flatten out the possible differences between the two subsets of women. In the first study (Flegr and Hrdý 1994) in which prominent differences between Toxoplasma-negative and Toxoplasma-positive were observed the toxoplasmin intradermal delayed hypersensitivity test (Feldman 1954) was used for diagnosis of latent toxoplasmosis. This old test monitors cellular rather then humoral immunity. The clinical experience shows that the positive reactions in the intradermal delayed hypersensitivity test persists for a very long time, probably for the whole life of an infected person (Remington and Krahenbuhl 1982). When the toxoplasmosis is diagnosed with a common serological test like CFT the presence of unknown percentage of false negatives must be anticipated and the existence of any differences between Toxoplasma-negative and Toxoplasma-positive subjects must be tested by proper statistical method (such as the permutation test with data reassignation).
In our study the permutation tests revealed the existence of differences in mean values of factors B, O, possibly also Q4 and Q1. In the factors F, L, N and Q3 the latent toxoplasmosis affected the distribution of personality factors= values, rather then their mean values. The lover kurtosis of the distribution as well as the absence of distinct peak in the histogram of the distribution can be explained by the fact that the Toxoplasma-induced personality shift is probably a long-lasting process. Our results (Flegr et al. 1996) suggest that the process is triggered by the infection, however, it takes many years to fully evolve. Consequently, the women with a relatively fresh infection are Toxoplasma-positive on the basis of serological tests, however, their personality profile has still the Toxoplasma-negative character. As our experimental set contains the women with toxoplasmosis of various length no distinct peak but rather a flat plateau can be observed on the histograms of personality factors of Toxoplasma-positive women. As we already discussed the absence of significant difference of mean values of the factor can be explained by missdiagnosis of the most changed subjects (with lowest antibody titres) as Toxoplasma-negative.
The results of present analysis of the set of young women slightly differ from those obtained on the set of students and teachers of biology of the Charles University (Flegr and Hrdý 1994, Flegr et al. 1996). They are, however, similar to those obtained on the set of acute toxoplasmosis patients and on the subset of 55 Toxoplasma-positive women (submitted). In the set of biologists the Toxoplasma-positive women had higher A (affectothymia), Q3 (strength of self sentiment), and lower L (protension). In the set of 230 women with clinical history of acute toxoplasmosis the duration of infection positively corelated with G (superego strength), and Q3 (strength of self sentiment) while in the set of 55 young women with latent toxoplasmosis the length of infection (estimated on the basis of antibody titres) positively corelated with A (affectothymia), F (surgence), G (superego strength), H (parmia) and L (protension). The differences between the results obtained on particular experimental sets can be probably explained by special nature of some of these sets. Especially the biologists represent a highly atypical population sample which differs in many personality traits from a general population. Despite the differences a similar set of personality factors (usually incorporating the factors A, F, G, L, O, Q3 and Q4) seems to by influenced by latent toxoplasmosis in all examined sets of women. The results of discrimination analysis and of logistic regression (Flegr and Hrdý 1994, Flegr et al. 1996) suggest that only some of these factors are influenced by the parasite directly while the others are changed because of their correlation with other (toxoplasmosis influenced) factors. As the correlation matrices of Cattells factors often differ among various social and professional groups, the changes in secondary-influenced factors might vary among different experimental sets.
The results of the current study are very important in two respects. First, in the comparison with all previous studies the experimental set represents a homogeneous sample of normal population of young women. The experimental set of biologists (Flegr and Hrdý 1994) represents highly untypical population of university students and teachers. The second experimental set (Flegr et al. 1996) is a relatively good representation of Czech population of women. However, the age-structure of the sample is highly heterogeneous. Moreover, all women in this sample experienced relatively severe acute toxoplasmosis disease (in contrast with most of other infected people they were diagnosed for acquired toxoplasmosis and received a medical help). In both cases it is not clear whether the results and conclusions can be extrapolated for normal population.
Secondly, in all previous studies the subjects were informed about the aim of the projects before the experiment. In this study neither toxoplasmosis nor T. gondii were mentioned in the cover letter (to avoid possible fear of young mothers of congenital toxoplasmosis). For the first time we fully excluded any possible intentional or unintentional distortion of data by the experimental subjects.
It is not possible to decide on the basis of present data whether the toxoplasmosis induces the changes in personality or whether the certain combination of the personality traits increases the probability of contact with T. gondii infection. There are, however, several reasons to believe that former possibility is the correct one: 1. Significant positive correlation exists between the duration of latent toxoplasmosis and the amount of personality shift in the sets of men (Flegr et al. 1996) and women (submitted) diagnosed with acute toxoplasmosis during the period of 13 and 14 years, respectively in various Prague hospitals. 2. Significant negative correlation exists between the level of anti-Toxoplasma antibodies (which indirectly reflects the duration of latent toxoplasmosis) and the amount of personality shift in the sets of biology students (Flegr and Hrdý 1994) and Toxoplasma-positive young women (submitted). 3. No correlation exists between the major toxoplasmosis-risk factors (consumption of raw meat and contact with cat) and the personality factors influenced by toxoplasmosis (Flegr et al. 1998). 4. All but one (factor O) personality factors influenced by toxoplasmosis are shifted in the opposite direction in Toxoplasma-positive men and women. It is difficult to explain how the oppositely changed factors can promote the same effect in men and women, namely the increase of probability of T. gondii infection.
It can be only speculated, whether the induction of personality changes in men is connected with an attempt of the parasite to manipulate the host behavior, or are only byproducts of a non-specific decline in the quality of host life (connected, for example, with Toxoplasma-induced general immunosupression).
Acknowledgements. This research was supported by the grant FRVŠ 1314/1997. We thank to Petr Kodym for his help with the data gathering and Monika Flegrová for an adaptation of the program TREEPT.
REFERENCES
ARNOTT M.A., CASSELLA J.P., AITKEN P.P., HAY J. 1990: Social interactions of mice with congenital Toxoplasma infection. Ann. Tropic. Med. Parasitol. 84: 149-156.
BERDOY M., WEBSTER J.P., MACDONALD D.W. 1995: Parasite-altered behaviour: Is the effect of Toxoplasma gondii on Rattus norvegicus specific? Parasitology 111: 403-409.
CATTELL R.B. 1970: Handbook for the sixteen personality factors questionnaire (16PF). Institute for Personality and Ability Testing, Champain 115 pp.
FLEGR J., HRDÝ I. 1994: Influence of chronic toxoplasmosis on some human personality factors. Folia Parasitol. 41: 122-126.
FLEGR J., ZITKOVÁ S., KODYM P., FRYNTA D. 1996: Induction of changes in human behaviour by the parasitic protozoan Toxoplasma gondii. Parasitology 113: 49-54.
FLEGR J., ZÁBOJ, P. 1997: PTPT, the freeware program for permutation testing concordance between phylogeny and the distribution of phenetic traits. Acta Soc.Zool.Bohem. 61: 91-95.
FLEGR J., HRDÁ Š., TACHEZY J. 1998: The role of psychological factors in questionnaire-based studies on routes of human toxoplasmosis transmission. Centr.eur.J.publ.Hlth 6: 45-50.
FELDMAN H.A. 1954: Laboratory methods in current use for the study of toxoplasmosis. Lausan. Bibl. Ophthal. 39: 1-11.
HEITMAN B.B., IRIZARRY A.F. 1997: Recognition and management of toxoplasmosis. Nurse.Pract. 22: 79-86.
HUTCHISON W.M., AITKEN P.P., WELLS B.W.P. 1980: Chronic Toxoplasma infection and familiarity-novelty discrimination in the mouse. Ann. Tropic. Med. Parasitol. 74: 145-150.
HUTCHISON W.M., BRADLEY M., CHEYNE W.M., WELLS B.W.P., HAY, J. 1980: Behavioural abnormalities in Toxoplasma-infected mice. Ann. Tropic. Med. Parasitol. 74: 337-345.
KOPPE J.G., ROTHOVA A. 1989: Congenital toxoplasmosis. A long-term follow-up of 20 years. Int.Ophthalmol. 13: 387-390.
KRAMER W. 1966: Frontiers of neurological diagnosis in acquired toxoplasmosis. Psych.Neurolog.Neurochir. 69: 43-64.
MOCSNY N. 1992: Toxoplasmic encephalitis in the AIDS patient. J.Neurosci.Nurs. 24: 30-33.
NEMEC R., NECAS S. HOLKOVA R., CATAR G., PORUBENOVA. A. 1988: Titre of toxoplasmic antibodies in workers with potentially higher probability of toxoplasmic infection. Bratisl.Lek.Listy 89: 779-783.
REMINGTON J.S., KRAHENBUHL J.L. 1982: Immunology of Toxoplasma gondii. In: A.J. Nahmias and J. O'reilly (Eds.), Immunology of human infection, Part II. Plenum Publishing Corporation, New York, pp. 327-371.
SENGBUSCH H.G., SENGBUSCH L.A. 1978: Toxoplasma antibody prevalence in veterinary personnel and a selected population not exposed to cats. Am.J.Epidemiol. 103: 595-597.
STIBBS H.H. 1985: Changes in brain concentrations of catecholamines and indoleamines in Toxoplasma gondii infected mice. Ann. Tropic. Med. Parasitol. 79: 153-157.
VARELA G., VAZQUEZ A., TARROELLA J. 1956: Probable existencia de la dietilamida del acido D-lisergico en la infeccion por Toxoplasma gondii. Rev. Inst. Salubr. Enferm. Tropic. 16: 29-32.
VARELA G., PALENCIA L., VAZQUEZ A. 1957: Utilization del pez Lebistes reticulatus (guppy) en el diagnostico de la toxoplasmosis. Rev. Inst. Salubr. Enferm. Tropic. 17: 75-80.
WARREN J., SABIN A.B. 1942: The complement fixation reaction in toxoplasmic infection. Proc. Soc. Exper. Biol. Med. 51: 11-16.
WEBSTER J.P. 1994: The effect of Toxoplasma gondii and other parasites on activity levels in wild and hybrid Rattus norvegicus. Parasitology 109: 583-589.
WEBSTER J.P., BRUNTON C.F.A., MACDONALD D.W. 1994: Effect of Toxoplasma gondii upon neophobic behaviour in wild brown rats, Rattus norvegicus. Parasitology 109: 37-43.
YAMAOKA M., KONISHI E. 1993: Prevalence of Antibody to Toxoplasma gondii Among Inhabitants Under Different Geographical and Climatic Conditions in Hyogo Prefecture, Japan. Jpn. J. Med. Sci. Biol. 46: 121-129.
Laura:
Increased risk of traffic accidents in subjects with latent toxoplasmosis: a retrospective case-control study
Jaroslav Flegr1 , Jan Havlícek2 , Petr Kodym3 , Marek Malý4 and Zbyněk Smahel5
1Department of Parasitology, Faculty of Science, Charles University, Prague, Czech Republic
2Research Centrum of Personality and Ethnic Studies, Faculty of Humanities, Charles University, Prague, Czech Republic
3National Reference Laboratory for Toxoplasmosis, National Institute of Public Health, Prague, Czech Republic
4Department of Biostatistics, National Institute of Public Health, Prague, Czech Republic
5Department of Anthropology and Human Genetics, Faculty of Science, Charles University, Prague, Czech Republic
BMC Infectious Diseases 2002, 2:11 doi:10.1186/1471-2334-2-11
Abstract
Background
The parasite Toxoplasma gondii infects 30–60% of humans worldwide. Latent toxoplasmosis, i.e., the life-long presence of Toxoplasma cysts in neural and muscular tissues, leads to prolongation of reaction times in infected subjects. It is not known, however, whether the changes observed in the laboratory influence the performance of subjects in real-life situations.
Methods
The seroprevalence of latent toxoplasmosis in subjects involved in traffic accidents (N = 146) and in the general population living in the same area (N = 446) was compared by a Mantel-Haenszel test for age-stratified data. Correlation between relative risk of traffic accidents and level of anti-Toxoplasma antibody titre was evaluated with the Cochran-Armitage test for trends.
Results
A higher seroprevalence was found in the traffic accident set than in the general population (Chi2MH = 21.45, p < 0.0001). The value of the odds ratio (OR) suggests that subjects with latent toxoplasmosis had a 2.65 (C.I.95= 1.76–4.01) times higher risk of an accident than the toxoplasmosis-negative subjects. The OR significantly increased with level of anti-Toxoplasma antibody titre (p < 0.0001), being low (OR = 1.86, C.I.95 = 1.14–3.03) for the 99 subjects with low antibody titres (8 and 16), higher (OR = 4.78, C.I.95 = 2.39–9.59) for the 37 subjects with moderate titres (32 and 64), and very high (OR = 16.03, C.I.95 = 1.89–135.66) for the 6 subjects with titres higher than 64.
Conclusion
The subjects with latent toxoplasmosis have significantly increased risk of traffic accidents than the noninfected subjects. Relative risk of traffic accidents decreases with the duration of infection. These results suggest that 'asymptomatic' acquired toxoplasmosis might in fact represent a serious and highly underestimated public health problem, as well as an economic problem.
Background
The parasitic protozoon Toxoplasma gondii (phylum Apicomplexa) infects various warm-blooded vertebrates, including 30–60% of humans in most countries [1]. After a short phase of acute toxoplasmosis the infection proceeds into its latent phase when cysts are formed and these survive for the rest of the host's life, mainly in neural and muscular tissues. In immunocompetent human subjects the latent phase of infection is usually considered asymptomatic and harmless [2].
Toxoplasma is known to induce specific behavioural changes in infected rodents. Observed decreases in motor performance [3], learning capacity [4], neophobia [5], and fear [6], and increases in activity [7,8], and reaction times [9] are usually considered evolutionary adaptations of the parasite that facilitate the transmission from intermediate to definitive host (typically from rodents to cat) by predation [10]. Human latent toxoplasmosis leads to prolongation of reaction times [11] and changes in personality profiles [12,13]. These changes are probably side effects either of the rodent-aimed manipulative activity of Toxoplasma or of some pathogenic activity of the parasites in the brain. The changes cannot influence the risk of predation in modern humans; nevertheless, prolongation of reaction times could increase the risk of other incidents such as traffic accidents. If this is true then the prevalence of toxoplasmosis in participants in traffic accidents should be higher than in the general population living in the same area.
Here we report the results of retrospective case-control study that compares the seroprevalence of toxoplasmosis in persons injured in traffic accidents with the seroprevalence of toxoplasmosis in general population living in the same area.
Methods
Study population
A) Traffic accident sample
This group consisted of 85 men and 61 women, outpatients at the Surgery Unit of Královské Vinohrady Hospital, one of two principal hospitals serving central Prague. Only residents of central Prague districts, 15–70 years old, with Czech citizenship and with a negative result of the laboratory test for alcohol (only 28 subjects were tested for alcohol) were included in the study. We included only the persons who could have actively influenced the probability of their accidents. All pedestrians hit by cars or trams on a carriage-way were included because, according to the Czech laws on road traffic valid until January 2001, pedestrians were obliged to give way to all approaching vehicles before entering the carriage-way, even on the pedestrian crossing. Drivers whose car was hit from the side or back or whose records contained the information that they did not cause the accident (the information in records was judged by three independent persons) were excluded from the sample before the results of their tests for toxoplasmosis were known. The series included all patients meeting the criteria listed including pedestrians and drivers who were involved in the same experiment. The serological testing for toxoplasmosis was performed using part of the blood samples collected for other purposes (e.g., testing for alcohol) between 1997–2000.
B) Controls
The controls consisted of 230 men and 216 women, residents of central Prague districts, selected by quota sampling and screened for toxoplasmosis in the 1990 and 1996 multipurpose immunological surveys (MIS) [14]. Samples of sera were collected by district and/or paediatric practitioners from about 20 randomly selected medical districts in the studied regions. Each participating medical practitioner was instructed to obtain quotas according to age group and gender from subjects without acute clinical symptoms.
Serological tests
All sera sent to the National Reference Laboratory for Toxoplasmosis in the National Institute of Public Health were examined by complement-fixation test (CFT) using a commercial CFT kit (SEVAC, Prague), by IgG ELISA (SEVAC, Prague), and by IgM ELISA (TestLine, Brno). The positive result of a CFT; (titres 8 and higher), together with a negative IgM ELISA test (positivity index
Laura:
Induction of changes in human behaviour by the parasitic protozoan Toxoplasma gondii
http://www.natur.cuni.cz/%7Eflegr/toxo95.htm
J. FLEGR1, Š. ZITKOVÁ1, P. KODYM2 and D. FRYNTA3
1 Department of Parasitology, Charles University, Vinièná 7, Prague 128 44, Czech Republic
2 National Diagnostic Laboratory for Toxoplasmosis, National Institute of Public Health, Prague 110 00, Czech Republic
3 Department of Zoology, Charles University, Vinièná 7, Prague 128 44, Czech Republic
Address: Jaroslav Flegr, Dep. Parasitol., Fac.Science, Charles Univ., Vinièná 7, Prague 128 44, Czech Republic, tel. 00422-24915522, fax 00422-299713, E-mail FLEGR@CSEARN.BITNET
SUMMARY
Toxoplasma gondii, the coccidian parasite, is known to induce changes in the behaviour of its intermediate hosts. The high prevalence of this parasite in the human population (20-80%) offers the opportunity of studying the influence of the parasite on human behaviour by screening of a normal population.
Two hundred and twenty-four men and one hundred and seventy women were tested for toxoplasmosis and their personality profiles were measured by Cattell's questionnaire. Highly significant differences between Toxoplasma infected and uninfected subjects were observed (p < 0.01). For men the factors G (low superego strength, p
Laura:
And finally, a blogger wrote:
--- Quote ---All this sounds pretty bad for us men, and perhaps not that great for women either. Men become dirty, dogmatic recluses, and women become naive, outgoing, and promiscuous (some of the evidence indicates that they have sex with more men). The authors of the 2003 paper (the first author is the same in each of the papers that I've linked) suggest that the specific behavioral differences in infected men may indicate that the parasite affects the dopamanergic system, which may be why there is a link between infection and schizophrenia.
--- End quote ---
He adds that more recent research says it isn't that bad. We wonder about that, however.
http://mixingmemory.blogspot.com/2005/06/your-cat-could-change-your-personality.html
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