Influence of latent toxoplasmosis on the phenotype of intermediate hosts

Flegr, Jaroslav

doi:10.14411/fp.2010.010

Cited by 53 publications

(49 citation statements)

References 42 publications

(12 reference statements)

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“…In women, the shift in these two factors is opposite to that of men; they mainly show a positive shift in Cattell's factor A -affectothymia (they are more warmhearted, outgoing and easy-going than the more reserved, detached and critical Toxoplasma-free women). With a new version of Cattell's questionnaire (v. 5), the infected men showed increased, rather than decreased, scores on superego strength [ (Flegr, 2010b) for an explanation of discordant results between studies, see chapter 4]. Cloninger's TCI showed that infected subjects, both men and women, have decreased scores on factor NS -novelty seeking, i.e.…”

Section: Changes In the Personality Profile Of Humans With Latent Toxmentioning

confidence: 99%

“…The NEO-PI-R questionnaire showed more extraversion in infected subjects, both men and women, and less conscientiousness in comparison with Toxoplasma-free subjects (Lindová et al, 2012). On the basis of predictions of the manipulation theory and introspection of the Toxoplasma-infected author, a special questionnaire called Toxo94 was constructed (Flegr, 2010b). This questionnaire consisting of only 10 questions was distributed to several groups of subjects tested for toxoplasmosis, such as two large groups of university students and a group of women screened for toxoplasmosis during pregnancy (Flegr, 2010b).…”

Section: Changes In the Personality Profile Of Humans With Latent Toxmentioning

confidence: 99%

“…On the basis of predictions of the manipulation theory and introspection of the Toxoplasma-infected author, a special questionnaire called Toxo94 was constructed (Flegr, 2010b). This questionnaire consisting of only 10 questions was distributed to several groups of subjects tested for toxoplasmosis, such as two large groups of university students and a group of women screened for toxoplasmosis during pregnancy (Flegr, 2010b). The results showed that infected men more often reported that diplomacy is not their strong point, that their instinctive (reflex) behaviour under imminent danger is rather slow and passive, that they believe that some people have the power to impose their will on others with hypnosis or through other means and that when they are attacked, physically or otherwise, or when they should fight for something important, they stop fighting at a certain moment because their own subconsciousness betrays them and they loss the will to fight back.…”

Section: Changes In the Personality Profile Of Humans With Latent Toxmentioning

confidence: 99%

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Influence of latentToxoplasmainfection on human personality, physiology and morphology: pros and cons of theToxoplasma–human model in studying the manipulation hypothesis

Flegr

2013

Journal of Experimental Biology

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217

162

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Toxoplasma as the model organism for studying the parasite manipulation hypothesisToxoplasma gondii is a parasitic protozoan whose effects on human behaviour, personality and other phenotypic traits have been studied most thoroughly, often in the context of the manipulation theory, the theory suggesting that many parasites change the phenotype of their host to increase their chances of transmission to a new host by, for example, predation. There are various reasons why this particular protozoon has become a favoured model for evolutionary parasitologists, biologists and also psychiatrists. First of all, Toxoplasma is a very common parasite both in developed and developing countries, and some forms of diseases caused by Toxoplasma infection have very serious impacts on human health; taken together, all forms of toxoplasmosis are a serious socio-economic burdens throughout the world (Pappas et al., 2009;Torgerson and Macpherson, 2011). It is also important to note that the study of the influence of toxoplasmosis on the behaviour of laboratory animals has a very long tradition; this includes a series of about 20 studies that started in the laboratory of William M. Hudtchison in the early 1980s, followed by studies by Joanne P. Webster and Manuel Berdoy in the 1990s, which were succeeded by several other teams (for reviews, see Skallová et al., 2006;Webster, 2007;Webster and McConkey, 2010).Toxoplasma is an excellent model for studying the manipulation hypothesis as it is trophically transmitted from an intermediate to a definitive host by predation. In contrast to behavioural patterns induced by directly or, more commonly, sexually transmitted parasites, the behavioural patterns induced by a trophically transmitted parasite are relatively easy to recognize (Parker et al., 2009). For example, in a sexually transmitted parasite, the parasite's and the host's genes have similar interests: they both 'try' to program the host to increase the probability of host reproduction. In contrast, the interests of the host and its trophically transmitted parasite radically differ. The intermediate host, e.g. the mouse, needs to survive (and reproduce) for as long as possible while the parasite, e.g. Toxoplasma, 'wants' the definitive host (here, a cat) to kill and SUMMARY The parasitic protozoan Toxoplasma gondii infects about one-third of the population of developed countries. The life-long presence of dormant stages of this parasite in the brain and muscular tissues of infected humans is usually considered asymptomatic from the clinical point of view. In the past 20years, research performed mostly on military personnel, university students, pregnant women and blood donors has shown that this ʻasymptomaticʼ disease has a large influence on various aspects of human life. Toxoplasma-infected subjects differ from uninfected controls in the personality profile estimated with two versions of Cattellʼs 16PF, Cloningerʼs TCI and Big Five questionnaires. Most of these differences increase with the length of time since the onset of infe...

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Section: Changes In the Personality Profile Of Humans With Latent Toxmentioning

confidence: 99%

Section: Changes In the Personality Profile Of Humans With Latent Toxmentioning

confidence: 99%

Section: Changes In the Personality Profile Of Humans With Latent Toxmentioning

confidence: 99%

See 1 more Smart Citation

Influence of latentToxoplasmainfection on human personality, physiology and morphology: pros and cons of theToxoplasma–human model in studying the manipulation hypothesis

Flegr

2013

Journal of Experimental Biology

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217

162

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“…Therefore, the behavioral changes observed in infected animals, like that of humans, are usually considered to be a feature of the adaptive manipulation of the parasite, intended to increase the probability of transmission of the dormant stages of Toxoplasma from intermediate to definitive host by trophic route. However, based on the nature of observed changes, especially based on the fact that many Toxoplasma-associated changes are in opposite directions in men and women (Flegr, 2010), it has been suggested that they are just nonspecific side-effects of mild but continuous stress induced by the parasitic disease (Lindová et al, 2010). It is known that men and women behaviorally cope with chronic stress in opposite ways.…”

Section: Introductionmentioning

confidence: 99%

Physical and Mental Health Status in Toxoplasma-Infected Women before and 3 Years after They Learn about Their Infection: Manipulation or Side-Effects of Impaired Health?

Šebánková

Flegr

2017

Front. Ecol. Evol.

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Latent toxoplasmosis is known to be associated with specific changes in animal and human behavior and human personality. Many toxoplasmosis-associated shifts, such as an extroversion-introversion shift or a trust-suspicion shift, go in opposite directions in men and women. The stress coping hypothesis suggests that such behavioral effects of toxoplasmosis are side effects of chronic stress caused by lifelong parasitosis and associated health disorders. Several studies have searched for, and typically found, indices of impaired health in infected subjects. However, subjects were always aware of their toxoplasmosis status, which could influence obtained data and cause false-positive results of the studies. Here we searched for differences in physical and mental health status among 39 Toxoplasma-infected and 40 Toxoplasma-free female university students who completed identical questionnaires (N-70, and anamnestic questionnaire), before and 3 years after they were informed of their toxoplasmosis status. Our results showed that infected women showed indices of poorer health status, not only after, but also before they were informed of their infection. In accordance with previously published data, these indices were more numerous and stronger in Rh-negative than in Rh-positive women. Present results suggest that observed indices of poorer health and symptoms of chronic stress in Toxoplasma-infected subjects are real. Due to its high (30%) prevalence, toxoplasmosis could represent an important factor for public health.

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“…In addition to the direct effects of latent toxoplasmosis on testosterone concentration, there are also some phenotypic traits in individuals with latent toxoplasmosis that related to higher levels of prenatal testosterone (Flegr et al, 2008b; Flegr, 2010, 2013b). For example, both men and women with latent toxoplasmosis have a lower 2D:4D ratio than non-infected subjects (Flegr et al, 2005).…”

Section: Indirect Evidences For Increased Prenatal Testosterone In Asmentioning

confidence: 99%

Are There any Relationships between Latent Toxoplasma gondii Infection, Testosterone Elevation, and Risk of Autism Spectrum Disorder?

Abdoli

Dalimi

2014

Front. Behav. Neurosci.

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Influence of latent toxoplasmosis on the phenotype of intermediate hosts

Cited by 53 publications

References 42 publications

Influence of latentToxoplasmainfection on human personality, physiology and morphology: pros and cons of theToxoplasma–human model in studying the manipulation hypothesis

Influence of latentToxoplasmainfection on human personality, physiology and morphology: pros and cons of theToxoplasma–human model in studying the manipulation hypothesis

Physical and Mental Health Status in Toxoplasma-Infected Women before and 3 Years after They Learn about Their Infection: Manipulation or Side-Effects of Impaired Health?

Are There any Relationships between Latent Toxoplasma gondii Infection, Testosterone Elevation, and Risk of Autism Spectrum Disorder?

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