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Start Over Creator Flegr, Jaroslav

2. Changes in the personality profile of young women with latent toxoplasmosis

Creator:
Flegr, Jaroslav and Havlíček, Jan
Format:
print
Type:
model:internalpart and TEXT
Subject:
Toxoplasma gondii, behaviour, Cattell’s questionnaire, manipulation hypothesis, and permutation test
Language:
English
Description:
Latent toxoplasmosis is the most widespread parasite infection in developed and developing countries. I'he 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 loxoplasma-posilive 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 selfsentiment integration) concerned changes in the variances, rather than the mean values of the factors.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

3. Does the prevalence of latent toxoplasmosis and frequency of Rhesus-negative subjects correlate with the nationwide rate of traffic accidents?

Creator:
Flegr, Jaroslav and Dama, Madhukar
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
parasite, Toxoplasma, manipulation hypothesis, correlation study, ecological regression, and Disability Adjusted Life Years
Language:
English
Description:
Latent toxoplasmosis is probably the most common protistan parasitic disease with many indirect negative impacts on human health. One of the important impacts is impaired psychomotor function leading to reduced driving efficiency in Toxoplasma-seropositive subjects. Numerous case-control studies have established a positive relation between the seroprevalence of Toxoplasma gondii (Nicolle et Manceaux, 1908) and probability of traffic accidents in study populations. The prevalence of toxoplasmosis varies between populations according to local geographical conditions, hygienic practices and kitchen habits. Similarly, we see a striking variation in the incidence of traffic accidents across countries. Hence, we compiled the largest ever data set on the seroprevalence of toxoplasmosis and tried to understand its role in traffic accident-related deaths and disabilities across 87 countries. Simple nonparametric analysis showed a positive and strong relation of T. gondii seroprevalence and traffic accident related disabilities. Further, we conducted multivariate analysis to control for confounding factors. After controlling for wealth, geographical latitude, health of population, length of roads and number of vehicles, the correlation disappeared. When the frequency of RhD negativity and its interaction with toxoplasmosis were included into the model, the effects of toxoplasmosis seemingly returned. However, the analysed data suffered from the problem of multicollinearity. When a proper method of analysis, ridge regression, was applied, the effects of toxoplasmosis prevalence and RhD negativity frequency disappeared again. The existence of a strong correlation between the prevalence of toxoplasmosis and health of population in particular countries, which was the probable cause of multicollinearity and possible reason for the negative result of the present study, suggests that ''asymptomatic'' latent toxoplasmosis could have a large impact on public health.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

6. Influence of latent ''asymptomatic'' toxoplasmosis on body weight of pregnant women

Creator:
Flegr, Jaroslav, Hrdá, Štěpánka, and Kodym, Petr
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
parasite, Toxoplasma, latent toxoplasmosis, pathology, permutation test, and gravidity
Language:
English
Description:
The latent toxoplasmosis is usually considered to be asymptomatic, however, this paradigm has never been rigorously tested. Here we searched for symptoms of deterioration of physical health (decrease of weight) in infected people by analysis of clinical records of 758 women tested for toxoplasmosis in the 16th week of gravidity. Toxoplasma-positive women have a lower body weight in the 16th week of gravidity (p = 0.02) than Toxoplasma-negative women. Moreover, a negative correlation between weight and the duration of toxoplasmosis was found in a subset of 174 Toxoplasma-positive women (p = 0.04), suggesting that slow and cumulative effects of latent toxoplasmosis, rather than a transient effect of acute toxoplasmosis, are responsible for the decreased weight of infected subjects. Longer duration of gravidity estimated from the date of last menstruation in the set of Toxoplasma-positive women in the 16th week of gravidity estimated with ultrasonography (p = 0.04) suggests a possibility of retarded foetal growth in Toxoplasma-positive women. The prevalence of latent toxoplasmosis is extremely high. Therefore, even its mild symptoms such as the decreased body weight in Toxoplasma-positive pregnant women might in fact indicate an unrecognized serious public health problem.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

8. Latent toxoplasmosis and vitamin D concentration in humans: three observational studies

Creator:
Kaňková, Šárka, Bičíková, Marie, Máčová, Ludmila, Hlaváčová, Jana, Sýkorová, Kateřina, Jandová, Dobroslava, and Flegr, Jaroslav
Format:
počítač and online zdroj
Type:
model:article and TEXT
Subject:
Toxoplasma gondii, calcidiol, depression, mental disorders, and schizophrenia
Language:
English
Description:
Numerous recent studies show that vitamin D deficiency potentiates various chronic physical and psychiatric disorders and diseases. It has been shown that a similar range of disorders is also associated with latent infection with Toxoplasma gondii (Nicolle et Manceaux, 1908). For instance, among cancer, diabetes and schizophrenia patients, we find a higher prevalence of both toxoplasmosis and vitamin D deficiency. Theoretically, therefore, vitamin D deficiency could be the missing link between toxoplasmosis and these disorders. We tested this hypothesis by searching for decreased vitamin D levels in the serum of subjects infected with T. gondii (furthermore called Toxoplasma-infected subjects) in two cross-sectional and one case-control study. Results of the first cross-sectional study (N = 72) suggest that Toxoplasma-infected neurasthenic patients have non-significantly lower levels of calcidiol than Toxoplasma-free patients (study A: P = 0.26 in women, P = 0.68 in men). However, two other studies (study B: N = 400; study C: N = 191) showed a non-significantly higher concentration of vitamin D in Toxoplasma-infected subjects than in Toxoplasma-free subjects both in men (study B: P = 0.70, study C: P = 0.55) and in women (study B: P = 0.64, study C: P = 0.12). Taken together, our preliminary results thus do not support the hypothesis that toxoplasmosis could be associated with vitamin D decrease.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

10. Pattern of money allocation in experimental games supports the stress hypothesis of gender differences in Toxoplasma gondii-induced behavioural changes

Creator:
Lindová, Jitka, Kuběna, Aleš A., Šturcová, Hana, Křivohlavá, Romana, Novotná, Martina, Rubešová, Anna, Havlíček, Jan, Kodym, Petr, and Flegr, Jaroslav
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
Toxoplasma, stress hypothesis, experimental games, coping, and gender differences
Language:
English
Description:
Latent toxoplasmosis has been previously found to cause behavioural and personality changes in humans, which are specific for each gender. Here we tested the stress hypothesis of these gender differences based on the assumption that latent toxoplasmosis causes long-term subliminal stress. In line with this hypothesis, the gender difference will appear specifically in situations with interpersonal context because in contrast to the typical individualistic coping style of men, women have a tendency to express elevated prosocial behaviour under stress. Altogether 295 biology students (29/191 females and 27/104 males infected by T. gondii) played a modified version of the Dictator Game and the Trust Game. As predicted, a gender difference in the effect of latent toxoplasmosis was found for the measure of reciprocal altruism in the Trust Game (p=0.016), but both genders appeared less generous when infected in the Dictator Game modified to minimize social connotation (p=0.048).
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public