Effects Of Latent Toxoplasmosis Research Articles

Relationship between Latent Toxoplasmosis and Depression in Clients of a Center for Assisted Reproduction.

Latent infection of the globally spread parasite Toxoplasma gondii in humans has been associated with changes in personality and behavior. Numerous studies have investigated the effect of toxoplasmosis on depression, but their results are inconsistent. Our study focused on the effect of latent toxoplasmosis on depression in men and women in association with their fertility. In 2016–2018, we recruited clients (677 men and 664 women) of the Center for Assisted Reproduction and asked them to complete a standardized Beck Depression Inventory-II. In women without fertility problems, we found higher depression scores in Toxoplasma-positive than in Toxoplasma-negative (p = 0.010, Cohen’s d = 0.48). Toxoplasma-positive infertile men, on the other hand, had lower depression scores than Toxoplasma-negative infertile men (p ≤ 0.001, Cohen’s d = 0.48). Our results are consistent with the previously described effects of latent toxoplasmosis, which seem to go in opposite directions regarding the effect on personality and behavior of men and women. Our results could be explained by gender-contrasting reactions to chronic stress associated with lifelong infection. This suggests that due to gender differences in the impact of latent toxoplasmosis, future studies ought to perform separate analyses for women and men.

Presence of Toxoplasma gondii infection in brain as a potential cause of risky behavior: a report of 102 autopsy cases

Toxoplasmosis was linked to impairment in brain function, encompassing a wide range of behavioral and neuropsychiatric changes. Currently, the precise localization of Toxoplasma gondii in the human brain is limited and the parasite DNA was not found in population-based screening of autopsy cases. The aim of proposed study was to identify the presence of parasite DNA within the brain and its association with risky behavior and alcohol consumption in postmortem examination. Preliminarily, 102 cases with certain circumstances of death at time of forensic autopsy was included. Due to high risk of bias, the females were excluded from the analysis and final study group consists 97 cases divided into three groups: risky behavior, inconclusively risky behavior, and control group. The obtained tissue samples for Nested PCR covered four regions of the brain: symmetric left/right and anterior/posterior horns of lateral ventricles comprising lining ependyma and hippocampus. The second type of material comprised blood evaluated for antibodies prevalence using ELISA and alcohol concentration using HS-GC-FID. Analysis demonstrated 16.5% prevalence concerning the parasite DNA presence in examined brain tissue samples without specific distribution and association with age at death or days after death until an autopsy was performed. Results have shown correlation between occurrence of risky behavior leading to death and higher proportions of positive parasite DNA presence within the brain. Correlation was not observed between parasite DNA presence and excessive alcohol consumption. Conducted screening demonstrated correlation between parasite DNA presence in the brain with risky behavior and provided new information on possible effects of latent toxoplasmosis.

Do differences in Toxoplasma prevalence influence global variation in secondary sex ratio? Preliminary ecological regression study.

Sex of the fetus is genetically determined such that an equal number of sons and daughters are born in large populations. However, the ratio of female to male births across human populations varies significantly. Many factors have been implicated in this. The theory that natural selection should favour female offspring under suboptimal environmental conditions implies that pathogens may affect secondary sex ratio (ratio of male to female births). Using regression models containing 13 potential confounding factors, we have found that variation of the secondary sex ratio can be predicted by seroprevalence of Toxoplasma across 94 populations distributed across African, American, Asian and European continents. Toxoplasma seroprevalence was the third strongest predictor of secondary sex ratio, β = -0·097, P < 0·01, after son preference, β = 0·261, P < 0·05, and fertility, β = -0·145, P < 0·001. Our preliminary results suggest that Toxoplasma gondii infection could be one of the most important environmental factors influencing the global variation of offspring sex ratio in humans. The effect of latent toxoplasmosis on public health could be much more serious than it is usually supposed to be.

Neurological and Neuropsychiatric Consequences of Chronic Toxoplasma Infection

The neurotropic pathogen Toxoplasma gondii infects about one third of human population. For a long time, it is well known that both acute and latent (life-long) forms of toxoplasmosis are associated with specific neurologic and neuropsychiatric symptoms. Here, the possible effects of latent toxoplasmosis on neurological and psychiatric disorders are surveyed and some general methodological problems of corresponding studies are discussed.

Study of Latent Toxoplasma gondii Role in Level of Testosterone, DHEA, Cortisol and Prolactin Hormones of Young Persons

Toxoplasmosis influences the behavior and personality of infected persons. Possible mechanisms for these psychic disorders include its effect on dopamine and on hormone levels. In the present research, the effect of latent toxoplasmosis on testosterone, DHEA, cortisol and prolactin hormones in the infected and noninfected individuals was examined. A total of 215 plasma sample were examined for IgG and IgM anti-Toxoplasma antibody, testosterone, DHEA, cortisol and prolactin levels. In addition the prevalence of hirsutism, acne and alopecia also evaluated in individuals. Serological analysis confirmed that 61 men (28.37%) and 58 women (26.97%) were sero-positive. A statistically significant correlation between toxoplasmosis and testosterone and cortisol increase were observed but there were no significant differences between infected and noninfected individuals in level of prolactin and DHEA. There were significant differences in frequency of allopcy, acne and hirsutism between two groups. Because of these hormones have though helps in management of stress and human behavior and personality so the direct correlation between toxoplasmosis and psychological disorders is suggested due to effect of Toxoplasma on host’s hormone levels

Toxoplasma gondii infection affects cognitive function - corrigendum

In the recent issue of Folia Parasitologica (59: 93–98), Guenter et al. (2012) published results of a study showing that the effect of latent toxoplasmosis on cognitive function of 70 subjects cannot be proved to exist using a panel of five neuropsychological tests (Guenter et al. 2012). It must be mentioned that the data (mostly ordinal variables without normal distribution) were analysed either with parametric tests (GLM) or with more proper nonparametric tests, but without controlling for age and sex of subjects. It is known for a long time that shifts in personality profile and behaviour associated with latent toxoplasmosis differ very often in their direction between men and women (Flegr and Hrdý 1994, Flegr et al. 1996; Lindova et al. 2006, 2010). This raises the question whether cognitive functions reveal a similar phenomenon. Therefore, we re-analysed the data on 56 women and 14 men separately. To control for the effect of age, which is known to influence the performance of subjects and also the probability of being Toxoplasma-infected, we analyzed the data with partial Kendall regression, the nonparametric technique that controls for one confounding variable (Kaňkova et al. 2011). The results showed that, generally, women scored worse in tests except Digit span-backward test (significantly worse only in the verbal fluency test, p = 0.015), whereas males scored better in all tests except in percentage of correct answers in N-back test (significantly better in digit span-forward, p = 0.008 and in Stroop test I, p = 0.017). Published results of a simple reaction time test show that psychomotor performance of both men and women is lower in subjects with latent toxoplasmosis (Flegr et al. 2008). However, most of personality factors and in some population also intelligence are shifted in an opposite direction in Toxoplasma-infected men and women FoLIa ParasIToLoGIca 59 [4]: 253–254, 2012 IssN 0015-5683 (print), IssN 1803-6465 (online) © Institute of Parasitology, Biology centre ascr http://folia.paru.cas.cz/

Rhesus Factor Modulation of Effects of Smoking and Age on Psychomotor Performance, Intelligence, Personality Profile, and Health in Czech Soldiers

BackgroundRhesus-positive and rhesus-negative persons differ in the presence-absence of highly immunogenic RhD protein on the erythrocyte membrane. This protein is a component of NH3 or CO2 pump whose physiological role is unknown. Several recent studies have shown that RhD positivity protects against effects of latent toxoplasmosis on motor performance and personality. It is not known, however, whether the RhD phenotype modifies exclusively the response of the body to toxoplasmosis or whether it also influences effects of other factors.Methodology/Principal FindingsIn the present cohort study, we searched for the effects of age and smoking on performance, intelligence, personality and self-estimated health and wellness in about 3800 draftees. We found that the positive effect of age on performance and intelligence was stronger in RhD-positive soldiers, while the negative effect of smoking on performance and intelligence was of similar size regardless of the RhD phenotype. The effect of age on four Cattell's personality factors, i.e., dominance (E), radicalism (Q1), self-sentiment integration (Q3), and ergic tension (Q4), and on Cloninger's factor reward dependency (RD) was stronger for RhD-negative than RhD-positive subjects, while the effect of smoking on the number of viral and bacterial diseases was about three times stronger for RhD-negative than RhD-positive subjects.ConclusionsRhD phenotype modulates the influence not only of latent toxoplasmosis, but also of at least two other potentially detrimental factors, age and smoking, on human behavior and physiology. The negative effect of smoking on health (estimated on the basis of the self-rated number of common viral and bacterial diseases in the past year) was much stronger in RhD-negative than RhD-positive subjects. It is critically needed to confirm the differences in health response to smoking between RhD-positive and RhD-negative subjects by objective medical examination in future studies.

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

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).