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Jaroslav Flegr - One of the best experts on this subject based on the ideXlab platform.
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Negative Effects of Latent Toxoplasmosis on Mental Health.
Frontiers in psychiatry, 2020Co-Authors: Jaroslav Flegr, Jiří HoráčekAbstract:Infection by the parasite Toxoplasma, which affects about 33% of world population, is associated with an increased risk of several mental health disorders, the most strongly with schizophrenia. It is unknown whether schizophrenia is associated with this infection the most strongly, or whether this association has just been the most intensively studied for historical reasons. We used the data from 6,367 subjects tested for Toxoplasmosis who took part in an internet survey to search for associations of these infections with 24 mental health disorders and evidence of otherwise impaired mental health. The typical symptom associated with Toxoplasmosis was anxiety, and the typical Toxoplasmosis-associated disorders were autism (OR = 4.78), schizophrenia (OR = 3.33), attention deficit hyperactivity disorder (OR = 2.50), obsessive compulsive disorder (OR = 1.86), antisocial personality disorder (OR = 1.63), learning disabilities (OR = 1.59), and anxiety disorder (OR = 1.48). Toxoplasmosis could play a substantial role in the etiopathogenesis of mental health disorders and its association with schizophrenia is the second strongest association, after autism.
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Latent Toxoplasmosis and olfactory functions of Rh positive and Rh negative subjects.
PloS one, 2018Co-Authors: Jaroslav Flegr, Šárka Kaňková, Manfred Milinski, Jana Hlaváčová, Martin Hůla, K SykorovaAbstract:Backgrounds The prevalence of Toxoplasmosis is higher in schizophrenics than in the general population. It has been suggested that certain symptoms of schizophrenia, including changes in olfactory functions, are in fact symptoms of Toxoplasmosis that can be easily detected in schizophrenics only due to the increased prevalence of Toxoplasmosis in this population. Schizophrenics have impaired identification of odors and lower sensitivity of odor detection, however, no information about these parameters of non-schizophrenic Toxoplasma-infected subjects is available. Methods Here we searched for differences in olfactory functions between 62 infected and 61 noninfected non-schizophrenic subjects using the case-controls experimental design. Results The infected men scored better than the non-infected controls in the standard odor-identification test. The infected women rated all smells as more intensive while the infected men rated nearly all smells as less intensive. Infected women rated the pleasantness of the smell of the cat urine as higher than the non-infected women and the opposite was true for the men–in contrast, higher pleasantness of odor in infected men and lower in infected women were observed and described in the 2011 study. Toxoplasmosis, Rh, and Toxoplasmosis-Rh interaction were not associated with the rated pleasantness of the smell of other stimuli. However, our sample contained only 17 Rh negative men and 30 Rh negative women. Therefore, all results concerning the main effects of Rh factor and the interaction with Rh factor must be considered only preliminary. Conclusions Our results suggest that Latent Toxoplasmosis is associated with changes in the olfactory functions in humans; however, the observed changes differ from those observed in schizophrenics.
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Lower performance of Toxoplasma-infected, Rh-negative subjects in the weight holding and hand-grip tests
PloS one, 2018Co-Authors: Jaroslav Flegr, Blanka Šebánková, Lenka Priplatova, Veronika Chvátalová, Sarka KankovaAbstract:Background Toxoplasma, a protozoan parasite of cats, infects many species of intermediate and paratenic hosts, including about one-third of humans worldwide. After a short phase of acute infection, the tissue cysts containing slowly dividing bradyzoites are formed in various organs and Toxoplasmosis proceeds spontaneously in its Latent form. In immunocompetent subjects, Latent Toxoplasmosis was considered asymptomatic. However, dozens of studies performed on animals and humans in the past twenty years have shown that it is accompanied by a broad spectrum of specific behavioural, physiological and even morphological changes. In human hosts, the changes often go in the opposite direction in men and women, and are mostly weaker or non-existent in Rh-positive subjects. Methods Here, we searched for the indices of lower endurance of the infected subjects by examining the performance of nearly five hundred university students tested for Toxoplasmosis and Rh phenotype in two tests, a weight holding test and a grip test. Results The results confirmed the existence of a negative association of Latent Toxoplasmosis with the performance of students, especially Rh-negative men, in these tests. Surprisingly, but in an accordance with some already published data, Toxoplasma-infected, Rh-positive subjects expressed a higher, rather than lower, performance in our endurance tests. Discussion Therefore, the results only partly support the hypothesis for the lower endurance of Toxoplasma infected subjects as the performance of Rh-positive subjects (representing majority of population) correlated positively with the Toxoplasma infection.
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Lower performance of Toxoplasma-infected, Rh-negative subjects in the weight holding and hand-grip tests
2018Co-Authors: Jaroslav Flegr, Blanka Šebánková, Lenka Priplatova, Veronika Chvátalová, Sarka KankovaAbstract:Toxoplasma, a protozoan parasite of cats, infects many species of intermediate and paratenic hosts, including about one-third of humans worldwide. After a short phase of acute infection, the tissue cysts containing slowly dividing bradyzoites are formed in various organs and Toxoplasmosis proceeds spontaneously in its Latent form. In immunocompetent subjects, Latent Toxoplasmosis was considered asymptomatic. However, dozens of studies performed on animals and humans in the past twenty years have shown that it is accompanied by a broad spectrum of specific behavioural, physiological and even morphological changes. In human hosts, the changes often go in the opposite direction in men and women, and are mostly weaker or non-existent in Rh-positive subjects. Here, we searched for the indices of lower endurance of the infected subjects by examining the performance of nearly five hundred university students tested for Toxoplasmosis and Rh phenotype in two tests, a weight holding test and a grip test. The results confirmed the existence of a negative association of Latent Toxoplasmosis with the performance of students, especially Rh-negative men, in these tests. Surprisingly, but in an accordance with some already published data, Toxoplasma-infected, Rh-positive subjects expressed a higher, rather than lower, performance in our endurance tests. Therefore, the results only partly support the hypothesis for the lower endurance of Toxoplasma infected subjects as the performance of Rh-positive subjects (representing majority of population) correlated positively with the Toxoplasma infection.
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Effects of Latent Toxoplasmosis on olfactory functions of men and women
2017Co-Authors: Jaroslav Flegr, Sarka Kankova, Manfred Milinski, M Hula, Jana Hlaváčová, K SykorovaAbstract:The prevalence of Toxoplasmosis is higher in schizophrenics than in the general population. It has been suggested that certain symptoms of schizophrenia, including changes in olfactory functions, are in fact symptoms of Toxoplasmosis that can be easily detected in schizophrenics only due to the increased prevalence of Toxoplasmosis in this population. Schizophrenics have impaired identification of odors and lower sensitivity of odor detection. Here we searched for differences in olfactory functions between 62 infected and 61 noninfected non-schizophrenic subjects. The infected men scored better in the standard odor-identification test. The infected women rated all smells as more intensive while the infected men rated nearly all smells as less intensive. Infected women rated the pleasantness of the smell of undiluted cat urine as higher than the non-infected women and the opposite was true for the men (the opposite direction shifts in men and women were described earlier for highly diluted cat urine). Toxoplasmosis had no effect on the rated pleasantness of the smell of other stimuli. Our results suggest that Latent Toxoplasmosis is associated with changes in the olfactory functions in humans; however, the observed changes differ from those observed in schizophrenics.
Jan Havlíček - One of the best experts on this subject based on the ideXlab platform.
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Pattern of money allocation in experimental games supports the stress hypothesis of gender differences in Toxoplasma gondii-induced behavioural changes.
Folia parasitologica, 2010Co-Authors: Jitka Lindová, Jan Havlíček, Petr Kodym, Martina Novotna, Ales A. Kubena, Hana Sturcova, Romana Krivohlava, Anna Rubešová, Jaroslav FlegrAbstract: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).
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Increased incidence of traffic accidents in Toxoplasma -infected military drivers and protective effect RhD molecule revealed by a large-scale prospective cohort study
BMC infectious diseases, 2009Co-Authors: Jaroslav Flegr, Martina Novotna, Jiří Klose, Miroslava Berenreitterová, Jan HavlíčekAbstract:Background Latent Toxoplasmosis, protozoan parasitosis with prevalence rates from 20 to 60% in most populations, is known to impair reaction times in infected subjects, which results, for example, in a higher risk of traffic accidents in subjects with this life-long infection. Two recent studies have reported that RhD-positive subjects, especially RhD heterozygotes, are protected against Latent Toxoplasmosis-induced impairment of reaction times. In the present study we searched for increased incidence of traffic accidents and for protective effect of RhD positivity in 3890 military drivers.
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Neurophysiological effect of the Rh factor. Protective role of the RhD molecule against Toxoplasma-induced impairment of reaction times in women.
Neuro endocrinology letters, 2008Co-Authors: Jaroslav Flegr, Martina Novotna, Jitka Lindová, Jan HavlíčekAbstract:BACKGROUND: The biological function of RhD protein, a major component of the Rh blood group system, is largely unknown. No phenotypic effect of RhD protein, except its role in hemolytic disease of newborns and protective role against Toxoplasma-induced impairment of reaction times in men, has been described. METHODS: Here we searched for a protective effect of RhD positivity against Toxoplasma-induced prolongation of reaction times in a set of 110 male and 226 female students of the Faculty of Science tested for Latent Toxoplasmosis and concentration of testosterone in saliva. RESULTS: RhD-positive subjects have been confirmed to be less sensitive to the influence of Latent Toxoplasmosis on reaction times than Rh-negative subjects. While a protective role of RhD positivity has been demonstrated previously in four populations of men, the present study has shown a similar effect in 226 female students. Our results have also shown that the concentration of testoster one in saliva strongly influences (reduces) reaction times (especially in men) and therefore, this factor should be controlled in future reaction times studies. CONCLUSIONS: The observed effects of RhD phenotype could provide not only a clue to the long-standing evolutionary enigma of the origin of RhD polymor phism in humans (the effect of balancing selection), differences in the RhD+ allele frequencies in geographically distinct populations (resulting from geographic variation in the prevalence of Toxoplasma gondii), but might also be the missing piece in the puzzle of the physiological function of the RhD molecule. 1. 2.
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Gender differences in behavioural changes induced by Latent Toxoplasmosis.
International journal for parasitology, 2006Co-Authors: Jitka Lindová, Jan Havlíček, Petr Kodym, Zdeněk Hodný, Martina Novotna, Anna Skallová, Petra Kolbeková, Eva Jozifkova, Jaroslav FlegrAbstract:Abstract There is growing evidence that the protozoan Toxoplasma gondii modifies behaviour of its intermediate hosts, including humans, where it globally infects about 20–60% of the population. Although it is considered asymptomatic in its Latent stage, it was previously found to have remarkable and gender different effects on the personality factors A (warmth), G (rule consciousness), L (vigilance, mistrust) and Q3 (self-control, self-image) from Cattell’s 16PF Questionnaire. We performed a double blind experiment testing 72 and 142 uninfected men and women, respectively, and 20 and 29 infected men and women, respectively, in order to verify these gender differences using behavioural experiments. Our composite behavioural variables Self-Control and Clothes Tidiness (analogue to the 16PF factors G – conscientiousness and Q3 – self-control) showed a significant effect of the Toxoplasmosis–gender interaction with infected men scoring significantly lower than uninfected men and a trend in the opposite direction in women. The effect of the Toxoplasmosis–gender interaction on our composite behavioural variable Relationships (analogue to factor A – warmth) approached significance; infected men scored significantly lower than uninfected men whereas there was no difference in women. In the composite behavioural variable Mistrust (analogue to factor L), the pattern was affected by environment (rural versus urban). Possible interpretations of the gender differences are discussed.
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Decreased level of psychobiological factor novelty seeking and lower intelligence in men Latently infected with the protozoan parasite Toxoplasma gondii Dopamine, a missing link between schizophrenia and Toxoplasmosis?
Biological psychology, 2003Co-Authors: Jaroslav Flegr, Jan Havlíček, Jiří Klose, Marek Preiss, Martina Vitáková, Petr KodymAbstract:Toxoplasma gondii , a parasitic protozoan, infects about 30/60% of people worldwide. The Latent Toxoplasmosis, i.e. life-long presence of cysts in the brain and muscular tissues, has no effect on human health. However, infected subjects score worse in psychomotor performance tests and have different personality profiles than Toxoplasma -negative subjects. The mechanism of this effect is unknown; however, it is supposed that presence of parasites’ cysts in the brain induces an increase of the concentration of dopamine. Here we search for the existence of differences in personality profile between Toxoplasma -positive and Toxoplasma negative subjects by testing 857 military conscripts using a modern psychobiological questionnaire, namely with Cloninger’s Temperament and Character Inventory (TCI). ANCOVA showed that Toxoplasma -positive subjects had lower Novelty seeking (NS) scores
Petr Kodym - One of the best experts on this subject based on the ideXlab platform.
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Research Article The Effect of Latent Toxoplasma gondii Infection on the Immune Response in HIV-Infected Patients
2016Co-Authors: Ondrej Beran, Petr Kodym, Marek Malý, Alzbeta Davidova, Gabriela Reinvartova, David Jilich, Michal Holub, Hanus RozsypalAbstract:Copyright © 2015 Ondrej Beran et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. A relationship between Latent Toxoplasmosis and the immune system during HIV disease is poorly understood. Therefore, the aim of this follow-up study was to characterize immunological parameters in HIV-infected patients with Latent Toxoplasmosis and noninfected individuals. A total of 101 HIV-infected patients were enrolled in the study. The patients were classified into two groups based on anti-Toxoplasma gondii antibodies: a group of 55 toxoplasma-positive persons (TP) and a group of 46 toxoplasma-negative persons (TN). Absolute counts of several lymphocyte subsets decreased in the TP group, namely, T cells
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Direct evidence of Toxoplasma-induced changes in serum testosterone in mice.
Experimental parasitology, 2011Co-Authors: Šárka Kaňková, Petr Kodym, Jaroslav FlegrAbstract:Latent Toxoplasmosis is known to influence the morphology of infected persons and also increases the probability of the birth of male offspring in both humans and mice. All these traits can be related to the observed differences in the concentration of testosterone between Toxoplasma-infected and Toxoplasma-free subjects. However, it is not possible to decide, using the Toxoplasma-human model, whether Toxoplasmosis influences the level of testosterone in the infected host or whether individuals with different levels of testosterone vary in the probability of toxoplasma infection. Here we studied changes in the testosterone levels in the Latent phase of Toxoplasmosis in laboratory mice artificially infected with cystogenic but relatively virulent strain T38 of T. gondii. We observed decreased testosterone levels in both female and male mice with Latent Toxoplasmosis in comparison to uninfected controls (P=0.001). The present results indicate that Toxoplasma infection changes the concentration of serum testosterone in mice and human rather than changed concentration of testosterone influences the probability of the Toxoplasma infection. It is possible that the decrease of testosterone is an adaptive mechanism of infected mice aimed to compensate Toxoplasmosis-induced immunosuppression observed during Latent Toxoplasma infection.
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Modulation of immunity in mice with Latent Toxoplasmosis—the experimental support for the immunosuppression hypothesis of Toxoplasma-induced changes in reproduction of mice and humans
Parasitology Research, 2010Co-Authors: Šárka Kaňková, Petr Kodym, Vladimír Holáň, Alena Zajícová, Jaroslav FlegrAbstract:The immunosuppression hypothesis suggests that the increased sex ratio in mice and women with Latent Toxoplasmosis, retarded embryonic growth in the early phases of pregnancy, prolonged pregnancy of Toxoplasma -infected women, and increased prevalence of Toxoplasmosis in mothers of children with Down syndrome can be explained by the presumed immunosuppressive effects of Latent Toxoplasmosis. Here, we searched for indices of immunosuppression in mice experimentally infected with Toxoplasma gondii . Our results showed that mice in the early phase of Latent infection exhibited temporarily increased production of interleukin (IL)-12 and decreased production of IL-10. In accordance with the immunosuppression hypothesis, the mice showed decreased production of IL-2 and nitric oxide and decreased proliferation reaction (synthesis of DNA) in the mixed lymphocyte culture in the early and also in the late phases of Latent Toxoplasmosis. Since about 30% of the world population are Latently infected by T. gondii , the Toxoplasmosis-associated immunosuppression might have serious public health consequences.
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modulation of immunity in mice with Latent Toxoplasmosis the experimental support for the immunosuppression hypothesis of toxoplasma induced changes in reproduction of mice and humans
Parasitology Research, 2010Co-Authors: Šárka Kaňková, Petr Kodym, Vladimír Holáň, Alena Zajícová, Jaroslav FlegrAbstract:The immunosuppression hypothesis suggests that the increased sex ratio in mice and women with Latent Toxoplasmosis, retarded embryonic growth in the early phases of pregnancy, prolonged pregnancy of Toxoplasma-infected women, and increased prevalence of Toxoplasmosis in mothers of children with Down syndrome can be explained by the presumed immunosuppressive effects of Latent Toxoplasmosis. Here, we searched for indices of immunosuppression in mice experimentally infected with Toxoplasma gondii. Our results showed that mice in the early phase of Latent infection exhibited temporarily increased production of interleukin (IL)-12 and decreased production of IL-10. In accordance with the immunosuppression hypothesis, the mice showed decreased production of IL-2 and nitric oxide and decreased proliferation reaction (synthesis of DNA) in the mixed lymphocyte culture in the early and also in the late phases of Latent Toxoplasmosis. Since about 30% of the world population are Latently infected by T. gondii, the Toxoplasmosis-associated immunosuppression might have serious public health consequences.
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Pattern of money allocation in experimental games supports the stress hypothesis of gender differences in Toxoplasma gondii-induced behavioural changes.
Folia parasitologica, 2010Co-Authors: Jitka Lindová, Jan Havlíček, Petr Kodym, Martina Novotna, Ales A. Kubena, Hana Sturcova, Romana Krivohlava, Anna Rubešová, Jaroslav FlegrAbstract: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).
Šárka Kaňková - One of the best experts on this subject based on the ideXlab platform.
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Latent Toxoplasmosis and olfactory functions of Rh positive and Rh negative subjects.
PloS one, 2018Co-Authors: Jaroslav Flegr, Šárka Kaňková, Manfred Milinski, Jana Hlaváčová, Martin Hůla, K SykorovaAbstract:Backgrounds The prevalence of Toxoplasmosis is higher in schizophrenics than in the general population. It has been suggested that certain symptoms of schizophrenia, including changes in olfactory functions, are in fact symptoms of Toxoplasmosis that can be easily detected in schizophrenics only due to the increased prevalence of Toxoplasmosis in this population. Schizophrenics have impaired identification of odors and lower sensitivity of odor detection, however, no information about these parameters of non-schizophrenic Toxoplasma-infected subjects is available. Methods Here we searched for differences in olfactory functions between 62 infected and 61 noninfected non-schizophrenic subjects using the case-controls experimental design. Results The infected men scored better than the non-infected controls in the standard odor-identification test. The infected women rated all smells as more intensive while the infected men rated nearly all smells as less intensive. Infected women rated the pleasantness of the smell of the cat urine as higher than the non-infected women and the opposite was true for the men–in contrast, higher pleasantness of odor in infected men and lower in infected women were observed and described in the 2011 study. Toxoplasmosis, Rh, and Toxoplasmosis-Rh interaction were not associated with the rated pleasantness of the smell of other stimuli. However, our sample contained only 17 Rh negative men and 30 Rh negative women. Therefore, all results concerning the main effects of Rh factor and the interaction with Rh factor must be considered only preliminary. Conclusions Our results suggest that Latent Toxoplasmosis is associated with changes in the olfactory functions in humans; however, the observed changes differ from those observed in schizophrenics.
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Research Article
2016Co-Authors: Šárka Kaňková, Jaroslav Flegr, Pavel CaldaAbstract:The influence of Latent Toxoplasmosis on women’s reproductive function: four cross-sectional studie
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Effects of Latent Toxoplasmosis on Autoimmune Thyroid Diseases in Pregnancy
PloS one, 2014Co-Authors: Šárka Kaňková, Jaroslav Flegr, Lucie Procházková, Pavel Calda, Drahomira Springer, Eliska PotlukovaAbstract:Background: Toxoplasmosis, one of the most common zoonotic diseases worldwide, can induce various hormonal and behavioural alterations in infected hosts, and its most common form, Latent Toxoplasmosis, influences the course of pregnancy. Autoimmune thyroid diseases (AITD) belong to the well-defined risk factors for adverse pregnancy outcomes. The aim of this study was to investigate whether there is a link between Latent Toxoplasmosis and maternal AITD in pregnancy. Methods: Cross-sectional study in 1248 consecutive pregnant women in the 9–12 th gestational weeks. Serum thyroidstimulating hormone (TSH), thyroperoxidase antibodies (TPOAb), and free thyroxine (FT4) were assessed by chemiluminescence; the Toxoplasma status was detected by the complement fixation test (CFT) and anti-Toxoplasma IgG enzyme-linked immunosorbent assay (ELISA). Results: Overall, 22.5% of the women were positive for Latent Toxoplasmosis and 14.7% were screened positive for AITD. Women with Latent Toxoplasmosis had more often highly elevated TPOAb than the Toxoplasma-negative ones (p = 0.004), and Latent Toxoplasmosis was associated with decrease in serum TSH levels (p = 0.049). Moreover, we found a positive correlation between FT4 and the index of positivity for anti-Toxoplasma IgG antibodies (p = 0.033), which was even stronger in the TPOAb-positive Toxoplasma-positive women, (p = 0.014), as well as a positive correlation between FT4 and log2 CFT (p = 0.009). Conclusions: Latent Toxoplasmosis was associated with a mild increase in thyroid hormone production in pregnancy. The observed Toxoplasma-associated changes in the parameters of AITD are mild and do not seem to be clinically relevant; however, they could provide new clues to the complex pathogenesis of autoimmune thyroid diseases.
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Slower postnatal motor development in infants of mothers with Latent Toxoplasmosis during the first 18 months of life
Early human development, 2012Co-Authors: Šárka Kaňková, Jan Šulc, Romana Křivohlavá, Aleš Kuběna, Jaroslav FlegrAbstract:Abstract Toxoplasmosis, a zoonosis caused by a protozoan, Toxoplasma gondii , is probably the most widespread human parasitosis in developed countries. Pregnant women with Latent Toxoplasmosis have seemingly younger fetuses especially in the 16th week of gestation, which suggests that fetuses of Toxoplasma -infected mothers have slower rates of development in the first trimester of pregnancy. In the present retrospective cohort study, we analyzed data on postnatal motor development of infants from 331 questionnaire respondents including 53 Toxoplasma -infected mothers to search for signs of early postnatal development disorders. During the first year of life, a slower postnatal motor development was observed in infants of mothers with Latent Toxoplasmosis. These infants significantly later developed the ability to control the head position (p = 0.039), to roll from supine to prone position (p = 0.022) and were slightly later to begin crawling (p = 0.059). Our results are compatible with the hypothesis that the difference in the rates of prenatal and early postnatal development between children of Toxoplasma -negative and Toxoplasma -positive mothers might be caused by a decreased stringency of embryo quality control in partly immunosuppressed Toxoplasma -positive mothers resulting in a higher proportion of infants with genetic or developmental disorders in offspring. However, because of relatively low return rate of questionnaires and an associated risk of a sieve effect, our results should be considered as preliminary and performing a large scale prospective study in the future is critically needed.
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Direct evidence of Toxoplasma-induced changes in serum testosterone in mice.
Experimental parasitology, 2011Co-Authors: Šárka Kaňková, Petr Kodym, Jaroslav FlegrAbstract:Latent Toxoplasmosis is known to influence the morphology of infected persons and also increases the probability of the birth of male offspring in both humans and mice. All these traits can be related to the observed differences in the concentration of testosterone between Toxoplasma-infected and Toxoplasma-free subjects. However, it is not possible to decide, using the Toxoplasma-human model, whether Toxoplasmosis influences the level of testosterone in the infected host or whether individuals with different levels of testosterone vary in the probability of toxoplasma infection. Here we studied changes in the testosterone levels in the Latent phase of Toxoplasmosis in laboratory mice artificially infected with cystogenic but relatively virulent strain T38 of T. gondii. We observed decreased testosterone levels in both female and male mice with Latent Toxoplasmosis in comparison to uninfected controls (P=0.001). The present results indicate that Toxoplasma infection changes the concentration of serum testosterone in mice and human rather than changed concentration of testosterone influences the probability of the Toxoplasma infection. It is possible that the decrease of testosterone is an adaptive mechanism of infected mice aimed to compensate Toxoplasmosis-induced immunosuppression observed during Latent Toxoplasma infection.
I. Villena - One of the best experts on this subject based on the ideXlab platform.
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Comparison of four commercially available avidity tests for Toxoplasma gondii-specific IgG antibodies.
Clinical and Vaccine Immunology, 2013Co-Authors: Odile Villard, L. Breit, B. Cimon, J. Franck, H. Fricker-hidalgo, N. Godineau, S. Houze, L. Paris, H. Pelloux, I. VillenaAbstract:Toxoplasma infection in pregnant women may cause congenital Toxoplasmosis. Diagnosis of infection is based on serological tests aimed at detecting IgM and IgG antibodies against Toxoplasma gondii. However, IgM antibodies are not an accurate marker for discriminating between acute and Latent infection. Detection of residual or persistent IgM may occur months or even years after primary infection, while the IgG avidity test is a rapid means of identifying Latent infections in pregnant women who exhibit both IgG and IgM anti-Toxoplasma antibodies on initial testing during pregnancy. In this study, we assessed and compared the performances of four commercially available Toxoplasma IgG avidity tests in immunocompetent and immunocompromised patients with acute and Latent Toxoplasmosis. The positive predictive value of high avidity to confirm Latent Toxoplasmosis was 100% for all the assays, indicating that high avidity is a hallmark of Latent infection. However, the negative predictive value of high avidity ranged from 99.2% (bioMérieux) to 95.3% (Abbott), indicating that acute Toxoplasmosis could not be reliably diagnosed based on low IgG avidity alone. Thus, the avidity test provides a rapid means for identifying Latent Toxoplasma infection in immunocompetent pregnant women presenting both IgG and IgM anti-Toxoplasma antibodies on initial testing. In terms of cost-effectiveness, avidity testing is a powerful tool that optimizes screening and follow-up of pregnant women while minimizing the costs of screening by avoiding subsequent costly maternal and fetal investigation and unnecessary treatment. The cheapest assay, Vidas Toxo IgG Avidity, also had the best performance for the diagnosis of Latent Toxoplasmosis.
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Comparison of Four Commercially Available Avidity Tests for Toxoplasma gondii-Specific IgG Antibodies
Clinical and vaccine immunology : CVI, 2012Co-Authors: Odile Villard, L. Breit, B. Cimon, J. Franck, H. Fricker-hidalgo, N. Godineau, S. Houze, L. Paris, H. Pelloux, I. VillenaAbstract:Toxoplasma infection in pregnant women may cause congenital Toxoplasmosis. Diagnosis of infection is based on serological tests aimed at detecting IgM and IgG antibodies against Toxoplasma gondii. However, IgM antibodies are not an accurate marker for discriminating between acute and Latent infection. Detection of residual or persistent IgM may occur months or even years after primary infection, while the IgG avidity test is a rapid means of identifying Latent infections in pregnant women who exhibit both IgG and IgM anti-Toxoplasma antibodies on initial testing during pregnancy. In this study, we assessed and compared the performances of four commercially available Toxoplasma IgG avidity tests in immunocompetent and immunocompromised patients with acute and Latent Toxoplasmosis. The positive predictive value of high avidity to confirm Latent Toxoplasmosis was 100% for all the assays, indicating that high avidity is a hallmark of Latent infection. However, the negative predictive value of high avidity ranged from 99.2% (bioMerieux) to 95.3% (Abbott), indicating that acute Toxoplasmosis could not be reliably diagnosed based on low IgG avidity alone. Thus, the avidity test provides a rapid means for identifying Latent Toxoplasma infection in immunocompetent pregnant women presenting both IgG and IgM anti-Toxoplasma antibodies on initial testing. In terms of cost-effectiveness, avidity testing is a powerful tool that optimizes screening and follow-up of pregnant women while minimizing the costs of screening by avoiding subsequent costly maternal and fetal investigation and unnecessary treatment. The cheapest assay, Vidas Toxo IgG Avidity, also had the best performance for the diagnosis of Latent Toxoplasmosis.
