personality – Toxoplasma gondii & Human Phenotype

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

February 1, 2020
Samojlowicz, D. Twarowska-Malczynska, J. Borowska-Solonynko, A. Poniatowski, L. A. Sharma, N. Olczak, M.
European Journal of Clinical Microbiology and Infectious Diseases 2019, 38: 305 - 317 Toxoplasma gondii Toxoplasmosis Brain Risky behavior Alcohol Mental health Drivers cerebral toxoplasmosis decreased level novelty seeking dopamine parasite host schizophrenia personality depression strategies

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Toxoplasma gondii infection and behavioral outcomes in humans: a systematic review

February 12, 2018
Martinez, V. O. , Lima, F. W. D., . de Carvalho, C. F, Menezes, J. A.
Parasitology Research 2018; 117: 3059-3065

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Toxoplasmosis, the insidious parasitic infection: dangers of asymptomatic carrier state

December 8, 2017
Bognar, L., Izso, T., Szakos, D., Kasza, G.
Magyar Allatorvosok Lapja 2017;139:479-487

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Background: The highly prevalent parasitic infection of humans, toxoplasmosis, can have serious consequences even during an asymptomatic course of the disease. The causative agente of infection is Toxoplasma gondii, which proliferates in the intestine of cats. Risk of infection by direct contact with cats is low, but the infection can occur due to contaminated soil, water, unwashed vegetables and fruits, as well as insufficiently heat-treated meat. Objectives: The aim of this study was to synthesize the current knowledge about infection caused by Toxoplasma gondii in a brief review focusing on latent toxoplasmosis in humans. Materials and Methods: More than hundred articles, studies and reports from scientific journals were considered to summarize the infection's characteristics such as prevalence and symptoms in humans. Results and Discussion: The symptoms of acute toxoplasmosis are either featureless, or non-existent, although, for people with immunosuppression it can be fatal, and for expectants it can result in foetal harm. The detection of the infection is conducted with serology methods, however, only in a few European countries are general screenings present. The asymptomatic carrier state is dangerous as well, because the cysts subsist in the brain of the host, which affects behaviour, the regulation of emotions, and also the level of several hormones. The latent toxoplasmosis can be connected to aggression, anxiety, schizophrenia, bipolar personality disorder, suicidal inclination, depression, and the reduction in intelligence quotient. For the reason of the deterioration of reaction time, the disease increases the risk of traffic accidents. The latent toxoplasmosis also influences personality traits; for women and men the alteration of the personality change differs. There is no data on the current epidemiological situation in Hungary, and not even in Europe. A research regarding the extent of asymptomatic carrier state and about the psychological changes in the Hungarian population has not been conducted so far.

Is Toxoplasma gondii infection related to brain and behavior impairments in humans? Evidence from a population-representative birth cohort

May 28, 2016
Sugden, K., Moffitt, T. E., Pinto, L., Poulton, R., Williams, B. S., Caspi, A.
Plos One 2016; 11: ARTN e0148435 10.1371/journal.pone.0148435

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The correlation between Toxoplasma gondii infection and prenatal depression in pregnant women

January 4, 2016
Shiadeh, M. N., Rostami, A., Pearce, B. D., Gholipourmalekabadi, M., Newport, D. J., Danesh, M., Mehravar, S., Seyyedtabaei, S. J.
European Journal of Clinical Microbiology & Infectious Diseases 2016; 35: 1829-1835

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“Latent” infection with Toxoplasma gondii: Association with trait aggression and impulsivity in healthy adults

October 9, 2015
Cook, T. B., Brenner, L. A., Cloninger, C. R., Langenberg, P., Igbide, A., Giegling, I., Hartmann, A. M., Konte, B., Friedl, M., Brundin, L., Groer, M. W., Can, A., Rujescu, D., Postolache, T. T.
Journal of Psychiatric Research 2015; 60: 87-94

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Toxoplasma gondii exposure in patients suffering from mental and behavioral disorders due to psychoactive substance use

January 10, 2015
Alvarado-Esquivel, C., Carrillo-Oropeza, D., Pacheco-Vega, S. J., Hernandez-Tinoco, J., Salcedo-Jaquez, M., Sanchez-Anguiano, L. F., Ortiz-Jurado, M. N., Alarcon-Alvarado, Y., Liesenfeld, O., Beristain-Garcia, I.
Bmc Infectious Diseases 2015; 15: Artn 172 10.1186/S12879-015-0912-1

Toxoplasmosis-associated difference in intelligence and personality in men depends on their Rhesus blood group but not ABO blood group

September 27, 2013
Flegr, J., Preiss, M., Klose, J.
PLoS ONE 2013; 8(4): e61272. doi:10.1371/journal.pone.0061272

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The relation of cortisol and sex hormone levels to results of psychological, performance, IQ and memory tests in military men and women

January 9, 2012
Flegr, J., Hampl, R., Černochová, D., Preiss, M., Bičíkova, M., Sieger, L., Příplatová, L., Kaňková, S., Klose, J.
Neuroendocrinology Letters 2012; 33: 224-235

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Toxoplasma infection in schizophrenia patients: A comparative study with control group

October 19, 2011
Alipour, A., Shojaee, S., Mohebali, M., Tehranidoost, M., Masoleh, F. A., Keshavarz, H.
Iranian Journal of Parasitology 2011; 6: 31-37

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Is there a relationship between Toxoplasma gondii infection and idiopathic Parkinson’s disease?

October 19, 2010
Celik, T., Kamisli, O., Babur, C., Cevik, M.O., Oztuna, D., Altinayar, S
Scandinavian Journal of Infectious Diseases 2010; 42: 604-608

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The influence of RhD phenotype on toxoplasmosis- and age-associated changes in personality profile of blood donors

September 26, 2010
Flegr, J., Novotná, M., Fialová, A., Kolbeková, P., Gasová, Z.
Folia Parasitologica 2010; 57: 57: 143-150

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Toxoplasma gondii: host-parasite interaction and behavior manipulation

October 26, 2009
da Silva, R.C., Langoni, H.
Parasitology Research 2009; 105: 893-898

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Higher prevalence of toxoplasmosis in victims of traffic accidents suggest increased risk of traffic accident in Toxoplasma-infected inhabitants of Istanbul and its suburbs.

October 26, 2009
Kocazeybek, B., Oner, Y. A., Turksoy, R., Babur, C., Cakan, H., Sahip, N., Unal, A., Ozaslan, A., Kilic, S., Saribas, S., Asian, M., Taylan, A., Koc, S., Dirican, A., Uner, H. B., Oz, V., Ertekin, C., Kucukbasmaci, O., Torun, M. M.
Forensic Science International 2009; 187: 103-108

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Reflexes of drivers who have toxoplasmosis have been shown to deteriorate from the actions of the parasitic cysts. The cysts can change the level of the neurotransmitters such as dopamine in the brain and by doing so extend the muscle response time and change personality profiles. In this Study, we aimed to determine the frequency of the latent toxoplasmosis (LT) in the driver population who were either injured or died in traffic accidents reported in Istanbul and its suburbs. We compared the results with a control group and discussed the relationship between the LT and the traffic accidents. We included 218 (89.7%) non-fatal, 25 (10.3%) fatal cases in our study as study groups. A total 243 subjects, 234 (96%) male, 9 (4%) female (who were alcohol negative) compared with 191 (95.5%) male and 9 (4.5%) female Subjects (control group) who had a traffic accident before but no history of toxoplasmosis were studied. Serologic tests, enzyme immunoassay (EIA) for IgG and IgM, and microimmunoflorescence (MIF) for IgG were used as the reference test, the Sabin-Feldman Dye test (SFDT) was used. According to serologic test results, LT seroprevalence in the study groups was 130 (53.5%) and in the control group 56 (28%) (p < 0.0001). A LT was present in 126 out of 234 (53.8%) males in the study groups, and 54 out of 191 (28.3%) males in the control group (p < 0.0001). In the 31-44 year age group, there was a significant difference with regard to toxoplasmosis between the study subjects and control groups (p < 0.0001). This difference was statistically very significant in (recent and former) cases with middle-aged men (31 44 years old). The results of this retrospective study Suggest that LT in drivers, especially those who are between 31 and 44 years might increase the risk for getting involved in a car accident. In a prospective study, Toxoplasma positive and negative subjects can be monitored before they are involved in a traffic accident to clarify the cause and result relationship. (C) 2009 Elsevier Ireland Ltd. All rights reserved.

The schizophrenia and Toxoplasma gondii connection: Infectious, immune or both?

October 26, 2008
Tamer, G. S., Dundar, D., Yalug, I., Caliskan, S., Yazar, S., Aker, A.
Advances in Therapy 2008; 25: 703-709

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Can the common brain parasite, Toxoplasma gondii, influence human culture?

October 30, 2006
Lafferty, K.D.
Proceedings of the Royal Society B-Biological Sciences 2006; 273: 2749-2755.

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Prevalence of Toxoplasma infection in first-episode schizophrenia and comparison between Toxoplasma-seropositive and Toxoplasma-seronegative schizophrenia

October 30, 2006
Wang, H. L., Wang, G. H., Li, Q. Y., Shu, C., Jiang, M. S., Guo, Y.
Acta Psychiatrica Scandinavica 2006; 114: 40-48.

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Toxoplasma gondii a potential risk for traffic accidents in Turkey?

October 30, 2006
Yereli, K., Balcioglu, .IC., Ozbilgin, A.
Forensic Science International 2006; 163: 34-37

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In Turkey, traffic accidents are the major causes of mortality and morbidity. According to the statistics made by Turkish Security Headquarters in the year 2000, 7500 people are killed in the traffic accidents every year. Drivers are mostly blamed for the traffic accidents. Tired, weary, sleepy and absentminded driving are common reasons for traffic accidents due to many reasons. Among these reasons mental and reflex conditions of drivers are significant. Toxoplasmosis is one of the most common zoonoses throughout the world. In immumocomponent adults, toxoplasmosis has no clinical signs or symptoms and infection in such people can only be detected by serological examinations. This kind of latent or dormant toxoplasmosis can be located in neural or muscular tissues and cause prolonged reaction times of the muscles. Extended reaction times also lead to deceleration of the reflexes which could be a major cause of the traffic accidents. By the light of this situation, the incidence of Toxoplasma gondii is investigated among the population who were involved in a traffic accident while driving. A total of 185 people (100 men and 85 women), aged between 21 and 40 years, living in Izmir and Manisa cities, were enrolled in the study group (SG) during a period of 6 months time. Their informed consents were taken initially and the laboratory tests of all these individuals related to blood alcohol levels after the accidents were found negative. The control group (CG) were also consisted 185 people (95 men and 90 women), residents of the same region, in same age group. The people in CG had no clinical signs or symptoms concerning toxoplasmosis. All collected sera were examined using a commercial IgG and IgM ELISA kit. According to the results of serological tests of the SG, 45 (24.32%) sera were IgG positive, six (3.24%) were IgM positive and 10 (5.40%) were both IgG and IgM positive. On the other hand in CG, 12 (6.48%) people found IgG positive, one (0.54%) found IgM positive and three (1.62%) found both IgG and IgM positive. This data was considered as statistically significant by Yates corrected chi(2)-test. (p < 0.05). In conclusion, there is an increased risk for traffic accidents for drivers owing to these high seroprevalence of latent toxoplasmosis. Prospective studies are still necessary on this subject but latent toxoplasmosis of drivers should be taken into account while developing strategies to prevent traffic accidents in Turkey. (c) 2005 Elsevier Ireland Ltd. All rights reserved.

Look what the cat dragged in: do parasites contribute to human cultural diversity?

October 30, 2005
Lafferty, K.D.
Behavioural Processes 2005; 68: 279-282

Probable neuroimmunological link between Toxoplasma and cytomegalovirus infections and personality changes in the human host

September 26, 2005
Novotná, M., Hanusova, J, Klose J., Preiss, M., Havlicek, J., Roubalová, K., Flegr, J.
BMC Infectious Diseases 2005; 5: 54

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Background: Recently, a negative association between Toxoplasma -infection and novelty s eeking was reported. The authors suggested that changes of pers onality trait were caused by manipula tion activity of the parasite, aimed at increasing the probability of tr ansmission of the parasite from an intermedia te to a definitive host . They also suggested that low novelty seeking indicated an in creased level of the neurot ransmitter dopamine in the brain of infected subjects, a phenomenon already observ ed in experimentally infected ro dents. However, the changes in personality can also be just a byproduct of any neurotropic infection . Moreover, the association between a pe rsonality trait and the toxoplasmosis can even be caused by an independent correlation of both the probability of Toxoplasma -infection and the personality trait with the third factor, namely with th e size of living place of a subject. To test these two alternative hypotheses, we studied the influence of another neurotropic pathogen, the cyto megalovirus, on the personali ty of infected subjects, and reanalyzed the original data after the effect of the potential confounder, the si ze of living plac e, was controlled. Methods: In the case-control study, 533 conscr ipts were tested for to xoplasmosis and presence of anti-cytomegalovirus antibodies and their novelty se eking was examined with Cloninger's TCI questionnaire. Possible association between the two infections and TCI dimensions was analyzed. Results: The decrease of novelty seeking is as sociated also with cytomegalovirus infe ction. After the size of living place was controlled, the effect of to xoplasmosis on novelty seeking increased. Si gnificant difference in novelty seeking was observed only in the largest city, Prague. Conclusion: Toxoplasma and cytomegalovirus probably induce a decrease of novelty seeking. As the cytomegalovirus spreads in population by direct contact (not by predation as with Toxoplasma ), the observed changes are the byproduct of brain infections rather than the result of manipulation activity of a parasite . Four independent line s of indirect evidence, namely direct measurement of neurotransmi tter concentration in mice, the nature of behavioral changes in rodents, the nature of personality changes in humans, and the observed association between schizophren ia and toxoplasmosis, suggest that the changes of dopamine concentration in brain coul d play a role in behavioral changes of infected hosts.

Rats, cats, people and parasites: the impact of latent toxoplasmosis on behaviour

November 7, 2001
Webster, J. P.
Microbes and Infection 2001; 3: 1037-1045

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Induction of changes in human behaviour by the parasitic protozoan Toxoplasma gondii

September 26, 1996
Flegr, J., Zitková, Š., Kodym, P., Frynta, D.
Parasitology 1996; 113: 49 - 54

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