humans – Toxoplasma gondii & Human Phenotype

The role of latent toxoplasmosis in the aetiopathogenesis of schizophrenia–the risk factor or an indication of a contact with cat?

February 6, 2020
Yuksel, P., Alpay, N., Babur, C., Bayar, R., Saribas, S., Karakose, A. R., Aksoy, C., Aslan, M., Mehmetali, S., Kilic, S., Balcioglu, I., Hamanca, O., Dirican, A., Kucukbasmaci, O., Oner, A., Torun, M. M., Kocazeybek, B.
Folia Parasitol (Praha) 2010, 57: 121 - 128 Adult Aged Animals Antibodies, Protozoan/blood Case-Control Studies Cats Cross-Sectional Studies Female Humans Immunoglobulin G/blood Male Middle Aged Retrospective Studies Risk Factors Schizophrenia/*blood/*etiology Toxoplasmosis/blood/*complications/immunology

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The relation of secondary sex ratio and miscarriage history with Toxoplasma gondii infection

August 31, 2018
Shojaee, S.,Teimouri, A., Keshavarz, H., Azami, S. J., Nouri, S.
Bmc Infectious Diseases 2018; 18: 307

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Risky business: linking Toxoplasma gondii infection and entrepreneurship behaviours across individuals and countries

August 31, 2018
Johnson, S. K., Fitza, M. A. , Lerner, D. A., Calhoun, D. M., Beldon, M. A. , Chan, E. T., Johnson, P. T. J.
Proceedings of the Royal Society B-Biological Sciences, 2018; 285

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Seroprevalence of Bartonella species, Coxiella burnetii and Toxoplasma gondii among patients with hematological malignancies: A pilot study in Romania

December 8, 2017
Messinger, C. J., Gurzau, E. S., Breitschwerdt, E. B., Tomuleasa, C. I., Trufan, S. J., Flonta, M. M., Maggi, R. G., Berindan-Neagoe, I., Rabinowitz, P. M.
Zoonoses and Public Health 2017;64:485-490

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Significance of chronic toxoplasmosis in epidemiology of road traffic accidents in Russian Federation

December 8, 2017
Stepanova, E. V., Kondrashin, A. V., Sergiev, V. P., Morozova, L. F., Turbabina, N. A., Maksimova, M. S., Brazhnikov, A. I., Shevchenko, S. B., Morozov, E. N.
PLoS ONE 2017;12: 10.1371/journal.pone.0184930

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Toxoplasmosis, leptospirosis, and brucellosis seroepidemiology in veterinary medical students and their relation with unique health

January 4, 2017
Clazer, M., Rodrigues, G. V., Ferreira, B. P. M., Zaniolo, M. M., Correa, N. A. B., Fortes, M. S., Navarro, I. T., Chiderolli, R. T., de Freitas, J. C., Goncalves, D. D.
Semina-Ciencias Agrarias, 2017, 38: 1347-1359

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Toxoplasmosis, leptospirosis, and brucellosis are global zoonoses, with humans as accidental participants in their transmission cycles. The can also be considered occupational diseases, because certain professionals are at greater risk of contact and infection by such zoonoses. These three diseases have different epidemiological characteristics because of the distinct environmental, social, cultural, and economic conditions where these pathogens circulate. Because of the importance of these diseases and their associations with specific occupations, we performed a seroepidemiological survey of Toxoplasma, Leptospira, and Brucella antibodies, with an analysis of the association between positive serum and certain occupational and environmental variables, in students of a veterinary medicine course (1st, 2nd, 3rd, 4th, and 5th year) in a university in the northwestern region in the state of Parana, Brazil. From May to November 2014, blood samples were collected from 157 volunteers by professionals trained in nursing and biomedicine from the same university as the veterinary students. At the time of blood collection, the students did not present any clinical signs of the three diseases of interest. To detect anti-Toxoplasma gondii, anti-Leptospira spp., and anti-Brucella antibodies, indirect immunofluorescence test (IIF), microscopic agglutination test (MAT), fast agglutination test (a screening test), and enzyme-linked immunosorbent assay (ELISA) were performed. To determine variables associated with these infections, the students were interviewed to complete an epidemiological questionnaire with environmental, behavioral, and occupational information. The associations between these variables and infections were assess by chi-square or Fischer's exact tests, with a 5% significance level (a). Of the 157 serum samples analyzed, 29.29% reacted to Toxoplasma antigens, with titers ranging from 16 to 4096 by IIF, 1.27% to Leptospira antigens, with titers ranging from 100 to 800 by MAT using Hardjo and Wolffi serovars, and 0.63% to Brucella antigens by ELISA; however, no variables were found to be associated with infection with any of these pathogens. The results of this study show that one-third of the students in the veterinary medicine course were exposed to Toxoplasma gondii, Leptospira spp., and Brucella spp. at some stage in their lives; however, it is not possible to determine whether these infections were acquired at the university, because no associations between occupational risk variables and these infections were found. An understanding of the transmission of each etiological agent and methods to prevent infection is important to maintain low prevalence levels of these zoonotic diseases during the veterinary medicine course and extra-curricular internships, when there is increased exposure to these pathogens.

Seroprevalence of Toxoplasma gondii infection and its as- sociated risk factors in neuropsychiatric patients in Jazan Province, Saudi Arabia

November 20, 2016
Zaki, W. M., Hofdi, R. Y., Shebiley, A. A., Saadi, Z. A.,Ageel, A. H.
J. Egypt. Soc. Parasitol. 2016; 46: 467-474

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Seroprevalence of Toxoplasma gondii infection and its as- sociated risk factors in neuropsychiatric patients in Jazan province, Saudi Arabia

October 30, 2016
Zaki, W. M., Hofdi, R. Y., Shebiley, A. A., Saadi, Z. A., Ageel, A. H.
Journal of the Egyptian Society of Parasitology 2016; 240: 1-8

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Sero-prevalence of anti- Toxoplasma gondii antibodies among patients with neuropsychiatric disorders: Epilepsy and depression

October 30, 2016
Abd El-Aal, N. F., Saber, M., Fawzy, N., Ashour, W. R.
Journal of the Egyptian Society of Parasitology 2016; 46: 729-736

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Toxoplasma gondii infection: Relationship with aggression in psychiatric subjects

October 6, 2016
Coccaro, E. F., Lee, R., Groer, M. W., Can, A., Coussons-Read, M., Postolache, T. T.,
Journal of Clinical Psychiatry 2016; 77: 334-341.

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Is chronic toxoplasmosis a risk factor for diabetes mellitus? A systematic review and meta-analysis of case-control studies

October 6, 2016
Majidiani, H., Datuand, S., Daryani, A., Galuan-Ramirez, M. D., Foroutan-Rad, M.
Brazilian Journal of Infectious Diseases 2016; 20: 605-609.

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Hepatitis C virus antibody titers associated with cognitive dysfunction in an asymptomatic community-based sample

May 24, 2016
Ibrahim, I., Salah, H., El Sayed, H., Mansour, H., Eissa, A., Wood, J., Fathi, W., Tobar, S., Gur, R. C., Gur, R. E., Dickerson, F., Yolken, R. H., El Bahaey, W., Nimgaonkar, V.
Journal of Clinical and Experimental Neuropsychology 2016; 38; : 861-868, 10.1080/13803395.2016.1168780

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Toxoplasma gondii and anxiety disorders in a community-based sample

October 29, 2015
Markovitz, A. A., Simanek, A. M., Yolken, R. H., Galea, S., Koenen, K. C., Chen, S.,Aiello, A. E.
Brain,Behavior, and Immunity 2015; 43: 192-197

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A meta-analysis of the prevalence of Toxoplasma gondii in animals and humans in Ethiopia

May 28, 2015
Gebremedhin, E. Z., Tadesse, G.
Parasites & Vectors 2015; 8: Artn 291 10.1186/S13071-015-0901-7

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Ocular toxoplasmosis past, present and new aspects of an old disease

October 30, 2014
Maenz, M., Schluter, D., Liesenfeld, O., Schares, G., Gross, U., Pleyer, U.
Progress in Retinal and Eye Research 2014; 39: 77-106

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Toxoplasma gondii impairs memory in infected seniors

October 10, 2014
Gajewski, P. D., Falkenstein, M., Hengstler, J. G., Golka, K.
Brain Behavior and Immunity 2014; 36: 193-199

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New findings: Depression, suicide, and Toxoplasma gondii infection

October 9, 2014
Hsu, P.C., Groer, M., Beckie, T.
Journal of the American Association of Nurse Practitioners 2014; 26: 629-637

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Masterpiece of epigenetic engineering – how Toxoplasma gondii reprogrammes host brains to change fear to sexual attraction

January 9, 2014
Flegr, J., Markos, A.
Molecular Ecology 2014; 23:5934-5936

The evolutionary puzzle of suicide

October 29, 2013
Aubin, H. J.,,Berlin, I., Kornreich, C.
International Journal of Environmental Research and Public Health 2013; 10.3390/ijerph10126873

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Toxoplasma gondii: A potential role in the genesis of psychiatric disorders

October 11, 2013
Fond, G., Capdevielle, D., Macgregor, A., Attal, J., Larue, A., Brittner, M., Ducasse, D., Boulenger, J. P.
Encephale-Revue De Psychiatrie Clinique Biologique Et Therapeutique 2013; 39: 38-43.

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INTRODUCTION: Toxoplasma gondii is the most common protozoan parasite in developed nations. Up to 43% of the French population may be infected, depending on eating habits and exposure to cats, and almost one third of the world human's population may be infected. Two types of infection have been described: a congenital form and an acquired form. Although the medical profession treats these latent cases as asymptomatic and clinically unimportant, results of animal studies and recent studies of personality profiles, behavior, and psychomotor performance have led to reconsider this assumption. PRECLINICAL DATA: Among rats: parasite cysts are more abundant in amygdalar structures than those found in other regions of the brain. Infection does not influence locomotion, anxiety, hippocampal-dependent learning, fear conditioning (or its extinction) and neophobia in rats. Rats' natural predator is the cat, which is also T. gondii's reservoir. Naturally, rats have an aversion to cat urine, but the parasite suppresses this aversion in rats, thus influencing the infection cycle. Tachyzoites may invade different types of nervous cells, such as neurons, astrocytes and microglial cells in the brain, and Purkinje cells in cerebellum. Intracellular tachyzoites manipulate several signs for transduction mechanisms involved in apoptosis, antimicrobial effectors functions, and immune cell maturation. Dopamine levels are 14% higher in mice with chronic infections. These neurochemical changes may be factors contributing to mental and motor abnormalities that accompany or follow toxoplasmosis in rodents and possibly in humans. Moreover, the antipsychotic haloperidol and the mood stabilizer valproic acid most effectively inhibit Toxoplasma growth in vitro with synergistic activity. CLINICAL DATA: The effects of the parasite are not due to the manipulation in an evolutionary sense but merely due to neuropathological or neuroimmunological effects of the parasite's presence. Toxoplasmosis and schizophrenia: epidemiological studies point to a role for toxoplasmosis in schizophrenia's etiology, probably during pregnancy and early life, this association being congruent with studies in animal models indicating that animal exposures of the developing brain to infectious agents or immune modulating agents can be associated with behavioral changes that do not appear until the animal reaches full maturity. Psychiatric patients have increased rates of toxoplasmic antibodies, the differences between cases and controls being greatest in individuals who are assayed near the time of the onset of their symptoms. The increase of dopamine in the brain of infected subjects can represent the missing link between toxoplasmosis and schizophrenia. Toxoplasmosis and Obsessive Compulsive Disorder (OCD): the seropositivity rate for anti-T. gondii IgG antibodies among OCD patients is found to be significantly higher than the rate in healthy volunteers. Infection of basal ganglia may be implicated in the pathogenesis of OCD among Toxoplasma seropositive subjects. Toxoplasmosis and personality: infected men appear to be more dogmatic, less confident, more jealous, more cautious, less impulsive and more orderly than others. Conversely, infected women seem warmest, more conscientious, more insecure, more sanctimonious and more persistent than others. It is possible that differences in the level of testosterone may be responsible for the observed behavioral differences between Toxoplasma-infected and Toxoplasma-free subjects. CONCLUSION: In the future two major avenues for research seem essential. On one hand, prospective studies and research efforts must still be carried out to understand the mechanisms by which the parasite induces these psychiatric disorders. On the other hand, it has not yet been demonstrated that patients with positive toxoplasmic serology may better respond to haloperidol's or valproic acid's antiparasitic activity. These results may appear as a major issue in the drug's prescribing choices and explain variability in response to the treatment of patients with schizophrenia that is not explained by the genetic polymorphism.

Prevalence of Toxoplasma gondii parasite infection among people who died due to sudden death in the capital city of Warsaw and its vicinity

September 4, 2013
Samojlowicz, D., Borowska-Solonynko, A., Golab, E.
Przegled Epidemiologicny 2013; 67: 29-33

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BACKGROUND: It has recently been shown that the behavioural effects resulting from latent T. gondii infection in immunocompetent people could pose as a threat to their welfare. AIM. The aim of the study was to evaluate the prevalence of T. gondii infection in a group of people who died suddenly in Warsaw and its vicinity. MATERIAL AND METHODS: The studied group (n = 169 people) included 42 road traffic accident victims who were driving a vehicle (bicycle (n = 6), a motorbike (n = 3), a motorcycle (n = 13), a car (n = 20)) prior to sudden death and 41 people whose death resulted from suicide. Blood samples were collected post-mortem and examined for the presence of T. gondii, IgG antibodies and ethyl alcohol. RESULTS: Of the 169 people tested, T. gondii IgG antibodies were found in the serum of 93 (55%) of which 25 (59.5%) were drivers and 26 (63.4%) people who died as a result of suicide. With respect to the prevalence of T. gondii infection no statistically significant differences were found between the study (61.4%) and control group (49.4%); (p = 0.09). A statistically significant result was recorded in the 38-58 age group between suicide and control groups (71.4% vs. 44.4%; p < 0.05). Positive test results for the presence of ethyl alcohol in the blood were reported among 49.7% of the studied population: 25.7% among drivers, 67.6% among suicides and 51.8% in the control group. To a statisctically siginificant degree, IgG T. gondii antibodies were found to occur more frequently in people with positive blood alcohol test results among suicides (72% vs. 50%; p < 0.05) and among the control group (60% vs. 40%; p < 0.05) than in their equivalents with negative test results. CONCLUSIONS: Our work confirmed the usefulness of serologically testing samples collected post-mortem for epidemiological purposes. The small size of the study group made it impossible to evaluate the potential associations between exposure to T. gondii infection and the probability of sudden death. The significance of Toxoplasma gondii infection as a risk factor for self-destructive behaviour merits further study.

High seroprevalence of Toxoplasma gondii infection in a subset of Mexican patients with work accidents and low socioeconomic status

October 16, 2012
Alvarado-Esquivel, C., Torres-Castorena, A., Liesenfeld, O., Estrada-Martinez, S., Urbina-Alvarez, J. D.
Parasites & Vectors 2012;5: Artn 13 10.1186/1756-3305-5-13

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BACKGROUND: Toxoplasma gondii has been associated with reflex impairment and traffic accidents. It is unknown whether Toxoplasma infection might be associated with work accidents. Therefore, using a case-control seroprevalence study design, 133 patients with a recent work accident and 266 control subjects of the general population from the same region were examined with enzyme-linked immunoassays for the presence and levels of anti-Toxoplasma IgG antibodies and anti-Toxoplasma IgM antibodies. Socio-demographic, work, clinical and behavioral characteristics from each worker were obtained. RESULTS: Eleven (8.3%) of 133 patients, and 14 (5.3%) of 266 controls had anti-T. gondii IgG antibodies. Anti-T. gondii IgG levels were higher than 150 IU/ml in 8 (6%) patients and 10 (3.8%) controls. Anti-T. gondii IgM antibodies were found in one (0.8%) of the workers, and in 6 (2.3%) of the controls. No statistically significant differences in the IgG seroprevalences, frequencies of high IgG levels, and IgM seroprevalences among patients and controls were found. In contrast, a low socio-economic level in patients with work accidents was associated with Toxoplasma seropositivity (P = 0.01). Patients with work accidents and low socioeconomic status showed a significantly (OR = 3.38; 95% CI: 0.84-16.06; P = 0.04) higher seroprevalence of T. gondii infection than controls of the same socioeconomic status (15.1% vs. 5%, respectively). Multivariate analysis showed a positive association of T. gondii infection with boar meat consumption (OR = 3.04; 95% CI: 1.03-8.94; P = 0.04). In contrast, a negative association between T. gondii infection and national trips (OR = 0.40; 95% CI: 0.17-0.96; P = 0.04), sausage consumption (OR = 0.20; 95% CI: 0.05-0.68; P = 0.01), and ham consumption (OR = 0.16; 95% CI: 0.05-0.51; P = 0.002) was found. CONCLUSIONS: In the study described here seropositivity to T. gondii was associated to work accidents in a subset of patients with low socioeconomic status. This is the first report of an association of T. gondii infection and work accidents. Further studies to confirm our results are needed. Results may help in designing optimal prevention strategies to avoid T. gondii infection.

Maternal antibodies to infectious agents and risk for non-affective psychoses in the offspring–a matched case-control study

October 16, 2012
Blomstrom, A., Karlsson, H., Wicks, S., Yang, S. J., Yolken, R. H., Dalman, C.
Schizophrenia Research 2012; 140: 25-30

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Epidemiologic studies of exposure to prenatal infection and risk of schizophrenia and autism

October 16, 2012
Brown, A.S.
Developmental Neurobiology 2012; 72: 1272-1276.

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Seroprevalence of anti-Toxoplasma gondii IgG antibody in patients with schizophrenia

October 16, 2012
Emelia, O., Amal, R. N., Ruzanna, Z. Z., Shahida, H., Azzubair, Z., Tan, K. S., Aadila, S. N., Siti, N. A. M., Aisah, M. Y.
Tropical Biomedicine 2012; 29: 151-159

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Does Toxoplasma gondii infection affect cognitive function? A case control study

October 16, 2012
Guenter, W., Bielinski, M., Deptula, A., Zalas-Wiecek, P., Piskunowicz, M., Szwed, K., Bucinski, A., Gospodarek, E., Borkowska, A.
Folia Parasitologica 2012; 59: 93-98.

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Rhesus factor modulation of effects of smoking and age on psychomotor performance, intelligence, personality profile, and health in Czech soldiers

January 9, 2012
Flegr, J., Geryk, J., Volny, J., Klose, J., Cernochova, D.
Plos One 2012; 7: ARTN e49478 10.1371/journal.pone.0049478

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Serum antibodies to Toxoplasma gondii and Herpesvidae family viruses in individuals with schizophrenia and bipolar disorder: a case-control study

October 16, 2011
Tedla, Y., Shibre, T., Ali, O., Tadele, G., Woldeamanuel, Y., Asrat, D., Aseffa, A., Mihret, W., Abebe, M., Alem, A., Medhin, G., Habte, A.
Ethiopian Medical Journal 2011; 49: 211-220

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Toxoplasma gondii: epidemiology, feline clinical aspects, and prevention

October 30, 2010
Elmore, S. A., Jones, J. L., Conrad, P. A., Patton, S., Lindsay, D. S., Dubey, J. P.
Trends in Parasitology 2010; 26: 190-196

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Toxoplasma gondii antibody titers and history of suicide attempts in patients with recurrent mood disorders

October 30, 2009
Arling, T. A., Yolken, R. H., Lapidus, M., Langenberg, P., Dickerson, F. B., Zimmerman, S. A., Balis, T., Cabassa, J. A., Scrandis, D. A., Tonelli, L. H., Postolache, T. T.
The Journal of Nervous and Mental Disease 2009; 3:905-908

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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

January 9, 2009
Flegr, J., Klose, J., Novotná, M., Berenreitterová, M., Havlíček, J.
Bmc Infectious Diseases 2009; 9: Artn 72 10.1186/1471-2334-9-72

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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. Methods: Male draftees who attended the Central Military Hospital in Prague for regular entrance psychological examinations between 2000 and 2003 were tested for Toxoplasma infection and RhD phenotype at the beginning of their 1 to 1.5-year compulsory military service. Subsequently, the data on Toxoplasma infection and RhD phenotype were matched with those on traffic accidents from military police records and the effects of RhD phenotype and Toxoplasma infection on probability of traffic accident was estimated with logistic regression. Results: We confirmed, using for the first time a prospective cohort study design, increased risk of traffic accidents in Toxoplasma-infected subjects and demonstrated a strong protective effect of RhD positivity against the risk of traffic accidents posed by latent toxoplasmosis. Our results show that RhD-negative subjects with high titers of anti-Toxoplasma antibodies had a probability of a traffic accident of about 16.7%, i.e. a more than six times higher rate than Toxoplasma-free or RhD-positive subjects. Conclusion: Our results showed that a common infection by Toxoplasma gondii could have strong impact on the probability of traffic accident in RhD negative subjects. The observed effects could provide not only a clue to the long-standing evolutionary enigma of the origin of RhD polymorphism in humans (the effect of balancing selection), but might also be the missing piece in the puzzle of the physiological function of the RhD molecule.

Selected infectious agents and risk of schizophrenia among U.S. military personnel

October 29, 2008
Niebuhr, D. W., Millikan, A. M., Cowan, D. N., Yolken, R., Li, Y., Weber, N. S.
The American Journal of Psychiatry 2008;1 65: 99-106

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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

January 9, 2008
Flegr, J., Novotná, M., Lindová, J., Havlíček, J.
Neuroendocrinology Letters 2008; 29: 475-481

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