infection – Toxoplasma gondii & Human Phenotype

Seroprevalence and risk factors of Toxoplasma gondii among pregnant women in Adwa district, northern northern Ethiopia

February 4, 2020
Teweldemedhin, M., Gebremichael, A., Geberkirstos, G., Hadush, H., Gebrewahid, T., Asgedom, S. W., Gidey, B., Asres, N., Gebreyesus, H.
BMC Infectious Diseases 2019, 19

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Toxoplasma gondii – obsessive -compulsive disorder relationship: is it different in children?

February 1, 2020
Miman, O., Ozcan, O., Unal, S., Atambay, M.
Nordic Journal of Psychiatry 2019, 72: 501 - 505

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

February 1, 2020
Brown, A. S.
Developmental Neurobiology 2012, 72: 1272 - 1276

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Large-scale study of Toxoplasma and Cytomegalovirus shows an association between infection and serious psychiatric disorders

January 31, 2020
Burgdorf, K. S., Trabjerg, B. B., Pedersen, M. G., Nissen, J., Banasik, K., Pedersen, O. B., Sorensen, E., Nielsen, K. R., Larsen, M. H., Erikstrup, C., Bruun-Rasmussen, P., Westergaard, D., Thorner, L. W., Hjalgrim, H., Paarup, H. M., Brunak, S., Pedersen, C. B., Torrey, E. F., Werge, T., Mortensen, P. B., Yolken, R. H., Ullum, H.
Brain Behavior and Immunity 2019, 79: 152 - 158

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Seroprevalence and molecular evaluation of Toxoplasma gondii in Schizophrenic patients hospitalized in Sistan and Baluchestan province, Southeast of Iran

January 31, 2020
Modrek, M. J., Hasanzadeh, R., Foroutan, M., Mirahmadi, H., Rahmati-Balaghaleh, M., Zarean, M.
Tropical Biomedicine 19, 36: 422 - 429

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The relation between serum Toxoplasma gondii IgG antibody in children and ADHD and its severity

January 30, 2020
Akaltun, I., Kara, T., Ayaydin, H., Alyanak, B., Beka, H., Agacfidan, A.
Psychiatry and Clinical Psychopharmacology 2019, 29: 326 - 331

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The association between Toxoplasma gondii infection and hypertensive disorders in T2DM patients: a case-control study in the Han Chinese population

September 4, 2018
Han, Y. J., Nie, L. H., Ye, X. H., Zhou, Z. X., Huang, S. Q., Zeng, C. L., Guo, C. C., Ou, M. L., Xiao, D., Zhang, B. H., Huang, C. C., Ye, X. G., Jing, C. X., Yang, G.
Parasitology Research 2018; 117: 689-695

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Toxoplasma gondii as a possible causative pathogen of type-1 diabetes mellitus: Evidence from case-control and experimental studies

September 3, 2018
Beshay, E. V. N., El-Refai, S. A., Helwa, M. A., Atia, A. F., Dawoud, M. M.
Experimental Parasitology 2018; 188: 93-101

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Toxoplasma gondii is the causative parasite of an important worldwide disease. This obligate intracellular parasite can infect and replicate inside any nucleated cells including those of pancreas. Insulin is a hormone secreted by the pancreas and is responsible for controlling blood glucose concentration. Deficiency of insulin production accounts for the occurrence of type-1 diabetes mellitus (T1D). Thus, theoretically, toxoplasmosis could play a possible role in the development of T1D. However, the studies on this theory are still insufficient; therefore, this work was designed. Interestingly, in the case-control study, seropositivity of anti-Toxoplasma IgG was significantly higher among T1D (86.37%) in comparison with T2D (66.67%) and the control group (60%). Moreover, the odd ratio of chronic toxoplasmosis was 4.2 folds higher among T1D patients than among controls. The experimental study included acute and chronic Me49 T gondii infected mice groups in addition to a control group. Pathological examination revealed the presence of T gondii zoites adjacent to the islets of Langerhans and in pancreatic parenchyma of acutely infected mice. With chronic infection, there was a significant reduction of islets number and sizes in association with grade-1 insulitis. Additionally, the immunohistochemical study showed significant infiltration of the islets of chronically infected mice by CD8(+) and CD45(+) immune cells. In contrary to the control group, the islets of the chronic group showed significantly higher expression of the apoptotic marker caspase-3 and a significantly lower expression of the proliferation marker Ki69. Finally, a significant reduction of insulin expression in the islets of chronic infection group was detected in association with a significant increase in serum glucose concentrations; however, the establishment of diabetes did not occur throughout this work. Thus, this study presents an evidence for the probable role of chronic toxoplasmosis in the development of T1D which should be considered in further studies

Seroprevalance Anti-Toxoplasma gondii antibodies in children and adolescents with tourette syndrome/chronic motor or vocal tic disorder: A case-control study

September 3, 2018
Akaltun, I., Kara, T., Kara, S. S., Ayaydin, H.
Psychiatry Research 2018; 263: 154-157

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Depressiveness and neuroticism in Bartonella seropositive and seronegative subjects-preregistered case-controls study

September 3, 2018
Flegr, J., Preiss, M., Balatova, P.
Frontiers in Psychiatry 2018; 9

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Is Toxoplasma gondii playing a positive role in multiple sclerosis risk? A systematic review and meta-analysis

August 31, 2018
Saberi, R., Sharif, M., Sarvi, S., Aghayan, S. A., Hosseini, S. A., Anvari, D., Chegeni, T. N., Hosseininejad, Z., Daryani, A.
Journal of Neuroimmunology 2018;322: 57-62

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Is there a relation between the manipulative activity of Toxoplasma and personalized medicine?

May 3, 2018
Flegr, J.
Expert Review of Anti-Infective Therapy 2018; 16: 1-3

The association between suicide attempts and Toxoplasma gondii infection

May 3, 2018
Bak, J. Shim, S.H., Kwon, Y.J., Lee, H.Y., Kim, J.S., Yoon, H., Lee, Y.J.
Clinical Psychopharmacology Neuroscience 2018; 16: 95-102

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Toxoplasma gondii: Biological parameters of the connection to schizophrenia

February 12, 2018
Xiao, J. C. ,Prandovszky, E. , Kannan,G., Pletnikov, M. V. Dickerson, ,F. , Severance , E. G., Yolken, R. H.
Schizophrenia Bulletin 2018; 44: 983-992

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Viral and parasitic pathogen burden and the association with stroke in a population-based cohort

February 12, 2018
Pearce, B. D.,Bracher, A. , Jones, J. L., Kruszon-Moran, D.
International Journal of Stroke 2018; 13_: 481-495

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Background Higher cumulative burden of viral and bacterial pathogens may increase the risk of stroke, but the contribution of parasitic infections in relation to cumulative pathogen burden and risk of stroke has rarely been examined. Aim To estimate the association of multiple persistent viral and parasitic infections with stroke in a representative sample of adults in the United States. Methods Serological evidence of prior infection was categorized as positive for 0-1, 2, 3, or 4-5 infections based on immunoglobulin G seropositivity to cytomegalovirus, hepatitis A virus, hepatitis B virus, Toxoplasma gondii, and Toxocara spp. in 13,904 respondents from the National Health and Nutrition Examination Survey III. Regression analysis was used to estimate the cross-sectional association between serological evidence of prior infection and history of stroke adjusting for demographic risk factors, and potential mediators of stroke. Results Age-adjusted models that included serological evidence of prior infection to cytomegalovirus, hepatitis A virus, hepatitis B virus, Toxoplasma gondii, and Toxocara spp. showed that adults in the highest serological evidence of prior infection category (4-5 infections) had a higher prevalence of stroke (5.50%, 95% confidence interval 2.44-10.46%) than those in the lowest serological evidence of prior infection categories (1.49%, 95% confidence interval 1.01-2.11%), and a trend test suggested a graded association between serological evidence of prior infection and stroke (p=0.02). In multivariable logistic regression models, the positive association of serological evidence of prior infection with stroke prevalence remained significant after adjustment for other significant risk factors (odds ratio=1.4, p=0.01) but was only significant among those aged 20-59 (odds ratio=2.0, p=0.005) and not among those aged 60-69 (p=0.78) or 70 and older (p=0.43). Conclusion We found support for a connection between serological evidence of prior infection to cytomegalovirus, hepatitis A virus, hepatitis B virus, Toxoplasma gondii, and Toxocara spp. and stroke among those aged 20-59. There may be a need to consider common parasitic infections in addition to viral and bacterial pathogens when calculating serological evidence of prior infection in relation to cerebrovascular disease.

Toxoplasma gondii seropositivity and substance use in US adults

February 12, 2018
Berrett, A. N., Gale, S. D., Erickson,L. D., Thacker, E. L., Brown, B. L., Hedges, D. W.
Folia Parasitologica 2018; 65: 011

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A critical assessment of the association between postnatal toxoplasmosis and epilepsy in immune-competent patients

December 8, 2017
Uzorka, J. W., Arend, S. M.
European Journal of Clinical Microbiology and Infectious Diseases 2017; 7:1111-1117

Neurophysiological changes induced by chronic Toxoplasma gondii infection

December 8, 2017
Tedford, E., McConkey, G.
Pathogens 2017; 6: Artn 19 10.3390/Pathogens6020019

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Toxoplasma gondii exposure and Parkinson’s disease: a case-control study

October 3, 2017
Alvarado-Esquivel, C., Mendez-Hernandez, E. M., Salas-Pacheco, J. M., Ruano-Calderon, L. A., Hernandez-Tinoco, J., Arias-Carrion, O., Sanchez-Anguiano, L. F., Castellanos-Juarez, F. X., Sandoval-Carrillo, A. A., Liesenfeld, O., Ramos-Nevarez, A.
Bmj Open 2017; 7

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Objectives: To determine the association between Toxoplasma gondii infection and Parkinson's disease and to investigate whether T. gondii seropositivity is associated with the general characteristics of patients with Parkinson's disease. Design: Case-control study. Setting: Cases and controls were enrolled in Durango City, Mexico. Participants: 65 patients with Parkinson's disease and 195 age-and gender-matched control subjects without Parkinson's disease. Primary and secondary outcome measures: Serum samples of participants were analysed for anti-T. gondii IgG and IgM antibodies by commercially available enzyme-linked immunoassays. Prevalence of T. gondii DNA was determined in seropositive subjects using PCR. The association between clinical data and infection was examined by bivariate analysis. Results: Anti-T. gondii IgG antibodies were found in 6/65 cases (9.2%) and in 21/195 controls (10.8%) (OR 0.84; 95% CI 0.32 to 2.18; p=0.81). The frequency of high (>150 IU/mL) antibody levels was similar among cases and controls (p=0.34). None of the anti-T. gondii IgG positive cases and four of the anti-T. gondii IgG positive controls had anti-T. gondii IgM antibodies (p=0.54). The prevalence of T. gondii DNA was comparable in seropositive cases and controls (16.7% and 25%, respectively; p=1.0). Seroprevalence of T. gondii infection was associated with a young age onset of disease (p=0.03), high Unified Parkinson Disease Rating Scale scores (p=0.04) and depression (p=0.02). Seropositivity to T. gondii infection was lower in patients treated with pramipexole than in patients without this treatment (p=0.01). However, none of the associations remained significant after Bonferroni correction. Conclusions: The results do not support an association between T. gondii infection and Parkinson's disease. However, T. gondii infection might have an influence on certain symptoms of Parkinson's disease. Further research to elucidate the role of T. gondii exposure on Parkinson's disease is warranted.

Toxoplasma gondii and schizophrenia: a review of published RCTs

October 2, 2017
Chorlton, S.D.
Parasitology Research 2017; 116: 1793-1799

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The association between Toxoplasma and the psychosis continuum in a general population setting

October 2, 2017
Lindgren, M., Torniainen-Holm, M., Yolken, R., Suvisaari, J.
Schizophrenia Bulletin 2017; 43: S108-S109

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Background: An increased prevalence of antibodies to Toxoplasma gondii has been found to be associated with psychosis. An association with positive symptom severity in a psychosis risk sample has also been reported. However, the possible association between toxoplasma and positive symptoms in the general population is unknown. Methods: We investigated whether Toxoplasma gondii is associated with psychosis diagnoses and psychotic symptoms in the general population. We used data from Health 2000, a large health survey of the Finnish population aged 30 and older (n = 5906). Levels of IgG antibodies to Toxoplasma gondii were determined and seropositivity defined as a cutoff of 50 IU/ml. Lifetime psychotic symptoms were identified with section G of the Composite International Diagnostic Interview, Munich version (M-CIDI). The CIDI screen was considered positive if the interviewee reported any clinically relevant symptom or at least 3 symptoms regardless of clinical relevance. Lifetime psychotic disorders were screened from the sample and were diagnosed with DSM-IV using case notes and SCID-I interview. The possible diagnoses were: any psychotic disorder, functional psychosis, schizophrenia, other nonaffective psychosis, and affective psychosis. Results: The seroprevalence of Toxoplasma in the population was 13%; 12% of the participants reported at least one psychotic symptom, the most common symptoms being delusions of reference and suspicion, and 4% were considered positive for the CIDI screen. In a logistic regression model, toxoplasma seropositivity was the only significant predictor of the CIDI screen status, when other variables associated with toxoplasma were adjusted for (age, gender, education, region of residence, cat ownership, and C-reactive protein measuring inflammation). Toxoplasma infection was not associated with any psychosis diagnoses. Conclusion: In a large sample representing the whole Finnish population aged 30 and older, we found that toxoplasma infection predicted psychotic symptoms but not psychosis diagnoses. The association between psychotic symptoms and toxoplasma was not explained by inflammation.

Relationship between Toxoplasma gondii seropositivity and acoustic startle response in an inner-city population

October 2, 2017
Massa, N. M., Duncan, E., Jovanovic, T., Kerley, K., Weng, L., Gensler, L., Lee, S. S., Norrholm, S., Powers, A., Almli, L. M., Gillespie, C. F., Ressler, K., Pearce, B. D.,
Brain Behavior and Immunity 2017; 61: 176-183

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Toxoplasma gondii (TOXO) is a neuroinvasive protozoan parasite that induces the formation of persistent cysts in mammalian brains. It infects approximately 1.1 million people in the United States annually. Latent TOXO infection is implicated in the etiology of psychiatric disorders, especially schizophrenia (SCZ), and has been correlated with modestly impaired cognition. The acoustic startle response (ASR) is a reflex seen in all mammals. It is mediated by a simple subcortical circuit, and provides an indicator of neural function. We previously reported the association of TOXO with slowed acoustic startle latency, an index of neural processing speed, in a sample of schizophrenia and healthy control subjects. The alterations in neurobiology with TOXO latent infection may not be specific to schizophrenia. Therefore we examined TOXO in relation to acoustic startle in an urban, predominately African American, population with mixed psychiatric diagnoses, and healthy controls. Physiological and diagnostic data along with blood samples were collected from 364 outpatients treated at an inner-city hospital. TOXO status was determined with an ELISA assay for TOXO-specific IgG. A discrete titer was calculated based on standard cut-points as an indicator of seropositivity, and the TOXO-specific IgG concentration served as serointensity. A series of linear regression models were used to assess the association of TOXO seropositivity and serointensity with ASR magnitude and latency in models adjusting for demographics and psychiatric diagnoses (PTSD, major depression, schizophrenia, psychosis, substance abuse). ASR magnitude was 11.5% higher in TOXO seropositive subjects compared to seronegative individuals (p = 0.01). This effect was more pronounced in models with TOXO serointensity that adjusted for sociodemographic covariates (F = 7.41, p = 0.0068; F = 10.05, p = 0.0017), and remained significant when psychiatric diagnoses were stepped into the models. TOXO showed no association with startle latency (t = 0.49, p = 0.63) in an unadjusted model, nor was TOXO associated with latency in models that included demographic factors. After stepping in individual psychiatric disorders, we found a significant association of latency with a diagnosis of PTSD (F = 5.15, p = 0.024), but no other psychiatric diagnoses, such that subjects with PTSD had longer startle latency. The mechanism by which TOXO infection is associated with high startle magnitude is not known, but possible mechanisms include TOXO cyst burden in the brain, parasite recrudescence, or molecular mimicry of a host epitope by TOXO. Future studies will focus on the neurobiology underlying the effects of latent TOXO infection as a potential inroad to the development of novel treatment targets for psychiatric disease.

Prenatal toxoplasmosis antibody and childhood autism

October 2, 2017
Spann, M. N., Sourander, A., Surcel, H. M., Hinkka-Yli-Salomaki, S., Brown, A. S.
Autism Research 2017; 10: 769-777

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Toxoplasma gondii-infected subjects report an obsessive-compulsive disorder diagnosis more often and score higher in obsessive-compulsive inventory

September 27, 2017
Flegr, J., Horáček, J.
European Psychiatry 2017; 40: 82-87

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Toxoplasma-infected subjects report an Obsessive-Compulsive Disorder diagnosis more often and score higher in Obsessive-Compulsive Inventory

May 11, 2017
Flegr, J., Horacek, J.
Academy of Management and Perspectives 2017; 31: 63-81

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Neurophysiological changes induced by chronic Toxoplasma gondii Infection.

March 13, 2017
Tedford, E., McConkey, G.
Pathogens. 2017; 6: 19-31

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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.

Infectious and immunogenetic factors in bipolar disorder

January 3, 2017
Oliveira, J., Oliveira-Maia, A. J., Tamouza, R., Brown, A. S., Leboyer, M.
Acta Psychiatrica Scandinavica 2017; 136:409-423

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Stability of Toxoplasma gondii: Antibody levels in schizophrenia

January 3, 2017
Yuksel, P., Kocazeybek, B, Ozdemir, A., Yolken, R. H., Torrey ,E.F.
Schizophrenia Research 2017; 189: 221-222

Association between anti-Toxoplasma gondii antibodies and schizophrenia and psychotic bipolar in patients hospitalized in the psychiatric ward

October 6, 2016
Dalimiasl, A., Mosayebi, M., Ghorbanzadeh, B., Ghasemi, M., Hajihossein, R.
Australasian Medical Journal 2016; 9: 313-318

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Seropositivity of Toxoplasma gondii and Toxocara spp. in children with cryptogenic epilepsy, Benha, Egypt

October 6, 2016
Eraky, M.A., Abdel-Hady, S., Abdallah, K.F.
Korean Journal of Parasitology 2016; 54: 335-338.

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No association between current depression and latent toxoplasmosis in adults

October 6, 2016
Gale, S. D., Berrett, A. N., Brown, B., Erickson, L. D., Hedges, D. W.
Folia Parasitologica 2016; 63: DOI 10.14411/fp.2016.032

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Changes in behaviour and cognition have been associated with latent infection from the apicomplexan protozoan Toxoplasma gondii (Nicolle et Manceaux, 1908) in both animal and human studies. Further, neuropsychiatric disorders such as schizophrenia have also been associated with latent toxoplasmosis. Previously, we found no association between T. gondii immunoglobulin G antibody (IgG) seropositivity and depression in human adults between the ages of 20 and 39 years (n = 1 846) in a sample representative of the United States collected by the Centers for Disease Control as part of a National Health and Nutrition Examination Survey (NHANES) from three datasets collected between 1999-2004. In the present study, we used NHANES data collected between 2009 and 2012 that included subjects aged 20 to 80 years (n = 5 487) and used the Patient Health Questionnaire 9 (PHQ-9) to assess depression with the overall aim of testing the stability of the results of the prior study. In the current study, the seroprevalence of T. gondii was 13%. The percentage of subjects reporting clinical levels of depression assessed with the PHQ-9 was 8%. As before, we found no association between T. gondii IgG seroprevalence and depression (OR = 1.01, 95% CI = 0.81-1.25; p = 0.944) while controlling for sex, educational attainment, race-ethnicity, age, poverty-to-income ratio and cigarette smoking. We also found no positive associations between anti-T. gondii antibody titre and depression (OR = 1.00, 95% CI = 0.96-1.06; p = 0.868). Moreover, we found no association between T. gondii seroprevalence or antibody titre and suicidal ideation (seroprevalence: OR = 1.22, 95% CI =.85-1.75; p = 0.277, titre: OR = 1.05, 95% CI = 0.98-1.14; p = 0.177). Defining depression to also include subjects currently taking antidepressant medication even with non-elevated questionnaires did not find evidence of a positive association between latent toxoplasmosis and depression. In the present study, neither T. gondii seroprevalence nor anti-T. gondii antibody titre was positively associated with depression or suicidal ideation among subjects aged 20 to 80 years.

Toxoplasmosis and Alzheimer: can Toxoplasma gondii really be introduced as a risk factor in etiology of Alzheimer?

October 6, 2016
Mahami-Oskouei, M., Hamidi, F., Talebi, M., Farhoudi, M., Taheraghdam, A. A., Kazemi, T., Sadeghi-Bazargani, H., Fallah, E.
Parasitology Research 2016; 115: 3169-3174.

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Seroprevalence and serointensity of latent Toxoplasma gondii in a sample of elderly adults with and without Alzheimer disease

October 3, 2016
Perry, C. E., Gale, S. D., Erickson, L., Wilson, E., Nielsen, B., Kauwe, J., Hedges, D. W.
Alzheimer Disease and Associated Disorders 2016; 30: 123-126

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Toxoplasma gondii-A gastrointestinal pathogen associated with human brain diseases

October 3, 2016
Severance, E. G., Xiao, J., Jones-Brando, L., Sabunciyan, S., Li, Y., Pletnikov, M., Prandovszky, E., Yolken, R.
In: Cryan JF, Clarke G, eds. Gut Microbiome and Behavior 2016: pp. 143-163. (International Review of Neurobiology).

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Serious psychiatric disorders such as schizophrenia, bipolar disorder, and major depression are important causes of mortality and morbidity worldwide. While these are primarily diseases involving altered brain functioning, numerous studies have documented increased rates of gastrointestinal inflammation and dysfunction in many individuals with these disorders. Toxoplasma gondii is an apicomplexan protozoan intracellular parasite with a widespread distribution in both developed and developing countries. Toxoplasma organisms enter the ecosystem through the shedding of oocysts by Toxoplasma-infected felines. In almost all cases of postnatal human infection, Toxoplasma enters its hosts through the intestinal tract either by the ingestion of oocysts or by the consumption of meat from food animals which themselves were infected by Toxoplasma oocysts. It had previously been thought that most cases of Toxoplasma infection in immune competent children and adults were inapparent and asymptomatic. However, recent studies cast doubt on this concept as exposure to Toxoplasma has been associated with a range of acute and chronic symptoms. Of particular note has been the finding of an increased rate of a range of neurological and psychiatric disorders associated with serological evidence of Toxoplasma exposure. A role of Toxoplasma infection in brain diseases is also supported by the consistent finding of altered cognition and behavior in animal models of infections. Much of the attention relating to the role of Toxoplasma infection in neuropsychiatric disorders has focused on the brain, where Toxoplasma tissue cysts can persist for extended periods of time. However, recent discoveries relating to the role of the gastrointestinal tract in cognition and behavior suggest that Toxoplasma may also increase susceptibility to human brain diseases through immune activation, particularly involving the gastrointestinal mucosa. The study of the pathways relating to the pathobiology and immunology of Toxoplasma infection may provide insights into the pathogenesis of a range of human neuropsychiatric disorders as well as into cognitive functioning in otherwise healthy individuals.

The role of infection in miscarriage

May 25, 2016
Giakoumelou, S., Wheelhouse, N., Cuschieri, K., Entrican, G., Howie, S.E.M., Horne, A.W.
Human Reproductive Update 2016; 22: 116-133

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BACKGROUND: Miscarriage is the spontaneous loss of a pregnancy before 12 weeks (early miscarriage) or from 12 to 24 weeks (late miscarriage) of gestation. Miscarriage occurs in one in five pregnancies and can have considerable physiological and psychological implications for the patient. It is also associated with significant health care costs. There is evidence that potentially preventable infections may account for up to 15% of early miscarriages and up to 66% of late miscarriages. However, the provision of associated screening and management algorithms is inconsistent for newly pregnant women. Here, we review recent population-based studies on infections that have been shown to be associated with miscarriage. METHODS: Our aim was to examine where the current scientific focus lies with regards to the role of infection in miscarriage. Papers dating from June 2009 with key words 'miscarriage' and 'infection' or 'infections' were identified in PubMed (292 and 327 papers, respectively, on 2 June 2014). Relevant human studies (meta-analyses, case-control studies, cohort studies or case series) were included. Single case reports were excluded. The studies were scored based on the Newcastle - Ottawa Quality Assessment Scale. RESULTS: The association of systemic infections with malaria, brucellosis, cytomegalovirus and human immunodeficiency virus, dengue fever, influenza virus and of vaginal infection with bacterial vaginosis, with increased risk of miscarriage has been demonstrated. Q fever, adeno-associated virus, Bocavirus, Hepatitis C and Mycoplasma genitalium infections do not appear to affect pregnancy outcome. The effects of Chlamydia trachomatis, Toxoplasma gondii, human papillomavirus, herpes simplex virus, parvovirus B19, Hepatitis B and polyomavirus BK infections remain controversial, as some studies indicate increased miscarriage risk and others show no increased risk. The latest data on rubella and syphilis indicate increased antenatal screening worldwide and a decrease in the frequency of their reported associations with pregnancy failure. Though various pathogens have been associated with miscarriage, the mechanism(s) of infection-induced miscarriage are not yet fully elucidated. CONCLUSIONS: Further research is required to clarify whether certain infections do increase miscarriage risk and whether screening of newly pregnant women for treatable infections would improve reproductive outcomes.

Toxoplasma gondii seroprevalence in the Portuguese population: comparison of three cross-sectional studies spanning three decades

May 24, 2016
Gargate, M. J., Ferreira, I., Vilares, A., Martins, S., Cardoso, C., Silva, S., Nunes, B., Gomes, J. P.
Bmj Open 2016; 6: ARTN e011648 10.1136/bmjopen-2016-011648

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