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Toxoplasma gondii & Human Phenotype

Compendium of Known Effects and Ongoing Research

toxoplasmosis

Mortality Patterns of Toxoplasmosis and Its Comorbidities in Tanzania: A 10-Year Retrospective Hospital-Based Survey

February 6, 2020
Mboera, L. E. G., Kishamawe, C., Kimario, E., Rumisha, S. F.
Frontiers in Public Health 2019, 7
Click for abstract
Introduction: Toxoplasmosis is a parasitic zoonosis and an important cause of abortions, mental retardation, encephalitis, blindness, and death worldwide. Few studies have quantified toxoplasmosis mortality and associated medical conditions in Sub-Saharan Africa. This retrospective hospital-based study aimed to determine the mortality patterns of toxoplasmosis and its comorbidities among in-patients in Tanzania. Methods: Data on causes of death were collected using customized paper-based collection tools. Sources of data included death registers, inpatient registers, and International Classification of Diseases report forms. All death events from January 2006 to December 2015 were collected. Data used in this study is a subset of deaths where the underlying cause of death was toxoplasmosis. Data was analyzed by STATA programme version 13. Results: Thirty-seven public hospitals were involved in the study. A total of 188 deaths due to toxoplasmosis were reported during the 10-years period. Toxoplasmosis deaths accounted for 0.08% (188/247,976) of the total deaths recorded. The age-standardized mortality rate per 100,000 population increased from 0.11 in 2006 to 0.79 in 2015. Most deaths due to toxoplasmosis affected the adult age category. Of the 188 deaths, males accounted for 51.1% while females for 48.9% of the deaths. Dar es Salaam, Mbeya, Pwani, Tanga, and Mwanza contributed to over half (59.05%) of all deaths due to Toxoplasmosis. Of the total deaths due to toxoplasmosis, 70.7% were associated with other medical conditions; which included HIV/AIDS (52.6%), HIV/AIDS+Cryptococcal meningitis (18.8%) and HIV+Pneumocystis pneumonia (6.8%). Conclusion: The age-standardized mortality rate due to toxoplasmosis has been increasing substantially between 2006 and 2015. Most deaths due to toxoplasmosis affected the adult age category and were highly associated with HIV/AIDS. Appropriate interventions are needed to

Tagged: co-morbidity, gondii infection, hospital, mortality, prevalence, risk factors, seroprevalence, Tanzania, toxoplasmosis, united-states

BehaviorMental health

Seroprevalence of Toxoplasma gondii infection in cancer patients: A systematic review and meta-analysis

February 4, 2020
Anvari, D., Sharif, M., Sarvi, S., Aghayan, S. A., Gholami, S., Pagheh, A. S., Hosseini, S. A., Saberi, R., Chegeni, T. N., Hosseininejad, Z., Daryani, A.
Microbial Pathogenesis 2019, 129: 30 - 42
Click for abstract
Toxoplasmosis, caused by Toxoplasma gondii, is a great public health concern in cancer patients, which can induce serious pathological effects. This systematic review and meta-analysis was performed to evaluate the worldwide seroprevalence rate of T. gondii infection among cancer patients. A search was conducted on five electronic databases that reported data on T. gondii seroprevalence in cancer patients. The searching process resulted in the inclusion of 57 studies. The results showed that T. gondii had the pooled prevalence of 30.8% in cancer patients using a random-effect model (95% CI: 26.3-35.6). Cancer patients had a higher overall prevalence of T. gondii infection, compared to those without cancer. Furthermore, the odds ratio of toxoplasmosis in cancer patients was 3.1 times, compared to that of controls (95% CI: 2.5-3.8, P < 0.0001). Toxoplasmosis had a higher prevalence in females (40%) than in males (33%). Furthermore, the age group of upper 40 years had the highest prevalence infection rate (30%). In addition, a significant association was also observed between toxoplasmosis infection and year (P < 0.001), type of cancer (P < 0.001), country (P < 0.001), gender (P < 0.001), age (P = 0.006) and diagnostic method (P < 0.001) in cancer patients. Considering the high prevalence of T. gondii infection in cancer patients and its serious outcomes, the researchers are suggested to carry out further studies to prevent and control toxoplasmosis among this population.

Tagged: antibodies, b1 gene, brain, childern, cncer patients, epidemiologymalignancies, healthy, individuals, liver-disease, meta-analysis, systematic review, Toxoplasma gondii, toxoplasmosis

Reviews

Lack of circulating toxoplasma gondii DNA in seropositive patients with bipolar or schizophrenia spectrum disorders

February 1, 2020
Galli, L., Del Grande, C. Rindi, L., Mangia, C., Mangano, V., Schiavi, E., Masci, I., Pinto, B., Kramer, L., Dell'Osso, L., Bruschi, F.
Psychiatry Research :2019, 173: 706 - 711
Click for abstract
Toxoplasmosis has been previously associated with an increased risk of having Schizophrenia or Bipolar disorder in several epidemiological studies. The aim of this observational, cross-sectional study was to examine the seroprevalence of Toxoplasma infection in a cohort of Italian psychiatric inpatients and to verify the presence of circulating Toxoplasma gondii DNA in the seropositive subjects. Sixty-three patients affected by bipolar or schizoaffective disorders according to DSM-5 criteria were enrolled. The presence of Toxoplasma infection was firstly examined using an indirect serological method (ELFA), and three different direct PCR-based methods were performed to detect circulating DNA in the seropositive patients. The seroprevalence of infection was 28.6%, with a significant association between higher age and the infection status. PCR, nested-PCR and Real-Time PCR revealed no positive samples for Toxoplasma gondii This result is in contrast with recent data from case-control studies that detected parasite genome in patients with different neuropsychiatric diagnosis without clinical evidence of acute toxoplasmosis. Our findings are to be interpreted with caution, because of the small sample size, the heterogeneity of enrolled patients and the observational nature of the study. Further studies are needed to better define the clinical features correlated to the seropositive status in neuropsychiatric patients.

Tagged: bipolar disorder, congenital, individuals, molecular diagnosis, nested pcr, pcr, population, risk factors, Rt-PCR, schizoaffective disorder, seroprevalence, Toxoplasma gondii, toxoplasmosis

Mental health

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

Tagged: alcohol, brain, Cerebral toxoplasmosis, decreased level, depression, health, host, mental, novelty seeking, Parasite, personality, risky behavior, Schizophrenia, Toxoplasma gondii, toxoplasmosis

BehaviorMental healthPersonality

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
Click for abstract
In this review, we provide a synopsis of work on the epidemiologic evidence for prenatal infection in the etiology of schizophrenia and autism. In birth cohort studies conducted by our group and others, in utero exposure to infectious agents, prospectively obtained after biomarker assays of archived maternal sera and by obstetric records was related to an increased risk of schizophrenia. Thus far, it has been demonstrated that prenatal exposure to influenza, increased toxoplasma antibody, genitalreproductive infections, rubella, and other pathogens are associated with schizophrenia. Anomalies of the immune system, including enhanced maternal cytokine levels, are also related to schizophrenia. Some evidence also suggests that maternal infection and immune dysfunction may be associated with autism. Although replication is required, these findings suggest that public health interventions targeting infectious exposures have the potential for preventing cases of schizophrenia and autism. Moreover, this work has stimulated translational research on the neurobiological and genetic determinants of these conditions.

Tagged: adult schizophrenia, association, birth cohort, Epidemiology, herpes-simplex-virus, immune activation, infection, influenza, maternal exposure, pregnancy, reproductive infections, Schizophrenia, spectrum disorders, toxoplasmosis

Mental health

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
Click for abstract
Background: Common infectious pathogens have been associated with psychiatric disorders, self-violence and risk-taking behavior. Methods: This case-control study reviews register data on 81,912 individuals from the Danish Blood Donor Study to identify individuals who have a psychiatric diagnosis (N = 2591), have attempted or committed suicide (N = 655), or have had traffic accidents (N = 2724). For all cases, controls were frequency matched by age and sex, resulting in 11,546 participants. Plasma samples were analyzed for immunoglobulin G (IgG) antibodies against Toxoplasma gondii and cytomegalovirus (CMV). Results: T. gondii was detected in 25.9% of the population and was associated with schizophrenia (odds ratio [OR], 1.47; 95% confidence interval [CI], 1-03-2.09). Accounting for temporality, with pathogen exposure preceding outcome, the association was even stronger (IRR, 2.78; 95% CI, 1-27-6-09). A very weak association between traffic accident and toxoplasmosis (OR, 141; 95% CI, 1-00-1.23, p = 0.054) was found. CMV was detected in 60.8% of the studied population and was associated with any psychiatric disorder (OR, 147; 95% CI, 1.06-1-29), but also with a smaller group of neurotic, stress-related, and somatoform disorders (OR, 1.27; 95% CI, 1.12-1-44), and with attempting or committing suicide (OR, 1.31; 95% CI, 1.10-1-56). Accounting for temporality, any psychiatric disorder (IRR, 1.37; 95% CI, 1.08-174) and mood disorders (IRR, 1.43; 95% CI, 1.01-2-04) were associated with exposure to CMV. No association between traffic accident and CMV (OR, 1.06; 95% CI, 0.97-1-17) was found. Conclusions: This large-scale serological study is the first study to examine temporality of pathogen exposure and to provide evidence of a causal relationship between T. gondii and schizophrenia, and between CMV and any psychiatric disorder.

Tagged: cytomegalovirus, infection, parasitepsychiatric diseases, Toxoplasma gondii, toxoplasmosis

BehaviorMental health

Sero-prevalence of Toxoplasma gondii and associated risk factors among psychiatric outpatients attending University of Gondar Hospital, Northwest Ethiopia

January 31, 2020
Achaw, B., Tesfa, H., Zeleke, A.J., Worku, L., Addisu, A., Yigzaw, N., Tegegne, Y.
BMC Infectious Diseases 2019, 19 Ethiopia
Click for abstract
BackgroundToxoplasmosis is caused by an obligatory intracellular coccidian protozoan organism, Toxoplasma gondii. It has a worldwide distribution, affecting one-third of the world population. Psychiatric patients have a higher risk of exposure to Toxoplasma gondii infection due to lack of good personal hygiene. The burden of toxoplasmosis among psychiatric patients in Ethiopia has not been studied extensively. Thus, the study aimed to determine the seroprevalence of Toxoplasma gondii and associated risk factors among psychiatric outpatients at the University of Gondar Comprehensive and Specialized Hospital Psychiatric clinic.MethodsA cross-sectional study was conducted at the University of Gondar Comprehensive and Specialized Hospital from February to May 2018. Venous blood was collected from 304 study participants (152 psychiatric outpatients and 152 control groups). Anti-toxoplasma antibodies were determined using Onsite Toxo immunoglobulin G (IgG) and immunoglobulin M (IgM) Rapid Test. A Chi-square test was carried out to compare the two groups and a logistic regression analysis was conducted to check the association between variables. P-value less than 0.05 was taken as statistically significant.ResultsThe seroprevalence rate of anti-Toxoplasma gondii IgG antibodies was 33.6, and 16.4% in the psychiatric outpatients and the control samples, respectively. Anti-Toxoplasma gondii IgM sero-prevalence was 1.3% in the former patients and 3.9% in the latter group. Owing cat (AOR=2.862 95% CI=1.445-5.666 P=0.003), cleaning cat excreta (AOR=2.966 95% CI=1.317-2.652 P=0.007), and farming (AOR=2.058 95% CI=1.018-4.163 P=0.045) were found to be significantly associated with the sero-prevalence of anti-Toxoplasma gondii IgG antibody.ConclusionsThis study highlighted that, the prevalence of anti-Toxoplasma gondii IgG antibodies was significantly higher in psychiatric outpatients than the control group (p=0.001). Cat ownership, cleaning of cat excreta, and farming were found to be statistically significantly associated with the seroprevalence of anti-Toxoplasma gondii IgG antibody.

Tagged: antibodies, individuals, prevalence, psychiatria, Schizophrenia, seroprevalence, toxoplasmosis, voluntary blood dnors

Mental health

Latent Toxoplasmosis and Human

January 29, 2020
Dalimi, A., Abdoli, A.
Iranian Journal of Parasitology 2012, 7: 1 - 17
Click for abstract
Toxoplasmosis is one of the most common parasitic diseases worldwide. Although estimated that one third of the world's population are infected with Toxoplasma gondii, but the most common form of the disease is latent (asymptomatic). On the other hand, recent findings indicated that latent toxoplasmosis is not only unsafe for human, but also may play various roles in the etiology of different mental disorders. This paper reviews new findings about importance of latent toxoplasmosis (except in immunocompromised patients) in alterations of behavioral parameters and also its role in the etiology of schizophrenia and depressive disorders, obsessive compulsive disorder, Alzheimer's diseases and Parkinson's disease, epilepsy, headache and or migraine, mental retardation and intelligence quotients, suicide attempt, risk of traffic accidents, sex ratio and some possible mechanisms of T gondii that could contribute in the etiology of these alterations.

Tagged: alzheimer disease, behavioral parametr, mental disorder, personality changes, Schizophrenia, toxoplasmosis

BehaviorMental health

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
Click for abstract
Several recent studies have demonstrated the association of cat-related injuries with major depression and with depressiveness in the general population. It was suggested that cat-scratch disease, the infection with the bacterium Bartonella henselae, can be responsible for the observed association. However, no direct evidence for the role of the Bartonella infection in this association has been published until now. In this preregistered case-controls study performed on 250 healthy subjects tested earlier for the presence of anti-Toxoplasma IgG antibodies, we searched for the positive association between presence of anamnestic anti-Bartonella IgG antibodies and depressiveness measured with Beck II inventory, depression subscale of neuroticism measured with N-70 questionnaire, and self-reported health problems. We found that that Bartonella seropositivity was positively correlated with Beck depression only in Toxoplasma-seronegative men and negatively correlated with health in Toxoplasma-seronegative women. Bartonella seropositivity expressed protective effects against Toxoplasma seropositivity-associated increased neuroticism in men while Toxoplasma-seropositivity expressed protective effects against Bartonella seropositivity-associated health problems in women. A comparison of the patterns of association of mental and physical health problems with Bartonella seropositivity and with reported cat-related injury suggests that different factor, possibly infection with different pathogen transmitted by cat related-injuries than the B. henselae, is responsible for the observed association of cat related-injuries with depressiveness and major depression. The existence of complex interactions between Bartonella seropositivity, Toxoplasma seropositivity, and sex also suggest that the effect of symbionts on the host's phenotype must by always studied in the context of other infections, and separately for men and women.

Tagged: animal-related injuries, Bartonella, bartonellosis, behavioral-changes, c-reactive protein, cat-scratch disease, depression, depressiveness, gender differences, health, infection, latent toxoplasmosis, major, Toxoplasma, Toxoplasma gondii, toxoplasmosis, women

Mental health

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
Tagged: allergy, blood group, immunity, infection, manipulation hypothesis, Parasite, personalized medicine, Rhesus factor, toxoplasmosis

Personality

The potential risk of toxoplasmosis for traffic accidents: A systematic review and meta-analysis

February 12, 2018
Gohardehi, S. , Sharif, M. , Sarvi, S., Moosazadeh, M., Alizadeh-Navaei,R., Hosseini,S. A., Amouei,A. , Pagheh, A. , Sadeghi , M., Daryani, A.
Experimental Parasitology 2018; 191: 19-24
Click for abstract
Toxoplasmosis is a prevalent infectious disease. Although most people infected by Toxoplasma gondii are asymptomatic, evidence has suggested that this disease might affect some aspects of a hoses behavior and associate with schizophrenia, suicide attempt, changes in various aspects of personality, and poor neurocognitive performance. These associations may play roles in increasing the risk of a number of incidents, such as traffic accidents, among infected people. In this regard, this study aimed to provide summary estimates for the available data on the potential risk of toxoplasmosis for traffic accidents. To this end, using a number of search terms, i.e. toxoplasmosis, Toxoplasma gondii, traffic accident, road accident car accident, crash, and prevalence, literature searches (up to October 1, 2017) were carried out via 6 databases. The meta-analysis was conducted using the StatsDirect statistical software and a P-value less than 0.05 was regarded as significant in all statistical analyses. Out of 1841 identified studies, 9 studies were finally considered eligible for carrying out this systematic review. Reviewing results of these studies indicated that 5 out of 9 studies reported a significant relationship between Toxoplasma gondii and traffic accidents. Additionally, data related to gender showed significant differences between infected and control men and women. Considering age, reviewing the results of these studies revealed a significant difference between the infected people and the Toxoplasma-negative subjects under 45 years of age. However, no significant difference was found between the two groups aged 45 or older. Given these results, it can be concluded that Toxoplasma gondii significantly increases the risk of having traffic accidents.

Tagged: behavior, gondii infection, latent asymptomatic toxoplasmosis, meta-analysis, performance, systematic review, Toxoplasma gondii, toxoplasmosis, traffic accidents, women

BehaviorReviews

Seroprevalence of Toxoplasma gondii infection in children with central nervous system disorders in Mansoura, Egypt: a case-control study

February 12, 2018
El-Beshbishi,S. N. , El-Tantawy,N. L, Elzeky, S. M., Abdalaziz , K. F. ,Atia, R. A.
Transactions of the Royal Society of Tropical Medicine and Hygiene 2018;112: 555-560
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Background: Toxoplasma gondii is a global infection with a crucial role in the development of neurological diseases. Data concerning the association between T. gondii and neurological illnesses in Egyptian children is scarce. Methods: A case-control study was conducted on 60 patients divided into children suffering from central nervous system manifestations without apparent chromosomal anomalies (n=30) and children with Down syndrome (n=30) recruited from Mansoura University Children's Hospital, Mansoura, Egypt. A total of 30 healthy children were included as controls. Demographics and clinical data were collected from all cases and Toxoplasma immunoglobulin (Ig) M and G antibodies were assessed by enzyme-linked immunosorbent assay. Results: Anti-T. gondii IgG was the most frequent antibody detected and the highest seropositivity rates were ranked for the neurologically disabled non-syndromic children, followed by Down syndrome, compared with controls (p <= 0.001). Statistically significant (p=0.05) associations were found between Toxoplasma IgG seropositivity and hydrocephalus and between Toxoplasma IgM and a history of contact with farm animals, soil and cats in children with Down syndrome. Conclusions: The association between Toxoplasma infection and neurological disorders in children should be kept in mind by paediatricians and assessment of T. gondii antibodies in early childhood is needed for timely management of afflicted patients.

Tagged: autism, children, cryptogenic epilepsy, down-syndrome, endocrine, Epidemiology, immune, individuals, neurological disorders, seropositivity, Toxoplasma gondii, toxoplasmosis

Mental healthPhysical health

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
Click for abstract
The intracellular parasite Toxoplasma gondii (Nicolle et Manceaux, 1908) infects humans resulting in acute toxoplasmosis, an infection that in immunocompetent people is typically mild but results in persistent latent toxoplasmosis. In that T. gondii appears to affect dopamine synthesis and because addicting drugs affect midbrain dopamine transmission, latent toxoplasmosis could influence substance use. Using both the third and continuous National Health and Nutrition Examination Surveys from the US Centers for Disease Control and Prevention, we used logistic regression to test for associations between T. gondii seropositivity and subject self-report of having ever used tobacco, alcohol, marijuana, cocaine, heroin, or methamphetamine. In the third NHANES dataset, which included data for tobacco, alcohol, marijuana and cocaine, T. gondii seropositivity was associated with a reduced likelihood of self-reported marijuana (OR = 0.71 [95% CI: 0.58; 0.87]; p = 0.001) and cocaine use (OR = 0.72 [95% CI: 0.56; 0.91]; p = 0.006). In the continuous National Health and Nutrition Examination Surveys dataset, which included data for all six substances, T. gondii seropositivity was associated with a reduced likelihood of self-reported tobacco (OR = 0.87 [95% CI: 0.76; 1.00]; p = 0.044), marijuana (OR = 0.60 [95% CI: 0.50; 0.72]; p < 0.001), heroin (OR = 0.60 [95% CI: 0.42; 0.85]; p = 0.005) and methamphetamine use (OR = 0.54 [95% CI: 0.38; 0.77]; p = 0.001). We observed interactions between sex and T. gondii seropositivity in the prediction of self-reported use of tobacco and alcohol. Further, T. gondii seropositivity appeared to remove the protective effect of education and economic status against self-reported cigarette smoking. These findings suggest that T. gondii seropositivity may be inversely associated with some but not all types of substance use in US adults.

Tagged: addiction, alcohol, Cocaine, decreased level, Dopamine, drug use, heroin, hypothesis, impulsivity, infection, marijuana, methamphetamine, novelty seeking, receptor, Schizophrenia, seroprevalence, tobacco, toxoplasmosis

Behavior

Fetomaternal and pediatric toxoplasmosis

December 6, 2017
Oz, H. S.
Journal of Pediatric Infectious Diseases 2017; 12: 202-208
Click for abstract
Toxoplasmosis is one of the most important causes of foodborne illnesses and inflammatory complications, as well as congenital disorders. Promiscuous Toxoplasma is transmitted by contaminated food and animal produce, water, vegetations, fruits, and sexually through semen. Toxoplasma infects nucleated cells with a unique tropism formuscles and central nervous system and amind bugging malicious effect. Pregnant women with acute or reactivated toxoplasmosis can transmit Toxoplasma via transplacental transmission to the fetus. The severity of congenital toxoplasmosis depends on the gestation period, as infection in early pregnancy causes more severe consequences. Congenital toxoplasmosis complications include miscarriage, encephalitis, neurological retardation, mental illnesses, auditory, and visual inflammatory disorders, cardiovascular abnormalities, and pains. Current therapies are inefficient for congenital and chronic toxoplasmosis or have severe side effects with life-threatening complications. There is an urgent need for effective and safe therapeutic modalities to treat complications of toxoplasmosis and effective vaccines to eliminate the infectious agent. This investigation will discuss the pathogenesis of fetomaternal, congenital, and pediatric toxoplasmosis, the currently available therapies in practice, and explore those therapeutic modalities in experimental stages for promising future trials.

Tagged: congenital, gondii infection, inflammatory-bowel-disease, mind, pediatric toxoplasmosis, pregnancy, Schizophrenia, sexual transmission, to-child transmission, toxoplasmosis

Mental healthPhysical health

New, previously unreported correlations between latent Toxoplasma gondii infection and excessive ethanol consumption

December 6, 2017
Samojlowicz, D., Borowska-Solonynko, A., Kruczyk, M.
Forensic Science International 2017; 280: 49-54
Click for abstract
A number of world literature reports indicate that a latent Toxoplasma gondii infection leads to development of central nervous system disorders, which in turn may lead to altered behavior in the affected individuals. T. gondii infection has been observed to play the greatest role in drivers, suicides, and psychiatric patients. Studies conducted for this manuscript involve a different, never before really reported correlation between latent T. gondii infection and ethanol abuse. A total of 538 decedents with a known cause of death were included in the study. These individuals were divided into three groups: the risky behavior group, inconclusively risky behavior group, and control group. The criterion for this division was the likely effect of the individual's behavior on the mechanism and cause of his/her death. The material used for analyses were blood samples collected during routine medico-legal examinations in these cases. The blood samples were used to measure anti-T. gondii IgG antibodies with an enzyme-linked immunosorbent assay (ELISA). Moreover, the following data were recorded for each decedent: sex, age, circumstances of death, cause of death, time from death to autopsy, and (if provided) substance abuse status (alcohol, illicit drugs). In those cases where blood alcohol level or toxicology tests were requested by the Prosecutor's Office, their results were also included in our analysis. Test results demonstrated a strong correlation between latent T. gondii infection and engaging in risky behaviors leading to death. Moreover, analyses demonstrated a positive correlation between the presence of anti-T. gondii IgG antibodies and psychoactive substance (especially ethanol) abuse, however, the causal relationship remains unclear. Due to the fact that alcohol abuse constitutes a significant social problem, searching for eliminable risk factors for addiction is extremely important. Our analyses provided new important information on the possible effects of latent T. gondii infection in humans.

Tagged: behavior, childhood/psychology, ethyl alcohol, post-mortem serological testing, risk behaviors, Schizophrenia, suicide, Toxoplasma gondii, toxoplasmosis, traffic accidents

BehaviorMental health

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
Click for abstract
here is evidence that some maternal infections during the prenatal period are associated with neurodevelopmental disorders, such as childhood autism. However, the association between autism and Toxoplasma gondii (T. gondii), an intracellular parasite, remains unclear. The authors examined whether serologically confirmed maternal antibodies to T. gondii are associated with odds of childhood autism in offspring. The study is based on a nested case-control design of a large national birth cohort (N=1.2 million) and the national psychiatric registries in Finland. There were 874 cases of childhood autism and controls matched 1: 1 on date of birth, sex, birthplace and residence in Finland. Maternal sera were prospectively assayed from a national biobank for T. gondii IgM and IgG antibodies; IgG avidity analyses were also performed. High maternal T. gondii IgM antibody was associated with a significantly decreased odds of childhood autism. Low maternal T. gondii IgG antibody was associated with increased offspring odds of autism. In women with high T. gondii IgM antibodies, the IgG avidity was high for both cases and controls, with the exception of three controls. The findings suggest that the relationship between maternal T. gondii antibodies and odds of childhood autism may be related to the immune response to this pathogen or the overall activation of the immune system.

Tagged: antibody, autism, avidity, c-reactive protein, childhood, congenital toxoplasmosis, gondii, igg, infection, latent toxoplasmosis, rheumatoid-arthritis, risk, spectrum disorder, toxoplasmosis

Mental health

Do Toxoplasma – infected subjects have better leadership skills? Comment on paper “Puppet 1 master: possible influence of the parasite Toxoplasma gondii on managers and employees“

September 27, 2017
Flegr, J.
Academy of Management Perspectives, in press
Click for abstract
none

Tagged: leadership skills, toxoplasmosis

BehaviorPersonality

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
Click for abstract
Background: Latent toxoplasmosis, the life-long presence of dormant stages of Toxoplasma in immunoprivileged organs and of anamnestic IgG antibodies in blood, affects about 30% of humans. Infected subjects have an increased incidence of various disorders, including schizophrenia. Several studies, as well as the character of toxoplasmosis-associated disturbance of neurotransmitters, suggest that toxoplasmosis could also play an etiological role in Obsessive-Compulsive Disorder (OCD). Methods: The aim of the present cross-sectional study performed on a population of 7471 volunteers was to confirm the association between toxoplasmosis and OCD, and toxoplasmosis and psychological symptoms of OCD estimated by the standard Obsessive-Compulsive Inventory-Revised (OCI-R). Results: Incidence of OCD was 2.18% ( n = 39) in men and 2.28% ( n = 83) in women. Subjects with toxoplasmosis had about a 2.5 times higher odds of OCD and about a 2.7 times higher odds of learning disabilities. The incidence of 18 other neuropsychiatric disorders did not differ between Toxoplasma - infected and Toxoplasma -free subjects. The infected subjects, even the OCD-free subjects, scored higher on the OCI-R. Limitations: Examined subjects provided the information about their toxoplasmosis and OCD statuses themselves, which could result in underrating the strength of observed associations. Conclusions: The results confirmed earlier reports of the association between toxoplasmosis and OCD. They also support recent claims that latent toxoplasmosis is in fact a serious disease with many impacts on quality of life of patients.

Tagged: infection, Learning disabilities, mental disorder, parasites, risk factors, toxoplasmosis

Mental health

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
Click for abstract
Background: Latent toxoplasmosis, the life-long presence of dormant stages of Toxoplasma in immunoprivileged organs and of anamnestic IgG antibodies in blood, affects about 30% of humans. Infected subjects have an increased incidence of various disorders, including schizophrenia. Several studies, as well as the character of toxoplasmosis-associated disturbance of neurotransmitters, suggest that toxoplasmosis could also play an etiological role in Obsessive-Compulsive Disorder (OCD). Methods: The aim of the present cross-sectional study performed on a population of 7471 volunteers was to confirm the association between toxoplasmosis and OCD, and toxoplasmosis and psychological symptoms of OCD estimated by the standard Obsessive-Compulsive Inventory-Revised (OCI-R). Results: Incidence of OCD was 2.18% (n = 39) in men and 2.28% (n = 83) in women. Subjects with toxoplasmosis had about a 2.5 times higher odds of OCD and about a 2.7 times higher odds of learning disabilities. The incidence of 18 other neuropsychiatric disorders did not differ between Toxoplasma-infected and Toxoplasma-free subjects. The infected subjects, even the OCD-free subjects, scored higher on the OCI-R. Limitations: Examined subjects provided the information about their toxoplasmosis and OCD statuses themselves, which could result in underrating the strength of observed associations. Conclusions: The results confirmed earlier reports of the association between toxoplasmosis and OCD. They also support recent claims that latent toxoplasmosis is in fact a serious disease with many impacts on quality of life of patients.

Tagged: infection, Learning disabilities, mental disorder, parasites, risk factors, toxoplasmosis

Mental health

Assessment of Toxoplasma seropositivity in children suffering from anxiety disorders

May 4, 2017
Afsharpaiman, S., Khosravi, M.H., Mahmoodinejad, M., Shirbazoo, S., Amirsalari, S., Torkaman, M., Radfar, S.
Iranian Journal of Child Neurology 2017; 11: 32-37
Click for abstract
Objective This study aimed to assess the seroprevalence of Toxoplasma gondii in children with anxiety disorders. Materials & Methods This cross-sectional study was conducted between Sep 2012 and May 2013 in Pediatrics Clinic of Baqiyatallah Hospital, Tehran, Iran. Children were assessed clinically. Diagnosis of patients with anxiety disorders was based on DSM-4 system, performed by child psychiatrist. Then their anti-Toxoplasma antibodies were measured. A questionnaire was verbally administered to all individuals' parents including demographic information and questions about life style, family history, medical history, economic situation, residence, nutritional patterns and contact with animals. Results Ninety-six male and female cases with a mean age of 8.56 +/- 2.5 and 8.42 +/- 1.9 yr underwent analysis. Anti-T. gondii IgG antibody was found in one case of each group. There was no significant difference between case and control groups for serum Toxoplasma IgG antibody (P=0.14). No case individuals had Anti-T. gondii IgM antibody, while it was found in one control individual. No significant difference was seen between case and control groups for Toxoplasma IgM antibody (P=0.27). Conclusion Toxoplasmosis has no direct effect on the incidence of anxiety disorders. More studies are needed with a larger volume of individuals in future.

Tagged: antibodies, anxiety disorders, Toxoplasma gondii, toxoplasmosis

Mental health

The seroprevalence of antibodies to Toxoplasma gondii among children with autism

May 3, 2017
Esnafoglu, E., Demir, E.Y., Cetinkol, Y., Calgin, M.K., Erdil, A., Erturk, E.Y., Dagli, A.
Dusunen Adam The Journal of Psychiatry and Neurological Sciences 2017; 30: 309-315
Click for abstract
Objective: Although attempts have been made to explain the pathogenesis of autism spectrum disorders (ASD) with many factors such as genetic, immunological, environmental, and infectious agents, this mechanism remains for the most part unknown. Toxoplasma gondii is a parasite that is investigated in many psychiatric diseases. This work examines whether toxoplasmosis plays a role in the pathogenesis of ASD through a seroprevalence study. Method: This study is based on a comparison of 102 children with ASD and 51 healthy children. In addition to routine laboratory tests, a sociodemographic form and a childhood autism rating scale were completed and the participants' anti-toxoplasma IgM and IgG titers were requested. Results: In 3 ASD children (2.9%) and in 1 control (2%), IgG positivity was identified. All subjects were negative for IgM. There was no statistically significant difference found between the two groups in terms of toxoplasma seropositivity. Conclusion: Our data does not confirm the involvement of toxoplasmosis in the etiopathogenesis of ASD

Tagged: autism, autism spectrum disorder, autism; autism spectrum disorder; toxoplasmosis; Toxoplasma gondii, Toxoplasma gondii, toxoplasmosis

Mental health

Schizophrenia and infections: The eyes have it

January 3, 2017
Torrey, E. F. ,Yolken, R. H.
Schizophrenia Bulletin 2017; 43: 247-252
Click for abstract
The visual tract is prominently involved in schizophrenia, as evidenced by perceptual distortions and a type of nystagmus found in many individuals affected. Genetic explanations for these abnormalities have been suggested. This study proposes an alternate explanation based on infection. Several infectious agents thought to be associated with some cases of schizophrenia are known to cause both infection of the fetus and abnormalities of the eye. Toxoplasma gondii is examined in detail, and rubella, cytomegalovirus, varicellazoster virus, and herpes simplex virus more briefly. Careful ophthalmic assessments, including funduscopy and direct examination of tissues for infectious agents, will clarify the role of such agents in ocular aspects of schizophrenia.

Tagged: adult schizophrenia, cat ownership, congenital toxoplasmosis, gondii, herpes-simplex-virus, infections, movement abnormalities, ocular, ocular toxoplasmosis, psychosis, risk factors, Schizophrenia, smooth-pursuit, toxoplasmosis

Mental health

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
Click for abstract
Introduction: Latent infection with Toxoplasma gondii has been associated with behavioral and cognitive changes in animal models and in humans. Early findings have suggested an association between latent toxoplasmosis and Alzheimer disease (AD). On the basis of these factors, we sought to determine whether there is an association between latent toxoplasmosis and AD using a large, well-characterized sample of subjects with AD and age-matched and sex-matched controls without dementia. Methods: Using ELISA, we determined anti-T. gondii IgG antibody titers in 114 control subjects and in 105 subjects diagnosed with AD through an Alzheimer's Disease Research Center. Results: There were no group differences between groups in age, ethnicity, or sex. Education and socioeconomic status was slightly higher in the control group. Neither the prevalence of anti-T. gondii IgG antibodies (33% in the nondemented control group compared with 41% in the AD group, P= 0.25) nor log-transformed antibody concentration (106.6 IU/mL in the control group compared with 140.9 IU/mL in the AD group, P= 0.85) differed between the control and AD groups. Discussion: In this sample, we found neither a higher prevalence of latent toxoplasmosis in the AD group compared with the control group nor differences in serum anti-T. gondii IgG titers between groups.

Tagged: alzheimer disease, association, dementia, diagnosis, infection, mechanisms, neurodegeneration, risk factors, Toxoplasma gondii, toxoplasmosis

Cognitive functionsMental health

Impaired health status and increased incidence of diseases in Toxoplasma-seropositive subjects – An explorative cross-sectional study

September 27, 2016
Flegr, J. Escudero, D. Q.
Parasitology, 143, 1974-1989, doi:10.1017/S0031182016001785, 2016
Click for abstract
parasites in tissue cysts located mainly in immunoprivileged organs was long considered asymptomatic. Recently, many studies have shown that latent Toxoplasma infections could have serious impacts on human health. Here we ran a cross-sectional study in a population of 1486 volunteers. The results showed that 333 infected subjects scored worse than 1153 controls in 28 of 29 health-related variables. Similarly, they reported higher rates of 77 of a list of 134 disorders reported by at least 10 participants of the study. Toxoplasmosis was associated most strongly with musculoskel- etal ( τ = 0·107, P < 0·0005), followed by neurological ( τ = 0·088, P < 0·0005), immune ( τ = 0·085, p < 0·0005), metabolic ( τ = 0·079, P < 0·0005), respiratory ( τ = 0·068, P = 0·0001), allergic ( τ = 0·053, P = 0·004), digestive system ( τ = 0·052, P = 0·004) and mental health disorders ( τ = 0·050, P = 0·008). Results of the present cohort study, along with the previous data from many case-control studies or ecological studies suggest that latent toxoplasmosis represents a large and so far underrated public health problem

Tagged: disease burden, neglected disease, neglected zoonosis, Parasite, public health, Toxoplasma gondii, toxoplasmosis

Physical health

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

September 27, 2016
Dama, S.M., Martinec Nováková, L., Flegr, J.
Parasitology 2016; 143, 1193–1203 doi:10.1017/S0031182016000597
Click for abstract
Sex of the fetus is genetically determined such that an equal number of sons and daughters are born in large populations. However, the ratio of female to male births across human populations varies signi fi cantly. Many factors have been impli- cated in this. The theory that natural selection should favour female o ff spring under suboptimal environmental conditions implies that pathogens may a ff ect secondary sex ratio (ratio of male to female births). Using regression models containing 13 potential confounding factors, we have found that variation of the secondary sex ratio can be predicted by seropreva- lence of Toxoplasma across 94 populations distributed across African, American, Asian and European continents. Toxoplasma seroprevalence was the third strongest predictor of secondary sex ratio, β = − 0·097, P < 0·01, after son pref- erence, β = 0·261, P < 0·05, and fertility, β = − 0·145, P < 0·001. Our preliminary results suggest that Toxoplasma gondii in- fection could be one of the most important environmental factors in fl uencing the global variation of o ff spring sex ratio in humans. The e ff ect of latent toxoplasmosis on public health could be much more serious than it is usually supposed to be.

Tagged: ecological regression, manipulation hypothesis, Secondary sex ratio, toxoplasmosis, Trivers Willard e ff ect

Physical health

Cat scratches, not bites, are associated with unipolar depression – cross-sectional study

September 27, 2016
Flegr,J., Hodný, Z.
Parasites & Vectors 2016:8 doi:10.1186/s13071-015-1290-7, 2016
Click for abstract
Background: A recent study performed on 1.3 million patients showed a strong association between being bitten by a cat and probability of being diagnosed with depression. Authors suggested that infection with cat parasite Toxoplasma could be the reason for this association. Method: A cross sectional internet study on a non-clinical population of 5,535 subjects was undertaken. Results: The subjects that reported having been bitten by a dog and a cat or scratched by a cat have higher Beck depression score. They were more likely to have visited psychiatrists, psychotherapists and neurologists in past two years, to have been previously diagnosed with depression (but not with bipolar disorder). Multivariate analysis of models with cat biting, cat scratching, toxoplasmosis, the number of cats at home, and the age of subjects as independent variables showed that only cat scr atching had positive effect on depression ( p = 0.004). Cat biting and toxoplasmosis had no effect on the depression, and the number of cats at home had a negative effect on depression ( p = 0.021). Conclusions: Absence of association between toxoplasmosis and depression and five times stronger association of depression with cat scratching than with cat biting suggests that the pathogen responsible for mood disorders in animals-injured subjects is probably not the protozoon Toxoplasma gondii but another organism; possibly the agent of cat-scratched disease – the bacteria Bartonella henselae .

Tagged: Bartonelosis, Injury, Major depression, Parasite, toxoplasmosis, Unipolar depression

Mental health

Seroprevalence of anti-Toxoplasma IgG and IgM among individuals who were referred to medical laboratories in Mazandaran province, northern Iran

May 25, 2016
Sharif, M., Daryani, A., Ebrahimnejad, Z., Gholami, S., Ahmadpour, E., Borhani, S., Lamsechi, N.
Journal of Infection and Public Health 2016; 9: 75-80
Click for abstract
Toxoplasma gondii (T. gondii) is a protozoan parasite that can cause toxoplasmosis in humans. However, there is no current data regarding Toxoplasma infection among individuals who were referred to medical laboratories in Mazandaran province (northern Iran). Therefore, we performed a population-based study of Toxoplasma seroprevalence in this region. A total of 1832 sera samples (from 654 men and 1178 women) were collected from people who were referred to medical laboratories in different cities throughout Mazandaran province between March and July 2012. The serum titers of anti-T. gondii IgG and IgM were measured using enzyme-linked immunosorbent assays. The seroprevalence of anti-Toxoplasma IgG was 55.5%; and 14.4% of the positive samples were seropositive for anti-Toxoplasma IgM. The highest seroprevalence was observed among people who were >50 years old (90.6%), and the lowest seroprevalence was observed among children who were 0-9 years old (9.4%; P < 0.001). There was no significant difference in the seroprevalences for each sex in the study population. However, a regional sex-specific difference in seroprevalence was observed between men (54.1%) and women (70.6%; P = 0.003) in the western cities of Mazandaran. As the seroprevalence of T. gondii in western and eastern Mazandaran was higher than that in the central cities, there is a need to evaluate the nature of the infection chain in these areas

Tagged: amazonas, antibodies, children, community, laboratory testing, patient referral, people, risk factors, Schizophrenia, schoolchildren, serological survey, seroprevalence, Toxoplasma gondii, toxoplasmosis

Mental health

Cerebral toxoplasmosis in a diffuse large B cell lymphoma patient

May 24, 2016
Savsek, L., Opaskar, T.R.
Radiology and Onkology 2016; 50: 87-93
Click for abstract
Background. Toxoplasmosis is an opportunistic protozoal infection that has, until now, probably been an underestimated cause of encephalitis in patients with hematological malignancies, independent of stem cell or bone marrow transplant. T and B cell depleting regimens are probably an important risk factor for reactivation of a latent toxoplasma infection in these patients. Case report. We describe a 62-year-old HIV-negative right-handed Caucasian female with systemic diffuse large B cell lymphoma who presented with sudden onset of high fever, headache, altered mental status, ataxia and findings of pancytopenia, a few days after receiving her final, 8th cycle of rituximab, cyclophosphamide, vincristine, doxorubicin, prednisolone (R-CHOP) chemotherapy regimen. A progression of lymphoma to the central nervous system was suspected. MRI of the head revealed multiple on T2 and fluid attenuated inversion recovery (FLAIR) hyperintense parenchymal lesions with mild surrounding edema, located in both cerebral and cerebellar hemispheres that demonstrated moderate gadolinium enhancement. The polymerase chain reaction on cerebrospinal fluid (CSF PCR) was positive for Toxoplasma gondii. The patient was diagnosed with toxoplasmic encephalitis and successfully treated with sulfadiazine, pyrimethamine and folic acid. Due to the need for maintenance therapy with rituximab for lymphoma remission, the patient now continues with secondary prophylaxis of toxoplasmosis. Conclusions. With this case report, we wish to emphasize the need to consider cerebral toxoplasmosis in patients with hematological malignancies on immunosuppressive therapy when presenting with new neurologic deficits. In such patients, there are numerous differential diagnoses for cerebral toxoplasmosis, and the CNS lymphoma is the most difficult among all to distinguish it from. If left untreated, cerebral toxoplasmosis has a high mortality rate; therefore early recognition and treatment are of essential importance.

Tagged: aids patients, b-cell, bone-marrow-transplantation, central-nervous-system, cerebral, diseases, encephalitis, hiv, hosts, immunocompromised, infections, lymphoma, magnetic resonance imaging, prevention, rituximab, strategies, toxoplasmosis, treatment

Mental healthPhysical health

Asymptomatic diffuse “encephalitic” cerebral toxoplasmosis in a woman with systemic lupus erythematosus

May 24, 2016
Murro, D ., Novo, J., Arvanitis, L.
J. Clin. Neurosci. 2016; 29: 194-196
Click for abstract
lassic cerebral toxoplasmosis typically presents with neurologic symptoms such as seizures and mental status changes and histological examination shows focal lesions with necrosis. However, in the diffuse "encephalitic" form, patients are asymptomatic with diffuse, inflammatory, non-necrotic lesions. Asymptomatic diffuse "encephalitic" toxoplasmosis has been reported only in four acquired immunodeficiency syndrome patients and one human immunodeficiency virus (HIV) negative patient with chronic lymphocytic leukemia. We present a 36-year-old HIV-negative woman with systemic lupus erythematosus and lupus nephritis who was on immunosuppression for 9 years after cadaveric renal transplant and died from pulmonary hemorrhage and cytomegalovirus pneumonia. Brain autopsy findings revealed multifocal microglial nodules containing Toxoplasma bradyzoites and associated astrogliosis. These nodules were prominent in the cerebellum, midbrain and medulla and also present in the cortex and thalamus. No coagulative necrosis, necrotizing abscesses, or other opportunistic infections were present. The patient had previously exhibited no neurologic symptoms and there was no clinical suspicion for toxoplasmosis. To the best of our knowledge, this is the first case of diffuse, non-necrotizing, "encephalitic" cerebral toxoplasmosis reported in a lupus patient and also the first reported female case.

Tagged: central-nervous-system, renal transplant, systemic-lupus-erythematosus, Toxoplasma, toxoplasmosis

Mental health

Toxoplasma gondii infection in the context of the risk of schizophrenia development

May 24, 2016
Dudzinska, E., Listos, P., Gryzinska, M., Krukowski, H., Trawinska, B.
Med. Weter. 2016; 72: 616-619
Click for abstract
Toxoplasma gondii (T. gondii) is a protozoan parasitizing all warm-blooded mammals, including humans. The main source of infection is contact with the feces of infected animals, particularly housecats the definitive hosts, in which T. gondii completes its life cycle. Alternative sources of infection are contact with and consumption of contaminated meat (particularly pork), transmission from mother to fetus, and infection by oocytes present in the soil or in polluted water. T. gondii is geographically ubiquitous; its level of seroprevalence is estimated to range from about 3% in South Korea to 76% in Costa Rica. Despite great efforts and considerable progress, toxoplasmosis remains a serious health threat worldwide. There is currently no available vaccine, and anti-toxoplasmosis drugs have substantial side effects and are not very effective. Furthermore, studies show that the parasite is able to develop resistance to them. Many recent studies have focused on how T. gondii is linked to psychiatric diseases and neurocognitive processes. Research has shown a correlation between T. gondii infection and schizophrenia.

Tagged: protozoan, Schizophrenia, toxoplasmosis

Mental health

Cerebral complement C1q activation in chronic Toxoplasma infection

May 24, 2016
Xiao, J.C., Li, Y., Gressitt, K.L., He, H., Kannan, G., Schultz, T.L., Svezhova, N., Carruthers, V.B., Pletnikov, M.V., Yolken, R.H., Severance, E.G.
Brain Behav. Immun. 2016; 58: 52-56
Click for abstract
Exposure to the neurotropic parasite, Toxoplasma gondii, causes significant brain and behavioral anomalies in humans and other mammals. Understanding the cellular mechanisms of T. gondii-generated brain pathologies would aid the advancement of novel strategies to reduce disease. Complement factor C1 q is part of a classic immune pathway that functions peripherally to tag and remove infectious agents and cellular debris from circulation. In the developing and adult brain, C1 q modifies neuronal architecture through synapse marking and pruning. T. gondii exposure and complement activation have both been implicated in the development of complex brain disorders such as schizophrenia. Thus, it seems logical that mechanistically, the physiological pathways associated with these two factors are connected. We employed a rodent model of chronic infection to investigate the extent to which cyst presence in the brain triggers activation of cerebral C1 q. Compared to uninfected mice, cortical C1 q was highly expressed at both the RNA and protein levels in infected animals bearing a high cyst burden. In these mice, C1 q protein localized to cytoplasm, adjacent to GFAP-labeled astrocytes, near degenerating cysts, and in punctate patterns along processes. In summary, our results demonstrated an upregulation of cerebral C1q in response to latent T. gondii infection. Our data preliminarily suggest that this complement activity may aid in the clearance of this parasite from the CNS and in so doing, have consequences for the connectivity of neighboring cells and synapses.

Tagged: glia, MAG1 antibodies, neurons, prefrontal cortex, psychiatry, toxoplasmosis

Mental health

Assessment of toxoplasma seropositivity in children suffering from attention deficit hyperactivity disorder

May 11, 2016
Afsharpaiman, S., Khosravi, M.H., Faridchehr, M., Komijani, M., Radfar, S., Amirsalari, S., Torkaman, M., Shirbazoo, S.
Galen Medical Journal 2016; 5: 188-193
Click for abstract
Background: Toxoplasmosis, a protozoan infection caused by Toxoplasma gondii, is suggested to be a risk factor for many psychological disorders such as schizophrenia and depression. Attention deficit hyperactivity disorder (ADHD) is one of the most common psychiatric disorders among children. Previous studies have assessed the correlation between ADHD and infectious diseases like toxoplasmosis. So we aimed to investigate the possible correlation between Toxoplasma seropositivity and ADHD in children. Materials and Methods: In this cross-sectional study children with signs of ADHD were regarded as patients and underwent clinical assessments. Diagnosis of these patients was based on DSM-IV-TR system which was performed by a pediatric psychiatrist. Forty-eight Children without signs of ADHD or other psychic disorders were considered as control, and 48 patients were considered as case group. Parents were asked to answer a questionnaire including demographic, pregnancy and habitual questions. Blood samples were taken from all individuals and assessed for anti-Toxoplasma IgM and IgG antibodies. Results: Ninety-six male and female patients with a mean age of 8.12 years underwent analysis. Seropositivity rate for anti-T.gondii IgG antibody was 4.2% in the case and 2.1% in control individuals (P=0.92). Anti-T.gondii IgM antibodies were not found in control individuals while it was found in 2.1% of case individuals (P=0.74). There was no statistically significant association between seroprevalence of IgM (P=0.74) and IgG (P=0.92) antibodies and ADHD in study individuals. Conclusion: Our findings showed that the toxoplasmosis seropositivity has no significant difference between children with and without ADHD. Further studies are needed with a larger amount of individuals.

Tagged: attention deficit hyperactivity disorder, children, Toxoplasma gondii, toxoplasmosis

BehaviorMental healthPersonality

Toxoplasmosis Titers and past Suicide Attempts Among Older Adolescents Initiating SSRI Treatment

March 23, 2016
Coryell, W., Yolken, R., Butcher, B., Burns, T., Dindo, L., Schlechte, J., Calarge, C.
Archives of Suicide Research 2016; 20: 605-613
Click for abstract
Latent infection with toxoplasmosis is a prevalent condition that has been linked in animal studies to high-risk behaviors, and in humans, to suicide and suicide attempts. This analysis investigated a relationship between suicide attempt history and toxoplasmosis titers in a group of older adolescents who had recently begun treatment with an SSRI. Of 108 participants, 17 (15.7%) had a lifetime history of at least one suicide attempt. All were given structured and unstructured diagnostic interviews and provided blood samples. Two individuals (11.9%) with a past suicide attempt, and two (2.1%) without this history, had toxoplasmosis titers >= 10 IU/ml (p = 0.166). Those with a past suicide attempt had mean toxoplasmosis titers that were significantly different (p = 0.018) from those of patients who lacked this history. An ROC analysis suggested a lower optimal threshold for distinguishing patients with and without suicide attempts (3.6 IU/ml) than that customarily used to identify seropositivity. Toxoplasmosis titers may quantify a proneness to suicidal behavior in younger individuals being treated with antidepressants.

Tagged: aggression, behavior, children, gondii antibody-titers, history, impulsivity, latent infection, mood disorder, risk, suicide attempt, toxoplasmosis, traffic accidents

Mental health

Infectious disease burden and cognitive function in young to middle-aged adults

January 4, 2016
Gale, S. D., Erickson, L. D., Berrett, A., Brown, B. L., Hedges, D. W.
Brain Behavior and Immunity 2016, 52: 161-168
Click for abstract
Prior research has suggested an association between exposure to infectious disease and neurocognitive function in humans. While most of these studies have explored individual viral, bacterial, and even parasitic sources of infection, few have considered the potential neurocognitive burden associated with multiple infections. In this study, we utilized publically available data from a large dataset produced by the Centers for Disease Control and Prevention that included measures of neurocognitive function, sociodemographic variables, and serum antibody data for several infectious diseases. Specifically, immunoglobulin G antibodies for toxocariasis, toxoplasmosis, hepatitis A, hepatitis B, and hepatitis C, cytomegalovirus, and herpes 1 and 2 were available in 5662 subjects. We calculated an overall index of infectious-disease burden to determine if an aggregate measure of exposure to infectious disease would be associated with neurocognitive function in adults aged 20-59 years. The index predicted processing speed and learning and memory but not reaction time after controlling for age, sex, race-ethnicity, immigration status, education, and the poverty-to-income ratio. Interactions between the infectious-disease index and some sociodemographic variables were also associated with neurocognitive function. In summary, an index aggregating exposure to several infectious diseases was associated with neurocognitive function in young- to middle-aged adults. (C) 2015 Elsevier Inc. All rights reserved.

Tagged: 3rd national-health, chronic hepatitis-c, cytomegalovirus, cytomegalovirus-infection, hepatitis, herpes, infectious disease, latent toxoplasmosis, neurocognitive function, nhanes, northern-manhattan, nutrition examination survey, risk factors, simplex-virus type-1, toxocariasis, toxoplasma gondii infection, toxoplasmosis, united-states

Cognitive functions

Assessment of Toxoplasma sweropositivity in children suffering from attention deficit hyperactivity disorder

January 4, 2016
Afsharpaiman, S., Khosravi, M. H., Faridchehr, M., Komijani, M., Radfar, S., Amirsalari, S., Torkaman, M., Shirbazoo, S.
Galen Medical Journal 2016; 5: 188-193
Click for abstract
Background: Toxoplasmosis, a protozoan infection caused by Toxoplasma gondii, is suggested to be a risk factor for many psychological disorders such as schizophrenia and depression. Attention deficit hyperactivity disorder (ADHD) is one of the most common psychiatric disorders among children. Previous studies have assessed the correlation between ADHD and infectious diseases like toxoplasmosis. So we aimed to investigate the possible correlation between Toxoplasma seropositivity and ADHD in children. Materials and Methods: In this cross-sectional study children with signs of ADHD were regarded as patients and underwent clinical assessments. Diagnosis of these patients was based on DSM-IV-TR system which was performed by a pediatric psychiatrist. Forty-eight Children without signs of ADHD or other psychic disorders were considered as control, and 48 patients were considered as case group. Parents were asked to answer a questionnaire including demographic, pregnancy and habitual questions. Blood samples were taken from all individuals and assessed for anti-Toxoplasma IgM and IgG antibodies. Results: Ninety-six male and female patients with a mean age of 8.12 years underwent analysis. Seropositivity rate for anti-T.gondii IgG antibody was 4.2% in the case and 2.1% in control individuals (P=0.92). Anti-T.gondii IgM antibodies were not found in control individuals while it was found in 2.1% of case individuals (P=0.74). There was no statistically significant association between seroprevalence of IgM (P=0.74) and IgG (P=0.92) antibodies and ADHD in study individuals. Conclusion: Our findings showed that the toxoplasmosis seropositivity has no significant difference between children with and without ADHD. Further studies are needed with a larger amount of individuals.

Tagged: antibodies, attention deficit hyperactivity disorder, children, gondii, metaanalysis, population, risk factors, Schizophrenia, Toxoplasma gondii, toxoplasmosis

Mental health

The prevalence of anti-Toxoplasma gondii antibodies in stutterers is higher than in the control group

October 9, 2015
Celik, T., Gokcen, C., Aytas, O., Ozcelik, A., Celik, M., Coban, N.
Folia Parasitologica 2015; 62
Click for abstract
The purpose of this study was to investigate the possible relationship between Toxoplasma gondii (Nicolle et Manceaux, 1908) and stuttering. We investigated the seropositivity rate for anti-T. gondii IgG and antibodies by enzyme-linked immunosorbent assay (ELISA) in stuttering children to ascertain a possible relationship between T. gondii infection and stuttering. We selected 65 stuttering children and 65 control children (non-stutterers) to investigate the seropositivity rate of anti-T. gondii antibodies by ELISA. Cranial magnetic resonance imaging (MRI) and scalp electroencephalography (EEG) were also performed in stuttering children. The seropositivity rate of anti-T. gondii IgG antibodies among stuttering children (28%) was significantly higher than in control group (5%; p = 0.001). No abnormality was detected in cranial MRI's of stutttering children and their EEG recordings were also normal. There was no significant difference in seropositivity rate regarding age, genders and residence area. The association between seroprevalence of infection with T. gondii and stuttering may be due to hyperdopaminergic state in brains of patients who are T. gondii-seropositive. Thus, there might be a causal relationship between toxoplasmosis and stuttering.

Tagged: disorder, Dopamine, electroencephalography (eeg), enzyme-linked immunosorbent assay (elisa), infection, latent toxoplasmosis, magnetic resonance imaging (mri), mice, risk factors, Schizophrenia, seroprevalence, stuttering, Toxoplasma gondii, toxoplasmosis, traffic accidents

Mental healthPhysical health

Association between latent toxoplasmosis and clinical course of schizophrenia – continuous course of the disease is characteristic for Toxoplasma gondii-infected patients

October 9, 2015
Celik, T., Kartalci, S., Aytas, O., Akarsu, G. A., Gozukara, H., Unal, S.
Folia Parasitologica 2015; 62
Click for abstract
The aim of the present study was to investigate the association between various clinical aspects of schizophrenia and seropositivity against Toxoplasma gondii (Nicolle et Manceaux, 1908). We selected 94 patients with schizophrenia and investigated the seropositivity rate for anti-T. gondii IgG antibodies by ELISA. Clinical parameters of schizophrenic patients such as illness type and status, clinical course, awareness of the illness and need for electroconvulsive therapy (ECT) were compared with their serological status. Anti-T. gondii IgG antibodies were detected in 43 (46%) of schizophrenic patients. Chronic patients had a rate of 34 (72%) seropositivity, whereas 9 (22%) of the patients with partial remission showed evidence of latent toxoplasmosis. Of continuous patients, 35 (81%) were found to be seropositive and this rate was significantly more than in the other groups. The rate of latent toxoplasmosis was detected significantly higher in patients who lack awareness of schizophrenia (36, i.e. 72%) than the patients who were aware of their illnesses (7, i.e. 16%). Anti-T. gondii IgG antibodies were detected in 38 (70%) of ECT performed patients while this percentage was 13% in the ones who had never been treated with ECT. This difference was also statistically significant. We showed that Toxoplasma-infected subjects had 15x higher probability of having continuous course of disease than Toxoplasma-free subjects. Our results put forth the possibility of latent toxoplasmosis to have a negative impact on the course of schizophrenia and treatment response of schizophrenic patients.

Tagged: agents, antibodies, cell-cultures, CMV, Dopamine, individuals, mechanism, mice, prognosis, risk factors, schizophrenia patients, serology, toxoplasmosis

Mental health

Association between latent toxoplasmosis and cognition in adults: a cross-sectional study

October 9, 2015
Gale, S. D., Brown, B. L., Erickson, L. D., Berrett, A., Hedges, D. W.
Parasitology 2015; 142: 557-565
Click for abstract
Latent infection from Toxoplasma gondii (T. gondii) is widespread worldwide and has been associated with cognitive deficits in some but not all animal models and in humans. We tested the hypothesis that latent toxoplasmosis is associated with decreased cognitive function in a large cross-sectional dataset, the National Health and Nutrition Examination Survey (NHANES). There were 4178 participants aged 20-59 years, of whom 191% had IgG antibodies against T. gondii. Two ordinary least squares (OLS) regression models adjusted for the NHANES complex sampling design and weighted to represent the US population were estimated for simple reaction time, processing speed and short-term memory or attention. The first model included only main effects of latent toxoplasmosis and demographic control variables, and the second added interaction terms between latent toxoplasmosis and the poverty-to-income ratio (PIR), educational attainment and race-ethnicity. We also used multivariate models to assess all three cognitive outcomes in the same model. Although the models evaluating main effects only demonstrated no association between latent toxoplasmosis and the cognitive outcomes, significant interactions between latent toxoplasmosis and the PIR, between latent toxoplasmosis and educational attainment, and between latent toxoplasmosis and race-ethnicity indicated that latent toxoplasmosis may adversely affect cognitive function in certain groups.

Tagged: attention, behavior, brain, cognition, deficits, disease, gondii infection, memory, Mexico, performance, processing speed, Schizophrenia, seroprevalence, socioeconomic position, Toxoplasma gondii, toxoplasmosis

Cognitive functions

Is there any role of latent toxoplasmosis in schizophrenia disease?

October 6, 2015
Karabulut, N., Bilgic, S., Gurok, M. G., Karaboga, F.
Journal of the Chinese Medical Association 2015; 78: 533-537
Click for abstract
Background: A large number of studies have hypothesized that Toxoplasma gondii is a potentially relevant etiological factor in some cases of schizophrenia. By contrast, some studies have disproved this association. The aim of this study was to investigate whether latent toxoplasmosis has any role in schizophrenia disease. Additionally, the association between T. gondii and subtypes of schizophrenia, and the impacts of toxoplasmosis on psychopathology were examined in the study. Methods: A total of 85 patients with schizophrenia and 60 healthy volunteers were included in this prospective study. Immunoglobulin G (IgG) antibody to T. gondii was examined by enzyme-linked immune-sorbent assay method. Results: Seropositivity rates were 43.5% for the patients with schizophrenia and 43.3% for the healthy controls (odds ratio: 1.008, 95% confidence interval: 0.517-1.964, p = 0.981). There was no significant difference in T gondii IgG positivity between the schizophrenia and control groups with respect to sex and age. The difference in seroprevalence of T gondii IgG antibodies among the schizophrenia subtypes was not statistically significant (p = 0.934). No significant difference was found in Positive and Negative Syndrome Subscales between Toxoplasma-infected and Toxoplasma-free patients. Conclusion: In the study area with a high prevalence of T gondii, no association between toxoplasmosis and schizophrenia was detected. These findings showed that toxoplasmosis has no role in the risk of schizophrenia disease.

Tagged: antibodies, gondii, Schizophrenia, Toxoplasma gondii, toxoplasmosis

Mental health

Immediate rather than delayed memory impairment in older adults with latent toxoplasmosis

October 6, 2015
Mendy, A., Vieira, E. R., Albatineh, A. N., Gasana, J.
Brain Behavior and Immunity 2015; 45: 36-40
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The neurotropic parasite Toxoplasma gondii infects one third of the world population, but its effect on memory remains ambiguous. To examine a potential relationship of the infection with immediate and delayed memory, a population-based study was conducted in 4485 participants of the Third National Health and Nutrition Examination Survey aged 60 years and older. Serum anti-Toxoplasma IgG antibodies were measured by enzyme immune assay and verbal memory was assessed using the Mini-Mental State Examination and the East Boston Memory Test. The prevalence of latent toxoplasmosis was 41%; in one way analysis of variance, anti-Toxoplasma IgG antibody levels significantly differed across tertiles for immediate (P = 0.006) but not delayed memory scores (P = 0.22). In multinomial logistic regression adjusting for covariates, Toxoplasma seropositivity was associated with lower immediate memory performance (OR: 0.65, 95% CI: 0.44, 0.97 for medium tertile and OR: 0.61, 95% CI: 0.37, 0.98 for highest tertile in reference to the lowest tertile), especially in non-Hispanic Whites (OR: 0.56, 95% CI: 0.36, 0.88 for medium tertile and OR: 0.51, 95% CI: 0.30, 0.87 for highest tertile in reference to the lowest tertile). However, no relationship with delayed memory was observed. In conclusion, latent toxoplasmosis is widespread in older adults and may primarily affect immediate rather than delayed memory, particularly in White Americans.

Tagged: aging, cognition, gondii infection, memory, mice, older age, rhd molecule, risk, short-term-memory, Toxoplasma gondii, toxoplasmosis

Cognitive functions
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