Psychosis may be associated with toxoplasmosis
Introduction
Toxoplasma gondii is an intracellular parasite that infects virtually all warm-blooded vertebrates including mans. It is estimated that about 30–60% of the population in both developed and developing countries are infected with this parasite through the ingestion of food and water contaminated with cysts or oocysts [1]. In immunocompetent person who infected with T. gondii, is characterized by reproduction of tachyzoite in cells of different tissues [2] and within weeks or months, tachyzoites disappear and tissue cysts form in various tissues, mainly in brain and muscles. These cysts are believed to persist throughout the life of the immunocompetent hosts in whom psychotic manifestation may be induced. Many epidemiological studies focused on patients with CNS diseases have been carried out in recent years, and increasing evidence supports the hypothesis that T. gondii infection may be an etiological factor for the development of psychosis in some patients [3], [4].
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Dopamine modulation and etiological implication of psychosis
Many reports indicated that T. gondii might be an etiological agent in some cases of psychosis. Huber et al. suggested that parasitosis might contribute to the increase of the dopamine level in mice brain [5]. Evidence showed that dopamine is one of the key compounds related to psychosis such as schizophrenia, and bipolar disorder in laten toxoplasmosis patients [6], [7]. Dopamine releasing in the nucleus accumbens by activating the retrohippocampal region can disrupt the fornix section of
Surveying the situation of T. gondii infection in patients with psychosis on the mainland of China
A large number of epidemiologic and clinic studies collected from 1953 to 2008 have shown that T. gondii infection may contribute to some cases of psychosis [16]. In animals, experimental infection indicated that T. gondii can alter their behavior and neurotransmitter levels [17]. In humans, however, clinic evidence appears that the acute infection with T. gondii can produce psychotic symptoms similar to those displayed in persons with schizophrenia. Recently, similar investigations on the
Conclusion
The clinical and epidemiological studies mentioned above showed that there are some positive correlation between T. gondii infection and psychosis. There are some reasons based on:
First, sero-prevalence investigation in various regions of China indicates there is a positive correlation between T. gondii infection and psychotic disease. That is confirmed the results of Mortensen and his colleagues’ found that as compared with the control subjects, the individuals with first-episode schizophrenia
Acknowledgements
This work is supported by grants from Science and Technology Key Projects of Henan Province (#200703008) and China Postdoctoral Science Foundation.
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2019, HeliyonCitation Excerpt :The pathophysiological mechanism involved in the development of psychiatric symptoms in Toxoplasma gondii infections has not been elucidated clearly yet. In 2009, Zhu [16] suggested that psychotic symptoms observed in Toxoplasma gondii infections might be linked with the direct effects of the infection on the functioning of neurons, and also suggested that several immune-mediated alterations might be involved, too in serotonin and dopamine production. The immune responses in the host during the Toxoplasma gondii infection result in the generation of proinflammatory cytokines like TNF and IL-6.
Is there any role of latent toxoplasmosis in schizophrenia disease?
2015, Journal of the Chinese Medical AssociationNeurobiological studies on the relationship between toxoplasmosis and neuropsychiatric diseases
2015, Journal of the Neurological SciencesCitation Excerpt :A growing number of studies have shown that infection with Toxoplasma involves the synthesis of DOPA and other neurotransmitters. Indeed, this parasite possesses genes encoding proteins homologous to the TH and to the D2R [33,35]. TH, the enzyme which catalyzes the conversion of l-tyrosine to l-dihydroxyphenylalanine (L-DOPA), is the rate limiting factor in DOPA synthesis within the brain.
Toxoplasmosis can be a sexually transmitted infection with serious clinical consequences. Not all routes of infection are created equal
2014, Medical HypothesesCitation Excerpt :About fifty studies have shown a strong connection between toxoplasmosis and schizophrenia [18–20]. A prospective study has even reported Toxoplasma infection to cause schizophrenia in genetically predisposed subjects and toxoplasmosis-associated schizophrenia to be a distinct, more severe form of this serious mental disease [21,22]. It is well known that the onset of schizophrenia is about 2–3 years earlier in men than in women.