Toxoplasma gondii infection in first-episode and inpatient individuals with schizophrenia

SummaryBackgroundA high seroprevalence of Toxoplasma gondii infection has been detected in psychiatric patients, particularly in schizophrenia cases.MethodsIn the present study 98 patients suffering from schizophrenia (58 inpatients and 40 first-episode patients) and 96 control patients (50 healthy volunteers and 46 with a depressive disorder) were examined for the presence of both IgG and IgM antibodies against T. gondii by enzyme-linked immunosorbent assay (ELISA). We applied the Bradford Hill criteria to identify the weight of causal inference.ResultsThe positivity rate of anti-T. gondii IgG antibodies among individuals with schizophrenia (57.1%) was significantly higher than in healthy controls (29.2%). There were no associations between immune status ratio (ISR) values and the risk of schizophrenia. The weight of evidence approach using the Bradford Hill criteria revealed a 92% probability of a causal association.ConclusionOur results show that exposure to T. gondii may lead to schizophrenia.