Toxoplasma gondii the cause of toxoplasmosis is intracellular parasite; when primary infection occurs during pregnancy the offspring has a markedly increased risk of CNS congenital abnormalities, including microcephaly, hydrocephalus, mental retardation, convulsions, cerebral calcifications, and chorioretinitis. Fifty-seven patients with schizophrenia with age range 12–60 years, study group 102 subjects without schizophrenia as control group ,with age range 15–60 years. Immunofluorecent assay were used to determine qualitative and quantitative IgG tested by automated VIDAS family instruments, this assay principle combines an enzyme immunoassay method by immunocapture with final fluorescent detection (ELFA). The present study show significant differences between schizophrenic patient (57) group and control group (102). Through a case–control study design, 57 schizophrenic patients and 102 control subjects matched by gender, age and residence place were examined with enzyme-linked immunfluorscent assays for the presence and levels of T. gondii IgG antibodies. Both the seroprevalence and the level of T.gondii IgG antibodies were higher in schizophrenic patients (15/57; 26%) as compare with control subjects (7/102; 7%). This study suggested the hypothesis that T. gondii is a risk factor for schizophrenia especially in old schizophrenic patients.

Toxoplasma gondii, Seroprevalence, Schizophrinic Patient, Hilla - Iraq