POTENTIAL ASSOCIATION BETWEEN LATENT TOXOPLASMOSIS AND SCHIZOPHRENIA SPECTRUM AND OTHER PSYCHOTIC DISORDERS

POTENTIAL ASSOCIATION BETWEEN LATENT TOXOPLASMOSIS

Abstract

 Studies of the potential association between latent toxoplasmosis and schizophrenia spectrum and other psychotic disorders (SSOPD) have yielded mixed results. In this study we aimed to investigate the potential association between a positive serology test for Toxoplasma gondii and the presence of SSOPD and selected demographic factors in order to determine if SSOPD patients should be screened for T. gondii. In this study, subjects were chosen from 2 groups: those with SSOPD (cases) and those without SSOPD (controls). Cases were purposely recruited from patients attending the Hospital Canselor Tuanku Muhriz, Kuala Lumpur and controls were recruited from a healthy population. The diagnosis of SSOPD was made by a mental health professional following the criteria of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV). In both groups, demographic factors were recorded and each subject had blood obtained to test for indirect ELISA for T. gondii antibodies. A total of 218 subjects were included in the study: 109 cases and 109 controls. The prevalences of confirmed positive tests for T. gondii among cases and controls were 24% and 32%, respectively (p = 0.227). Those aged 18-35 years had a significantly lower seroprevalence of T. gondii among cases than controls (45% vs 70%, p = 0.001). Ethnic Malays had a significantly lower seroprevalence of T. gondii among cases than controls (41% vs 80%, p<0.001). Those with a tertiary education had a significantly lower seroprevalence of T. gondii among cases than controls (51% vs 93%, p<0.001). Unemployed subjects had a significantly greater seroprevalence of T. gondii among cases than controls (77% vs 30%, p<0.001). Those who were unmarried had a significantly greater seroprevalence of T. gondii among cases than controls (67% vs 38%, p<0.001). Those with a family history of psychiatric illness had a significantly greater seroprevalence of T. gondii among cases than controls (51% vs 6%, p<0.001). These other factors may have affected our study results. In our study, there was no significant association between toxoplasmosis and SSOPD. SSOPD patients in the study population do not need to be routinely screened for the presence of T. gondii. Further studies in the study population need to control for demographic factors significantly associated with positive serology for T. gondii in order to determine if this changes our findings.