Seroprevalence Study of Toxoplasma gondii Infection in Psychiatric and Neurological Disorders

Toxoplasma gondii infects one-third of the global human population and invades and chronically persists in the central nervous system of the infected host. Chronic infection in the brain correlates with changes in the neuronal architecture and behavior. To the best of our knowledge, the association between T. gondii and neurological and psychiatric disorders has not been studied in the Indian population. Therefore, this study was conducted to determine the association between T. gondii in these patients.

This cross-sectional study was conducted in a large Neuroscience Center by the Department of Microbiology in collaboration with the Psychiatry and Neurology Departments for 7 months from March to September 2025. A total of 281 neuropsychiatric patients and an equal number of controls were taken. They were further classified using the International Classification of Diseases, ICD-10 codes. After carefully explaining the procedure and goal of the study, informed written consent was taken. 3 mL of blood specimens was drawn under aseptic conditions by venipuncture, which was collected in sterile plain vials. Serum samples were tested for the presence of specific anti-T. gondii immunoglobulin G antibodies using a commercial qualitative enzyme-linked immunosorbent assay.

Our results reveal a higher prevalence of T. gondii antibodies among schizophrenia (33.34%), mental and behavioral disorder due to substance abuse (30%), bipolar affective disorder (32%), Parkinson's disease (31.03%), and dementia (35%).

Our results suggest that T. gondii seropositivity is higher among the psychiatric and neurological patients, but it is not significantly associated as compared to controls.