The association between toxoplasma gondii infection and psychiatric disorders among psychiatric patients in hospital Universiti Sains Malaysia

• Main Author: Azli, Alia Maisarah Mohd
• Format: Thesis
• Language: English
• Published: 2023
• Subjects: R Medicine; RA440-440.87 Study and teaching. Research; RC475-489 Therapeutics. Psychotherapy
• Online Access: http://eprints.usm.my/60707/1/ALIA%20MAISARAH%20BINTI%20MOHD%20AZLI-E.pdf; http://eprints.usm.my/60707/

Toxoplasma infection, caused by the protozoon Toxoplasma gondii, is one of the most common parasitic zoonoses globally. This facultative heteroxenic, polyxenic organism has been identified as playing a role in the etiology of various psychiatric disorders. The present comparative cross-sectional study purposed to investigate the association between Toxoplasma infection and psychiatric disorders in patients at Hospital Universiti Sains Malaysia, Kelantan. Fifty-four psychiatric disorder patients from each category (schizophrenia, bipolar disorder, and depressive disorder) and 54 healthy individuals were analyzed by an enzyme-linked immunosorbent assay (ELISA) that detects anti-T. gondii immunoglobulin G (IgG). Subsequently, all IgG- positive plasma samples were analyzed for Toxoplasma-specific IgM. IgG avidity ELISA was tested for the positive samples of T. gondii IgM. The presence of the Toxoplasma B1 gene and ITS-1 region was determined in all extracted deoxyribonucleic acids (DNAs) from the whole blood using the polymerase chain reaction (PCR). The sociodemographic, clinical manifestations, and behavioural factors of the psychiatric patients and healthy individuals were assessed using a data collection form. Out of 54 patients with depressive disorder, 24/54 (44.4%) were IgG+/IgM-, and four (16.7%) were IgG+/IgM+. A high avidity index that described a past infection for more than 20 weeks was reported in half of the sample (50.0%) and the other half (50.0%) showed a contradicting result that indicated a possible recent infection within 20 weeks. Moreover, 30/54 (55.6%) patients with bipolar disorder were IgG+/IgM-, five (16.7%) were IgG+/IgM+, and four of them had high avidity index and one showed a low avidity index. Meanwhile, 29/54 (53.7%) patients with schizophrenia were IgG+/IgM-, 2 (6.9%) were IgG+/IgM+, one of them had a high avidity index, and one low avidity index. Out of 54 healthy individuals, 37.0% (20/54) were seropositive for T. gondii antibodies. In this study, no positive results were found for the presence of the Toxoplasma B1 gene and ITS-1 region. A Chi-Square and multiple logistic regression proved age (p=0.031), marital status (p=0.007), and employment (p=0.012) were significantly associated with Toxoplasma seropositivity rate in patients with psychiatric disorders. Close contact with cats/pets (p=0.033) and contact with soil (p=0.012) also were significantly associated with Toxoplasma seropositivity rate in the patients. In conclusion, the findings revealed varying seropositivity rates, indicating that individuals with psychiatric disorders such as schizophrenia, bipolar disorder, and depressive disorder may have experienced both past and potentially recent infections with T. gondii. However, additional research is needed to elucidate the causal relationships and underlying mechanisms. This is essential for the development of targeted interventions and preventive strategies, with the potential to enhance overall mental health outcomes for those affected.