Folia Parasitologica 57[2] 121-128 (2010) | DOI: 10.14411/fp.2010.015

The role of latent toxoplasmosis in the aetiopathogenesis of schizophrenia - the risk factor or an indication of a contact with cat?

Pelin Yuksel¹, Nihat Alpay², Cahit Babur³, Reha Bayar⁴, Suat Saribas¹, Ali Riza Karakose¹, Cana Aksoy⁴, Mustafa Aslan¹, Seyfi Mehmetali⁴, Selcuk Kilic³, Ibrahim Balcioglu⁴, Ozlem Hamanca¹, Ahmet Dirican⁵, Omer Kucukbasmaci¹, Ali Oner⁶, Muzeyyen Mamal Torun¹, Bekir Kocazeybek¹

¹ Department of Microbiology and Clinical Microbiology, Cerrahpasa Medical Faculty, Istanbul University, Istanbul, Turkey

² T. C. Health Ministry, Bakirkoy Mental Health (Ruh ve Sinir) Hospital, Istanbul, Turkey

³ Refik Saydam Hifzisihha (Public Health) Medical Center, Parasitology Laboratory, Ankara, Turkey

⁴ Department of Psychiatry, Cerrahpasa Medical Faculty, Istanbul University, Istanbul, Turkey

⁵ Department of Biostatistics, Cerrahpasa Medical Faculty, Istanbul University, Istanbul, Turkey

⁶ Department of Microbiology and Clinical Microbiology, Istanbul Medical Faculty, Istanbul University, Istanbul, Turkey

We assessed IgG antibody to Toxoplasma gondii in 300 inpatients with schizophrenia (SG), 150 outpatients with anxiety and depressive disorders (PCG), and 150 healthy blood donors (HCG). Seropositivity rates were 60.7% for SG, 36.7% for PCG, and 45.3% for HCG (p<0.001). The seropositivity rate for anti-Toxoplasma IgG antibodies in SG was significantly higher that in PCG (X²=23.11, OR=2.66, p=0.001) and HCG (X²=9.52, OR=1.86, p=0.002). Among SG, 85% of those who reported close cat contact had IgG antibodies to T. gondii. Close cat contacts were reported by 59% of SG, 6% of PCG, and 9% of HCG (p<0.001). There was a nonsignificant positive association between toxoplasmosis and schizophrenia for people with a contact with a cat (OR=2.221, p=0.127, CI₉₅=0.796-6.192), and significant negative association between toxoplasmosis and schizophrenia for people without contact with a cat (OR=0.532, p=0.009, CI₉₅=0.332-0.854). Close cat contact (OR=2.679, p<0.001), 51-65-year age group (OR=1.703, p<0.001) and education [illiterate+primary (OR=6.146, p<0.001) and high school (OR=1.974, p=0.023)] were detected as independent risk factors in multivariate logistic regression. The effect of toxoplasmosis on risk of schizophrenia disappeared in the complex model analyzed with multivariate logistic regression. In conclusion, our data suggest that the toxoplasmosis has no direct effect on the risk of schizophrenia in Turkey but is just an indication of previous contacts with a cat.

Keywords: schizophrenia, Toxoplasma gondii, latent toxoplasmosis, Turkey

Received: March 3, 2009; Accepted: April 7, 2010; Published: June 1, 2010  Show citation