Folia Parasitologica, vol. 59 (2012), issue 2

Folia Parasitologica 59[2] 93-98 (2012) | 10.14411/fp.2012.014

Does Toxoplasma gondii infection affect cognitive function? A case control study

Wojciech Guenter1, Maciej Bieliński1,3, Aleksander Deptuła2, Patrycja Zalas-Więcek2, Małgorzata Piskunowicz1, Krzysztof Szwed1, Adam Buciński4, Eugenia Gospodarek2, Alina Borkowska1
1 Chair and Department of Clinical Neuropsychology, Nicolaus Copernicus University, Collegium Medicum, M. Skłodowskiej- Curie 9, 85-094 Bydgoszcz, Poland
2 Chair and Department of Microbiology, Nicolaus Copernicus University, Collegium Medicum, M. Skłodowskiej-Curie 9, 85-094 Bydgoszcz, Poland
3 Division of Vascular Diseases and Internal Medicine, Dr Jan Biziel University Hospital No. 2, Ujejskiego 75, 85-168 Bydgoszcz, Poland
4 Department of Biopharmacy, Nicolaus Copernicus University, Collegium Medicum, A. Jurasza 2, 85-089 Bydgoszcz, Poland

According to studies, latent Toxoplasma gondii infection may affect several functions of the human brain. Here we search for the association between latent toxoplasmosis and cognitive performance. We tested 70 individuals for latent T. gondii infection. There were 26 Toxoplasma-infected subjects and 44 Toxoplasma-free subjects. Within these two groups we assessed cognitive performance using a set of standardized, widely recognized neuropsychological tests: Trail Making Test, Stroop Test, Verbal Fluency Test, Digit Span Test and N-back test. The relationship between chronic toxoplasmosis and cognitive performance was assessed, with adjustment for age and sex. Patients with latent toxoplasmosis performed worse on one neuropsychological test, N-back Test - percentage of correct answers (β -8.08; 95%CI -15.64 to -0.53; p<0.05) compared to seronegative patients. However, after adjustment for age and sex, no statistically significant associations between latent toxoplasmosis and the scores on any cognitive tests were noticed. As statistically significant relationship was not observed, this study does not confirm that chronic latent T. gondii infection affects cognition.

Keywords: Toxoplasma gondii, latent toxoplasmosis, cognitive function, cognitive impairment, neuropsychological tests

Received: August 16, 2011; Accepted: January 5, 2012; Published: June 1, 2012


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