Nearly ⅓ of the population are believed to be infected with the parasite, including 350,000 in the UK and 60 million in the USA, according to the University of Chicago. Copenhagen University scientists analysed data from over 80,000 participants in the Danish Blood Donor Study, 2,591 of which had registered psychiatric conditions; the parasite was detected in the blood of ¼ of the study population, and 61% of the participants were found to carry cytomegalovirus which has shown similar evidence of cognitive impairment.
When accounting for temporality the association was found to be even stronger. Findings corroborate Toxoplasma has a positive effect on the rate of schizophrenia, and Toxoplasma gondii may be a contributing casual factor for schizophrenia, but T.gondii was not associated with any other psychiatric disorders.
CMV was associated with other disorders, including risk of neurotic and stress related disorder, somatoform disorder, and attempting and/or committing suicide. The parasite may disrupt action of tryptophan amino acid essential precursor to serotonin, leading to secretion of large amounts of metabolites such as kynurenic acid.
Socio-economic factors were not controlled for which may influence probability of having a psychiatric disorder. However the researchers are still confident their statistically significant findings add to a growing evidence of the parasite having strange cognitive effects.
Toxoplasma gondii can lead to toxoplasmosis in humans which causes flu like symptoms which can go unrecognized, and exposed pregnant woman may have a miscarriage or stillbirth, according to NHS.
