Toxoplasmosis is caused by an intracellular parasite transmitted by cats that can cause a variety of chronic diseases. It is most closely connected to psychiatric diseases, but can cause a wide range of chronic diseases in the body and brain, from neurologic diseases, to eye diseases, to psychiatric diseases, to brain cancer.  Literature confirms the toxoplasma parasite can travel from the intestine to the brain and can alter genes.

The toxoplasma parasite can cross the placenta and cause neurologic damage to the fetus. The earlier in the pregnancy toxoplasmosis is acquired, the more severe the impact on the fetus. Symptoms in a fetus may not appear until months or years after birth, when the infant develops a central nervous system disease, such as epilepsy. Many types of epilepsy and regressive developmental disorders have been linked to toxoplasmosis; and the specific neurologic diagnosis may be impacted by the volume of the parasite in the brain, the location of the parasite in the brain, and duration of infection.

Toxoplasmosis is an under-recognized and under-appreciated intracellular pathogen in adults, children and infants.  Toxoplasma can spread throughout the body and cause chronic diseases, which are not often recognized as related to or caused by toxoplasmosis.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3603208/