The parasite, Toxoplasma gondii, is potentially deadly. It infects warm-blooded animals, but it's typically passed to people by cats or by consuming contaminated produce or undercooked meat. Once it's made its way inside you, the parasite spreads throughout your body and takes up permanent residence in your brain.
It's estimated about a third of all people around the world have the parasite, yet, amazingly, few ever have symptoms. The disease it can cause, toxoplasmosis, is primarily a problem for people who are immunocompromised.
https://medicalxpress.com/news/2026-01-common-brain-parasite-infect-immune.html