About 1 in 3 people worldwide have been infected with a microscopic parasite called Toxoplasma gondii—or simply "toxo"—which can cause toxoplasmosis. After the initial infection, toxo settles into our muscles and brains, where it can remain for life.
Source: [Phys.org](https://phys.org/news/2026-07-people-toxoplasmosis-dangerous-brain-parasite.html)