The Brain Colonizer (S05E09)

A 13-month-old toddler in Canada experiences trouble breathing and slight vomiting after accidentally ingesting a button battery, which doctors initially mistaken for a coin. Meanwhile, a college freshman suffers from migraines, nausea, intermittent blindness, and hallucination-like partial seizures, as well as a terrible taste in her mouth and two brain lesions due to a Taenia solium infection. In 2008, a 6-year-old girl develops a headache, rash, and high fevers, ultimately succumbing to Rocky Mountain spotted fever.