Lurkers (S02E04)

A young girl falls ill after being infected by the Cryptosporidium parasite, leading to intense vomiting and diarrhea. Meanwhile, a firefighter suffering from an autoimmune condition succumbs to meningitis brought on by a microscopic amoeba. Additionally, a rare and aggressive tapeworm detaches the retina of a teenage girl, resulting in the loss of vision in her left eye.