Little House on the Prairie - Season 3 Episode 13 -

Counting on his immunity to protect him from the deadly mountain fever that killed his first wife and daughter, Isaiah Edwards takes Doc Baker to help with neighboring Elmsville's outbreak. But after contact with an infected townsman, Mr. Edwards unwittingly carries the disease back to Walnut Grove and when daughter, Alicia, develops symptoms, he must fight to save his new family while the rest of the town goes into quarantine.