[Ed. – Of course. Measles was eradicated in the U.S. Patient Zero had to have contracted it abroad.]
The measles outbreak that started in Disney’s California theme parks appears to be from an international source.
From NBC News:
An outbreak of measles that started in California’s Disneyland probably came from overseas, carried either by a foreign tourist or by an American coming back with the virus, a top federal health official said Thursday. …
“We don’t know exactly how this outbreak started but we do think it was likely a person infected with measles overseas,” Dr. Anne Schuchat of the Centers for Disease Control and Prevention told reporters.
“We assume that someone got infected with measles overseas, visited Disneyland park, and spread the disease to others.”
While not mentioned in the story, it’s possible the source of the measles virus was from an illegal immigrant.