The measles outbreak has spread across many states due to tourists visiting Disneyland and then returning home from their vacations. The outbreak began at the end of December, a prime vacation time period when Disneyland is filled to its full capacity.

Even though the disease was said to be eliminated in the United States in 2000, it has steadily made a return in the last year.

The CNN video below discusses more in depth why measles is coming back and why Disneyland was linked to the outbreak: