Measles is an deadly, infectious disease that typically strikes children. The disease comes on as a fever and runny nose, and causes an uncomfortable blotchy, rash all over the body. It's airborne, so it spreads quite easily, too: it just takes an infected person breathing or coughing near someone who is unvaccinated. One person with measles can infect 12 to 18 others.
For these reasons, the disease quickly and easily moved through Disneyland in Orange County and beyond. To date, it has reached 67 people in nine California counties, as well as Utah, Washington, Oregon, Colorado, and Mexico.