Overview

Measles is a childhood infection caused by a virus. Once quite common, measles can now almost always be prevented with a vaccine.

Also called rubeola, measles can be serious and even fatal for small children. While death rates have been falling worldwide as more children receive the measles vaccine, the disease still kills more than 100,000 people a year, most under the age of 5.

As a result of high vaccination rates in general, measles hasn't been widespread in the United States for more than a decade. The United States had about 30 cases of measles in 2004 but more than 600 cases in 2014. Most of these cases originated outside the country and occurred in people who were unvaccinated or who didn't know whether or not they had been vaccinated.