In a given year, more measles cases can occur for any of the following reasons:

  • an increase in the number of travelers who get measles abroad and bring it into the U.S., and/or
  • further spread of measles in U.S. communities with pockets of unvaccinated people.
Regarding the spread of measles:
  • The majority of people who get measles are unvaccinated.
  • Measles is still common in many parts of the world including some countries in Europe, Asia, the Pacific and Africa.
  • Travelers with measles continue to bring the disease into the United States.
  • Measles can spread when it reaches a US community where groups of people are unvaccinated.

Six outbreaks (defined as three or more cases) have been reported in 2019 in the following jurisdictions:

  • New York State, Rockland County
  • New York City
  • Washington
  • Texas
  • Illinois
  • California

These outbreaks are linked to travelers who brought measles back from other countries such as Israel and Ukraine, where large measles outbreaks are occurring. Make sure you are vaccinated against measles before traveling internationally. You can also read more about this information from the CDC here.