From January 1 to February 28, 2019, 206** individual cases of measles have been confirmed in 11 states.
The states that have reported cases to CDC are California, Colorado, Connecticut, Georgia, Illinois, Kentucky, New Jersey, New York, Oregon, Texas, and Washington.
*Cases as of December 29, 2018. Case count is preliminary and subject to change.
**Cases as of February 28, 2019. Case count is preliminary and subject to change. Data are updated weekly.
Six outbreaks (defined as 3 or more cases) have been reported in 2019 in the following jurisdictions:
- New York State, Rockland CountyExternal
- New York State, Monroe CountyExternal
- New York CityExternal
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.
- The majority of people who got measles were 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 U.S.
- Measles can spread when it reaches a community in the U.S. where groups of people are unvaccinated.
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.
Reasons for an increase in cases some years:
- 2018: The U.S. experienced 17 outbreaks in 2018. Three outbreaks in New York State, New York City, and New Jersey, respectively, contributed to most of the cases. Cases in those states occurred primarily among unvaccinated people in Orthodox Jewish communities. These outbreaks were associated with travelers who brought measles back from Israel, where a large outbreak is occurring. Eighty-two people brought measles to the U.S. from other countries in 2018. This is the greatest number of imported cases since measles was eliminated from the U.S. in 2000.
- 2017: A 75-case outbreak was reported in Minnesota in a Somali-American community with poor vaccination coverage.
- 2015: The United States experienced a large (147 cases), multi-state measles outbreak linked to an amusement park in California. The outbreak likely started from a traveler who became infected overseas with measles, then visited the amusement park while infectious; however, no source was identified. Analysis by CDC scientists showed that the measles virus type in this outbreak (B3) was identical to the virus type that caused the large measles outbreak in the Philippines in 2014.
2014: The U.S. experienced 23 measles outbreaks in 2014, including one large outbreak of 383 cases, occurring primarily among unvaccinated Amish communities in Ohio. Many of the cases in the U.S. in 2014 were associated with cases brought in from the Philippines, which experienced a large measles outbreak.
- 2013: The U.S. experienced 11 outbreaks in 2013, three of which had more than 20 cases, including an outbreak with 58 cases. For more information see Measles — United States, January 1-August 24, 2013.
- 2011: In 2011, more than 30 countries in the WHO European Region reported an increase in measles, and France was experiencing a large outbreak. These led to a large number of importations (80) that year. Most of the cases that were brought to the U.S. in 2011 came from France. For more information see Measles — United States, January-May 20, 2011.
- 2008: The increase in cases in 2008 was the result of spread in communities with groups of unvaccinated people. The U.S. experienced several outbreaks in 2008 including three large outbreaks. For more information see Update: Measles — United States, January–July 2008.
See also: The Surveillance Manual chapter on measles that describes case investigation, outbreak investigation, and outbreak control for additional information.