Measles Cases and Outbreaks

Español: Casos y brotes de sarampión

Measles Cases

From January 1 to September 18, 2015, 189 people from 24 states and the District of Columbia were reported to have measles (AK, AZ, CA, CO, DC, DE, FL, GA, IL, MA, MI, MN, MO, NE, NJ, NY, NV, OH, OK, PA, SD TX, UT, VA, WA). Most of these cases [117 cases (62%)] were part of a large multi-state outbreak linked to an amusement park in California.

The United States experienced a record number of measles cases during 2014, with 668 cases from 27 states reported to CDC's National Center for Immunization and Respiratory Diseases (NCIRD). This is the greatest number of cases since measles elimination was documented in the U.S. in 2000.

• 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.

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Measles Outbreaks

Outbreaks in countries to which Americans often travel can directly contribute to an increase in measles cases in the U.S.

Reasons for an increase in cases some years:

• 2015: The United States experienced a large, 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. For more information see the Measles in the Philippines Travelers' Health Notice.
• 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. 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.

Publications

MMWR: 2015 Outbreaks

• Measles — United States, January 4–April 2, 2015
  MMWR. April 17, 2015
  From January 1 through April 2, 2015, a total of 159 measles cases have been reported to CDC….
• Measles Outbreak—California, December 2014-February 2015
  MMWR. Feb 20, 2015
  As of February 11, a total of 125 measles cases had been confirmed among U.S. residents in an ongoing measles outbreak linked to two Disney theme parks in Orange County, California...

MMWR: 2014 Outbreaks

• Measles Outbreak in an Unvaccinated Family and a Possibly Associated International Traveler — Orange County, Florida, December 2012-January 2013
  MMWR. Sep 12, 2014
  Four children in a Florida family were diagnosed with measles in January 2013. None of the four were vaccinated against measles, and none had traveled outside of Orange County, Florida, during the periods when they likely had been exposed...
• Notes from the Field: Measles in a Micronesian Community — King County, Washington, 2014
  MMWR. Sep 12, 2014
  This outbreak demonstrates the ease with which measles can be imported from a country with an ongoing outbreak and spread among a local population...
• Measles — United States, January 1-May 23, 2014
  MMWR May 29, 2014
  From January 1 through May 23, 2014, a total of 288 confirmed measles cases have been reported to CDC, surpassing the highest reported yearly total of measles cases since elimination.
• Notes from the Field: Measles — California, January 1-April 18, 2014
  MMWR. Apr 25, 2014
  During January 1-April 18, 2014, 58 confirmed measles cases were reported in California, the highest number reported for that period since 1995.

MMWR: 2013 Outbreaks

• Measles — United States, January 1-August 24, 2013
  MMWR. Sep 13, 2013
  During the first 8 months of 2013, 159 people in the United States were reported to have measles.
• Notes from the field: Measles outbreak among members of a religious community — Brooklyn, New York, March-June 2013
  MMWR. Vol 62, No 36;752-3 09/13/2013
• Notes from the field: Measles outbreak associated with a traveler returning from India — North Carolina, April-May 2013
  MMWR. Vol 62, No 36;753