From CDC:
From January 1 to May 10, 2019, 839** individual cases of measles have been confirmed in 23 states. This is an increase of 75 cases from the previous week. This is the greatest number of cases reported in the U.S. since 1994 and since measles was declared eliminated in 2000.
The states that have reported cases to CDC are Arizona, California, Colorado, Connecticut, Florida, Georgia, Illinois, Indiana, Iowa, Kentucky, Maryland, Massachusetts, Michigan, Missouri, Nevada, New Hampshire, New Jersey, New York, Oregon, Pennsylvania, Texas, Tennessee, and Washington.
*Cases as of December 29, 2018. Case count is preliminary and subject to change.
**Cases as of May 10, 2019. Case count is preliminary and subject to change. Data are updated every Monday.
**Cases as of May 10, 2019. Case count is preliminary and subject to change. Data are updated every Monday.