The total measles cases in California are now up to 79 cases, Orange County accounts for 31 percent of the state total (25), according to new data released Wednesday by the California Department of Public Health (CDPH).
Fifty-two of the cases are linked to Disneyland Parks since December 17, 2014.
In Arizona, Arizona Department of Health director, Will Humble wrote that the total measles cases in the state increased by two to seven cases to date.
A case reported in Oakland County, Michigan last Friday has now been epidemiologically linked to the state of California, not to Disney. An additional case in Mexico has been reported; however, this case is linked to California and not the Anaheim theme parks.
The vast majority of cases reported in the current outbreak are in people unvaccinated or undervaccinated against measles.
In the decade before the live measles vaccine was licensed in 1963, an average of 549,000 measles cases and 495 measles deaths were reported annually in the United States, according to the Centers for Disease Control and Prevention (CDC).
However, it is likely that, on average, 3 to 4 million people were infected with measles annually; most cases were not reported. Of the reported cases, approximately 48,000 people were hospitalized from measles and 1,000 people developed chronic disability from acute encephalitis caused by measles annually.
In 2000, measles was declared eliminated from the United States.
The United States experienced a record number of measles cases during 2014, with 644 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.