Nine people who visited Disneyland or Disneyland California Adventure Park during December have confirmed measles cases, state health officials said Wednesday. Seven of the patients live in California and two live in Utah.
State and county health officers are investigating an additional four suspected cases, two in Utah and two in California. All the patients visited the parks in Orange County between Dec.15-20, California Department of Public Health officials said.
“If you have symptoms, and believe you may have been exposed, please contact your health care provider,” Dr. Ron Chapman, CDPH director and state health officer, said in a statement. “The best way to prevent measles and its spread is to get vaccinated.”
Kathleen Harriman, chief of vaccine preventable diseases with the department, said that "it's our speculation that there was an (infected) international visitor at one of the parks, and that person or persons was able to infect a lot of people."
Measles is "a very infectious disease," she added, and was eliminated from the United States in 2000. "So all the cases of measles in the United States originate with an imported case, even though there can be transmission once one of those cases gets here." Measles is airborne and highly contagious. It can live on a surface where an infected person coughed or sneezed up to two hours and possibly infect others.
The California cases are in Alameda, Orange, Pasadena, Riverside and San Diego. The patients range in age from 8 months to 21 years. Of the seven California cases, six were not vaccinated, although two were too young to be vaccinated. The first of two recommended measles vaccine doses is typically given at 1 year of age.
Just one of the cases was fully vaccinated. Harriman said that while the measles vaccine is highly effective, "it confers lifelong immunity in 99 percent of people who receive two doses," and there will always be a small number of people who can be infected despite vaccination.
One of the cases is in Alameda County. Deputy Chief Health Officer Dr. Erica Pan said officials are "working with the health facility where the patient was seen" to identify other patients and health care workers who may have been exposed.
Pan said health officers will quarantine susceptible contacts, especially those at high risk of developing disease, "to make sure that contact stays home and away from other people to make sure that person does not infect others."
Initial measles symptoms include fever, cough, running nose and red eyes. After a few days, a red rash appears on the face and then spreads downward to the rest of the body.
Pan said if people are concerned they "should check on their immunization status and get vaccinated" if needed.
Disney officials told the Associated Press that they had not received any reports of staff contracting measles. Park officials are working with the health department to provide any necessary information, said Dr. Pamela Hymel, chief medical officer for Walt Disney Parks and Resorts.
The California Department of Public Health has notified the Centers for Disease Control of the cases.
This post has been updated with a response from Disney.