19 people who visited Disneyland or Disney California Adventure in California last month have contracted measles, health officials say.

According to officials, 16 of those cases are in California, two in Utah and one in Colorado.

California officials say that they have only verified that two those of the patients in their state were fully vaccinated against the disease.

Disney spokespersons have said they are working with public health authorities to provide any necessary assistance.

The Associated Press reported:

More people may have been exposed when measles patients were treated at two local hospitals and a lab, said Nicole Stanfield, a spokeswoman for the Orange County's health care agency. Stanfield urged anyone with measles symptoms to call their doctor before seeking medical attention to avoid exposing others to the highly contagious illness.

"The medical provider may visit them in the car or may have a special room for them to go where they're not contaminating everyone else in the waiting room," she said.

Nine cases had been reported earlier in the week with 10 more emerging Thursday and Friday in California and Colorado, where the El Paso County Public Health department said a patient was diagnosed with measles at a Colorado Springs hospital after visiting a California theme park.

[...]

Measles is a highly contagious virus that lives in an infected person's nose and throat mucus and spreads through coughing and sneezing, according to the federal Centers for Disease Control and Prevention. Symptoms include fever, cough, runny nose and red eyes and a red rash that usually first appears on the face and spreads to the rest of the body.

Health experts say the best prevention against measles is vaccination. While officials declared measles eliminated in the United States in 2000 because of a lack of continuous transmission, the illness is still brought into the country by foreign visitors or unvaccinated Americans.

Watch more above.