( CNN ) Some recent visitors to Disneyland left the fabled theme park with a souvenir they wo n't soon forget : measles . Public health officials in California and Utah confirmed nine cases Wednesday , all of them visitors of either Disneyland or Disney California Adventure Park in Anaheim between December 15 and December 20 . The California Department of Public Health said it suspects an additional three cases but had not yet confirmed those diagnoses . According to the CDC , measles is respiratory disease caused by a virus and spread through the air . It was considered eradicated in the United States in 2000 , though 2014 saw a record-breaking number of confirmed cases : 610 according to the Centers for Disease Control , `` the highest number of cases since measles elimination was documented in the U.S. in 2000 , '' the CDC says on its website . Nevertheless , California health officials speculate that since Disneyland attracts visitors from around the world -- including places where the highly contagious disease is prevalent -- that was likely the case here . `` Travelers to areas where measles is endemic can bring measles back to the U.S. , resulting in limited domestic transmission of measles , '' read a statement from California Department of Public Health . `` Disney and other theme parks in California are international attractions and visitors come from many parts of the world , including those where measles is endemic . '' Dr. Pamela Hymel , Disney 's chief medical officer , issued a brief statement : `` We are working with the health department to provide any information and assistance we can . '' As for symptoms , `` measles starts with a fever , runny nose , cough , red eyes and sore throat , '' according to the CDC . Those showing such symptoms should n't be bashful about seeing their doctor , because a full body rash is likely to break out next . `` If you have symptoms , and believe you may have been exposed , please contact your health care provider , '' said Dr. Ron Chapman , California 's state health office . Chapman says prevention is the key : `` The best way to prevent measles and its spread is to get vaccinated . '' 5 things to know about measles .
Nine visitors to Disneyland or Disney California Adventure Park have been infected with measles . The people with measles hail from California and Utah . They visited the theme park between December 15 and December 20 .