ATLANTA Measles cases in the United States hit a 15-year high in 2011, with 90 percent of the cases traced to other countries with lower immunization rates, the Centers for Disease Control and Prevention reported.
There were 222 cases of measles in the United States last year, more than triple the usual number, the CDC said. There had been only about 60 cases per year between 2001 and 2010.
No one has died of the disease in the United States since 2008. But approximately 20 million people contract the measles virus each year worldwide, and about 164,000 die from it, said Dr. Anne Schuchat, director of the health agency's National Center for Immunization and Respiratory Diseases.
The agency said in 2000 that home-grown measles had been eliminated, but cases continued to arrive in the United States from abroad.
There have been more than 25 measles cases reported so far in 2012, most of them imported, the CDC said. The virus can easily enter the country through foreign visitors or Americans traveling abroad who bring the disease back with them.
Measles is highly contagious and is transmitted when an infected person breaths, coughs or sneezes, Schuchat said. The disease can be spread even before an infected person has developed the rash from the virus.
"You can catch measles just by being in a room where a person with measles has been even after that person has left the room," Schuchat said on Thursday.
Measles cases were found in 31 states in 2011. Last year's count marked the highest number of cases since 1996, when there were 508 cases in the United States.
All but 22 of the 222 cases last year involved patients who had been infected overseas or caught the virus from someone who had been abroad, the CDC said. The source of the other 22 cases could not be determined.
Many of the cases were traced to Europe, where in some countries immunization rates are lower than in the United States. Europe suffered an outbreak of the disease in 2011, reporting more than 37,000 measles cases.
France, Italy and Spain, popular destinations for U.S. tourists, were among the hardest hit, said Schuchat.
"It's very important for travelers heading off to Europe to make sure they are up to date on their immunizations and that their children are too," she said.
Those who have already had measles or have been inoculated are not considered at risk of contracting the virus, the CDC said. The CDC recommends children receive two doses of measles, mumps and rubella vaccine starting at 12-15 months of age.
More than 90 percent of U.S. children have been vaccinated against measles, the CDC said.
"We don't have to have this much measles," Schuchat said. "Measles is preventable. Unvaccinated people put themselves and other people at risk for measles and its complications."
(Editing By Colleen Jenkins and Todd Eastham)