More than 50 cases of measles have now been linked to the outbreak that started spreading at Disney theme parks in Southern California right before Christmas. And health officials report an increase in cases among people who did not visit the parks, indicating that the illness is now spreading to others exposed in their communities.
The latest figures from the California Department of Public Health identify 51 confirmed cases of measles. The majority -- at least 41 cases -- are in California. Most of the patients had not been vaccinated.
Health officials in Utah confirmed Monday that a third person in that state has been diagnosed: an unvaccinated child who had contact with two siblings who were infected at one of the parks.
In Orange County, California, where at least 16 people have gotten sick, officials say the 6 most recent patients were not at Disney and did not have known contact to any of the confirmed Disney visitors. That worrisome development "indicates exposure to measles is more widespread throughout the county," the agency said in a statement. It went on to say officials expect "the measles outbreak will continue to spread."
Measles is highly contagious and can spread through a sneeze or cough before a person even knows they have it. The virus can remain airborne and live on surfaces for a period of time, making transmission harder to trace.
Before the vaccine became available in 1963, the CDC says 400 to 500 Americans died of measles every year and 4,000 suffered encephalitis from it.
Vaccination efforts were successful enough that measles was officially declared eliminated in the U.S. in 2000. But cases still occasionally emerge, mostly among unvaccinated people who contracted it overseas in countries where the illness is more common. Experts say a crowded place full of international visitors like Disneyland would be an easy place for it to spread.
California had its worst measles outbreak in decades last year, and many cases were linked to families who opted out of having their children vaccinated. Overall the U.S. had 644 confirmed cases of measles in 2014, the most in 20 years.