California's Worst Measles Outbreak in 15 Years

Julie Shenkman
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During December 2014, a measles outbreak hit California after the disease was found at Disneyland during the theme park's busiest week of the year. One of the most contagious diseases known, it spread quickly, with 102 people across 14 states confirmed ill in the outbreak by the beginning of February 2015. The spread of this infection in California and beyond is a cautionary tale for scientists, public health officials and the public in general.

How the Measles Outbreak Started

While public health officials and epidemiologists haven't been able to trace the Disneyland outbreak to any one person, they suspect that a foreign visitor infected with the disease visited the park and inadvertently transmitted it to those were susceptible. Most of the victims had not been vaccinated against measles, including several infants who were too young undergo the treatment, allowing the disease to spread quickly.

The Spread of the Measles Outbreak

Nationally, about 85 percent of those who have come down with measles since December, 2014 are unvaccinated or only partially vaccinated against the disease. Because measles is highly contagious even before the telltale red spots appear, with its symptoms often mimicking those of a bad cold, those infected can easily spread the virus through the air whenever they are in a public place. As a result, in some counties, unvaccinated children have been required to stay home from school until the measles outbreak subsides.

What Could Happen Next

While the measles outbreak in California does pose real danger to those who are unvaccinated, people who are vaccinated or who have had measles in the past are by and large safe when visiting public areas such as shopping malls or airports, as well as tourist attractions. Because so many people in the United States are appropriately vaccinated, it is unlikely that something on the scale of the Ebola epidemic in Africa could occur. However, even a small number of cases can have significant consequences, as measles can cause brain damage, hearing loss, pneumonia and even death.

How to Prevent Future Outbreaks

Public health officials declared in 2000 that measles had been eradicated in the United States due to the success of widespread vaccination. However, the disease has been brought back into the country, transmitted by unvaccinated travelers to foreign countries where measles is still prevalent who carry it back home. The California Department of Public Health and the Centers for Disease Control and Prevention strongly recommend that anyone who is unvaccinated should be vaccinated against measles as soon as possible, with parents making sure that their children's shots are complete and up-to-date.

Vaccination is the only way to prevent the spread of any measles outbreak, including the one that began in California in 2014. When parents prevent their children from being vaccinated due to personal beliefs, they put their own children in danger as well as other people medically unable to receive vaccinations due to age or immunity problems.


Photo courtesy of David Castillo Dominici at



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