According to the Centers for Disease Control and Prevention, the U.S. had 288 measles cases so far this year. That's the highest number of cases since the "elimination" of the disease from the country 14 years ago. You did it, measles! You're back! 

Source: CDC

Of course, a victory for measles is not so great for the actual human beings who live in America, particularly among Amish communities in Ohio were there have been 166 cases of measles so far, according to USA Today's report. And the CDC has made it very clear why this outbreak is happening: not enough Americans are getting vaccinated.

"Measles can spread when it reaches a community in the U.S. where groups of people are unvaccinated," the CDC said in their announcement of the 20-year high, adding that most people who get the disease are unvaccinated. Specifically, CDC's National Center for Immunizations and Respiratory Diseases director Anne Schuchat told USA Today, this is what public health officials have seen happening this year: 

"The current increase in measles cases is being driven by unvaccinated people, primarily U.S. residents, who got measles in other countries, brought the virus back to the United States and spread to others in communities where many people are not vaccinated. Many of the clusters in the U.S. began following travel to the Philippines where a large outbreak has been occurring since October 2013."

In Ohio, the Amish communities affected by the outbreak had low immunization rates when a group of missionaries brought the disease into the community following a trip to the Philippines. However, in response to the outbreak, the community has put aside their reluctance to vaccinate and taken advantage of clinics set up to help those communities combat the outbreak, as NBC News reported in April. Others who chose not to be vaccinated have quarantined themselves for the 21-day incubation period for measles. 

There are other significant measles outbreaks in California and New York this year, with 60 and 26 confirmed cases, respectively. The number of cases this year is only expected to climb. So, contra Jenny McCarthy, vaccinate your kids.