It seems like something out of the Middle Ages. Many of us believe that measles has been eradicated in the United States. The vast majority of people who caught the disease as children are largely older than age 50 now, part of the Baby Boomer wave that last experienced the disease as a common childhood ailment.

Statistics seem to back that up. Because of high United States vaccination rates, citizens were averaging about 60 cases per year as of 2000, according to the Centers for Disease Control and Prevention. Most of those cases originated outside the country.

But statistics can be deceiving. While United States citizens born in this country are largely vaccinated thanks to good health care and school admission requirements, those born outside the country have not been so fortunate. As a result, the CDC estimate that measles still causes the death of more than 100,000 people per year on a worldwide basis, most of them age 5 or younger.

Considering the high immigration rates to the first world, many unvaccinated children are starting to show up in schools, amusement parks and other areas where there are communal gatherings. And that can spell trouble for a world that may have relaxed too much against the threat of this often-deadly disease.

Disneyland Outbreak

In December 2014, a measles outbreak believed to have started at Disneyland in Anaheim, Calif., soon spread to an estimated 24 states, with approximately 117 people believed to have been infected. Many of the children who caught the disease had not received the vaccination as infants, thereby leaving them vulnerable.