Health officials with the Centers for Disease Control and Prevention are monitoring the spread of measles cases throughout 21 US states, including Michigan.

The states that have reported measles cases to the CDC are Arkansas, California, Connecticut, Florida, Illinois, Indiana, Kansas, Louisiana, Maryland, Michigan, Missouri, Nevada, New Jersey, New York, North Carolina, Oklahoma, Oregon, Pennsylvania, Tennessee, Texas, and Washington.

2018 is on track to become one of the worst years for measles outbreaks in the last decade. As of July 14, 107 cases have been reported in the US so far this year. In 2014, however, 667 cases of measles were reported across 27 states. This is the greatest number of cases ever reported since the CDC began tracking measles cases in 2000.

Measles is an airborne disease which is spread through sneezing and coughing. The CDC says the majority of people who contract the disease are unvaccinated. The disease is still common in many parts of the world, including Europe, Asia, the Pacific, and Africa.