Health officials warn of measles exposure at 5 US airports "A small number of cases are capable of quickly producing epidemics."

Five U.S. airports had travelers pass through with confirmed cases of measles this month, exposing an unknown number of fellow passengers to the highly infectious disease, according to health officials in those cities.

In Chicago, an individual with measles traveled through two terminals at O'Hare International Airport over the course of a week. On Dec. 17, the individual passed through O'Hare's Terminal 1, and on Dec. 12, they passed through O'Hare's Terminal 3, according to the Chicago Department of Public Health.

The health department noted Chicago has one of the highest rates of measles, mumps and rubella vaccination in the nation.

In Virginia, a person with the measles visited Richmond International Airport on Dec. 17, according to the Virginia Department of Health.

In Austin, an individual with a diagnosed case of measles visited the United Airlines gate area at Austin-Bergstrom International Airport on Dec. 17, Austin Public Health reports.

“Measles is an acute, highly contagious viral disease," Dr. Mark Escott, medical director for Austin Public Health, said in a statement. "A small number of cases are capable of quickly producing epidemics."

Earlier in December, three unvaccinated children who had traveled to a country with an ongoing measles outbreak tested positive for measles when they returned. The children visited several parts of Denver International Airport on Dec. 11, including Concourse A, the baggage area and the pickup area, Colorado's Tri-County Health Department reported. They also traveled through Terminals 4 and 5 at Los Angeles International Airport on Dec. 11, according to the Los Angeles Department of Public Health.

The best way to protect against the measles is to get the measles vaccine. People who think they have been exposed to the measles should check their vaccination records and contact their health care provider.

The exposures cap off the worst year for measles in more than two decades, with the Centers for Disease Control and Prevention reporting 1,276 cases, which affected the majority of U.S. states. There were more cases of the infectious disease this year than there have been in the four years prior combined.

Outbreaks of the disease in Brooklyn and in New York state lasted nearly a full year, and threatened to end the United States' coveted measles elimination status. If outbreak lasted more than 12 months it would have ended that status, which the U.S. has held for nearly 20 years.

The year was even worse from a global standpoint. As of mid-November, the number of measles cases that countries around the world reported to the World Health Organization was three times higher than the number of cases reported during the same time in 2018.