Health officials have confirmed an international traveler who passed through Denver International Airport on Dec. 13 has tested positive for measles.

The adolescent, whose vaccination status is unknown, allegedly visited several Colorado counties, and has been in isolation since Dec. 18, health officials stated in a news release. 

"On Monday, Dec. 18, the adolescent went to Children’s Hospital Colorado’s Emergency Department at the Anschutz Medical Campus from 8:30 to 11 a.m. The hospital is notifying healthcare providers, patients and others who were in a similar area as the measles patient," the release said. 

Arapahoe County Public Health is leading the investigation and has been notifying people who may have been directly exposed, according to the Colorado Department of Public Health and the Environment (CDPHE).

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The CDPHE also provided a timeline of when the adolescent was at the airport.

According to the timeline, the adolescent was at Denver International Airport from 4:30 to 8 p.m. on Dec. 13 with possible exposure to people moving through Concourse A, bridge security, baggage claim and the passenger pickup area, the release said. 

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The last confirmed case of measles in a Colorado resident before this was in January 2019, according to the state.

Denver International Airport was not immediately available for comment.