An adolescent who arrived in Colorado earlier this month has tested positive for measles, the Colorado Department of Public Health and Environment said. The health department said the last confirmed case of measles in a Colorado resident was in January 2019. It's unclear if the disease has been confirmed in the state since then. The health department said the person had visited several countries. They arrived in Colorado at Denver International Airport on Dec. 13, the health department said. On Dec. 18, they went to the emergency department at Children's Hospital Colorado. The child has been in isolation since Dec. 18, the health department said. The health department said it's unclear if they are vaccinated. Public health workers are notifying people who may have been directly exposed, the health department said.