The person tested positive for measles and may have exposed others in southwestern Utah.
Health experts say the risk to the general population is low, but the public should be aware of the increased risk of measles in the southwest region and the increasing number of cases in surrounding states.
KSL News Radio reports a few days before the Memorial Day holiday a Canadian traveler with an undiagnosed case of measles flew into Salt Lake City.
Health officials told KSL the passenger arrived in Salt Lake City, rented a car and then drove to Idaho where they later developed symptoms.
Utah health officials said they have been in contact with passengers on the flight. As of Tuesday afternoon, none had developed measles.
Measles symptoms generally appear 10 to 14 days after exposure to the virus, according to the Centers for Disease Control.
Common symptoms include high fever, cough, runny nose, sore throat, red eyes and tiny white spots inside the mouth.
A rash with small red spots begins three to five days after other signs of the illness.
Public health officials encourage anyone who has measles-like symptoms to stay home and away from others for at least four days.
