Health officials in Washington state on Sunday warned people who used Seattle-Tacoma International Airport this month that they could have been exposed to measles after a passenger was confirmed to be carrying the virus.

The passenger was at the airport on Sept. 6 during a period when the illness is contagious, and can spread easily through the air by breathing, coughing or sneezing, Public Health -Seattle & King County said in a news release.

"The traveler was likely exposed to measles outside of the United States," the agency said.

The passenger used the airport's north satellite terminal, the inter-terminal train and the baggage claim, and also dined at a restaurant at the Courtyard Seattle Federal Way hotel that evening, the agency said.

Measles is a highly contagious and potentially severe respiratory disease. Symptoms begin seven to 21 days after exposure and include high fever, rash, cough, and red, watery eyes.

People who might have been exposed would likely become sick between Sept. 13 and 27, health officials said.

Health officials advised those with possible exposure to seek immediate medical attention. But in order to avoid possibly spreading measles to other patients, people were instructed not to go to a clinic or hospital without calling to request an evaluation.

A measles outbreak in Ohio earlier this year sickened nearly 400 people ranging in age from 6 months to 53 years, authorities said.

The majority of those who fell ill were unvaccinated, health officials said.

People at the highest risk from exposure to measles include those who are not vaccinated, pregnant women, infants under 6 months of age and those with weakened immune systems.