Measles is a highly contagious virus but most people in Washington are immune because they have been vaccinated.
The disease is mainly spread through the air when a person with measles coughs or sneezes.
People at highest risk from exposure are the unvaccinated, pregnant women, infants under six months of age and those with weakened immune systems.
The contagious traveler flew from Beijing to Seattle on Thursday.
The Centers for Disease Control and Prevention is contacting people who were on the same flights as the contagious traveler.
On the Net
Measles fact sheet: www.kingcounty.gov/healthservices/health/communicable/diseases/measles
More Northwest Headlines
Yakima youngsters mix Legos, science education Activists rappel off Oregon bridge to stop Shell icebreaker Stanwood man pleads guilty to stealing from Swinomish tribe Death penalty dropped from Carnation killings trial Poll: Just 30 percent inclined to re-elect Gov. Inslee GOP lawmakers want Washington to look at Planned Parenthood Salvation Army sets up charging ports for Portland homeless Spokane criminal faces 30th felony charge
Our new comment system is not supported in IE 7. Please upgrade your browser here.