A King County woman has been diagnosed with measles, the sixth confirmed case of the highly contagious disease in the Puget Sound region this week.

The woman, who is in her 40s, spent time in Auburn and Kent while she was contagious but didn’t know she was infected, according to Public Health – Seattle & King County.

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All six people spent time at Seattle-Tacoma International Airport, and the cases point to a common exposure from an unidentified person contagious with measles on April 25, likely in the morning, health officials said Friday.

On Sunday, a Pierce County man was diagnosed with measles, and four other measles diagnoses were confirmed Wednesday. Two of the cases involve King County women, one is a high-school student in Snohomish County and the fourth is another Pierce County man.

Health officials in the three counties have identified more than 40 locations where the six people could have exposed others to measles. Among those sites are Issaquah High School, where one King County woman is a staff member, and North Creek High School, where the Snohomish County patient is a student.

Issaquah High closed Thursday so officials could verify the immunization records of all staff. Teachers scrambled to locate their medical documents, and those who were unsuccessful won’t be allowed to come back to school until they find them.


Thirteen seniors and an unknown number of younger students are barred from the school until May 31, according to the school district.

North Creek had enough staff members with records to keep school open, but sent letters to staff and students who haven’t been vaccinated. Ten students will be excluded from school until June 3, said Northshore School District spokeswoman Lisa Youngblood Hall.

Washington state’s measles cases account for about 9% of the more than 840 cases reported in the United States this year. Health officers predict that outbreaks are likely to continue in the state, given that the disease is so contagious.

One person who contracted measles was immunized, and another was not, according to the state health department. The status of the other four hasn’t been determined.

Gov. Jay Inslee recently signed a law that eliminates personal belief and philosophical exemptions for the measles, mumps and rubella (MMR) vaccine for children who attend a day-care center or school. The law takes effect in July.