Measles exposure alert issued after infected family visits King, Snohomish counties
Jan 9, 2026, 10:36 AM | Updated: 3:49 pm
A dose of the measles, mumps and rubella vaccine is displayed at the Neighborcare Health clinics at Vashon Island High School on Vashon Island. (Photo: Elaine Thompson, The Associated Press)
(Photo: Elaine Thompson, The Associated Press)
A warning has been issued regarding potential measles exposures in King and Snohomish counties.
One adult and three children visiting from South Carolina after Christmas got sick. They visited multiple locations in Marysville, Mukilteo, and Everett while they were contagious, but before their diagnosis.
They also flew in and out of Seattle-Tacoma International Airport (SEA).
Regional health workers are urging people to check if they’ve been fully vaccinated. If not, they say getting both doses of the shot provides 97% protection.
“Measles is one of the most contagious diseases we know, and often brings serious illness,” Dr. James Lewis, Snohomish County Health Officer, said. “The MMR vaccine is the best way to prevent outbreaks and protect our community, especially for infants and those who cannot be vaccinated.”
Young children are especially vulnerable and can suffer serious side effects.
Infection rates are at their highest level since 1992. In South Carolina, the state health department reported 26 new cases since last Friday.
Exposure locations
Anyone who was at the following locations during the times listed could have been exposed to measles:
These times include the estimated period when family members were at the location and two hours after. The measles virus can remain in the air for up to two hours after someone infectious with measles leaves the area.
You can find more at this Snohomish County Public Health measles page.

