Health Alert: Measles Case in VisitorS to King and Snohomish Counties

Jan. 8, 2026

Action Requested

Be aware of possible measles exposures in King and Snohomish counties from three confirmed measles cases in a family visiting from South Carolina. The family -- including one adult and two children who were infectious -- spent time in King and Snohomish counties between Dec. 27, 2025, and Jan. 1, 2026. The adult reportedly received on MMR vaccine and the children were unvaccinated. 

Secondary cases would be expected to occur Jan. 4 – Jan. 22, 2026.

Isolate

Have a planned triage process for patients with fever and rash so these patients are not waiting in common areas with other people.
Patients with rash and fever should not stay in waiting rooms or other common areas.
Immediately isolate patients with suspected measles in an airborne infection isolation room (AIIR) or a private room with a closed door.
Follow standard and airborne precautions when evaluating suspected cases, regardless of vaccination status.
After patient is discharged, do not use or have staff enter the room for 2 hours.

Notify

Report suspected measles cases to the Snohomish County Health Department at (425) 339-3503 immediately AND before discharging or transferring patients.
Public Health will ensure appropriate, rapid testing and investigation.

Test

Collect the following specimens on patients with suspected measles:
Nasopharyngeal swab placed in viral transport media; AND
Urine, minimum 20mL, in sterile leak proof container; AND
Serum, minimum 1mL, in red top or red-grey top tube
Public Health will facilitate diagnostic testing with Washington State Public Health Laboratory (WAPHL).

Manage

Health care facilities should inform their Infection Prevention Program to identify potentially exposed persons at the facility (patients, visitors, staff, and volunteers).
Public Health will identify close contacts and recommend post-exposure prophylaxis (PEP) for eligible people.
If a patient requests titers to determine immunity, providers should accommodate this request. If the patient is concerned about potential recent exposure, take appropriate precautions, including drawing titers outdoors when no AIIR is available if it has been more than 72 hours since exposure.

Vaccinate

Assess immunization status during healthcare visits at every visit and strongly recommend measles, mumps and rubella (MMR) vaccination based on the recommended schedule, health condition, occupation, and other risk factors such as travel.
If you are reviewing your client’s immunization record in the state immunization registry (WAIIS), please note that the first section displayed is the ‘forecast,’ which will outline any due or overdue immunizations. The forecast section does not confirm that a vaccine has been given, only that one (or more) are due.
Under-vaccinated individuals may be at risk for measles infection due to outbreaks that occur in the US or anywhere else in the world. 
If you are treating pediatric patients 6-11 months old, please inquire about upcoming international travel, or potential travel to an area with a measles outbreak. If there is upcoming travel that could result in measles exposure, offer a single MMR single vaccine dose for protection in case of an exposure. The two standard doses of the MMR vaccine, starting at 12 months, will still be required.
If you are running low on critical supplies, including doses of the MMR vaccine, and have exhausted all local options for additional supplies, you can contact the NWHRN duty officer (425.988.2897), who can help you fill out a resource request to the state or source mutual aid from other healthcare facilities.

Background

One adult and two children were infectious from Dec. 27, 2025, through Jan. 1, 2026, while visiting King and Snohomish counties on a trip from South Carolina. The parent reported having received at least one vaccine to protect against measles; the children were unvaccinated.

The family visited multiple locations in Marysville, Mukilteo and Everett while contagious – but before being diagnosed – with measles. They also traveled through Seattle-Tacoma International Airport and visited a car rental facility near the airport.

If a person was at a listed location below, during the noted dates and times, and they are not immune to measles, the most likely time a person would become sick would be between Jan. 4 – 22, 2026.

DATE	TIME	LOCATION
12/27/25 12/28/25	1 PM – 3 PM 2 PM – 6:30 PM	McDonald’s 530 128^th St. SW, Everett, WA 98204 Slavic Christian Church Awakening 4223 78^th St SW, Mukilteo, WA 98275
12/29/25	11 AM – 2 PM	Flying Squirrel Trampoline Park 1325 SE Everett Mall Way, Everett, WA 98208
12/29/25	1 PM – 3 PM	Chick-fil-A 8810 36^th Ave, Marysville, WA 98270
12/30/25	1 PM – 3 PM	Mukilteo-Clinton Ferry Mukilteo, WA 98275
12/30/25	6 PM – 9:30 PM	Fisherman Jack’s 1410 Seiner Dr., Everett, WA 98201
1/1/26 1/1/26	6:45 AM – 9 AM 7 AM – 11:15 AM	Travelers on rental car shuttles going to and from the airport and the Consolidated Rental Car Facility 3150 S 160th, SeaTac, WA, 98188 Seattle-Tacoma International Airport N Concourse (Gate N4) + Green Train Line Sea-Tac, WA, 98158

Measles illness starts with a prodrome of fever, cough, coryza, and conjunctivitis (typically lasting 2-4 days) and then a generalized maculopapular rash that typically begins on the face/head then spreads to the neck, trunk and extremities. Increases in measles cases and outbreaks are occurring in every region of the world.

CDC recommends all U.S. residents aged 6 months and older without evidence of immunity, who plan to travel internationally, get the MMR vaccine at least 2 weeks prior to departure. Infants 6 to 11 months of age who get the MMR vaccine before international travel should get an additional 2 doses of MMR according to the recommended schedule, after 1 year of age.

For further guidance or to report a case, contact Snohomish County Health Department at: (425) 339-3503

shd-CDQuestions@co.snohomish.wa.us