Measles outbreak declared in Snohomish County as 3 local children test positive

EVERETT, Wash. — The Snohomish County Health Department has confirmed three new cases of measles in local children, prompting officials to declare an outbreak as the disease spreads within the community.

Health officials said the unvaccinated children were exposed to a contagious family visiting from South Carolina and tested positive on Jan. 14 after developing fever, cough, and a rash consistent with measles.

The health department notified the district on Wednesday of confirmed student cases at Serene Lake Elementary School and Pathfinder Kindergarten Center. Both schools will be closed on Thursday, Jan. 16, to allow officials time to coordinate next steps.

Health officials warned that measles can spread before symptoms appear and before a rash develops. The virus can also remain in the air for up to two hours after an infectious person leaves an area.

The Snohomish County Health Department said the infected children were at the following public locations before being diagnosed. Anyone at these locations during the listed times may have been exposed:

• Jan. 8, 9:30 a.m.-12:30 p.m. — Stellar Kids Dentistry, 111 SE Everett Mall Way, Everett
• Jan. 9, 8:30 a.m.–5:15 p.m. — Pathfinder Kindergarten Center, 11401 Beverly Park Road, Everett
• Jan. 9, 8:30 a.m.–5:15 p.m. — Serene Lake Elementary School, 4709 Picnic Point Rd, Edmonds
• Jan. 13, 1:10–3:10 p.m. — Swedish Mill Creek Campus medical facility, 13020 Meridian Ave. S., Everett

The times include two hours after the children were at each location, when the virus may have remained airborne.

Officials said they were notified last week, along with Public Health – Seattle & King County, that three members of the South Carolina family were infectious while visiting King and Snohomish counties from Dec. 27 through Jan. 1.

Dr. James Lewis, a Health Officer with the Snohomish County Health Department, says that immunization rates for Snohomish County are upwards of 90%, which is why they still anticipate more notifications of infections.

“We’re expecting more measles cases,” Lewis said. “There are likely more cases in the community that we do not know about yet.”

The incubation period for measles can be anywhere from 7 to 21 days. Once a rash forms, Lewis says that is indicative of peak contagiousness.

“You can spread it to people four to five days before the rash, and then you can then continue to be infectious to other people about four days after the rash,” Lewis explained.

Health officials urged families to monitor for symptoms and contact a health care provider with concerns. Measles is a highly contagious disease that can cause serious complications, including brain swelling and death in rare cases, officials said.

More information can be found through the Snohomish County Health Department.

According to the Mukilteo School District Website for the 2025-2026 school year, “Students entering school (preschool – grade 12) must be in compliance with required vaccinations before they may attend public school according to Washington state law.”

The website provides a chart, which illustrates that any students Kindergarten through 6th grade, must have two MMR shots, which cover measles, mumps and rubella.

KOMO News has reached out to Mukilteo School District to ask:

What penalties, if any, are given to parents of children who are not properly immunized and still attend classes? How does the District screen students before the school year to confirm their immunizations, and whether those two students would be allowed to continue to attend their respective schools for the remainder of the school year?

The district responded with the following:

Parents do not face monetary or legal penalties for having children attend Mukilteo School District without the required immunizations. However, in accordance with WAC 246-105-050, students who are not fully immunized and who do not have appropriate documentation (conditional status, approved exemption, or medical vulnerability) may be excluded from school when there is a public health risk.

In partnership with the Snohomish County Health Department (SCHD), the district has identified students at Pathfinder Kindergarten Center and Serene Lake who are in conditional status, have exemptions, and/or are immunocompromised. Due to current health conditions, these students are required to quarantine from school through January 30, for a total of nine school days. During this time, the district is working to provide alternative educational opportunities to ensure continued learning.

Mukilteo School District follows all state immunization documentation requirements as outlined in WAC 246-105-050.

Will those students be allowed to return to their respective schools for the remainder of the year?

Yes. In accordance with guidance from the SCHD, students at Pathfinder Kindergarten Center and Serene Lake who are not fully vaccinated for this isolated incident are required to quarantine through January 30. Following the completion of the quarantine period, students will be allowed to return to their respective schools for the remainder of the school year.

What steps are taken to screen a student before the start of the school year to confirm vaccinations and other shots are up to date?

Mukilteo School District collects immunization records for all students at the time of registration. Families are asked to provide consent for the district to verify immunization records through the Washington State Immunization Information System. The district conducts ongoing monitoring, including monthly reviews, to ensure compliance with WAC 246-105-050.

The Snohomish County Health Department has confirmed three new cases of measles in local children, prompting officials to declare an outbreak after determining the disease is now spreading within the community.

Health officials said the children were exposed to a contagious family visiting from South Carolina and tested positive for the virus on Jan. 14 after experiencing fever, cough, and a rash consistent with measles. The children were unvaccinated.

The health department notified the district on Wednesday of three confirmed student cases, including one at Serene Lake Elementary School and another at Pathfinder Kindergarten Center. District officials said both schools will be closed Thursday, Jan. 16, to allow time to coordinate next steps with public health officials.

“We’re expecting more measles cases as a result of the previous exposures as well as these new outbreak cases,” Snohomish County Health Officer Dr. James Lewis said. “We are hoping to contain it, but unfortunately, there have been a number of exposure sites already, and there are likely more cases in the community that we do not know about yet.”

Health officials said they were notified last week, along with Public Health – Seattle & King County, that three members of the South Carolina family, one adult and two children, were infectious with measles while visiting King and Snohomish counties from Dec. 27, 2025, through Jan. 1, 2026.

During that time, officials said, the family visited multiple locations in Everett, Marysville, and Mukilteo, traveled through Seattle-Tacoma International Airport, and visited a car rental facility near the airport.

Health officials urged families and staff to monitor for measles symptoms and contact a health care provider with any health-related concerns.

“We’re concerned about the health and safety of our Snohomish County children,” Health Department Director Kim Van Pelt said. “Measles is a serious disease that often brings unpleasant symptoms and, in rare cases, swelling of the brain and even death.”

When a confirmed case of measles is identified, the Snohomish Health Department requires proof of immunity for all staff, students, and visitors to affected school buildings, according to the district.

Acceptable proof of immunity includes documentation showing a birth date before 1957; records verifying two doses of a live measles-containing vaccine administered by a licensed health care provider; a signed letter from a licensed health care provider confirming previous measles infection and recovery; or laboratory evidence, such as a blood test or serology, demonstrating measles immunity, according to the Snohomish County Health Department

More information about measles symptoms is available through the Snohomish Health Department.