This page will be updated when a new case is confirmed or potential exposure location identified.
- All numbers are accurate as of Year-to-Date.
- The most recent confirmed case was August 25, 2025.
- All data are preliminary and subject to change.
Washington State Cases in 2025 (Year-to-Date)
Total confirmed measles cases: 11
Age
- Under 5 years: 5 (46%)
- 5-17 years: 1 (9%)
- 18+ years: 5 (45%)
Source of Infection
- International travel related: 10 (91%)
- US travel related: 0 (0%)
- Unknown: 1 (9%)
Washington State Outbreaks in 2025 (Year-to-Date)
Measles Outbreaks
- There have been zero (0) outbreaks of measles.
- An outbreak is defined as 3 or more related cases.
Measles Activity and Surveillance
Visit the Measles Notifiable Conditions page for measles reporting and testing resources.
View the Measles Cases and Outbreaks web page from the Centers for Disease Control and Prevention (CDC) to see measles cases reported in the United States.
County Media Releases
Washington measles cases and potential exposure locations
- Feb 26, 2025. King County case. Public Health - Seattle and King County media release with potential exposure locations
- March 17, 2025. Snohomish County case. Snohomish County Health Department media release with potential exposure locations and Public Health - Seattle & King County media release with potential exposure locations.
- April 1, 2025. Snohomish County case. Snohomish County Public Health media release with potential exposure locations and Public Health - Seattle & King County media release with potential exposure locations
- April 4, 2025. King County case. Public Health - Seattle & King County media release with potential exposure locations
- April 20, 2025. King County case. Public Health - Seattle & King County media release with potential exposure locations
- May 20, 2025. King County case. Public Health - Seattle & King County media release with potential exposure locations
- June 20, 2025. Two Whatcom County cases. Whatcom County Health and Community Services media release for lab confirmed case and media release about second case and potential exposure locations.
- June 25, 2025. Two King County cases. Public Health - Seattle & King County media release with potential exposure locations
- August 25, 2025. Spokane County infant, linked to a confirmed Idaho case through a public exposure. Spokane Regional Health District media release with potential exposure locations
Additional potential exposure locations in Washington from travelers
- Jan 10, 2025. SeaTac Airport Public Health - Seattle & King County media release with potential exposure locations
- April 6 -7, 2025. SeaTac Airport and Tukwila hotel Public Health - Seattle & King County media release with potential exposure locations
- April 30 – May 3, 2025. SeaTac Airport and multiple locations in King and Snohomish Counties Public Health – Seattle & King County media release with potential exposure locations and Snohomish County Health Department media release with potential exposure locations
- August 12, 13, and 15, 2025. Providence Sacred Heart Emergency Department and Pediatric Oncology and Hematology Clinic Spokane Regional Health District media release with potential exposure locations