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Measles
Measles is a serious and very contagious disease that causes rash and fever. It can cause serious health problems like pneumonia, permanent brain damage, and immune amnesia, which means the measles virus can cause your body’s immune system to forget how to fight off diseases it has run into before. In rare cases, measles can be deadly. Getting vaccinated is the best way to protect yourself against measles.
On this page, you can find the most up-to-date information about measles cases in King County. Find times and locations of measles exposures, and information on how to protect against measles.
Find more information on measles cases in Washington state.
Short URL: kingcounty.gov/measles
Measles cases in King County residents
Updated 10/17/25
- 2025: 6, to date
- 2024: 3
- 2023: 3
- 2022: 0
- 2021: 0
- 2020: 1
- 2019: 16
- 2018: 1
- 2017: 2
- 2016: 0
- 2015: 0
Note that the numbers above reflect the number of measles cases in King County residents. The numbers do not include people who have traveled through King County while contagious with measles.
Places and dates where measles could have been present
The chart below lists public locations and times where someone who was sick with measles spent time while contagious (includes King County residents and non-residents).
Anyone who was at the following locations during the times listed could have been exposed to measles:
| Date | Time | Location | Watch for symptoms until: |
|---|---|---|---|
| 10/13/25 | 11:30 am – 2:40 pm |
Seattle-Tacoma International Airport
|
10/20/25 - 11/03/25 |
If you were at the locations at the times listed above and are not immune to measles, the most likely time people would become sick would be between 10/20/2025 - 11/03/2025.
What to do if you think you were exposed to measles
If you were at one of the locations during the times listed above, find out if you have immunity against measles. This means you have been vaccinated for measles or have had measles previously. Call your healthcare provider if you develop symptoms such as a fever or rash.
To prevent possible spread to other people at the healthcare facility, do not go in person without calling first. Wear a well-fitting mask when you go.
How you can protect against measles
Measles vaccination is your best protection. When you get 2 doses of the measles-mumps-rubella (MMR) vaccine, it’s 97% effective at preventing measles. Numerous studies of MMR vaccine have concluded that the MMR vaccine is safe. Measles vaccine is recommended for everyone 1 year and older.
Declines in measles vaccination rates have increased the risk of measles outbreaks in Washington, the U.S., and around the world. Local cases of measles are often linked to unvaccinated travelers who returned from an area that has measles.
If you are planning on traveling internationally or areas in the United States where a measles outbreak is ongoing, talk to your doctor about what vaccines you and your family may need. All international travelers should be up to date on MMR vaccine at least two weeks before leaving. Infants under 12 months of age can get an early dose of MMR starting at six months of age.
Find more information about measles and international travel.
Resources
More information on vaccination
- About the measles vaccine and where to get it
- Immunization for travelers, WA State Dept. of Health
- What is evidence of immunity against measles?
Resources for child care facilities and schools
- Measles resources for schools, workplaces, healthcare, and organizations
- Measles in child care facilities and schools
- School immunization rates in King County
- Letter to school nurses (255 KB)
- School susceptible list (130 KB)
- School and Child Care Immunization, WA State Dept. of Health
Resources for health care professionals
- Measles One-Pager (3.3 MB), American Academy of Pediatric
- Measles guidance for healthcare providers