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May 20, 2025

New measles case in King County resident brings total to six cases in Washington state this year

News release summary

Summary

Public Health – Seattle & King County is informing the community of a confirmed measles case in a King County resident who may have exposed others to the measles virus at Seattle-Tacoma International Airport (SEA) and at Overlake Medical Center.

Public Health – Seattle & King County was notified of a confirmed measles case in a King County adult. The individual traveled through Seattle-Tacoma International Airport (SEA) and was at Overlake Medical Center while infectious. The individual was likely exposed to measles during recent international travel. Their vaccination status is unknown.

This case is not connected to any of the previous local measles cases. This is the sixth case of measles in Washington state residents in 2025, with cases having occurred in King and Snohomish counties. In addition, Public Health responded to three other measles cases this year among people who traveled through King County while infectious with measles but are not Washington state residents, including the recent case in a Canadian resident.

“With more measles cases globally and in the U.S., if you are planning to travel, it’s always a good idea to make sure you’re up to date on all your vaccinations. But if you’re traveling abroad or to an area of the U.S. with a measles outbreak, it’s especially important that you’re well protected from measles. Vaccination will not only protect you but will also protect others you may come in contact with if you develop measles. Make sure to get vaccinated at least two weeks before your trip. This gives your body a chance to build immunity. Talk to your doctor about your family’s specific health needs and travel plans,” said Meagan Kay, Medical Epidemiologist for Public Health – Seattle & King County.

Fortunately, the measles vaccine is very effective. Two doses of measles, mumps and rubella (MMR) vaccine provides about 97% protection against getting infected by measles and that protection lasts a lifetime. 

Locations of potential exposure to the public 

Spread of measles can occur before people know they have the disease, before a rash appears.

The infected person was at the following public locations before being diagnosed with measles. These times include the estimated period when the individual was at the location and two hours after. Measles virus can remain in the air for up to two hours after someone infectious with measles leaves the area. Anyone who was at the following locations during the times listed could have been exposed to measles: 

Date Time Location
5/17/25

4:30 pm to 8:45 pm

Seattle-Tacoma International Airport:

  • S Concourse International Arrivals (Gate S8)
  • International Arrivals Facility through Customs and access to baggage claim (Carousel 21)
  • Exited International Arrivals Facility through Gina Marie Hall (south end of main terminal)
5/18/25 6 pm to 8:20 pm

Overlake Medical Center – emergency department entrance and waiting area

1035 116th Ave NE
Bellevue, WA 98004

What to do if you were in a location of potential measles exposure 

Most people in our area have immunity to measles through vaccination, so the risk to the general public is low. However, anyone who was in the locations of potential exposure to measles around the times listed should: 

  • Find out if you have been vaccinated for measles or have had measles previously. Make sure you are up to date with the recommended number of measles (MMR) vaccinations. 
  • Call a healthcare provider promptly if you develop an illness with fever or with an unexplained rash. To avoid possibly spreading measles to others, do not go to a clinic or hospital without calling first to tell them you want to be checked for measles after an exposure. It is also important to limit contact with others, especially those without known immunity. 

If you were at the locations at the times listed above and are not immune to measles, the most likely time you would become sick would be between May 24, 2025 – June 8, 2025. People who are immuno-compromised may take longer to experience symptoms.

About measles 

Measles is a highly contagious and potentially severe disease that causes fever, rash, cough, runny nose, and red, watery eyes. If one person has it, up to 9 out of 10 people nearby will become infected if they are not protected. It mainly spreads through the air after a person with measles coughs or sneezes. 

Measles symptoms begin 7 to 21 days after exposure. Measles is contagious from about 4 days before the rash appears through 4 days after the rash appears. People can spread measles before they have the characteristic measles rash. 

Measles can lead to ear infections, diarrhea, pneumonia, and rarely, encephalitis (brain inflammation) or death. 

Complications from measles can happen even in healthy people, but those at highest risk include infants and children under 5 years, adults over 20 years, pregnant people, and people with weakened immune systems from medications or underlying disease. 

If you are in one of these high-risk groups and were exposed to measles at one of these locations, be sure to contact your health care provider to discuss any steps you need to take to protect yourself or loved ones against complications from measles. 

Measles is preventable with the safe and highly effective measles, mumps, and rubella (MMR) vaccine. Two doses of the MMR vaccine are about 97% effective at preventing measles and that protection is long lasting. 

For more information about measles and measles vaccination, including where to get measles vaccinations: kingcounty.gov/measles  

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