Public Health – Seattle & King County was notified on April 4 of a positive measles case in a King County adult.

This is the fourth case of measles in Washington state in 2025. This case is not connected to any of the previous local measles cases, according to a Friday, April 11 media release from Public Health – Seattle & King County.

The individual was likely exposed to measles during recent international travel, according to the release.

Public Health disease experts assess each measles case to determine the potential risk of exposure to the public and determined that there is minimal to no risk of measles to the general public from this new case, according to the release.

“This is the fourth case of measles in Washington state this year, and we continue to see that measles is spreading around the U.S. and world,” said Elysia Gonzales, medical epidemiologist for Public Health – Seattle & King County. “The good news is that we have a very safe and effective vaccine to protect our children and our community from measles. If you’re planning international travel, it’s important to speak with your health care provider about what vaccines may be needed for you and your family to stay healthy and protected while traveling. Babies ages 6-11 months should get an early dose of the MMR vaccine if traveling internationally. They will still need two additional doses later. In Washington state, all children under age 19 can get vaccines for free.”

About measles

According to Public Health – Seattle & King County, 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.

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, go to: www.kingcounty.gov/measles.