Measles outbreak in Washington likely to grow
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Washington's measles outbreak — with 26 confirmed cases so far this year — is likely to worsen before summer is over, local infectious disease experts say.
Why it matters: Washington has already recorded more than twice as many measles cases as it did all of last year — marking the state's first outbreak since 2023, according to the state Department of Health (DOH).
State of play: Measles, one of the most contagious diseases worldwide, was declared eliminated in the U.S. in 2000, but cases are surging again nationwide, with more than 1,280 confirmed infections reported this year, per the Centers for Disease Control and Prevention.
Threat level: People can spread measles days before the telltale rash appears — when symptoms may resemble a common cold — and remain contagious for more than a week, said UW Medicine infectious disease specialist Shireesha Dhanireddy at a news conference on Wednesday.
- The virus can also cause "immune amnesia," wiping out immune memory for two to three years after infection and leaving patients more vulnerable to illnesses, said Alex Greninger, head of infectious disease diagnostics at UW Medicine.
- Among unvaccinated children, nine out of 10 will contract the infection if exposed, according to Johns Hopkins Medicine.
What they're saying: "Even in the short run right now, I would expect it to get a little bit worse," said Greninger, pointing to the upcoming cruise season, summer travel and the World Cup that's expected to draw hundreds of thousands to Puget Sound in June and July.
By the numbers: 24 of Washington's cases are in unvaccinated people, while the vaccination status of two is unknown, per the state Department of Health (DOH).
- 21 cases are linked to a Washington outbreak, defined as three or more related measles cases.
- 16 cases are in children ages 5–17, with four more in kids under 5.
- 0 hospitalizations and 0 deaths.
Flashback: All of the 12 cases Washington recorded in 2025 were tied to travel, not linked to an in-state outbreak, per DOH.
What's next: Health officials are urging residents to get vaccinated, or verify their MMR vaccination status, and check the state's public exposure map.