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King County Washington home
Logos for the Snohomish County Health Department, Public Health - Seattle and King County and the Tacoma-Pierce County Health Department

August 12, 2026

Health advisory: Take Steps Now. Measles Stops with Us.

➜ This health advisory is also available in PDF format (374 KB)

Current situation

Since 2025, large outbreaks of measles across the U.S. have led to the highest annual case counts since 1991. National reporting of cases signals the likely return of endemic measles circulation in the U.S. The country is expected to lose measles elimination status when evaluated later this year. Additionally, Washington State Department of Health (DOH) has confirmed 53 measles cases in 2026 compared to 12 in the state in 2025.

Unimmunized people of all ages are at risk for infection. Although most measles cases are in children, more than 30% of 2026 U.S. cases have been in adults. Measles causes systemic complications, including impacts to the immune system that puts a person at risk for secondary infections. Even domestic travel may result in exposure; risk increases in locations with outbreaks or greater numbers of measles infections. Risk during international travel also increases as global measles burden grows and countries lose elimination status.

Public health, healthcare organizations, and community members can act to limit transmission and decrease societal impacts. For example, isolation of sick people and quarantine of exposed people are critical to controlling further measles transmission; but these require people without documented immunity to remain out of school or work for weeks, risking consequences such as children falling behind their peer groups, lost income, lost jobs, lost housing, and decreased willingness to seek appropriate healthcare in order to remain under the radar.

Measles, mumps and rubella (MMR) vaccine is the best way to prevent infections, complications, and transmission.

Actions requested

  1. Strengthen vaccination coverage and documentation of immunity across all age groups

    Review and document proof of immunity for patients. Every medical encounter is an opportunity to determine whether patients have proof of immunity. Adults are less likely to have

    documentation and will need to find records or get vaccinated.

    • Check the WA State Immunization Information System (WAIIS) and medical records for measles vaccination or immunity.
    • Request vaccine records and document in the patient's record and WAIIS.
    • In the setting of a measles exposure, self-attestation of prior measles vaccination is not sufficient proof of measles immunity.

    Ensure all patients without documented proof of immunity get recommended MMR vaccination.

    • If patients have no proof of immunity, vaccination is recommended instead of testing

    serologies unless there is a contraindication (e.g. pregnancy, previous allergic reaction to MMR vaccine). It is not harmful to get an additional dose of MMR vaccine.

    • Allow parents to choose to get their child's second dose prior to age 4-6 years so long as the appropriate interval is met.
    • Ask about upcoming international travel plans and vaccinate all patients ≥6 months of age at least 2 weeks before travel according to CDC travel guidance. As measles circulation in Washington and in the US evolves, refer to DOH vaccine schedules for updates including recommendations for those 6-11 months traveling domestically.

  2. Implement systematic methods in clinical settings to enhance surveillance and increase vaccine coverage

  3. Review measles signs and symptoms for early recognition of cases

    • Enhance monitoring and ensure all staff are trained to recognize measles and are aware of facility protocols and national guidelines on how to prevent measles transmission.
    • Rapidly triage patients with febrile rash illness and immediately isolate from other people, if measles is on the differential diagnosis. Suspect measles in patients with compatible symptoms and exposure history even if they have proof of immunity.
    • Stay informed about current measles activity in WA and public exposure sites.

  4. Stop transmission. Ensure rapid public health and healthcare response for suspected measles cases with standardized practices and prompt reporting.

    • Encourage suspect measles patients to call ahead to the healthcare facility.
    • Mask suspect measles patients immediately.
    • Isolate suspect measles patients immediately in an airborne infection isolation room if available. Do not allow them to remain in the waiting area or other common areas.
    • Allow only healthcare personnel with documentation of two doses of MMR vaccine or laboratory evidence of immunity (measles IgG positive) to enter the patient's room.
    • All health care personnel entering the room should use an N95 or similarly effective respirator (regardless of immunity status).
    • Close examination room for two hours after the suspect measles patient leaves.
    • Immediately report all suspected cases of measles to Public Health at 206-296-4774.

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