Measles case spent time at multiple locations in King County and one Snohomish County location while contagious

Actions requested

➜ This health advisory is also available in PDF format (246 KB).

• Be aware of a confirmed measles case in a Canadian resident who was exposed in Canada and spent time while contagious at multiple locations in King County and one Snohomish County location during April 30–May 3, 2025. See table below for public exposures.
  • Secondary cases would most likely occur between May 7–May 24, 2025.
• Consider measles in anyone with fever (≥101°F or 38.3°C) and a generalized maculopapular rash with cough, coryza, or conjunctivitis who has recently traveled internationally or domestically to a region with a known measles outbreak or has other suspected exposure to measles, including visiting the locations listed below during the relevant time frames.
  
  • Refer to Measles actions for Healthcare Providers for more details on immediate isolation, notification, testing, and management of patients with suspected measles.
• MMR vaccination remains the most important tool for preventing measles infections and spread from imported cases.
  
  • Ensure all patients without evidence of immunity are up to date on MMR vaccine per routine ACIP recommendations.
  • Ensure that patients who are planning to travel internationally (regardless of the destination) or domestically (to outbreak areas) are fully vaccinated at least 2 weeks before departure.

Background

The person with measles was at the following public locations while contagious before being diagnosed with measles. These times include the estimated period when the individual was at the location and two hours afterward. Measles virus can remain in the air for up to two hours after someone infectious with measles leaves the area.

There is no ongoing risk for measles exposure at these locations.