Measles case associated with a domestic flight in a King County resident

Actions requested

Be aware of a confirmed measles case in a vaccinated King County adult that was exposed to a previously reported measles case on an October 13, 2025 flight.

• Visit our measles website to view public locations and times where this confirmed measles case spent time while contagious. Anyone who was at these locations during the times listed could have been exposed to measles.
  • There is no ongoing risk for measles exposure at these locations.
• Secondary cases would most likely occur between October 29 – November 17, 2025. 
• Remain vigilant for possible cases of measles even in patients that are vaccinated.
  • MMR vaccination remains the most important tool for preventing measles infections and spread but with increasing measles infections in the United States, rare breakthrough infections are more likely.
  • Nationally, 92% of cases this year are among people who are unvaccinated, 4% have one dose, and 4% are people with two doses of the MMR vaccine.
• Refer to Measles actions for Healthcare Providers for more details on immediate isolation, notification, testing, and management of patients with suspected measles.