Measles case in visitors to Snohomish and King Counties

Actions requested

Be aware of three confirmed measles cases in a South Carolina family that spent time in King and Snohomish Counties while infectious, including at SEA Airport on January 1, 2026.

• Visit our measles website to view more specific information about potential areas of exposure within the airport and other exposure locations, primarily in Snohomish County.
• Secondary cases would most likely occur between January 4 - 22, 2026.  
• MMR vaccination remains the most important tool for preventing measles infections and spread from imported cases.

Refer to Measles actions for Healthcare Providers for more details on immediate isolation, notification, testing, and management of patients with suspected measles, plus vaccination information and resources.