The Public Health office in Seattle has confirmed a case of measles in a Canadian resident who was in King and Snohomish counties from April 30 to May 3, while potentially infectious. The individual visited several public locations, including Seattle-Tacoma International Airport, and a list of 16 sites with exposure times has been provided to the public. This case is unrelated to previous local measles cases, highlighting concerns over declining vaccination rates that have led to outbreaks in North America, prompting advisories for travelers crossing borders.