Cases of mumps in an ongoing outbreak in Washington state have continued to rise, with at least 298 likely or confirmed mumps cases, according to the state health department and the Spokane Regional Health District. There are at least 166 likely cases in King County, where Seattle is located, and 94 cases in Spokane, where at least 300 students were told to stay home due to concerns they were not up to date on their vaccinations, the health departments in those counties said Thursday.