The Yakima County resident, a man in his 50’s, was hospitalized due to the infection. The Benton County resident, a man in his 60’s, was not hospitalized.
Prior to this case, all West Nile virus cases in King County had a history of travel either out of Washington state or to eastern Washington.
This is the first detection of the virus in mosquitoes west of the Cascades. Mosquito season usually ends in mid-September.