10:45 AM PST on Monday, November 1, 2004

Associated Press

(kgw.com Graphic)

SEATTLE - Washington is apparently the only state in the Lower 48 to remain free of the West Nile virus this year.

State Health Department epidemiologist Joe Hofmann says experts have no idea why Washington was spared.

Public health officials have been testing blood donors, horses that show symptoms of the disease, about 500 dead birds and 40-thousand mosquitoes.

The threat is believed to be over for the year because cooler weather keeps down mosquitoes. The virus was found two years ago in a few birds and horses in Snohomish County.