October 2002: West Nile virus is confirmed for the first time in Washington, found in a dead raven from Pend Oreille County. State health officials ask residents to report sightings of dead birds to help track the disease. A dead crow found near Snohomish tests positive for the virus, the first time the disease, which had spread to 43 states, reached the Puget Sound region.

November 2002: The Snohomish Health District approves $50,000 for local planning on how to combat the West Nile virus. A horse in Island County tests positive for the virus. Horse owners are told to get their animals vaccinated before spring.

February 2003: Snohomish Health District officials say residents should take simple steps to reduce mosquito breeding area.

March 2003: Snohomish Health District sets aside up to $248,000 to battle West Nile virus through beefed up monitoring and public education. It eventually spends $180,000.

April 2003: Based on how the disease is spreading nationally, the Snohomish Health District warns there could be up to 11 local cases of West Nile in 2003. Local governments, private pest control companies working for farmers, homeowner associations and businesses are allowed to apply online with the state Health Department for permits to kill mosquito larva before they can fly, as part of the effort to battle West Nile.

September 2003: A Yakima County man, suspected of having the state’s first case of West Nile virus in 2003, showed he did not have it.

June 2004: Mosquito traps are set up throughout the county to check for the density of mosquitoes and if the type of mosquito that can spread West Nile is present.

August 2004: A dead crow in Oregon tests positive for West Nile, but no evidence of the virus is found in Washington. The Snohomish Health District annual cost for monitoring for the virus is $114,000.

November 2004: Facing a budget crunch, the Snohomish Health District cuts its West Nile virus budget, since no human cases have been reported in Washington state.

May 2005: Because of budget cuts, if local residents see dead birds, a possible sign of West Nile virus, they are asked to bring the bird to the Snohomish Health District. The countywide public health agency sets aside $100,000 for monitoring.

July 2005: Tests show a Yakima woman suspected of having West Nile was not infected with the virus.