OLYMPIA, Wash. (AP) — Health officials say West Nile virus has been detected in mosquitoes in Yakima County.

The Washington state Department of Health said Thursday it's the first confirmed detection in the state this year.

Last year, nine people in Washington were reported to have contracted West Nile.

Officials say the majority of people infected with the disease do not get sick. About one in five will develop a fever or other symptoms that go away without medical treatment.

For a small number of people, West Nile disease can lead to permanent neurologic effects or death.

People over age 60 and those with certain medical conditions are most at risk of severe disease.

Health officials advise people to be cautious of mosquito bites and to eliminate and avoid mosquito breeding areas.