Tuesday, August 11, 2009

West Nile virus found early in western Washington this year

Mason County crow tests positive for the virus

OLYMPIA / A crow collected in Mason County has tested positive for West Nile virus — the first detection of the virus in western Washington this year.

The discovery in late July comes more than a month earlier than last year’s first appearance of the virus west of Cascades, which occurred in September. This early appearance may indicate greater West Nile virus activity as summer progresses.

It also means a greater risk for people to become infected if they don’t take precautions. Avoid mosquito bites, stay indoors at dawn and dusk if possible, and use repellent. Standing water can become mosquito habitat, so don’t let water collect without being freshened.

Other West Nile virus detections this week include five more birds from Benton County. The virus has also been detected in three horses and 161 mosquito samples in eastern Washington counties: Adams, Grant, Benton, Kittitas, and Yakima. Statewide this year, seven birds have tested positive among 47 tested overall.

In people, mild symptoms include fever, headache, and body aches. A few people may develop severe symptoms that include headache, high fever, neck stiffness, stupor, disorientation, tremors, convulsions, muscle weakness, paralysis, and coma. In rare cases, it can be fatal.

For more information, see the West Nile virus (www.doh.wa.gov/wnv) Web site.