West Nile Virus Update: Two More Washington Cases Confirmed
OLYMPIA—A Benton County woman is the second Washington resident to be infected with West Nile virus without leaving the state. The woman in her 50s was hospitalized. Another travel-related case has
also been confirmed — a teenage boy who lives in Clark County.
Test results were confirmed at the Washington State Public Health Laboratories in Shoreline, bringing the
total 2012 West Nile virus case count in Washington to four. Nationally, 48 states have
reported human West Nile virus infections this year.
In Washington, tests have also confirmed the virus in five mosquito samples so far this year, all from the
south central part of the state. A horse in Benton County was diagnosed with
West Nile virus infection in August and was euthanized.
West Nile virus is primarily a bird disease, and often dead birds are an early sign that the
disease is active in an area. People may report dead birds online. No
dead birds have been reported with the infection so far this year in the state.
The virus is spread when mosquitoes feed on infected birds then bite people,
horses, and other mammals.
Avoiding mosquito bites is the best prevention for West Nile virus, and the state Department of Health
recommends using an effective mosquito repellent when mosquitoes are active.
Always follow label instructions when using mosquito repellents. Other West Nile
virus prevention tips are available online. West Nile infection can cause encephalitis
(inflammation of the brain) or meningitis (inflammation of the lining of the
spinal cord and brain). People over age 50 have the highest risk for serious
illness. Symptoms may include fever, headache, body aches, neck stiffness,
stupor, disorientation, tremors, convulsions, muscle weakness, paralysis, and
coma. People with severe symptoms should contact a health care
In 2009, there were 38 human cases of West Nile virus infection among Washington residents, including
the only death from the disease in our state. In 2010, there were two human cases in the state, along with detections in two dead birds and 126 mosquito samples. Five mosquito samples tested positive in 2011 but there were no human or horse cases or dead bird detections.
The West Nile virus information line, 866-78-VIRUS, and an online West Nile
virus chart are updated as conditions and detections change. The agency YouTube site has
three fun videos that remind viewers of the personal protection measures they can take to avoid West Nile