For immediate release: August 19, 2008 (08-138)

Contacts:
Tim Church, Communications Office 360-236-4077
Donn Moyer, Communications Office 360-236-4076

King County blood donor could be state’s first West Nile virus case in 2008

Most likely acquired in eastern Washington but also briefly visited Oregon

OLYMPIA ¾ A King County woman in her 50s may be the first case of West Nile virus infection reported in the state. The exact location of her exposure may never be confirmed because she traveled through eastern Washington and into Oregon during the exposure period. The case was detected while she was being screened to donate blood; she did not develop either West Nile fever or the more serious neuro-invasive form of the disease.

Agencies that collect blood test for West Nile virus to prevent the infection from spreading from unknowingly infected blood donors to transfusion recipients. It’s safe to donate blood; and testing donations helps to safeguard the blood supply. Testing is also a valuable tool in the effort to monitor human West Nile virus infections in our state. This case is a reminder of the importance of preventing mosquito bites to avoid West Nile Virus infection.

“Like this case, most people who are infected with West Nile virus don’t ever get sick or have symptoms, yet it can be a very serious disease for a small number of people, especially those older than 50,” said Dr. Marcia Goldoft, Acting State Epidemiologist for Communicable Disease. “Avoiding mosquito bites is the best prevention. We know West Nile virus is present in our state, so it’s vital to take the simple precautions that can help protect you from West Nile infection.”

So far this year, environmental monitoring has detected West Nile virus in 14 mosquito samples and six horses, all in eastern Washington.

People can avoid mosquito bites at home or on the road by following a few precautions: stay indoors around dawn and dusk when mosquitoes are most active; be sure that door and window screens are working; and use a mosquito repellent in areas where mosquitoes are active. Always follow label instructions when using mosquito repellents.

It’s also important to reduce mosquito habitat around the home. Turning over old buckets or cans; emptying water from old tires; and frequently changing water in birdbaths, pet dishes, and water troughs helps eliminate the small puddles of water in which many mosquito larvae grow.

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.

Mosquitoes become infected with West Nile virus by feeding on infected birds, and then pass the virus to uninfected birds, people, horses, or other hosts. Crows, ravens, magpies, and jays are especially susceptible to dying from the virus. State and local public health monitor for West Nile virus by tracking mosquito samples, horses, and dead birds.

The Department of Health West Nile virus information line 1-866-78-VIRUS (1-866-788-4787) and the agency’s West Nile virus Web site (www.doh.wa.gov/WNV) are excellent resources for anyone who wants to learn more.

The Department of Health is working with local health partners as well as other state agencies, including the Departments of Agriculture, Ecology, and Fish and Wildlife on West Nile virus monitoring, planning, control, and prevention.

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