Watching for West Nile virus, dead bird and mosquito monitoring resumes

Warmer spring weather and the coming mosquito season has the Department of Health on the lookout for West Nile virus again, working with local health departments to identify mosquitoes, track dead birds and monitor any human illness across Washington. This season brings mosquito-breeding weather and the threat of mosquito-borne disease, including West Nile virus.

"Last year we did intensive monitoring and we didn’t find any evidence of West Nile virus in Washington," said Maryanne Guichard, director of the Department of Health’s Office of Environmental Health and Safety. "We are starting our monitoring program up again in hopes of tracking the virus because the disease is often found in dead birds before there are human cases in a state."

West Nile virus has been moving west since 1999 and, though it was not detected in our state last year, it was confirmed in two dead birds and in two horses in Washington in 2002. No human cases have been acquired in our state.

West Nile virus is primarily a bird disease. Mosquitoes become infected by feeding on infected birds, and then pass the virus to uninfected birds, humans, horses or other hosts. Crows, ravens and jays are especially susceptible to dying from the virus.

Anyone who finds a dead bird that isn’t decomposed should report it to their local health department. People should use caution to avoid handling dead birds with bare hands. Gloves or shovels should be used to place the carcass inside two plastic bags. Keep the carcass in a cool place while the local health department is notified. Some dead birds may be submitted for testing.

In addition to monitoring dead birds, the agency is also working to identify mosquito species around the state and test some of them for the virus. At least one mosquito species known to become infected with WNV has been found in every county in the state.

"The best defense is to avoid mosquito bites," Guichard added. "There are simple steps we can all take, including personal protection and making sure that there are no places for mosquitoes to breed around the home."

Turning over old buckets or cans, emptying water from old tires, and frequently changing water in birdbaths and water troughs helps eliminate the small puddles of water in which many mosquito species breed. People can avoid being bitten by staying indoors around dawn and dusk when mosquitoes are most active; making sure that door and window screens are in good working condition; and using a mosquito repellent containing DEET when outdoors in areas where mosquitoes are active. Always follow label instructions when using mosquito repellents.

Even after being bitten by a West Nile virus-infected mosquito, most people won’t show any signs of illness. Some people may develop mild flu-like symptoms that go away without treatment. In a small number of cases the virus can cause serious illness including fever and inflammation of the brain. People over age 50 have the highest risk for serious illness.

The Department of Health West Nile virus information line 1-866-78-VIRUS (1-866-788-4787) has again been activated. Improvements to the information line include more menus and shorter messages in both English and Spanish. More information is also available on the Department of Health West Nile virus Web site.

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