Even as the mosquito season draws to a close, Public Health ? Seattle & King County continues to find birds infected with West Nile virus. A dead crow found near downtown Kent on October 26th and tested at the Washington Animal Disease Diagnostic Laboratory last week was determined to be positive for West Nile virus. This is the sixth positive bird finding in King County since early October, and is an indication that the virus is likely spread throughout the region.
West Nile virus is spread to people by mosquitoes that have bitten infected birds. West Nile can cause serious illness, especially in older age adults. While heavy rains and colder temperatures have significantly reduced the number of mosquitoes, the public is still urged to minimize the chances that they will be bitten by a mosquito. Prevention tips may be found at www.metrokc.gov/health/westnile.
While testing of dead birds will end on November 30th, King County residents are asked to report dead birds year-around by calling Public Health at 206-205-4394 or by using the web-based report at www.metrokc.gov/health/westnile/deadbird.htm. West Nile testing of dead birds will resume in the spring.
West Nile virus is a virus of the family Flaviviridae, found in both tropical and temperate regions. It mainly infects birds, but is known to infect humans, horses, cats, bats, chipmunks, skunks, squirrels, and domestic rabbits. The main route of human infection is through the bite of an infected mosquito.
Image reconstructions and cryoelectron microscopy reveal 50-nm virions covered with a relatively smooth protein surface. This structure is remarkably similar to the dengue fever virus. Both belong to the genus flavivirus within the family Flaviviridae.