DANVILLE — The Vermilion County Health Department is beginning its annual surveillance for the West Nile virus and is accepting a limited number of dead birds of certain types as part of that effort.

"Finding out early if the virus is present in Vermilion County allows us to alert residents to take precautions when they are outside and make sure their homes are free of places where mosquitoes breed," environmental health director Douglas Toole said in a news release.

A mosquito infected with West Nile virus can spread the disease by biting humans. The virus was first noted in Illinois in the summer of 2001. By 2002, the Illinois Department of Public Health reported over 800 human cases of West Nile in Illinois.

No human cases of West Nile virus in Vermilion County have been reported to the Illinois Department of Public Health since a single case in 2006. The state health department says that most people are not affected when bitten by a West Nile-infected mosquito, but some people, including those who are over the age of 50 and who may have chronic health problems are most at risk from the West Nile virus.

Dead birds are collected locally and then sent to the state laboratory to determine if they have been bitten by infected mosquitoes. Positive results may mean the virus is present in a community. The department will accept for testing a limited number of certain types of dead birds, including crows, blue jays, grackles, starlings, sparrows, finches, robins, cardinals, flycatchers, swallows, catbirds, mockingbirds, warblers and wrens.

Larger birds are preferred, because they provide more tissue for testing. Birds should not be in a state of decomposition and should not have been attacked by animals.

To report a dead bird in Vermilion County for possible testing, call the health department at 431-2662, extension 247. For information on making your home safer from mosquitoes, visit the health department's website at http://www.vchd.org . Additional information is available from the Illinois Department of Public Health web site at http://www.idph.state.il.us/envhealth/wnv.htm.