September 10, 2001

SPRINGFIELD, IL – A dead crow found in Rockford and four dead crows and a pool of mosquitoes from Cook County have been reported as preliminarily positive for West Nile virus, Dr. John R. Lumpkin, state public health director, today announced. No human cases of West Nile disease have been reported.

These preliminary test results are in addition to dead crows collected in Arlington Heights (Cook County) and Lombard (DuPage County) that were confirmed positive for West Nile virus Sept. 5 by the U.S. Geological Survey National Wildlife Health Center in Madison, Wis.

"The fact West Nile virus is being found throughout the Chicago-area and now Rockford is consistent with what we would expect given that the virus is carried by birds that can fly several hundred miles," Dr. Lumpkin said. "As has been mentioned previously, people in Illinois should presume that West Nile virus is present throughout the state and take the necessary precautions."

The five dead crows were identified as preliminarily positive by the Illinois Department of Agriculture laboratory in Galesburg. Samples from the birds have been shipped to the U.S. Geological Survey lab in Madison, Wis., for confirmatory testing that may not be completed for several weeks.

The dead birds were collected between Aug. 23 and Sept. 5 in the following locations: Mount Prospect, Cook County (Aug. 23); Burbank, Cook County (Aug. 24); Crestwood, Cook County (Sept. 3); Arlington Heights, Cook County (Sept. 4); and Rockford, Winnebago County (Sept. 5).

The preliminarily positive mosquitoes were collected Sept. 4 in Palatine, Cook County, by the Northwest Mosquito Abatement District and are pending confirmation by the U.S. Centers for Disease Control and Prevention.

West Nile virus is transmitted through the bite of a mosquito that has picked up the virus by feeding on an infected bird. Surveillance for sick and dead wild birds appears to be the best way of detecting the virus' activity. Citizens who observe sick or dying birds, particularly crows, blue jays and raptors (such as hawks), should contact their local health department or district Illinois Department of Natural Resources office.

While most people infected with West Nile virus have no symptoms of illness, some may become ill, usually three to 15 days after the bite of an infected mosquito.

When people do become ill, symptoms may be mild, such as a fever or headache. In some individuals, however, particularly the elderly and those with weakened immune systems, West Nile virus can cause serious disease that includes inflammation of the brain (encephalitis), muscle weakness, high fever, convulsions, paralysis, coma or death. Dr. Lumpkin said the following steps should be taken to reduce the risk of being bitten by mosquitoes:

• Stay indoors at dawn, dusk and in the early evening when mosquitoes are most active.
• Whenever outdoors during high-risk times, wear shoes and socks, long pants and a long-sleeved shirt.
• Use mosquito repellent containing 25 percent to 35 percent DEET when it is necessary to be outdoors, applied sparingly to exposed skin or clothing, as indicated on the repellent label. Consult a physician before using repellents on young children.
• Check residential screens, including porches and patios, for tears and other openings.
• Eliminate stagnant water in bird baths, ponds, flower pots, wading pools, old tires and other receptacles in which mosquitoes might breed.

Besides Illinois, West Nile virus has been detected in a total of 21 states and in Washington, D.C., and Ontario, Canada, since it was first discovered in this country in New York in 1999.

Additional information about West Nile virus can be found on the Department’s web site at http://www.idph.state.il.us/envhealth/wnv.htm.