September 13, 2001

SPRINGFIELD, IL – Eighteen more dead birds found in Chicago and various Cook and DuPage county locations have preliminarily tested positive for the West Nile virus, bringing to 25 the number of birds that have either been confirmed or are possible positives since the virus was first detected in the state Sept. 5, the Illinois Department of Public Health today announced.

In addition, two new pools of mosquitoes collected in Cook County suburbs are preliminarily positive for West Nile virus. No human cases of West Nile disease have been reported.

Dr. John R. Lumpkin, state public health director, reiterated that the continued findings of positive birds and mosquitoes is what would be expected given that the virus is spread by birds that can fly hundreds of miles. He said Illinoisans should presume the virus is present throughout the state.

The 18 dead birds were identified as preliminarily positive by the Illinois Department of Agriculture lab 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 -- crows and blue jays -- were collected between Sept. 5 and 7 in the following locations with collection dates in parenthesis: three crows from Arlington Heights, Cook County (Sept. 5 and 6); a crow and blue jay from Chicago (Sept. 6); a crow from Elmhurst, DuPage County (Sept. 6); two crows from Glendale Heights, DuPage County (Sept. 7); a blue jay from Glen Ellyn, DuPage County (Sept. 6); a crow from Glenview, Cook County (Sept. 6); a crow from Lombard, DuPage County (Sept. 6); a crow from Midlothian, Cook County (Sept. 6), three crows from Mount Prospect, Cook County (Sept. 6); a crow from Palatine, Cook County (Sept. 5); a crow from Park Ridge, Cook County (Sept. 6); and a crow from Wheeling, Cook County (Sept. 6).

The preliminarily positive mosquitoes were collected Sept. 10 in Palatine, Cook County, and in the Cook County Forest Preserve's Allison Woods (located between Arlington Heights and Glenview) by the Northwest Mosquito Abatement District. Samples of the mosquitoes will be sent to the U.S. Centers for Disease Control and Prevention laboratory in Colorado for confirmation. A third pool of mosquitoes, collected in Palatine, Cook County, that tested preliminarily positive were reported by the Department on Sept. 10.

(Editor's note: A complete recap of the positive birds and mosquitoes identified so far in Illinois are on the Department's Web site at www.idph.state.il.us. Go to the West Nile virus page and select "surveillance.")

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. Persons who observe sick or dying crows, blue jays or 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 has 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 breed.

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.