Press Release

August 11, 2006


First human case of West Nile virus in Cook County reported

Clinton and Grundy counties report West Nile virus positive crows

SPRINGFIELD, Ill. – A woman in her 80’s is the first Cook County resident and second person in Illinois to be diagnosed with West Nile virus. The woman became ill in July with West Nile neuroinvasive disease and is now recovering. The first human case of West Nile virus in Illinois this year was reported by the St. Clair County Health Department on August 1. The St. Clair County man, who is in his 60s, became ill in July with West Nile fever and is recovering.

“Illinois is seeing significant West Nile activity in mosquitoes and birds across Illinois, but especially in Cook County,” said Dr. Eric E. Whitaker, state public health director. “There is a greater risk of humans contracting West Nile virus when 10 percent or more of the mosquitoes collected test positive for the illness. Currently in Cook County, approximately 20 percent of mosquito samples collected are testing positive. The Illinois Department of Public Health, in line with the Centers for Disease Control, is recommending adult mosquito control in areas of Cook County where local surveillance data indicates a high level of West Nile virus activity in mosquitoes to help protect people against this illness.”

West Nile virus is transmitted through the bite of a mosquito that has picked up the virus by feeding on an infected bird. Most people with the virus have no clinical symptoms of illness, but some may become ill three to 14 days after the bite of an infected mosquito.

Only about two persons out of 10 who are bitten by an infected mosquito will experience any illness. Illness from West Nile disease is usually mild and includes fever, headache and body aches, but serious illness, such as encephalitis and meningitis, and death are possible. Persons older than 50 years of age have the highest risk of severe disease.

The latest new counties to report a positive bird sample are Clinton and Grundy. The Clinton County Health Department collected a Crow on August 1 in Carlyle that tested positive for West Nile virus. On August 3, the Grundy County Health Department collected a West Nile virus positive Crow in Gardner.

So far this year, West Nile virus in mosquitoes have been found in Adams, Bond, Bureau, Champaign, Christian, Cook, DuPage, Ford, Iroquois, Jackson, Kane, Kankakee, Kendall, Knox, Lake, LaSalle, Lee, Macon, Macoupin, Marion, McHenry, McLean, Peoria, Putnam, Saline, Sangamon, Stephenson, St. Clair, Whiteside, Will, Williamson and Winnebago counties. Positive samples in birds have been found in Adams, Bond, Boone, Champaign, Clinton, Coles, Cook, DeKalb, DeWitt, DuPage, Effingham, Ford, Franklin, Gallatin, Grundy, Hancock, Henry, Kane, Kankakee, Knox, Lake, LaSalle, Livingston, Macon, Macoupin, Madison, McHenry, McLean, Peoria, Sangamon, Scott, Stephenson, Tazewell, Vermilion, Whiteside, Will, Williamson and Winnebago counties.

To date, 48 counties out of 102 have reported positive test results for West Nile virus in mosquitoes and birds.

In 2005, Illinois recorded 252 human cases, of West Nile disease, including 12 deaths.

Individuals can reduce their risk of West Nile illness and other mosquito-borne diseases by taking these precautions:

  • Avoid being outdoors when mosquitoes are most active, especially between dusk and dawn.

  • When outdoors, wear shoes and socks, long pants and a long-sleeved shirt, and apply insect repellent that includes DEET, picaridin or oil of lemon eucalyptus according to label instructions. Consult a physician before using repellents on infants.

  • Make sure doors and windows have tight-fitting screens. Repair or replace screens that have tears or other openings. Try to keep doors and windows shut, especially at night.

  • Eliminate all sources of standing water that can support mosquito breeding, including water in bird baths, ponds, flowerpots, wading pools, old tires and any other receptacles. In communities where there are organized mosquito control programs, contact your municipal government to report areas of stagnant water in roadside ditches, flooded yards and similar locations that may produce mosquitoes.

Additional information about West Nile virus can be found on the Department’s Web site at or people can call the West Nile Virus Hotline at 866-369-9710 Monday through Friday from 8:00 a.m. to 5:00 p.m.

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Illinois Department of Public Health
535 West Jefferson Street
Springfield, Illinois 62761
Phone 217-782-4977
Fax 217-782-3987
TTY 800-547-0466
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