SPRINGFIELD, IL – The Illinois Department of Public Health today reported that dead birds found in Henry, LaSalle, Madison, Marion, Rock Island, St. Clair and Winnebago counties have tested positive for West Nile virus.

A dead blue jay was found July 12 in Alma in Marion County. Dead crows were found July 15 in Mendota (LaSalle County), Collinsville (Madison County), Silvis (Rock Island County), Washington Park (St. Clair County) and Rockford (Winnebago County). A dead crow was found July 16 in Kewanee in Henry County.

A total of 70 birds in Illinois have tested positive this year for West Nile virus since surveillance for the mosquito-transmitted virus began May 1. Other positive birds have been reported in Boone County (1), Champaign County (6), Clark County (1), Cook County (7), DeKalb County (1), DuPage County (14), Edgar County (2), Franklin County (2), Jackson County (2), Kane County (4), Kankakee County (2), Lake County (6), Mercer County (1), Sangamon County (1), Stephenson County (2), Vermilion County (1), Whiteside County (2), Will County (7) and Williamson County (1). Three mosquito pools from Cook County also have tested positive for West Nile virus. No human cases of West Nile encephalitis have been reported in Illinois.

The Culex or house mosquito, which can carry West Nile virus or St. Louis encephalitis, breeds in warm, stagnant water and begins to increase in numbers early in the summer. Recent temperatures have been ideal for the rapid development and activity of the Culex mosquito. As a result, hospitals and infectious disease physicians have been notified of the increase in detection of birds with West Nile virus and were reminded to order tests for arbovirus infections for patients with appropriate symptoms.

Dr. John R. Lumpkin, state public health director, said identification of positive birds is a reminder that the virus is present in the state and the following precautions should be taken to reduce the risk of any mosquito-borne disease:

• Whenever outdoors between dusk and dawn, wear shoes and socks, long pants and a long-sleeved shirt. Loose-fitting, light colored clothing is best.
• 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 for and repair any tears in residential screens, including porches and patios.
• Eliminate stagnant water in bird baths, ponds, flower pots, wading pools, old tires and any other receptacles in which mosquitoes might breed.

West Nile virus activity has been reported this year in Alabama, Connecticut, Florida, Georgia, Indiana, Kentucky, Louisiana, Maryland, Massachusetts, Michigan, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Rhode Island, Tennessee, Texas, Virginia and Washington, D.C., as well as Illinois.

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.

West Nile virus was first confirmed in Illinois in September 2001 when two dead crows from the Chicago metropolitan area tested positive for the virus. A total of 138 birds from seven Illinois counties (Cook, Crawford, DuPage, Kane, Lake, McHenry and Will) tested positive for the virus last year. In addition, two horses – one from Cook County and one from Kane – tested positive for the virus in 2001.

In the past three years, there have been 150 human cases of West Nile encephalitis in the United States, mostly in the New York area, including 18 deaths.

2002 West Nile virus surveillance information can be found on the Department's Web site at www.idph.state.il.us/envhealth/wnvsurveillance_data_02.htm.