West Nile virus found in Illinois crows

Jun 2 2004

Five birds have now been confirmed positive for West Nile virus since state and local health departments began surveillance for the mosquito-borne disease on May 1. No human cases have been reported.

Besides the birds from Stephenson and Winnebago counties, other positive birds have been reported in DuPage County (May 12), Adams County (May 20) and Champaign County (May 21). In addition, two mosquito pools in DuPage County have been confirmed positive for West Nile.

The crow from Stephenson County was collected in Freeport on May 24 and the crow in Winnebago County was found May 25 in Machesney Park. The birds were tested at the Illinois Department of Agriculture laboratory in Galesburg and the positive results were reported today to the Illinois Department of Public Health.

In 2003, 75 of the state’s 102 counties had a West Nile positive bird, mosquito, horse or human. A total of 54 human cases of West Nile disease, including one fatality, were reported last year in Illinois. In 2002, the state led the nation with 884 human cases, including 66 deaths, and West Nile activity was reported in 100 of 102 counties.

Surveillance for West Nile virus includes collecting dead crows and blue jays. Citizens who observe a sick or dying crow or blue jay should contact their local health department, which will determine if the bird is to be picked up for testing.

WNV 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.

West Nile infections can be mild and include fever, headache and body aches, or can be severe and marked by headache, high fever, neck stiffness, stupor, convulsions, muscle weakness, paralysis and, rarely, death. Serious West Nile virus illness is most often present in individuals 50 years of age or older.

Dr. Whitaker said individuals can reduce their risk of West Nile disease 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 according to label instructions.
• Consult a physician before using repellents on young children. Make sure doors and windows have tight-fitting screens. Repair or replace screens that have tears or other openings.
• 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.

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