Press Release

May 13, 2010


First birds in Illinois tests positive for West Nile virus  

SPRINGFIELD, ILL. – Dr. Damon T. Arnold, state public health director, today announced the first birds testing positive for West Nile virus in Illinois this year were found in Carroll County and St. Clair County.

“As temperatures start to warm up, we’re going to start seeing more mosquito activity and an increased risk for West Nile virus,” said Dr. Arnold. “Although most cases of West Nile virus are mild, the virus can still cause serious, life-altering and even fatal disease. That is why it is so important to protect yourself against mosquito bites by wearing insect repellent and getting rid of any standing water around your home.”

A house sparrow collected in Lanark, Carroll County, on May 8 and a cowbird collected in Belleville, St. Clair County, on May 10, both tested positive for West Nile virus.

The first bird testing positive for West Nile virus in 2009 was from LaSalle County and was reported on June 5. The first positive mosquito samples were collected May 11 last year in Cook County. No mosquito batches have tested positive for West Nile virus so far this year.

Last year 36 of the state’s 102 counties were found to have a West Nile positive bird, mosquito, horse or human case. A total of five human cases of West Nile disease were reported in Illinois last year, the first reported on August 31.

Surveillance for West Nile virus in Illinois began on May 1 and includes laboratory tests on mosquito batches, dead crows, blue jays, robins and other perching birds, as well as the testing of sick horses and humans with West Nile-like disease symptoms. People who observe a sick or dying crow, blue jay, robin or other perching bird should contact their local health department, which will determine if the bird will be picked up for testing.

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 15 days after the bite of an infected mosquito. The first human case in Illinois is not usually reported until July or later.

Only about two people in 10 who are bitten by an infected mosquito will experience any illness. Illness from West Nile 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 best way to prevent West Nile disease or any other mosquito-borne illness is to reduce the number of mosquitoes around your home and to take personal precautions to avoid mosquito bites. Precautions include:

  • 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, oil of lemon eucalyptus or IR 3535 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.

Public health officials believe that a hot summer could increase mosquito activity and the risk of disease from West Nile virus.

Additional information about West Nile virus can be found on the Illinois Department of Public Health’s Web site at

idph online home
idph online home

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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