May 8, 2007
First mosquitoes test positive for West Nile virus in Illinois
SPRINGFIELD, Ill. – Dr. Eric E. Whitaker, state public health director, today announced mosquito samples collected in DuPage County have been confirmed as the first positive test results in Illinois this year for West Nile virus.
The Illinois Department of Public Health (IDPH) was notified by DuPage County Health Department of the findings as part of its routine surveillance for West Nile virus. A positive mosquito sample each was collected May 7 from the communities of Naperville, Lisle and Woodridge.
“It’s not unexpected to receive a report of the first positive West Nile virus mosquitoes this time of May, but this positive sample is slightly ahead of reports from previous years in Illinois,” said Dr. Whitaker. “ West Nile virus activity has been present in the state since August 2001 and we expected to see activity again this year. This positive report should serve as a reminder to people to take precautions to protect themselves against mosquitoes.”
In 2006, the first positive mosquito sample was reported May 24th in DuPage County. Last year 77 of the state’s 102 counties were found to have a West Nile positive bird, mosquito, horse or human case. A total of 215 human cases of West Nile disease, including 10 deaths, were reported last year in Illinois.
Surveillance for West Nile virus in Illinois began May 1st and includes laboratory tests on mosquitoes, 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. Citizens 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 is to 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 14 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 persons out of 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. Use prevention methods whenever mosquitoes are present.
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 Department’s Web site at www.idph.state.il.us/envhealth/wnv.htm or people can call the West Nile Virus Hotline at 866-369-9710 Monday through Friday from 8:00am to 5:00pm.
of Public Health
535 West Jefferson Street
Springfield, Illinois 62761
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