Mosquito samples collected by the City of Evanston Department of Health and Human Services have tested positive for West Nile virus.
Evanston ’s positive sample is the second positive sample collected in Illinois this year.
Health Department staff members say virus activity will likely increase in the next few weeks as temperatures rise.
Last year the first positive mosquito sample was reported May 7 in DuPage County and 46 of the state’s 102 counties had a West Nile positive bird, mosquito, horse or human case. A total of 101 human cases of West Nile disease, including four deaths, were reported last year in Illinois .
Surveillance for West Nile virus in Evanston began May 1 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.
Community members who observe a sick or dying crow, blue jay, robin or other perching bird should contact the City of Evanston Department of Heath and Human Services, (847) 866-2947, which will determine if the bird should 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 experience symptoms of any illness. Illness from West Nile is usually mild and includes fever and headache and body aches. Serious illnesses, such as encephalitis and meningitis, and death are possible.
People older than 50 years of age have the highest risk of severe disease.
Health officials say 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 take personal precautions to avoid mosquito bites.
People should avoid being outdoors when mosquitoes are most active, especially between dusk and dawn. Use prevention methods whenever mosquitoes are present.
When outdoors, community members should 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. Physicians should be consulted before repellents are used on infants.
Homeowners should make sure doors and windows have tight-fitting screens and repair or replace screens that have tears or other openings. They should also try to keep doors and windows shut, especially at night.
Lastly, community members should eliminate all sources of standing water that can support mosquito breeding, including water in bird baths, ponds, flowerpots, wading pools, old tires and other receptacles. Contact the Department of Health and Human Services to report areas of stagnant water in roadside ditches, flooded yards and similar locations that may produce mosquitoes.