The City of Evanston’s Health Department announced mosquitoes collected in Evanston tested positive on July 1 for West Nile virus (WNV). Mosquitoes were collected by the North Shore Mosquito Abatement District (NSMAD) on June 28, 2013 and were the first to test positive for WNV this year. In 2012, the first mosquitos to test positive for WNV were collected on June 18.

 “To protect yourself against illness, wear insect repellent and get rid of any stagnant water around your home to reduce the number of mosquitoes,” said Evanston Health Department Director Evonda Thomas-Smith.

Surveillance for WNV in Illinois began early this year, around mid-April, and continues. The surveillance 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.

West Nile virus is transmitted through the bite of a mosquito that has been infected with 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. 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, 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, flower pots, wading pools, old tires and any other receptacles. E-mail NSMAD at nsmad@nsmad.com or call 847-446-9434 to report areas of stagnant water in roadside ditches, flooded yards and similar locations that may produce mosquitoes.

For additional information, e-mail the Evanston Health Department at health@cityofevanston.org, call 3-1-1 or visit www.nsmad.com.