Health Department Cautions Residents About Increasing Risk of West Nile Virus

The DuPage County Health Department cautions DuPage County residents that current weather conditions indicate we are entering a period of high risk for West Nile virus (WNV) infection in humans.

State public health officials report that the dry conditions have eliminated "floodwater mosquitoes," which are very rarely infected with WNV. In contrast, the extreme heat and dry weather are producing more Culex mosquitoes, the primary carriers of WNV, which breed in street catch basins (storm drains) and similar locations. Also, the high temperature accelerates WNV multiplication in mosquitoes and mosquitoes feeding on birds.

DuPage County is among 26 Illinois counties reporting positive mosquito tests for WNV so far this summer, with positive tests coming earlier than normal. The Health Department reports 89 positive mosquito tests this year in DuPage County compared to only one positive test at this same time in 2011. No human cases have been reported in DuPage County so far in 2012.

DuPage County residents who want to track WNV in their communities may visit http://maps.google.comdchdsurveillancemap. This map of mosquito traps throughout the county will be updated as mosquitoes test positive for WNV.

The Health Department is collecting freshly-dead birds (such as crows or blue jays) for WNV testing. The birds must not show any signs of decay or trauma. To report a dead bird, call (630) 682-7400.

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 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 WNV is usually mild and includes fever, headache and body aches, but serious illness, such as encephalitis and meningitis, and death are possible. Individuals over the age of 50 have the highest risk of severe disease.

The best way to prevent WNV 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:

REDUCE exposure - avoid being outdoors when mosquitoes are most active, especially between dusk and dawn.
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 where mosquitoes can breed, including water in bird baths, ponds, flowerpots, wading pools, old tires and any other receptacles.
REPEL - when outdoors, wear shoes and socks, long pants and a long-sleeved shirt, and apply insect repellent that contains DEET, picaridin, oil of lemon eucalyptus or IR 3535, according to label instructions. Consult a physician before using repellents on infants.
REPORT - 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.