A 66-year-old Evanston resident has been confirmed by the Illinois Department of Public Health (IDPH) laboratory to have the West Nile virus (WNV). This is the first case of WNV identified in an Evanston this year. The Illinois Department of Public Health (IDPH) has confirmed the human WNV case which is the second reported case in Cook County for 2010.

“Residents need to be cognizant that West Nile virus prevention does not stop with the adult mosquito operations performed by the North Shore Mosquito Abatement District,” said Evanston Health Department Director Evonda Thomas. “Residents play a key role in prevention and should protect themselves proactively against mosquitoes by wearing insect repellent and reducing any standing water around their homes to prevent mosquito breeding.”

The City of Evanston is a member of the North Shore Mosquito Abatement District which is responsible for larviciding (mosquito larvae control) and adulticiding spraying (adult mosquito control). To learn more about NSMAD, visit their web site at www.nsmad.org or call 847/446-9434.

So far this year, 25 Illinois counties have reported mosquito batches or birds testing positive for West Nile virus. The first WNV positive results this year were reported on May 13 and included two birds, one from Carroll County and the other from St. Clair County.

Along with local health department surveillance, the Illinois Natural History Survey, a division of the Institute of Natural Resource Sustainability at the University of Illinois, also monitors mosquito activity and has reported a dramatic upswing in positive West Nile virus samples, especially in Cook County.

“Although only six percent of the mosquito batches tested positive for West Nile virus in the last week of July, the analysis from the weeks of August 15 and 22 indicates that more 40 percent and 50 percent, respectively, of the mosquito samples from three mosquito abatement districts in Cook County were positive for West Nile virus,” according to Dr. Ephantus J. Muturi, Interim Medical Entomology Director at the Illinois Natural History Survey.
In 2009, IDPH reported the first positive mosquito samples on June 1 in Cook County. The Department reported the first human case of WNV in 2009 on August 31. Last year, 36 of the state’s 102 counties reported having a positive WNV tested bird, mosquito sample, horse or human case. Five human cases of WNV were reported for 2009.

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. Human cases of WNV are not usually reported until July or later in Illinois.

Only about two out of 10 people 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, meningitis or death are possible. Persons older than 50 years of age have the greatest 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 or property 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 contains 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; and
  • 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.

For more information, to report water that has been standing for more than five days or for instructions on dead bird disposal, call the Evanston Health Department at 847/866-2949 or email health@cityofevanston.org.