Bird Tests Positive For West Nile Virus In McHenry County

Press release from the McHenry County Health Department:

The McHenry County Department of Health (MCDH) reports a robin collected in unincorporated McHenry on July 22 has tested positive for West Nile Virus (WNV). All other bird samples have been negative. This is the first bird that has tested positive for West Nile Virus in McHenry County this year, but is not unusual during this time and the risk of WNV typically remains until the first hard frost. According to the Illinois Department of Public Health (IDPH), there have been 5 WNV positive birds, 111 WNV positive mosquito batches, and 0 reported human cases in Illinois so far this year.

Infected birds can become carriers of WNV through the bite of an infected mosquito and then pass the virus onto mosquitoes that feed on them. WNV is transmitted to humans predominantly through the bite of Culex mosquitoes, which is the primary vector for WNV transmission in Illinois. Illness from WNV is usually mild and includes fever, headache and body aches but serious illnesses, such as encephalitis, meningitis and death, are possible. Persons 60 and older have the highest risk of serious illness. There is no vaccine available for WNV.

The best way to prevent WNV is to reduce the number of mosquito breeding sites around your home and to take personal precautions.

• Empty standing water from containers around the house (tires, neglected swimming pools, bird baths, clogged gutters and buckets); make sure doors and windows have tight-fitting screens.
• Limit outdoor activities when Culex mosquitoes are most active (dusk, dawn) and wear long sleeved shirts and long pants for extra protection.
• Use and apply insect repellents per label directions:
• Insect repellents containing 20% or more DEET (less for children) are effective.
• Insect repellents including oil of lemon eucalyptus or Picaridin may be used as an alternative to DEET.
• Apply repellents per label directions. Consult with a doctor before using any repellent on infants.

From May through October, Health Department staff conducts WNV surveillance throughout the county. Mosquito batch collections and testing are conducted weekly. In addition, MCDH collects a limited number of dead birds for testing each mosquito season. Contact the Division of Environmental Health at 815-334-4585 if you find a dead crow, blue jay or other perching birds. Bird specimens must be in good condition in order to be tested (no signs of insects, obvious injury or decay). Avoid bare-hand contact when handling any dead animal, although there is no evidence WNV infection occurs this way.

For more information on mosquitoes and West Nile Virus visit the Division of Environmental Health’s website under Nuisance Control at www.mcdh.info or call 815-334-4585.

This press release was produced by the McHenry County Health Department. The views expressed here are the author’s own.