2 West Nile Virus Cases Confirmed In McHenry County

MCHENRY COUNTY,IL — The McHenry County Department of Health has confirmed two human cases of neuroinvasive West Nile virus in the county this year, with three additional probable cases under investigation.

Both confirmed cases involve people in their 70s who developed symptoms in early to mid-August, according to the health department. No common link has been identified among the cases, according to the health department.

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As of Sept. 2, 13 mosquito batches collected in McHenry County have tested positive for West Nile virus, according to the McHenry County Department of Health. Statewide, 24 additional human cases of West Nile virus had been reported in Illinois as of Sept. 2, including one death, according to the Illinois Department of Public Health.

Most people infected with West Nile virus do not develop symptoms. About 20% develop mild illness, which can include headache, body aches, joint pain, vomiting or a skin rash.

In some cases, the virus can cause neuroinvasive disease affecting the nervous system. Symptoms can include high fever, severe headache, neck stiffness, disorientation, coma, tremors, seizures, muscle weakness, vision loss, numbness and paralysis.

Symptoms typically develop two to 14 days after a person is bitten by an infected Culex mosquito. Severe illness can require hospitalization and may cause permanent neurological effects or death.

People 50 years and older and those with certain underlying health conditions face a higher risk of severe illness, according to the health department. Anyone who develops symptoms that could be associated with West Nile virus should contact a health care provider.

There is no vaccine to prevent West Nile virus infection in humans.

The McHenry County Department of Health recommends residents take steps to reduce mosquito exposure, including:

• Eliminate standing water around homes by regularly emptying bird baths, buckets and other containers.
• Keep gutters clear and make sure doors and windows have tight-fitting screens.
• Wear light-colored, long-sleeved shirts, long pants and socks when outdoors.
• Limit outdoor activities during evening and early morning hours, when Culex mosquitoes are most active.
• Use an EPA-registered insect repellent and follow the product label instructions. Repellents may contain DEET, picaridin, IR3535, oil of lemon eucalyptus, para-menthane-diol or 2-undecanone.

Culex mosquitoes typically breed in stagnant water with high organic content. Potential mosquito breeding sites can be reported to the McHenry County Department of Health's Environmental Health Division at 815-334-4585.