The Illinois Department of Public Health (IDPH) announced the first human case of West Nile Virus (WNV) in Will County. In the Will County case, a 74-year-old male from Naperville has been diagnosed with West Nile neuroinvasive disease. He became ill the first week of August, was hospitalized, and is recovering. The Will County Health Department’s Environmental Health Division has also reported that mosquito batches in eight different Will County communities have tested positive for WNV this summer.
IDPH reported a total of 12 human cases of WNV have now been detected throughout the state. In addition to the case in Will County, seven were reported in Cook County while Kane, Macon, Madison and Woodford counties all reported one positive case. Additionally, IDPH announced the first human WNV-related death in the state of Illinois. An individual, who was in their 90’s and lived in suburban Cook County, had an onset of symptoms of WNV in early August and died soon after.
“We are sad to report the first death of the year from West Nile virus in Illinois,” said IDPH Director Dr. Sameer Vohra. “This death and the 11 additional cases are a stark reminder that West Nile virus poses a serious risk, especially to older people and those with weakened immune systems. While the weather is warm and mosquitoes are breeding, we should all take precautions to ‘Fight the Bite’. Please protect yourself and your loved ones by reducing exposures, repelling insects with clothing and repellants, and reporting locations at high risk for producing mosquitoes.”
So far in 2023, there have been 1,817 WNV-positive mosquito batches and 13 positive birds from 42 counties throughout the state. In Will County, mosquitoes trapped in Crete, Frankfort, Bolingbrook, Plainfield, Lockport, Joliet, Homer Glen and Mokena have tested positive for WNV this summer. Additionally, the first dead bird to test positive for WNV was recently collected in Plainfield.
WNV typically causes mild, flu-like symptoms. According to the Centers for Disease Control and Prevention (CDC), most people [8 out of 10] infected with West Nile virus do not develop any symptoms. About 1 in 5 people who are infected develop a fever with other symptoms such as headache, body aches, joint pains, vomiting, diarrhea, or rash. Most people who develop symptoms from WNV recover completely, but fatigue and weakness can last for weeks or months.
However, according to the CDC, about 1 in 150 people who are infected develop a severe illness that affects the central nervous system such as inflammation of the brain (encephalitis) or inflammation of the membranes that surround the brain and spinal cord [meningitis). Severe illness can occur in people of any age, however people over 60 years of age are at greater risk for severe illness if they are infected. People with certain medical conditions, such as cancer, diabetes, hypertension, kidney disease, and people who have received organ transplants, are also at greater risk.
Because there is no vaccine available to prevent West Nile virus, it is important to avoid mosquito bites.
IDPH encourages the public to Fight the Bite by practicing the three “R’s” – reduce, repel, and report:
- REDUCE– 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. Eliminate, or refresh each week, all sources of standing water where mosquitoes can breed, including water in bird baths, ponds, flowerpots, wading pools, old tires, and any other containers.
- REPEL– when outdoors, wear shoes and socks, long pants and a light-colored, long-sleeved shirt, and apply an EPA-registered 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– report locations where you see water sitting stagnant for more than a week such as roadside ditches, flooded yards, and similar locations that may produce mosquitoes. The local health department or city government may be able to add larvicide to the water, which will kill any mosquito larvae.
For more information on WNV and what can be done to prevent getting bitten by mosquitoes, visit the Centers for Disease Control and Prevention’s West Nile virus page at https://www.cdc.gov/westnile/ or at the Illinois Department of Public Health’s West Nile Virus page at https://dph.illinois.gov/topics-services/diseases-and-conditions/west-nile-virus.html .