With some mosquitoes in Illinois, Indiana, and now Kentucky testing positive for West Nile virus, it's more important than ever to make sure you take precautions to prevent mosquito bites.

What is West Nile Virus?

West Nile virus is the leading mosquito-borne illness in the United States. According to the CDC, it's contracted through getting bitten by an infected mosquito.  Most people who contract West Nile never feel sick, but there are instances where West Nile can become very serious, even deadly.

Is West Nile Virus Dangerous?

The short answer is, yes, it can be.  The CDC says that about 1 in 5 people who are infected develop a fever and other symptoms, and about 1 out of every 150 infected people develop a serious and sometimes deadly illness.

From the CDC: 

• West Nile virus (WNV) can cause an acute febrile illness or neurologic disease, including meningitis, encephalitis, and acute flaccid myelitis.
• The incubation period ranges from 2–14 days but can be longer in immunocompromised persons.
• The overall fatality in persons with WNV neuroinvasive disease is approximately 10%, and long-term neurologic sequelae are common with encephalitis and acute flaccid myelitis.

West Nile Virus Detected in Kentucky

West Nile Virus has officially been detected in Kentucky for the first time this year.  According to officials, on July 8, 2025, the Louisville Metro Department of Public Health and Wellness detected West Nile in a surveillance trap.  This trap was set in the Tyler Park neighborhood.

West Nile Detected in Illinois and Indiana

Unfortunately, no state in the Tri-State region seems to be free from West Nile, as a few counties across Indiana and Illinois have also had mosquitoes test positive for the virus. You can find the CDC West Nile tracking map, here.

How to Protect Yourself from West Nile Virus

If you want to protect yourself from getting West Nile virus, the best thing to do is to prevent mosquito bites in the first place.  While that's not always possible, there are ways you can mitigate the chances of being bitten. The CDC recommends wearing long sleeves and pants, using bug spray, and taking steps to control mosquitoes both inside and outside.

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What Type of Bug Spray Protects Against West Nile

The CDC recommends using an EPA-registered insect repellent.

Specifically mentioning the following ingredients to look for:

• DEET

• Picaridin (known as KBR 3023 and icaridin outside the United States)

• IR3535

• Oil of lemon eucalyptus (OLE)—A plant-derived ingredient

• Para-menthane-diol (PMD)

• 2-undecanone—A plant-derived ingredient