Neuroinvasive Mosquito Bites Trigger Seizures, Stroke

A St. George man suffered seizures and a stroke after a mosquito bite gave him the rare, severe form of West Nile virus.

Quick Take

Kevin Gill, a Washington County resident, was hospitalized with neuroinvasive West Nile virus, the disease’s most serious form.
Utah County health officials confirmed their first 2026 human case on August 31, also neuroinvasive.
Utah County has now logged five probable cases this year, and four of them are neuroinvasive.
Health departments across the state are urging residents to protect themselves as mosquito season continues.

A Family’s Warning After a Sudden Illness

Kevin Gill’s wife is speaking out after her husband developed a severe neuroinvasive West Nile virus infection. He suffered seizures and a stroke, according to his wife’s account shared with KSL News. She wants other Utah families to understand how fast the illness can turn dangerous, even for someone who felt fine just days before getting bitten.

West Nile virus spreads through mosquito bites. Most infected people never feel sick. But a small number develop the neuroinvasive form, which attacks the brain and nervous system. This can cause meningitis, encephalitis, or paralysis, according to state health tracking data. Doctors confirm it only after ruling out other likely causes for those symptoms.

Utah County Confirms Its First 2026 Case

The Utah County Health Department announced on August 31 that it confirmed its first human West Nile case of 2026. Officials said the case is neuroinvasive, calling it “the more serious form of the illness” in a media release posted on the department’s website. It marked the county’s first confirmed infection of the year.

That single case has since grown into a bigger cluster. The health department’s tracking page now lists five probable human cases in Utah County this year, and four of those are neuroinvasive. That is a notably high share of severe cases compared to typical seasonal patterns, where most infections cause mild or no symptoms.

Cases Reported Across Several Utah Counties

Utah County is not alone. Salt Lake County confirmed its first 2026 case in an adult who health officials expect to fully recover. Davis County has previously reported multiple cases in a single season, including deaths, while Cache and Salt Lake counties have also confirmed infections in past years, with one Salt Lake patient hospitalized before recovering at home.

Local mosquito control districts also track the virus in insect populations, not just in people. Davis County’s mosquito abatement district previously found West Nile virus in mosquitoes collected from six different cities, a sign the virus was circulating in the area before any human cases were confirmed. That kind of surveillance helps counties warn residents earlier in the season.

🦟🦠 #Utah County has confirmed its first human #WestNileVirus case of 2026, involving the rare but serious neuroinvasive form of the #mosquito-borne #disease.#WNV #PublicHealth #VectorBorneDisease #Microsky via @ksl.com https://t.co/ieqqfaCBff

— Microbes.info (@MicrobesInfo) September 2, 2026

How Officials Confirm the Diagnosis

Health departments do not label a case neuroinvasive lightly. Under national surveillance guidelines, a patient must show documented signs like meningitis, encephalitis, or paralysis, and doctors must rule out other explanations before confirming the diagnosis. Labs typically test blood or spinal fluid for the virus or for specific antibodies to confirm an infection meets that standard.

This process explains why public updates from county health departments, like the one Utah County issued, often stay brief. The detailed lab work and case review happen behind the scenes, following standard case definitions that states use to report data to national health trackers. The public announcement is simply the confirmed result of that process.

Basic Precautions Health Departments Recommend

State and county officials continue to repeat the same core advice as mosquito season runs its course. Residents should wear insect repellent, drain standing water around homes, and avoid outdoor activity during dawn and dusk hours when mosquitoes are most active. Older adults and people with weaker immune systems face the highest risk of developing severe, neuroinvasive symptoms if infected.