Utah County confirmed its first human case of West Nile virus on Monday, Aug. 31. Health officials said the patient contracted the neuroinvasive form, the more serious type of the illness.

The case is significant for Draper, which sits on the Salt Lake-Utah County border. Mosquitoes in the Draper area tested positive for West Nile virus by Aug. 12.

Utah County Health Department (UCHD) spokesperson Aislynn Tolman-Hill said in a news release reported by KSL that the neuroinvasive form is rare but severe. "Less than 1% of people who are infected develop neuroinvasive disease, such as meningitis, encephalitis or acute flaccid myelitis," Tolman-Hill stated.

Neuroinvasive symptoms include high fever, neck stiffness, disorientation, seizures and muscle weakness, according to The Salt Lake Tribune. There is no vaccine or specific treatment for West Nile virus, according to the CDC.

The virus has been active across the Wasatch Front this summer. As of Aug. 22, the Utah Department of Health and Human Services (DHHS) had reported 15 human cases statewide, with five in Salt Lake County. The first case was reported June 29.

Statewide, 1,050 mosquito pools had tested positive as of Aug. 22, a positivity rate of 12.3%, according to the state's arboviral surveillance report. That compares with 2.4% in 2024 and 3.0% in 2025.

Salt Lake County's positivity rate stood at 11.6%, with 373 positive pools. Utah County had 32 positive pools at a 4.6% rate. During the week of Aug. 16-22, more than one in five mosquito pools tested statewide came back positive.

Draper City warned residents about positive mosquito tests Aug. 12 on X, urging precautions.

Utah County Mosquito Abatement is increasing assessments and conducting targeted treatments in areas where the virus has been identified, the Tribune reported. Health officials first found mosquitoes carrying West Nile in Utah County in mid-July.

The UCHD recommended residents take these steps:

• Wear insect repellent containing DEET, picaridin, IR3535 or oil of lemon eucalyptus when outdoors.
• Wear long sleeves and pants at dawn and dusk, when mosquitoes are most active.
• Dump and drain standing water in buckets, bird baths, flower pots and clogged gutters.
• Keep window and door screens in good repair.
• Take extra caution if older, have underlying health conditions or are at higher risk of severe illness.

A statewide flood watch through Monday evening could leave additional standing water in yards and ditches, according to Utah Public Radio. The UCHD urged anyone who develops symptoms to contact a health care provider.