THURSDAY, June 26, 2025 (HealthDay News) — Illinois has confirmed its first human case of West Nile virus this year, health officials say. The person, who lives in southern Illinois, was hospitalized with complications from the mosquito-borne virus, according to the U.S. Centers for Disease Control and Prevention (CDC).

This week, a sample of the mosquito population in Larimer County in Northern Colorado tested positive for West Nile virus.

Mosquito samples taken from the 75211 zip code in Cockrell Hill have tested positive for West Nile Virus, according to Dallas County officials. The Dallas County Health and Human Services’ Thursday announcement came just under a month after mosquito samples from Irving, Richardson and Rowlett also tested positive for the virus.