KERN COUNTY, Calif. (KERO) — Kern County Public Health has confirmed the county's first human case of West Nile virus this year. The virus spreads through the bite of an infected mosquito and is most common during the summer and early fall. Health officials say about 1 in 5 people infected will develop symptoms, which can include fever, headache, body aches, nausea or a rash. Kern County reported 21 confirmed human cases of West Nile virus in 2025. Public health officials are reminding residents to remove standing water around their homes, use insect repellent, and limit time outdoors around dawn and dusk when mosquitoes are most active.