LOS ANGELES —The Los Angeles County Department of Public Health has confirmed the county’s first human case of West Nile virus for the 2026 season.


The patient, a resident of the Antelope Valley, developed symptoms in late June and was hospitalized after developing West Nile virus encephalitis, according to health officials.

“The first human cases of West Nile virus are an important reminder that we all need to take steps to prevent mosquito bites and mosquito breeding,” said Los Angeles County Health Officer Dr. Muntu Davis.

West Nile virus is primarily spread through the bite of an infected mosquito. Symptoms may include fever, headache, nausea, body aches, and a mild skin rash. In severe cases, the virus can affect the nervous system and cause meningitis, encephalitis, paralysis, or death.

Adults over age 50 and people with chronic health conditions face a higher risk of severe illness. Los Angeles County has reported an average of 41 human West Nile virus cases annually over the past five years, although health officials say the actual number of infections is likely much higher because many people experience no symptoms or only mild illness.

Approximately one in 10 patients who develop severe neurological illness die from related complications, according to Public Health.

There is currently no specific treatment or vaccine for West Nile virus. Health officials urge residents to use EPA-registered insect repellent, remove standing water around their homes, maintain swimming pools, and repair window and door screens.

Residents are also advised to take additional precautions during dawn and dusk, when mosquitoes that spread West Nile virus are most active.

Public Health said it will continue working with local vector control agencies to monitor mosquito activity and provide prevention information to residents.