Person tests positive for first Los Angeles County case of West Nile virus of 2026

A Los Angeles County person has tested positive for West Nile virus, becoming the county's first case of 2026, officials said.

According to the Los Angeles County Department of Public Health, the individual first developed symptoms in late June. The Antelope Valley resident is currently hospitalized.

Spreading through bites from infected mosquitoes, symptoms of West Nile could include fever, headache, nausea, body aches and a mild skin rash. It could cause meningitis, encephalitis, paralysis or death.

"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 Muntu Davis, MD, MPH, Los Angeles County Health Officer. "Mosquitos thrive in hot weather, increasing the risk of bites and mosquito-borne diseases. People should follow these simple steps to reduce their risk of exposure: 1) Use insect repellent on you and your family; 2) Remove items that hold standing water around your home where mosquitoes can lay eggs and breed; and 3) Use, install, or repair window and door screens to prevent mosquitoes from entering your home."    

The county says it averages about 41 confirmed cases per year over the last five years, although the actual number is likely much higher, as not every infected person gets tested. About one in every 10 patients with severe neurological illness dies from the infection.

That data doesn't include Pasadena or Long Beach, as they report their own. The latter reported a case just last month. 

West Nile has no specific treatment or vaccine, the county says. The best way to prevent West Nile is to prevent mosquito bites.

Spread is more common during the warm weather months, as mosquitoes are more active in the summer.