The first human case of West Nile virus was reported in Los Angeles County for the 2026 mosquito season, the LA County Public Health Department announced Monday.
The patient was hospitalized as of Monday after developing West Nile encephalitis, brain inflammation caused by the West Nile virus, at the end of June. The symptoms of West Nile encephalitis include fever, neck stiffness, disorientation, muscle weakness, paralysis and coma.
The LA County resident lives in the Antelope Valley area, according to public health officials.
The Public Health Department is working with local vector control agencies to monitor and target mosquito activities.
“Detecting West Nile virus in our district is a reminder that this virus has been present in California — and right here in our community — for over 20 years,” said Brenna Bates-Grubb, Community Outreach Specialist, Antelope Valley Mosquito and Vector Control District. “It’s part of our local environment and continues to reappear year after year.”
Los Angeles typically sees about 41 human cases per year since 2021, the county said.
Officials are urging the public to take simple steps to protect themselves from the mosquito-borne virus:
Use insect repellent
Remove items that hold standing water around your home where mosquitoes can lay eggs and breed
Use, install or repair window and door screens to prevent mosquitoes from entering your home
Clean and chlorinate swimming pools; drain any water collecting on pool cover
Stock garden ponds with mosquitofish, goldfish, Koi or other mosquito-eating fish
Typical West Nile virus symptoms are fever, headache, nausea, body aches and a mild skin rash. The infection is especially dangerous for people over the age of 50 and those with chronic health problems.