An Antelope Valley resident is hospitalized with West Nile virus encephalitis, a rare brain inflammation that strikes less than 1% of those infected, marking LA County's first confirmed human case of the 2026 season. The virus is already spreading at levels not seen since 2004.
The Los Angeles County Department of Public Health announced the case Monday, July 13. The Antelope Valley is roughly 60 miles north of Beverly Hills, but the threat is countywide. The announcement lands as a dangerous heat wave builds across Southern California, with the National Weather Service forecasting peak temperatures Wednesday through Friday, July 15–17. Heat accelerates mosquito breeding.
Beverly Hills falls within the LA County West Vector Control District's service area. Residents of Bel Air and Holmby Hills, as parts of the City of Los Angeles, should confirm their coverage at glamosquito.org. Anyone with pools, birdbaths, or other standing water should take precautions.
A bad year nationwide
This is not an isolated case. The CDC reported at least 48 human West Nile cases nationwide by the end of June, including 38 cases of severe neuroinvasive disease. That's the highest mid-year total since 2004.
Locally, the Greater Los Angeles County Vector Control District had detected 38 virus-positive mosquito samples as of early July, compared with a five-year average of about four at this point in the season. Caroline Gongora, the district's public information coordinator, called it "a significant increase in activity compared to recent years."
LA County Public Health averages 41 confirmed human cases per year over the past five years, though the department noted the true infection count is far higher because most people experience no symptoms or only mild illness.
What officials are saying
"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 Dr. Muntu Davis, Los Angeles County Health Officer.
The county said it is coordinating with local vector control agencies to target areas for mosquito control activities.
Heat wave compounds the risk
The National Weather Service forecasts highs of 90 to 105 degrees across inland areas this week, with Woodland Hills forecast to hit 110 on Wednesday, July 16. Overnight lows will stay in the 70s, offering little relief. An excessive heat watch took effect Tuesday morning, July 15.
Warm overnight temperatures keep mosquitoes active longer. The Culex species that carries West Nile virus is most active between dusk and dawn.
What residents should do
LA County officials recommend:
- Apply repellent containing DEET, IR3535, oil of lemon eucalyptus, or Picaridin to exposed skin
- Wear long sleeves and pants outdoors, especially at dawn and dusk
- Clean and chlorinate swimming pools; drain water collecting on pool covers
- Remove standing water from pet bowls, birdbaths, and outdoor containers at least once a week
- Install or repair door and window screens
- Report neglected pools or dead birds to the vector control district
People over 50 and those with preexisting conditions face higher risk of serious illness. About 1 in 10 people who develop severe neuroinvasive West Nile disease die, according to the CDC.
Beverly Hills residents can report neglected pools, large mosquito breeding sites, or unusual mosquito activity to the LA County West Vector Control District at (310) 915-7370 or online at glamosquito.org/submit-service-request.
