Beverly Hills and Bel Air residents face heightened West Nile virus risk after Los Angeles County confirmed its first death of the year and officials warned the mosquito season is running nearly two months ahead of schedule across the entire county.
The LA County Department of Public Health announced the death Friday, Aug. 21. The victim, a San Fernando Valley resident whose name was not released, was hospitalized with neurological illness caused by severe West Nile virus.
Fifteen infections have been documented countywide so far in 2026, excluding Long Beach and Pasadena, which run their own health departments. That count already exceeds the five-year average for this point in the season, according to the county's weekly arboviral disease report. LA County averages 41 human West Nile cases per year over the past five years, county officials have said. Half of those infected this year live in the San Fernando Valley.
Of the 15 cases, 13 involved neuroinvasive disease and 13 required hospitalization. The median age of those infected is 70, with a range of 32 to 86.
No Beverly Hills or Bel Air residents are among the confirmed cases. But the county report notes that cities of residence do not necessarily indicate places of exposure, and Susanne Kluh, general manager of the Greater Los Angeles County Vector Control District, described "widespread activity countywide."
Season started early
Kluh said the warmest winter on record caused virus detection to start "almost two months early this year, leading to widespread activity countywide." Although mosquito abundance has been suppressed, virus detections remain frequent, she said, urging residents to wear repellent at dawn and dusk when West Nile-carrying mosquitoes are most active.
The same day, the California Department of Public Health reported statewide West Nile activity has reached a five-year high. More than 24% of dead birds collected through surveillance tested positive for the virus, compared with a five-year average of 13%, according to ABC7. Eight of every 1,000 mosquitoes tested are positive, versus a five-year average of five per 1,000.
Who is most at risk
People older than 60 face the highest risk of severe illness, along with those who have diabetes, high blood pressure, chronic kidney disease or take immune-suppressing medication, according to county health officials. About one in 150 infections leads to severe illness including high fever, stiff neck and muscle weakness. There is no vaccine. There is no specific treatment.
How to protect yourself
LA County Public Health recommends:
- Use EPA-registered repellents containing DEET, picaridin, IR3535, 2-undecanone or oil of lemon eucalyptus.
- Wear long sleeves and pants outdoors, particularly at dawn and dusk.
- Check that window and door screens are tight-fitting and hole-free.
- Dump standing water in flowerpots, birdbaths, buckets and other containers at least once a week.
- Maintain swimming pools and spas; drain water from pool covers.
Residents can report persistent mosquito problems by calling 2-1-1 or visiting socalmosquito.org. The LA County Public Health InfoLine is 1-833-540-0473, open daily 8 a.m. to 8 p.m. The department publishes updated West Nile data every Friday through the season.
