For Immediate Release:

October 24, 2025

First West Nile Virus Death of 2025 Reported

in LA County

Public Health Urges Residents to Take Action to Prevent the Spread of Mosquito-Borne Diseases   

The Los Angeles County Department of Public Health has confirmed the first local death due to West Nile virus for the 2025 mosquito season. The person, a resident of San Fernando Valley, was hospitalized and died from neurological illness caused by severe West Nile virus. 

"To the family and friends grieving the loss of a loved one due to West Nile virus, we extend our heartfelt condolences,” said Muntu Davis, MD, MPH, Los Angeles County Health Officer. “This tragic loss reminds us how dangerous mosquito-borne diseases like West Nile virus and dengue can be. Protect yourself and your neighbors by using insect repellent, getting rid of standing water where mosquitoes breed, and keeping window and door screens in good repair. Small actions like these can make a big difference in preventing illness.”

A total of 14 West Nile virus infections have been documented in Los Angeles County so far this year (excluding Long Beach and Pasadena as cases identified in those cities are reported by their local health departments). Half of infected people live in the San Fernando Valley region (50%).

Peak mosquito season lasts from June to November in LA County. West Nile virus is the most common mosquito-borne disease that affects residents in LA County. Public Health reports cases of West Nile virus every year, as the virus is endemic to the region. In collaboration with local vector control agencies, Public Health monitors risk of West Nile virus infection and actively engages residents to provide information about reducing the risk by promoting protective measures against mosquitoes. 

Residents are encouraged to take the following precautions to reduce their risk: 

• Wear Mosquito Repellent: Mosquito repellents can prevent mosquito bites. EPA-registered repellents containing DEET, picaridin, IR3535, 2-undecanone, and oil of lemon eucalyptus are the longest lasting and most effective. They are available as sprays, wipes, and lotions. Consider wearing long-sleeved clothes and pants when outside. 
• Keep mosquitoes out their homes: Make sure that doors and windows have tight-fitting screens to keep out mosquitoes. Repair or replace screens with tears or holes. 
• Prevent mosquito breeding: Eliminate standing water where mosquitoes can lay eggs. 
  • Clear standing water in flowerpots, saucers, birdbaths and other outdoor containers. Empty items that hold water inside and outside your home once a week. Mosquito eggs only need a thimbleful of water to hatch. 
  • Cover water storage containers such as buckets and rain barrels. For containers with no lid, use wire mesh with holes smaller than an adult mosquito. 
  • Clean and maintain swimming pools, spas and drain water from pool covers. 
  • Throw away old items in your patio or yard that can hold water, e.g., old car tires and children’s toys. 
  • Call 2-1-1 or click here to find your local vector control agency to report persistent problems to your mosquito control district

About West Nile Virus 

West Nile virus is a disease caused by the bites of infected mosquitoes. The virus survives in nature in several types of birds and is transmitted by the bites of mosquitoes that feed on infected birds. West Nile virus spreads during warm weather months when mosquitoes are most active. While not all mosquitoes carry this virus, the type of mosquito that spreads this virus is found throughout Los Angeles County. While everyone is at risk for West Nile virus, people over 50 and those with health problems are at greater risk of serious illness, which can include meningitis (brain infection), encephalitis (swelling of the brain) and limb paralysis. There is no specific treatment for West Nile virus disease and no vaccine to prevent infection.

Most people who get West Nile virus don’t have any symptoms. About 1 in 5 people who are infected develop a fever with other symptoms such as: 

• headache 
• body aches 
• joint pains 
• vomiting 
• diarrhea 
• rash 

About 1 in 150 people will have severe symptoms that may include high fever, stiff neck, muscle weakness, and sometimes rash. Symptoms usually appear 3 to 14 days after being infected. If symptoms are severe, residents are encouraged to call their doctor right away. 

For more information, visit: publichealth.lacounty.gov/acd/vectorwestnile.htm 

For questions or to find a nearby clinic or doctor, call the Public Health InfoLine at 1-833-540-0473, open every day from 8 a.m. to 8 p.m.