First West Nile Virus Death Reported in LA County

First West Nile Virus Death Reported in LA County. First death of 2023 reinforces need for all residents to take precautions against mosquitoes


September 7, 2023

The Los Angeles County Department of Public Health (Public Health) has confirmed the first death due to West Nile virus (WNV) for the 2023 season in Los Angeles County. The patient, a resident of the San Fernando Valley area, was hospitalized and died from West Nile virus -associated neuro-invasive disease.

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“I send my deepest condolences to the family and friends of this resident who sadly passed away from West Nile virus,” said Muntu Davis, MD, MPH, Los Angeles County Health Officer. “Their death reminds us how important it is to protect ourselves from mosquitoes and prevent them from breeding near our homes. Using mosquito repellent and keeping mosquitoes out of our homes can help prevent West Nile virus. Let’s all work together to keep our homes and neighborhoods mosquito-free for everyone’s safety.”

Humans get West Nile virus through the bite of an infected mosquito. Most mosquitoes do not carry the virus; therefore, most people bitten by a mosquito are not exposed to the virus. Those who do get West Nile virus may experience mild symptoms including fever, muscle aches, and tiredness.

In some cases, especially in persons over 50 years of age and those with chronic medical conditions, such as cancer and diabetes, severe WNV infection can occur and affect the brain and spinal cord causing meningitis, encephalitis, and paralysis. There is no specific treatment for West Nile virus disease and no vaccine to prevent infection.

A total of 19 cases 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). Human infections will likely continue to occur through the rest of summer and fall, with the highest number of cases typically arising in this month, September. West Nile virus -infected mosquitoes and dead birds have been identified across Los Angeles County. Public Health monitors cases of West Nile virus infection and collaborates with local vector control agencies to reduce the risk of West Nile virus to humans by promoting prevention and mosquito reduction.

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

• Protect yourself: Mosquito repellents can keep mosquitoes from biting you. 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.

• Mosquito proof your home: Make sure that your doors and windows have tight-fitting screens to keep out mosquitoes. Repair or replace screens with tears or holes.

• Reduce mosquitoes: Mosquitoes lay their eggs on standing water.

• Empty items that hold water inside and outside your home once a week

• Cover water storage containers such as buckets and rain barrels. If no lid, use wire mesh with holes smaller than an adult mosquito

•  Clear standing water in flower pots, saucers, birdbaths and other outdoor containers

•  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 visit to report persistent problems to your mosquito control district

For more information on West Nile virus, visit To find a local vector control district, visit

Other information sources:
• West Nile virus information by phone: (800) 232-4636
•  West Nile virus in California:
•  Health education materials on mosquito control and preventing West Nile virus infections:

Stagnant swimming pools or “green pools” should be reported to the Public Health Environmental Health Bureau at (626) 430-5200, or to a local vector control agency. Dead birds may be reported by calling (877) 968-2473 or online: