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West Nile Virus Activity 2023

West Nile Virus in Los Angeles County

West Nile virus is the most common mosquito-borne disease that affects residents in Los Angeles County. Public health agencies detect West Nile virus every year in L.A. County which means it's endemic and found naturally in our city environments.

Our agency reports data related to mosquitoes. Human cases are reported by the L.A. County Department of Public Health.

The disease surveillance program serves as an early warning system in the detection of mosquito-borne viruses that can infect people and animals.

The District uses the following factors to assess health risk in your community:

  • Higher-than-average daily temperatures
  • Mosquito Population Monitoring – Using traps set up in every community
  • Mosquito Testing for Diseases
  • Dead Birds – A CA state program: Dead birds help determine spread of West Nile virus
  • Sentinel Chickens – Chickens develop antibodies to West Nile virus, which can be detected by testing.

Using these measurements, the District is able to protect your health by responding appropriately to mosquito-borne disease threats.

Year-to-Date Statistics for 2023

2023 WNV+ Mosquito Samples

City/Community Date of First DetectionPositives
Arleta8/11/20231
Artesia8/24/20231
Bellflower7/21/20233
Burbank5/24/202311
Canoga Park6/29/20237
Carson8/31/20231
Cerritos7/26/20236
Chatsworth7/27/20233
Commerce8/18/20231
Cudahy8/16/20232
Downey9/6/20231
Downtown Los Angeles9/8/20231
Encino8/16/20233
Gardena8/11/20232
Glendale9/1/20232
Hawaiian Gardens8/2/20232
Huntington Park8/16/20232
La Mirada7/26/20233
Lake Balboa7/26/20233
Lake View Terrace8/25/20233
Lakewood8/2/20232
Long Beach7/19/20234
Los Angeles City8/10/20232
Los Feliz9/1/20231
Lynwood8/3/20231
Mission Hills8/25/20231
North Hills9/6/20231
North Hollywood7/25/20233
Northridge8/29/20232
Norwalk7/26/20233
Reseda7/26/20232
Rowland Heights7/25/20232
Panorama City8/1/20232
Paramount8/3/20231
Pico Rivera8/24/20231
Porter Ranch8/10/20232
San Fernando8/11/20232
San Pedro8/31/20231
Santa Fe Springs8/24/20232
Sherman Oaks8/1/20234
Signal Hill8/2/20233
South El Monte8/23/20231
South Gate7/21/20233
South Whittier8/9/20232
Studio City8/9/20235
Sunland8/25/20232
Sun Valley8/11/20233
Tarzana8/29/20231
Toluca Lake7/12/2023 4
Valley Glen8/9/20233
Valley Village8/9/20234
Van Nuys9/6/20232
Vernon9/6/20231
West Hills7/27/20237
Whittier8/23/20231
Winnetka7/27/20234
Woodland Hills7/27/20235
 Total # of Positive Mosquito Samples This Year148

2023 WNV+ Dead Birds

City/CommunityDate of First Detection Positives
Canoga Park8/22/20232
Cerritos 8/15/20231
Lakewood8/6/20231
Long Beach6/13/20232
Northridge 7/5/20231
Pacoima8/31/20231
Tujunga8/25/20231
Whittier8/29/20231
Woodland Hills 6/6/20231
Total # of Positive Dead Birds this Year11

Take a look at mosquito and disease activity throughout California by utilizing the VectorSurv map! 

To experience the full site, visit: VectorSurv.org 

 

Did you know Los Angeles County is serviced by five vector control districts?

Visit our Other Agencies page to find your local vector control district.