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West Nile Virus Activity 2022

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 2022

2022 WNV+ Mosquito Samples

City/Community Date of First DetectionPositives
Canoga Park8/4/20221
Eagle Rock8/3/20221
Elysian Valley7/31/20221
Granada Hills 6/28/20227
Hacienda Heights6/30/2022 3
Hawaiian Gardens7/29/20221
La Habra Heights7/27/20221
Lake Balboa6/30/2022 3
Long Beach7/29/20221
Los Angeles City8/4/20221
Los Feliz7/19/20221
Mission Hills 7/15/2022 1
North Hills7/13/20222
Norwalk 7/12/20221
Panorama City6/28/2022 5
Porter Ranch7/28/20221
Reseda 7/14/20223
Rowland Heights7/27/20221
San Fernando7/29/20221
San Marino7/1/20226
Santa Fe Springs7/26/20222
Signal Hill7/14/20221
South El Monte 7/13/20221
South Whittier7/26/20221
Van Nuys7/13/20223
 Total # of Positive Mosquito Samples This Year76

2022 WNV+ Dead Birds

City/CommunityDate of First Detection Positives
Bellflower7/22/2022 1
North Hills5/26/20223
La Cresenta-Montrose6/7/20221
Panorama City7/14/20221
San Marino7/28/2022 2
Sherman Oaks7/18/2022 2
 Total # of Positive Dead Birds this Year13

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

To experience the full site, visit: 


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.