West Nile virus dead bird infections by county for California 2024

(2024-04-23) - Source: http://westnile.ca.gov

*Birds reported as "chronic" do not have sufficient virus to cause mortality from WNV. Similarly, these birds do NOT indicate recent WNV transmission in the county and they cannot spread WNV to mosquitoes or other animals.

Birds reported as "positive" have high levels of virus, indicating the bird was recently infected with WNV. They are an indicator of current WNV in the county.

Results are determined by molecular testing of bird tissues.

More information:

CountyPositiveChronic*Total
Alameda505
San Diego202
San Mateo303
Santa Clara303
Totals: 13013

Source: Vector-Borne Disease Section, California Department of Public Health