West Nile virus (WNV) is a mosquito-borne virus that causes disease in humans, horses, and birds. WNV spreads to people through the bite of an infected mosquito, and it can make people sick and even cause death. WNV is common in the United States, especially in California, and is a problem that is here to stay. The best way to prevent WNV is to protect yourself from mosquito bites.

Mosquitoes often get WNV from birds. Dead bird reports are one way of tracking where WNV could be spreading. You can help the California Department of Public Health (CDPH) track WNV in California by reporting dead birds.

Report a Dead Bird Look Up Local Vector Control Agency
WNV Transmission Cycle

2023 West Nile Virus Activity in California

Last Updated: May 24, 2024 3:44pm PST

Human Cases
0

Human Cases

Dead Birds
15

Dead Birds

Mosquito Samples
12

Mosquito Samples

Sentinel Chickens
0

Sentinel Chickens

Horses
0

Horses

Latest West Nile Virus Reports

West Nile Virus and Mosquito Related Resources