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 Lookup Local Vector Agency
WNV Transmission Cycle

2020 West Nile Virus Activity in California

Last Updated: Oct 16, 2020 4:34pm PST

Human Cases
123

Human Cases

Dead Birds
314

Dead Birds

Mosquito Samples
2,534

Mosquito Samples

Sentinel Chickens
123

Sentinel Chickens

Horses
16

Horses

Found a dead bird? Report it online.

CDPH accepts dead bird reports throughout the year. West Nile virus testing is limited from November to March but dead birds are still collected and tested in some areas of California during this time. Dead bird reports are often the first sign that WNV is active in an area, and they help CDPH track WNV in California all year long. Start your report here.

Latest West Nile Virus Reports

West Nile Virus and Mosquito Related Resources