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
West Nile virus is the most common and serious vector-borne disease in California. There have been more than 7,000 human cases and over 300 deaths reported in California since 2003. The mosquitoes that spread WNV are found throughout the state.
There were 11 new WNV positive human cases reported in California this week from the following counties: Butte (2), Contra Costa (1), Madera (2), Merced (3), Placer (1), and Tulare (2). These are the first WNV positive human cases from Contra Costa and Placer counties this year.
4 WNV-related fatalities have been reported to CDPH this year from 3 jurisdictions: Butte (1), Madera (2), San Luis Obispo (1).
There were 9 new WNV positive dead birds reported in California this week from the following counties: Los Angeles (3), Sacramento (2), and Yolo (4).
There were 155 new WNV positive mosquito samples reported in California this week from the following counties: Fresno (7), Kern (3), Kings (4), Lake (2), Los Angeles (26), Madera (3), Merced (1), Napa (1), Orange (5), Riverside (1), Sacramento (7), San Joaquin (42), Stanislaus (7), Tulare (38), Yolo (7), and Yuba (1). This is the first indication of WNV from Napa County this year.
A mosquito sample may contain up to 50 individual mosquitoes.
There were 4 new WNV positive sentinel chickens reported in California this week from Tulare County.
There was 1 new WNV positive horse reported in California this week from San Joaquin County.
Don’t Give Bugs a Biting Chance!
Insect Repellent Toolkit
If you find a dead bird (especially a crow, jay, magpie, raven, sparrow, finch, or hawk) please file a report online or call toll-free 1-877-968-2473 (1-877-WNV-BIRD). 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.