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
West Nile virus is the most common and serious vector-borne disease in California. There have been more than 7,500 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), Kings (1), Orange (1), Sacramento (2), San Bernardino (1), San Joaquin (1), Santa Clara (1), Tehama (1), and Yolo (1). These are the first WNV positive human cases from Orange, Sacramento, San Joaquin, and Tehama counties this year.
There were 39 new WNV positive dead birds reported in California this week from the following counties: Alameda (3), Placer (1), Sacramento (2), San Joaquin (1), San Mateo (1), Santa Clara (30), and Yolo (1).
There were 137 new WNV positive mosquito samples reported in California this week from the following counties: Alameda (1), Butte (6), Fresno (15), Kern (4), Los Angeles (21), Madera (17), Orange (6), Placer (8), Riverside (5), Sacramento (1), San Bernardino (3), San Joaquin (8), Santa Clara (1), Shasta (3), Stanislaus (11), Sutter (1), Tulare (19), Yolo (6), and Yuba (1).
A mosquito sample may contain up to 50 individual mosquitoes.
There were 18 new WNV positive sentinel chickens reported in California this week from the following counties: Butte (7), Merced (1), Nevada (1), Shasta (2), Sutter (4), Tehama (2), and Tulare (1). This is the first WNV positive sentinel chicken from Shasta County this year.
This is the first indication of WNV from Nevada County this year.
There was 1 new WNV positive horse reported in California last week from San Diego County. This is the first WNV positive horse from San Diego County this year.
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