Menu

Lookup Agency

Search for local vector control agency based on zip code

Latest West Nile Virus Activity in California

Last Updated: Jul 05, 2020 9:23am PST
Data is updated on Fridays by 4pm.

Due to different reporting schedules, case totals on this website may not always be consistent with those reported by local health departments.
alt : Download
Download WNV Activity Map PDF

Total Counties with WNV in 2020: 15
New counties highlighted in red.
Fresno, Imperial, Kern, Kings, Los Angeles, Madera, Merced, Napa, Riverside, Sacramento, San Diego, San Joaquin, Santa Clara, Stanislaus, and Tulare.

Human Cases: 1 YTD

YTD: 1 Counties: 1

1 human case from 1 county has tested positive for WNV in 2020.

Horses: 0 YTD

YTD: 0 Counties: 0
No horses have tested positive for WNV in 2020.

Dead Birds: 23 YTD

YTD: 23 Counties: 8
There were 4 new WNV positive dead birds reported in California last week from the following counties: Fresno (2), Merced (1), and Stanislaus (1). This is the first WNV positive dead bird from Merced County this year.

23 dead birds from 8 counties have tested positive for WNV in 2020.

Mosquito Samples: 135 YTD

YTD: 135 Counties: 14
There were 43 new WNV positive mosquito samples reported in California last week from the following counties: Fresno (11), Imperial (1), Kern (1), Kings (1), Madera (1), Riverside (4), San Joaquin (1), Santa Clara (1), and Stanislaus (22). This is the first indication of WNV from Imperial, Kern, Kings, and Madera counties this year.

135 mosquito samples from 14 counties have tested positive for WNV in 2020.

Sentinel Chickens: 0 YTD

YTD: 0 Counties: 0
No sentinel chickens have tested positive for WNV in 2020.

View all Case Counts by County