Human Cases
Year-to-date: 9 Counties: 4
There were 2 new WNV positive human cases reported in California last week from Tulare County.
1 WNV-related fatalities have been reported to CDPH this year from 1 jurisdiction: Tulare (1)
9 human cases from 4 counties have tested positive for WNV in 2025.
Dead Birds
Year-to-date: 76 Counties: 13
There were 6 new WNV positive dead birds reported in California last week from the following counties: Sacramento (3), and San Diego (3).
76 dead birds from 13 counties have tested positive for WNV in 2025.
Mosquito Samples
Year-to-date: 1,162 Counties: 25
There were 193 new WNV positive mosquito samples reported in California last week from the following counties: Butte (2), Fresno (10), Kern (5), Kings (11), Los Angeles (4), Madera (44), Merced (3), Orange (31), Placer (15), Sacramento (4), San Diego (7), San Joaquin (14), Solano (2), Stanislaus (8), Tulare (30), and Yolo (3). This is the first indication of WNV from Solano County this year.
1,162 mosquito samples from 25 counties have tested positive for WNV in 2025.
A mosquito sample may contain up to 50 individual mosquitoes.
Sentinel Chickens
Year-to-date: 7 Counties: 3
There were 4 new WNV positive sentinel chickens reported in California last week from Tulare County. This is the first WNV positive sentinel chicken from Tulare County this year.
7 sentinel chickens from 3 counties have tested positive for WNV in 2025.
Horses
Year-to-date: 0 Counties:
No horses have tested positive for WNV in 2025.