Human Cases
Year-to-date: 85 Counties: 19
There were 11 new WNV positive human cases reported in California this week from the following counties: Los Angeles (7), Monterey (1), Orange (1), San Joaquin (1), and Santa Clara (1). These are the first WNV positive human cases from Orange and Santa Clara counties this year.
This is the first indication of WNV from Monterey County this year.
8 WNV-related fatalities have been reported to CDPH this year from 8 jurisdictions: Butte (1), Fresno (1), Kings (1), Los Angeles (1), Placer (1), San Joaquin (1), Santa Clara (1), and Tulare (1).
85 human cases from 19 counties have tested positive for WNV in 2025.
Dead Birds
Year-to-date: 151 Counties: 21
There have been 2 new WNV positive dead birds reported in California this week from Orange (1) and San Diego (1) counties.
151 dead birds from 21 counties have tested positive for WNV in 2025.
Mosquito Samples
Year-to-date: 2,730 Counties: 27
There were 6 new WNV positive mosquito samples reported in California this week from the following counties: Los Angeles (3), and Orange (3).
2,730 mosquito samples from 27 counties have tested positive for WNV in 2025.
A mosquito sample may contain up to 50 individual mosquitoes.
Sentinel Chickens
Year-to-date: 61 Counties: 8
There was 1 new WNV positive sentinel chicken reported in California this week from Los Angeles County.
61 sentinel chickens from 8 counties have tested positive for WNV in 2025.
Horses
Year-to-date: 5 Counties: 5
5 horses from 5 counties have tested positive for WNV in 2025.