Human Cases
Year-to-date: 502 Counties: 24
There were 50 new WNV positive human cases reported in California this week from the following counties: Los Angeles (42), Merced (1), Orange (2), Riverside (2), Stanislaus (2), and Tulare (1).
31 WNV-related fatalities have been reported to CDPH this year from 9 jurisdictions: Butte (3), Glenn (2), Kings (1), Los Angeles (12), Orange (7), Sacramento (2), Stanislaus (1), Tuolumne (1), and Yolo (2).
502 human cases from 24 counties have tested positive for WNV in 2026.
Dead Birds
Year-to-date: 772 Counties: 25
There were 19 new WNV positive dead birds reported in California this week from the following counties: Los Angeles (1), Riverside (2), San Diego (15), and Santa Clara (1).
772 dead birds from 25 counties have tested positive for WNV in 2026.
Mosquito Samples
Year-to-date: 4098 Counties: 29
There were 23 new WNV positive mosquito samples reported in California this week from the following counties: Fresno (1), Los Angeles (14), Riverside (1), and San Bernardino (7).
4,098 mosquito samples from 29 counties have tested positive for WNV in 2026.
A mosquito sample may contain up to 50 individual mosquitoes.
Sentinel Chickens
Year-to-date: 149 Counties: 11
149 sentinel chickens from 11 counties have tested positive for WNV in 2026.
Horses
Year-to-date: 17 Counties: 14
17 horses from 14 counties have tested positive for WNV in 2026.