vector-borne disease section

CDPH Monthly Update on Number of Dengue Cases in California

September 1, 2026

The following table provides the number of symptomatic dengue cases in California residents from 2016 to 2026. Nearly all dengue cases reported in California have been associated with exposure through travel to an area affected by dengue outside of California. Both travel-associated and locally-acquired cases are listed below.

Dengue virus cases in California, 2016–2026 (as of September 1, 2026)

County	2026 Travel-Associated	2025 Travel-Associated	2025 Locally-Acquired	2016-2024 Travel-Associated Average (Range)	2016-2024 Locally-Acquired Average (Range)
Total	36	200	7	212 (33, 702)	2 (0, 18)
Alameda	0	18	0	18 (2, 52)	0 (0, 0)
Butte	2	0	0	1 (0, 2)	0 (0, 0)
Colusa	0	1	0	0 (0, 0)	0 (0, 0)
Contra Costa	1	6	0	8 (0, 27)	0 (0, 0)
El Dorado	0	0	0	1 (0, 2)	0 (0, 0)
Fresno	1	2	0	3 (0, 8)	0 (0, 0)
Humboldt	0	0	0	0 (0, 1)	0 (0, 0)
Imperial	0	1	1	0 (0, 2)	0 (0, 0)
Kern	0	1	0	2 (0, 8)	0 (0, 0)
Kings	0	0	0	0 (0, 3)	0 (0, 0)
Lake	0	1	0	0 (0, 2)	0 (0, 0)
Los Angeles	9	59	6	59 (5, 238)	2 (0, 14)
Madera	0	1	0	0 (0, 1)	0 (0, 0)
Marin	0	4	0	2 (0, 4)	0 (0, 0)
Mendocino	0	1	0	0 (0, 1)	0 (0, 0)
Merced	1	2	0	0 (0, 1)	0 (0, 0)
Mono	0	0	0	0 (0, 1)	0 (0, 0)
Monterey	1	2	0	1 (0, 6)	0 (0, 0)
Napa	0	1	0	1 (0, 3)	0 (0, 0)
Nevada	0	0	0	0 (0, 1)	0 (0, 0)
Orange	3	15	0	15 (5, 47)	0 (0, 0)
Placer	0	1	0	1 (0, 3)	0 (0, 0)
Riverside	2	7	0	6 (0, 32)	0 (0, 0)
Sacramento	0	7	0	6 (1, 17)	0 (0, 0)
San Benito	0	0	0	0 (0, 2)	0 (0, 0)
San Bernardino	0	6	0	5 (0, 23)	0 (0, 1)
San Diego	1	17	0	19 (3, 61)	0 (0, 3)
San Francisco	3	11	0	7 (0, 20)	0 (0, 0)
San Joaquin	0	4	0	3 (0, 11)	0 (0, 0)
San Luis Obispo	1	1	0	1 (0, 5)	0 (0, 0)
San Mateo	4	10	0	7 (1, 16)	0 (0, 0)
Santa Barbara	2	2	0	2 (0, 5)	0 (0, 0)
Santa Clara	0	6	0	23 (7, 46)	0 (0, 0)
Santa Cruz	1	4	0	1 (0, 6)	0 (0, 0)
Shasta	0	1	0	0 (0, 1)	0 (0, 0)
Solano	1	1	0	3 (0, 10)	0 (0, 0)
Sonoma	1	1	0	3 (0, 9)	0 (0, 0)
Stanislaus	1	1	0	3 (0, 8)	0 (0, 0)
Sutter	0	0	0	1 (0, 3)	0 (0, 0)
Tehama	0	0	0	0 (0, 1)	0 (0, 0)
Tulare	1	1	0	1 (0, 4)	0 (0, 0)
Tuolumne	0	0	0	0 (0, 1)	0 (0, 0)
Ventura	0	3	0	4 (0, 15)	0 (0, 0)
Yolo	0	2	0	3 (0, 10)	0 (0, 0)
Yuba	0	0	0	0 (0, 1)	0 (0, 0)