vector-borne disease section

CDPH Monthly Update on Number of Dengue Infections in California

April 1, 2025

The following table provides the number of infections with dengue virus in California residents from 2016 to 2025. Nearly all dengue cases reported in California have been associated with exposure through travel to an area affected by dengue outside of California.

There were 18 locally acquired infections reported in California in 2024. Locally acquired dengue cases are indicated by an asterisk (*) in the table below.

Dengue infections in California, 2016–2025 (as of April 1, 2025)

County	2016	2017	2018	2019	2020	2021	2022	2023	2024	2025
Total	201	132	107	267	86	33	128	250	711	22
Alameda	16	19	7	23	5	2	12	22	51	0
Butte	0	1	0	2	0	0	0	1	1	0
Contra Costa	10	4	6	16	1	0	3	4	26	0
Colusa	0	0	0	0	0	0	0	0	0	1
El Dorado	1	2	0	1	1	0	0	0	1	1
Fresno	6	2	0	2	1	1	2	4	8	0
Humboldt	1	1	0	0	1	0	0	0	1	0
Imperial	0	0	0	0	0	0	0	1	1	0
Kern	0	0	3	3	1	0	2	4	8	0
Kings	0	0	0	0	0	0	0	0	3	0
Lake	1	0	0	0	0	0	0	0	2	0
Los Angeles	52	20	28	55	24	5	35	78, 2*	236, 14*	3
Madera	0	0	0	1	0	0	0	0	0	0
Marin	4	2	0	3	1	0	0	3	2	0
Mendocino	1	0	0	0	0	0	0	1	0	0
Merced	0	0	0	1	1	0	0	1	0	0
Mono	0	0	0	0	0	0	0	0	1	0
Monterey	1	3	0	1	0	0	1	1	6	0
Napa	0	0	0	0	2	0	1	0	3	0
Nevada	0	1	0	0	0	0	0	0	0	0
Orange	12	10	12	20	8	5	6	18	47	0
Placer	2	1	1	3	0	0	1	0	3	0
Riverside	3	1	1	5	3	0	3	4	32	1
Sacramento	3	6	1	10	1	3	6	3	15	0
San Benito	0	0	1	0	0	0	0	1	2	0
San Bernardino	7	3	0	6	3	0	0	5	23, 1*	2
San Diego	23	8	9	26	4	3	14	25	49, 3*	0
San Francisco	4	4	3	14	1	0	6	12	19	0
San Joaquin	3	2	0	2	2	2	1	4	11	0
San Luis Obispo	1	1	1	5	0	0	1	1	2	1
San Mateo	8	3	7	8	4	1	7	8	16	0
Santa Barbara	5	1	0	0	0	1	2	3	5	0
Santa Clara	20	24	15	41	7	8	17	29	43	0
Santa Cruz	1	2	1	1	1	0	0	1	6	0
Shasta	0	0	1	0	0	0	1	0	0	1
Solano	3	4	2	2	0	2	2	0	9	0
Sonoma	2	1	0	4	4	0	0	4	10	0
Stanislaus	4	2	2	0	2	0	0	5	8	0
Sutter	0	0	0	1	3	0	0	0	1	0
Tehama	1	0	0	0	0	0	0	1	1	0
Tulare	1	0	1	0	1	0	0	2	4	0
Tuolumne	1	0	1	1	0	0	0	0	0	0
Ventura	3	3	2	6	3	0	1	1	16	1
Yolo	1	1	1	4	1	0	4	1	10	1
Yuba	0	0	1	0	0	0	0	0	0	0