vector-borne disease section

CDPH Monthly Update on Number of Chikungunya Infections in California

March 1, 2025

The following table provides the number of travel-associated infections with chikungunya virus in California residents from 2016 to 2025. Travel-associated infections include people exposed through travel to an area affected by chikungunya. All chikungunya cases reported in California have been associated with travel; there have been zero locally acquired infections reported in California.

Travel-associated chikungunya infections in California, 2016–2025 (as of March 1, 2025)

County	2016	2017	2018	2019	2020	2021	2022	2023	2024	2025
Total	60	32	26	34	5	7	24	23	33	1
Alameda	10	3	2	5	0	0	4	2	5	1
Contra Costa	2	3	1	1	1	0	0	1	5	0
Fresno	3	0	0	0	0	0	0	1	0	0
Kern	0	0	0	1	0	0	0	0	1	0
Los Angeles	9	9	8	2	1	0	8	4	2	0
Marin	0	0	0	1	0	1	1	0	0	0
Nevada	0	0	0	1	0	0	0	0	0	0
Orange	1	2	0	2	1	0	1	1	1	0
Placer	0	0	0	0	0	0	0	0	1	0
Riverside	1	0	0	2	0	0	1	2	2	0
Sacramento	1	1	1	1	0	0	2	4	2	0
San Bernardino	2	0	0	0	1	0	0	0	0	0
San Diego	6	2	5	3	0	1	2	0	2	0
San Francisco	3	0	1	3	0	1	0	0	0	0
San Joaquin	0	1	0	0	0	0	0	0	1	0
San Luis Obispo	0	0	0	1	0	0	0	0	1	0
San Mateo	4	1	1	1	0	0	1	1	0	0
Santa Barbara	0	0	0	1	0	0	0	1	0	0
Santa Clara	14	10	5	9	1	3	4	3	9	0
Santa Cruz	1	0	0	0	0	0	0	1	0	0
Solano	1	0	0	0	0	0	1	0	1	0
Sonoma	0	0	0	0	0	0	0	1	0	0
Stanislaus	0	0	1	0	0	0	0	1	0	0
Sutter	1	0	0	0	0	0	0	0	0	0
Tehama	0	0	1	0	0	0	0	0	0	0
Ventura	1	0	0	0	0	0	0	0	0	0