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CDPH Monthly Update on Number of Zika Infections in California
March 1, 2025
The following table provides the number of travel-associated infections with Zika virus in California residents during 2015 to
2025. Travel-associated infections include people exposed through travel to an area affected by Zika, or by contact with a
person who recently traveled to an affected area. There have been zero locally acquired Zika infections reported in California.
Travel-associated Zika infections in California, 2015–2025 (as of March 1, 2025)
| County | 2015–16 | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|---|---|---|---|
| Total | 508 | 126 | 68 | 43 | 5 | 2 | 5 | 3 | 7 | 0 |
| Alameda | 35 | 10 | 7 | 2 | 1 | 0 | 1 | 0 | 0 | 0 |
| Butte | 2 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Contra Costa | 26 | 4 | 2 | 3 | 0 | 0 | 0 | 0 | 1 | 0 |
| Fresno | 7 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Humboldt | 2 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Imperial | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Kern | 5 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Kings | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Lake | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Los Angeles | 114 | 22 | 18 | 6 | 2 | 0 | 2 | 0 | 2 | 0 |
| Marin | 9 | 2 | 1 | 0 | 0 | 1 | 0 | 0 | 0 | 0 |
| Mendocino | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Merced | 3 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Monterey | 5 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Napa | 3 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Nevada | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Orange | 31 | 12 | 4 | 5 | 1 | 0 | 0 | 0 | 0 | 0 |
| Placer | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Riverside | 14 | 4 | 1 | 2 | 0 | 0 | 0 | 1 | 0 | 0 |
| Sacramento | 7 | 0 | 0 | 2 | 0 | 0 | 0 | 2 | 0 | 0 |
| San Benito | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| San Bernardino | 18 | 7 | 0 | 3 | 0 | 0 | 0 | 0 | 0 | 0 |
| San Diego | 84 | 20 | 8 | 7 | 0 | 0 | 1 | 0 | 0 | 0 |
| San Francisco | 29 | 11 | 9 | 5 | 1 | 1 | 1 | 0 | 0 | 0 |
| San Joaquin | 7 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| San Luis Obispo | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 0 |
| San Mateo | 13 | 2 | 5 | 2 | 0 | 0 | 0 | 0 | 0 | 0 |
| Santa Barbara | 8 | 2 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Santa Clara | 36 | 14 | 8 | 3 | 0 | 0 | 0 | 0 | 2 | 0 |
| Santa Cruz | 3 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Solano | 3 | 2 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 |
| Sonoma | 11 | 5 | 2 | 1 | 0 | 0 | 0 | 0 | 1 | 0 |
| Stanislaus | 4 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Tulare | 5 | 2 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Ventura | 9 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 0 |
| Yolo | 6 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Yuba | 3 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
- Total infections: 767
- Cumulative number of infections due to sexual transmission: 12
- Cumulative number of infections in pregnant women: 244
- Cumulative number of completed pregnancies: 233
- Liveborn infants with birth defects: 16
- Pregnancy losses with birth defects: 0
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