Currently, there is no mosquito-borne spread of Zika virus in Alameda County, and all cases that have been reported in the county have been travel-associated or spread sexually. For the number of cases in California by county visit: CDPH Case Numbers for Zika Virus in CA. CDPH has declared Alameda County at "extremely low risk" for mosquito-borne Zika transmission because the mosquitoes that spread Zika are not found in our county.
In order to avoid infection with Zika virus, the Alameda County Public Health Department advises pregnant women, those considering pregnancy, and their partners to avoid travel to areas with risk of Zika virus transmission. For the most up to date information about Zika risk areas, visit the CDC’s Zika Risk page.
UPDATE (8/10/18): Mosquito bite prevention and safe sex practices are recommended during and after travel to areas with risk of Zika transmission. Also, after return from travel, female travelers should wait at least 2 months before having unprotected sex or to attempt conception. Male travelers should wait at least 3 months before having unprotected sex.