Update: 4:50 p.m., Friday, 4 March 2016
Health officials confirmed three Zika virus cases in the East Bay today and said they post no threat to public health. Alameda County has one case and Contra Costa County has two cases; neither county is releasing further information.
San Francisco health department spokeswoman Rachael Kagan said the city got confirmation of its Zika virus case on February 4, but delayed announcing it to the public because there was no health threat. The city announced the confirmed case yesterday.
San Francisco Health Officer Tomas Aragon says the person who tested positive for Zika virus is fully recovered, and there is no risk of transmission. Zika is transmitted when a particular species of mosquito bites a person with an active infection, and then bites another person. The Aedes mosquito that spreads Zika has not been found in San Francisco.
"There is no reason for the general public to be concerned that they are at risk for getting Zika in San Francisco at this time," Aragon said in a statement. "Zika is not circulating in San Francisco."