https://www.mercurynews.com/2020/03/03/coronavirus-two-new-santa-clara-county-cases-of-unknown-origin/

Santa Clara County health officials urged older adults or those with medical conditions to avoid large public gatherings as they announced two additional coronavirus cases in which the source of the potentially deadly infection is unclear, further raising the specter of it spreading in the community.

The latest announcement brings to 11 the total number of cases in Santa Clara County, which announced its first case Jan. 31. Of the nine previously announced, four involved recent travelers to China, where the outbreak originated, three involved close contacts of infected people and two had no known risk factors and are believed to have involved community spread.