Bay Area counties, as of 2020-03-15:

   Alameda County: 15 cases
   Contra Costa County: 29 cases
   Marin County: 5 cases
   Napa County: 0 reported cases
   San Francisco County: 37 cases
   San Mateo County: 32 cases, 1 death
   Santa Clara County: 114 cases, 2 deaths
   Solano County: 6 cases
   Sonoma County: 5 cases

https://abc7news.com/health/coronavirus-updated-number-of-co...

Ease of deployment in employees knowing the area, existing relationships with people in the community, less likely to make mistakes. Pretty obvious why, really.

> Not a hot county like Solano?

Would you like to explain how Solano county is more important than Santa Clara, despite the fact that Santa Clara has almost 20x the cases?

Santa Clara announced 23 new cases today. With the amount of testing we're doing it could easily be 5-10x more than that on a daily basis.

I would say those two counties are actually in critical stages right now. No reason to downplay its significance.