The first known case of community-contracted COVID-19 in the United States was in Solano County last month. When someone does show symptoms, public health officials go through a lengthy process to figure out who they've had contact with.

It's something these epidemiologists have trained for. But the sheer scale of this outbreak is what's new. Dr. Bela Matyas is one of these people tracing the path of the new coronavirus from Solano County.

Guest: Danielle Venton, editor for KQED Science

Keep up to date on the latest Coronavirus news in the Bay Area here.