By Anna Giles

EL DORADO COUNTY (CBS13) — Widespread reopening is sparking fear about a possible second wave of coronavirus.

Now doctors are focused on the key weapon in that battle: aggressive contact tracing of every person who tests positive.

“It is probably one of the most important factors at this point,” Dr. Nancy Williams, the El Dorado County Health Officer.

El Dorado County is moving fast through phase 2. Doctors said stopping that second wave starts with preventing spread beyond the home in places everyone has access to, like a restaurant.

The El Dorado County Health Department has opened at least two tracing cases in the last week. One involved someone who went to work while sick. Nine of their coworkers were tested and so far, four have had negative results.

However, Dr. Williams said the spread is under control. She said the county usually deals with several contact tracing cases a week.

“The spread has been minimal. Even the ones we are investigating now. So that’s really good news,” Williams said.

In Yolo County, the West Sacramento mayor has concerns about reopening too soon. Mayor Chris Cabaldon calls contact tracing a better way to contain the virus than shelter in place.

READ ALSO: West Sacramento Mayor Pushes Back Against Reopening As State Gives Yolo County Green Light

“What we really can’t afford is another outbreak and resurgence that would be devastating and catastrophic,” he said.

Dr. Williams said if we can contain the spread of positive cases to just people within the same home, that could stop a second wave.

“Once something spread to a different house through a coworker or a community member someone spent time with, then that kind of sparks a new investigation,” she said.

It’s an issue that’s top of mind for Sally Raslear and her friends as they enjoyed a socially distant day out in El Dorado Hills.

“I do feel this is going to come back and I think people need to be aware we can’t just jump in right away,” Raslear said.

Good contact tracing goes hand-in-hand and even depends on easy to access testing sites. Earlier this month, El Dorado County opened two free testing sites earlier this month.