See Your Indoor Coronavirus Exposure Risk In Rohnert Park, Cotati

ROHNERT PARK-COTATI, CA — As the holiday season kicks off and officials warn residents about limiting their interactions with others outside of their own household to curb the spread of the coronavirus, a tool developed by researchers from several universities lets you see your risk of exposure to the virus at an indoor gathering.

The tool shows the estimated chance — between 0 and 100 percent — that you'll encounter at least one person with the coronavirus at an event in your county. You can reduce the risk by wearing a mask, distancing and gathering outdoors in smaller groups, researchers said.

As of Wednesday, if you were to attend an event with at least 15 people in Sonoma County, there’s an 11 percent chance that someone in the group could expose you to the virus, according to the COVID-19 Risk Assessment Planning Tool. If your gathering has 10 people, that risk would be 8 percent.

Two Georgia Institute of Technology professors led the creation of the project, and their team included researchers from Stanford University and the Applied Bioinformatics Laboratory.

"By default we assume there are five times more cases than are being reported," the research team said in a statement. "In places with less testing availability, that bias may be higher."

>> Access the COVID-19 Event Risk Assessment Planning Tool here.

In Sonoma County, gatherings of different households for nonessential activities are prohibited between 10 p.m. and 5 a.m. under California's limited stay-at-home order. The curfew remains in effect through Dec. 21 in Sonoma County and at least 40 other California counties in the state's Purple Tier on the Blueprint to a Safer Economy.

Further, for Sonoma County and others in the state's Purple Tier, all gatherings must be held outside and gatherings with people from more than three households are prohibited.

Public health officials recommend that households keep the people they interact with stable over time.

A host or other designee should collect names of all attendees and their contact information in case contact tracing is later needed, according to officials.

"When people mix from different households it poses a higher risk of transmission and spread of COVID-19," health officials said. "The likelihood of transmission and spread increases with laughing, singing, loud talking and difficulty maintaining physical distance."

On Wednesday, the number of coronavirus cases in Sonoma County increased by 104 bringing the total cases to 11,712 since the onset of the pandemic. Click here to see the number of cases by ZIP code in Sonoma County.

Patch staffer Amber Fisher contributed to this report.