Poor DS1 has just gone back to work after being contacted through the app when a colleague tested positive. They are operating a "Covid secure" model and no one else at work has been ill.
Now DS2 has cough, so if he tests positive, DS1 will have to isolate again.
At my own workplace, with appropriate measures in place, we've had 4 positive tests now, resulting in a number of people isolating but none of them has gone on to develop symptoms.
From my own very small experience it seems this isn't passing around at work but is causing a lot of disruption to people's work.