It is less likely to live on food stuffs but loves HARD surfaces. Counters, door handles, loo flush, car boots, trolley handles. So a good swab down with HOT SOAPY water once an hour drowns the Bug.
Tc - if you have given advice then step back. Parents are unlikely to listen to us, what do *we* know

. If they go for a walk they will find less people about and those will be keeping their distance if sensible. We went out hand in hand earlier ........ met people walking their dogs and others who kept their distance.
No one is getting tested as the Labs. can't keep up. Not even GPs who are isolating due to a family member having cold symptoms. So the NHS has backed itself into a corner over that one! 3 GPs in 1 family who could be at work, if they were tested for C-19 as a child has a cold. Go figure

It's up to people not to stand close in supermarkets. I usually back into people if they start breathing down my neck, the "You are invading my space" usually does it ;-) or standing on toes certainly moves them. If I mutter in2 a carrier bag, people keep well away - 1 has 2B inventive and that's me on a normal shopping outing ;-) I jest not. I HATE people too close
