This virus is spreading because it's easily picked up from smooth surfaces. It can live on smooth surfaces for up to nine (9) days, and on cardboard or cloth for 1-3 days. This wasn't widely believed or publicized at first, and a lot of people were infected as a result. It also has a long incubation period, so don't assume you or anyone else isn't infected.

Good intentions aside, I wouldn't let anyone touch my groceries. I agree that wiping down the outside of anything that comes into your home is a good idea. Wash your hands!!