Just a back of the fag packet scribble.
Leo
Let's go further:
Probability of infection while in the store with the virus (keeping a meter of distance, washing hands, etc., rough estimate): 10%
Probability of getting infected per store visit 4.51%
Duration of the epidemic (estimate): 8 weeks
Number of visits to the store per week (case 1): 3
Number of visits to the store during epidemic (case 1): 24
Probability of getting infected by shopping (case 1): 1-(1-0.0451)^24 = 67%
Number of visits to the store per week (case 2, a semi-"hoarder" like me): 1
Number of visits to the store during epidemic (case 2): 8
Probability of getting infected by shopping (case 2): 1-(1-0.0451)^8 = 31%
Number of visits to the store per week (case 3, a prepared survivalist): 0
Number of visits to the store during epidemic (case 3): 0
Probability of getting infected by shopping (case 3): 0
(Still a demonstration of bag-of-the-envelope calculation. Might be off by an order of magnitude.)