Someone told me i shouldn't be eating supermarket sandwiches (m&s mostly) due to listeria risk. I googled and while there's nothing on the nhs there's some on other websites saying this...I know there's always a slight risk eating out or at others that they won't have washed or refrigerated foods properly but as someone with a long commute (so I don't take food to work) I've been eating shop sandwiches about once a week quite happily. Is anyone else avoiding them? Would doing so be paranoid?