Yeah - just be careful. Its easy to say we are being too careful, but really how silly (mortified?) would you feel if something happened as a result of a bad choice.
I didn't eat any salads from deli's or anything like that, but I did eat lots of subway sandwiches. I think you juts have to make sure its a busy place with lots of turnover of food - so the sliced stuff isn't sitting there for very long.
Also, bagged salads are fine if you wash them first. Maybe try not to get the cut ones - just whole leaves perhaps.
Fi