Reminder that if you're getting your lettuce from a local farm at the farmers market, you probably don't have to worry about this. This outbreak is from some industrial romaine lettuce growing and processing operation.
(Yes, it's possible for local produce to be contaminated with E. coli as well. I have no idea if it's more or less likely on average. But it shouldn't be involved in this outbreak, so go ahead and make your salad.)