Unfortunately, even fruit, especially melons can be contaminated with e.coli. It's strongly suggested that melons be washed before cutting the skin off.
Eating fresh vegetables is going to become one of those 'should I or shouldn't I?' sort of things. Personally, I prefer loose vegetables to prebagged ones. No guarantee it's any safer, but still, I prefer it. Organic might be the way to go, but again, no guarantee.
I do believe that with all these recent outbreaks, the FDA is going to introduce some extremely strict guidelines for every thing from planting the seeds to the temperatures of the trucks that deliver it. It could effect the cost of fresh produce. It's unfortunate, because years were spent marketing fresh fruit and vegetables and now frozen is flying off the shelves.
Keep your own body in mind. Know what you feel and if anything changes. If you have immune deficiency, perhaps you should avoid fresh produce. On the other hand, when you consider all the acres of farms producing fresh vegetables, it's amazing that there are not more cases of contaminations.
Wash, cook, and hope for the best.