Diners skip fresh produce and chefs revamp wedding menus to steer clear of leafy greens. The cyclospora outbreak has consumers across the country holding the lettuce. And the U.S. lettuce industry fears it will be left holding the bag—whether or not their leafy greens are truly to blame.

"Being prosecuted in the court of Reddit and social media is just devastating to the industry without any evidence," said Max Teplitski, chief science officer at the International Fresh Produce Association.

The Food and Drug Administration has said that a range of produce items are being investigated to trace the origins of the current outbreak, which can cause explosive diarrhea and vomiting. In Michigan, the hardest-hit state in terms of number of cases, state health officials this week pointed to lettuce and salad greens as a possible culprit.