The investigation into a multi-year, multi-state listeriosis outbreak traced to package salads from Dole might have yielded results several months earlier had sick people been asked if they had eaten leafy greens, according to a report published Thursday. The salad production facility in Springfield, OH, was highlighted in Dole’s 2010 corporate report. The salad production facility in Springfield, OH, was highlighted in Dole’s 2010 corporate…