E. coli outbreaks associated with lettuce or spinach, specifically the “pre-washed” and “ready-to-eat” varieties, are by no means a new phenomenon. In fact, the frequency with which this country’s fresh produce consuming public has been hit by outbreaks of pathogenic bacteria is astonishing. By way of illustration, in October 2003, thirteen residents of a California retirement home were sickened, and two people died, after eating E. coli-contaminated, pre-washed spinach; in September 2003, nearly forty patrons of a California restaurant chain fell ill after eating salads prepared with bagged, pre-washed lettuce; and in July 2002, over fifty young women fell ill with E. coli O157:H7 at a dance camp after eating “pre-washed” lettuce, leaving several hospitalized and one with life-long kidney damage. And this is just a small sampling of the twenty or more E. coli outbreaks since 1995 in which spinach or lettuce was the source. Several more, including the September 2005 Dole lettuce outbreak, and the infamous September 2006 Dole baby spinach outbreak, appear in the chart below, which is based on information gathered by the Center for Science in the Public Interest:

Screen shot 2011-06-03 at 2.13.53 PM.pngWe should also not be surprised that a non-O157 E. coli outbreak can happen – in Europe or in the U.S. because it has happened.

According to the CDC, 26 confirmed and 7 probable cases from 5 states were linked to the Freshway E. coli O145 outbreak in April and May 2010. The number of cases identified from each state involved in the outbreak is as follows: MI (11 confirmed and 2 probable), NY (5 confirmed and 2 probable), OH (8 confirmed and 3 probable), PA (1 confirmed), and TN (1 confirmed). Multiple students attending The Ohio State University are included in the CDC’s confirmed and probable case counts.

In the large-scale, multi-state investigation that occurred into this outbreak, multiple lines of evidence implicated Freshway’s shredded romaine lettuce as the outbreak vehicle. First, case-control studies in Michigan and Ohio found significant associations between illness and consumption of Freshway’s romaine lettuce. Second, the romaine lettuce implicated in Michigan and Ohio’s case-control studies was processed at the same Freshway facility that processed lettuce consumed by outbreak cases in New York, Pennsylvania, and Tennessee. Third, an unopened bag of Freshway lettuce that had been distributed from the same Freshway facility to a school in New York tested positive for the outbreak strain of E. coli O145. And finally, another bag of romaine processed at Freshway tested positive for E. coli O145, providing powerful evidence that the Freshway lettuce had experienced a contamination event at some point in the manufacturing process.