E. coli outbreaks linked to lettuce and other leafy green vegetables have happened again and again, particularly over the past decade and a half. Not all have garnered the media attention that the 2006 spinach outbreak did, and some have even gone unreported publicly. Here is a list of lettuce and other leafy green outbreaks since 1993:
1. August 1993 – E. coli O157:H7 outbreak linked to a salad bar; 53 reported cases in Washington State
2. July 1995 – Lettuce (leafy green; red; romaine) E. coli O157:H7; 70 reported cases in Montana
3. September 1995 – Lettuce (romaine) E. coli O157:H7; 20 reported cases in Idaho
4. September 1995 – Lettuce (iceberg) E. coli O157:H7; 30 reported cases in Maine
5. October 1995 – Lettuce (iceberg; unconfirmed) E. coli O157:H7; 11 reported cases in Ohio
6. May-June 1996 – Lettuce (mesclun; red leaf) E. coli O157:H7; 61 reported cases in Connecticut, Illinois, and New York
7. May 1998 – Salad E. coli O157:H7; two reported cases in California
8. February.-March 1999 – Lettuce (iceberg) E. coli O157:H7; 72 reported cases in Nebraska
9. July-August 2002 – Lettuce (romaine) E. coli O157:H7; 29 reported cases in Washington and Idaho
10. October 2003-May 2004 – Lettuce (mixed salad) E. coli O157:H7; 57 reported cases in California
11. April 2004 – Spinach E. coli O157:H7; 16 reported cases in California
12. September 2005 – Lettuce (romaine) E. coli O157:H7; 32 reported cases in Minnesota, Wisconsin, and Oregon
13. September 2006 – Spinach E. coli O157:H7; 205 case (five deaths) nationwide
14. November 2006 – Lettuce E. coli O157:H7; New York, New Jersey, Pennsylvania; 71 sickened
15. December 2006 – Lettuce E. coli O157:H7; Iowa, Minnesota, Wisconsin; 81 ill
16. May 2008 – Lettuce E. coli O157:H7; Washington; 9 ill
On February 5, 2004, the FDA wrote a letter to the produce industry to voice its concern about the frequent outbreaks linked to leafy green and tomato products. In the letter, the FDA counted 14 such outbreaks since 1996 that it had investigated. Among other things, the letter stated:
In view of continuing outbreaks associated with fresh lettuce and fresh tomatoes, we strongly encourage firms in your industries to review their current operations in light of the agency’s guidance for minimizing microbial food safety hazards in fresh lettuce and fresh tomatoes, as well as other available information regarding pathogen reduction or elimination on fresh produce. We further encourage these firms to consider modifying their operations accordingly, to ensure that they are taking the appropriate measures to provide a safe product to the consumer. Since the available information concerning some of the recent outbreaks does not definitively identify the point of origin of the contamination, we recommend that firms from the farm level through the distribution level undertake these steps.
On September 30, 2005, a year and a half after the FDA’s 2004 letter to the lettuce industry, the Minnesota Department of Health issued a press release stating that 11 Minnesota residents had been infected by E. coli O157:H7 from contaminated Dole romaine lettuce. Two days later, the FDA issued a nationwide public health alert regarding Dole pre-packaged salads. Further investigation indicated that 22,321 cases of potentially contaminated Dole romaine lettuce had been sent to market from a processing facility in central California. Ultimately, at least 32 people were sickened in the outbreak.
One month after the 2005 Dole lettuce outbreak, the FDA wrote the industry again. The November 4, 2005 letter began as follows: “This letter is intended to make you aware of the Food and Drug Administration’s (FDA’s) serious concern with the continuing outbreaks of foodborne illness associated with the consumption of fresh and fresh-cut lettuce and other leafy greens.” The letter continued:
FDA is aware of 18 outbreaks of foodborne illness since 1995 caused by Escherichia coli O157:H7 for which fresh or fresh-cut lettuce was implicated as the outbreak vehicle. In one additional case, fresh-cut spinach was implicated. These 19 outbreaks account for approximately 409 reported cases of illness and two deaths. Although tracebacks to growers were not completed in all 19 outbreak investigations, completed traceback investigations of eight of the outbreaks associated with lettuce and spinach, including the most recent lettuce outbreak in Minnesota, were traced back to Salinas, California.