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.

  • keith Warriner

    If it was fresh produce then how can the outbreak be so centered around Hamburg. Although there are cases away from Hamburg most, if not all, had visited the city. Fresh produce outbreaks tend to be more spread.

  • Chuck

    Admittedly I’m a meat head but I’ve been in several plants (Dole, T&A etc.) that produce “pre-washed” produce. Educate me. What gets screwed up that allows E. coli to survive their wash and spin cycle? And is head lettuce safer?

  • Dear Sir, I am missing in this site information on the final results on the analysis of Spanish cucumber which you initially cited as source of the outbreak first, and tainted with EHEC later, during several posts in your blog. And finally they weren’t either. I recommend you reading the interview published on the Spanish newspaper “El Pais” on June 4 to Holger Rhode, a German scientist, probably one of the persons that knows this E. coli best. He declares Spanish cucumbers were unjustly accused. The origin of the disease is in northern Germany; all the cases are related there. The bathes of Spanish cucumbers had been distributed to south east and southwest Germany and even France, and this was known from the start, on May 27th at least. This is not consistent with the site of infection being so located. Just as you precisely updated information on this false track during several days I wish I could read something on the outcome. To err is human, but to recognize the error and correct it and learn from it gains respect from others.

  • I still see that cucumbers, tomatoes and lettuce are still on the menu for likely culprits of this outbreak.
    I am aware that the EHEC found on the cucumbers in Hamburg is not a match to the so called outbreak strain, but that does not mean that cucumbers has been eliminated as the source.
    Hopefully, this will get clearer in the next few days.

  • Here is a very good explanation:
    It was a legitimate call by the Hamburg Health authorities to blow the whistle on Spanish cucumbers.
    Reason 1: All the EHEC-strickened victims have quoted eating raw tomatoes, cucumbers and salads which definitely makes these 3 vegetables prime suspect.
    Reason 2: The German health authorities tested 4 cucumbers out of 1500 samples from vegetables sold in Hamburg and these 4 cucumbers ARE EHEC-infected. But they didn’t know the exact variant yet because it takes at least 4 days to a week to conclusively determine the correct strain is the one (HUS-41) killing the 17 EHEC deaths. 3 of these cucumbers come from Spain and 1 from Netherlands. So the Hamburg health authorities blew the whistle on Spanish cucumbers (knowing that they irrigated their export crops with shit in water fertilizer. It was either wait 1 week, have more people falling sick and dying or pre-alerting them. (That 1 cucumber from Netherlands they knew later after they had blown the whistle.)
    NOTE : the 4 cucumbers ARE EHEC-infected. If they were not even EHEC-infected, I would agree with you at this point.
    Then, the German doctors found out that the particular variant causing the HUS-41 EHEC fatalities is the 0104 EHEC variant/strain.
    Then they had to grow and culture some of it and match with the dead victims and found no, the 4 cucumbers which although are EHEC-infected, do not constitute the deadly 0104 EHEC strain.
    So source of infection is once more open, anybody’s guess which are the actual culprits but the warning of no raw tomatoes, cucumbers and salads still exist. Would you eat these vegetables now, knowing the EHEC-infected victims had eaten these and had fallen sick in due course?
    If you do, you have more guts than me. I won’t.

  • Interesting this dropped into my inbox:
    EHEC: WHO thinks meat is the source
    Via Stern.de: EHEC epidemic: WHO does not believe in guilt of the vegetables. Excerpt from a computer translation, with my editing:
    At first four cucumbers from Spain were identified as the prime suspect. But because they were eliminated as a source for the EHEC pathogens, suspicion fell generally on vegetables, mainly tomatoes, cucumbers and lettuce, as a carrier of the dangerous intestinal germ.
    But now the World Health Organisation (WHO) in Geneva says: The infection with the bacterium had its origin in the meat rather than vegetables.
    The WHO expert Donato Greco told the Italian newspaper La Repubblica: “The virus is found in intestines of cattle and therefore usually in raw meat such as tartar or poorly cooked hamburgers.” He said he had never yet seen such dangerous intestinal bacteria on fruits and vegetables.
    Italian researchers now also exclude plants. Tests have shown that vegetables are not contaminated. But since the source of infection remains unclear, the German authorities keep warning against the consumption of raw vegetables.
    Federal Health Minister Daniel Bahr (FDP) told the “Ruhr Nachrichten”: “It cannot be excluded that the infection source is still active. We must remain vigilant,” because there are still new infections.
    520 people suffer dangerous HU syndrome
    The current number of infected is shocking: The European Food Safety Authority has counted 1,700 cases of EHEC in Germany. 520 people have the serious complication of hemolytic-uremic syndrome (HUS); 70 percent of them are women.
    Outside Germany the pathogen is rampant: in Sweden 46 EHEC infections (15 HUS) have occurred. Most patients had previously been in Germany. The ten patients in France also have direct connections to Germany.

  • Your answer above is very reasonable, and Im happy you clarify it with the note
    ” the 4 cucumbers ARE EHEC-infected. If they were not even EHEC-infected, I would agree with you at this point.”
    Perhaps we finally arrive to an agreement.
    1. As you say, two samples of Malaga’s cucumber were positive to EHEC according to Hamburg, but that doesn’t prove they were contaminated in the production site.
    2. the results of the contradictory analysis initiated by the Spanish authorities on the samples that had tested positive for EHEC were found to be negative (held in Hamburg).
    3. Samples analyzed by the Spanish health authorities during the investigation in the manufacturing industry (90 samples of products, irrigation water and soil) were also negative and were analyzed in the reference laboratory for E. coli in Spain.
    From the outset of the alert the European Commission said that the contamination could have occurred in other post-production. Now we are waiting for Rome to identify the serotype of the first samples where EHEC was found, these results may shed light on this issue.
    4. Signaling in public Spanish cucumbers as the source of the outbreak was not going to aid in anyway to its evolution. Once an alert enters the RASFF system there is an immediate withdrawal and recall of the products and that is responsibility of the food operator, and it was correctly done. The fact is, as I noted in my first comment, the Malaga cucumbers had gone at least to four other location in Germany and no cases where notified in any this places (unless related to previous visit to northern Germany). Not to mention other locations out of Germany
    5. Simply matching on a map the human cases and the distribution of the suspected cucumbers on the 27th was revealing enough to look for other sources and to begin to investigate what had happened in the north of Germany around the second week of May instead and leave a confounding and very unlikely track.
    6. I am not very familiar to cucumber producing, but I will sure try to learn about it. Because Spain has specific regulations on the use of what we call organic fertilizer (you call it shit) and there are requirements related to previous fermentation of the shit to prevent E. coli and other pathogens in it, and also on the timing when it can be applied before the fruit are picked to assure its microbiological safety. And producers keep records on these treatments and of plenty other control points
    I am conscious the situation was and is still very hard on the German authorities and I can understand their initial reaction and it’s not them that I address this comments. I wish the outbreak gets to an end as soon as possible and patients recover well. I just ask for objective information on the outbreak and the alert. Without prejudices.

  • Minkpuppy

    In one of these articles the other day, I read someone quoted as saying that if you trace back far enough in an E. coli outbreak, you’ll find a cow. There’s no doubt that this bug orginated with cattle, the question is how did it get into the food chain. Is it meat or did the produce become contaminated with fecal material somewhere along the way?

    WHO seems to be adamant that it could only be meat as the source when anyone involved in the US spinach outbreak knows cross contamination can occur in produce at the source. What about runoff and wildlife carriers? WAke up, WHO.