This strain of E. coli produces a toxin that causes vomiting and diarrhea and potentially other severe symptoms, including kidney failure. Information was available on 129 of the people who were sickened. Of those — ranging in age from 1 to 88 — half have been hospitalized. Seventeen have developed severe kidney failure, and one person in California has died. About 65 percent of those sickened are women.
There is a time lag in reporting and confirming these cases, however. Officials may not yet be aware of people who have gotten sick in the last two or three weeks. The most recent illness reported started April 25.
The outbreak has proved to be a complicated case for federal investigators. They have identified one farm in Yuma, Ariz., as having grown whole-head lettuce linked to cases of food poisoning in an Alaska prison, but they do not know where that lettuce became contaminated.
The rest of the cases involve chopped lettuce that did not come from that Yuma farm, according to the Food and Drug Administration. Many of the people sickened across the country ate chopped lettuce that had been sold in bagged form to restaurants. The bacteria could have contaminated the lettuce at any point in the production process.
“We still continue to go full-bore in trying to identify the source, not only the source of the contamination but also how the contamination actually happened,” Stephen Ostroff, FDA deputy commissioner for foods and veterinary medicine, told The Washington Post.
The CDC is still urging consumers to avoid eating or buying any kind of romaine lettuce from the Yuma region. That region grows the overwhelming majority of the lettuce and other leafy greens consumed in the United States in the winter months through early April. The lettuce season then shifts to California's Central Valley and Salinas Valley. Lettuce from California is not implicated in the outbreak.
Joel Achenbach contributed to this report.