On Jan. 10, 2018, the U.S. FDA issued a statement indicating it is working with the CDC and state and local authorities in an investigation of an outbreak of Shiga toxin-producing Escherichia coli (E. coli) O157:H7 illnesses. The FDA has also been in contact with Canadian food safety authorities on this outbreak, since cases were first identified in Canada.
Whole genome sequencing showed that the U.S. and Canadian E. coli O157:H7 strains are closely related, suggesting a common source of illness. Canadian health officials identified romaine lettuce as the likely source of their outbreak. CDC has been working to determine the source of the outbreak in the U.S., and recently announced it believes that this outbreak is likely linked to leafy greens. Health officials have not identified a specific type of leafy greens that sick people ate in common.
The known illnesses in the U.S. had illness onsets in late November and early December. According to the agency, this suggests that suspect leafy greens linked to this outbreak are likely no longer in the food supply.
The FDA’s outbreak investigation team is working with CDC and state and local officials to determine what ill people ate, where they bought it, and the distribution chain—all with the goal of reaching where these foods were produced, to see if there’s any common food, or point where the food might have become contaminated. The FDA has currently not identified a common or single point of origin for the food that made people ill.