The US Food and Drug Administration (FDA), the US Centers for Disease Control and Prevention (CDC), the Public Health Agency of Canada (PHAC), the Canadian Food Inspection Agency (CFIA) and various state and provincial agencies are jointly investigating an outbreak of E. coli O157:H7 illnesses in eleven US states and two Canadian provinces.

The genetic strain of E. coli O157:H7 recovered from patients appears to be the same as the strain implicated in a 2017 outbreak of E. coli O157:H7 illnesses linked to leafy greens in the USA and to romaine lettuce in Canada.

The current outbreak appears to be linked to romaine lettuce, based on epidemiological evidence. FDA is conducting lab tests and traceback investigations to determine the source or sources of the lettuce.

CDC reports 32 cases in 11 states: California (10), Connecticut (1), Illinois (2), Massachusetts (2), Maryland (1), Michigan (7), New Hampshire (2), New Jersey (3), New York (2), Ohio (1), and Wisconsin (1). Thirteen people have been hospitalized.

In Canada, confirmed outbreak cases have been reported in Ontario (3) and Quebec (15). Six people have been hospitalized, one of them suffering from hemolytic uremic syndrome (HUS).

The outbreak began in October in both countries, with the onset of the first case in the US on October 6th; the initial cases in Canada developed the week of October 14th. Additional cases are expected in both countries.

CDC is advising U.S. consumers not eat any romaine lettuce, and retailers and restaurants not serve or sell any, until more is learned about the outbreak. The CDC investigation is ongoing and the agency will issue updates as more information is available.

PHAC recommends that consumers in Ontario and Quebec should avoid eating romaine lettuce and salad mixes containing romaine lettuce until more is known about the outbreak and the cause of contamination.

FDA recommends that consumers not eat romaine lettuce or any mixed salads containing romaine, until more information on the source of the contamination and the status of the outbreak can be determined. Consumers are advised to discard any romaine lettuce or mixed salads containing romaine.