The U.S. Food and Drug Administration (FDA), along with the U.S. Centers for Disease Control and Prevention (CDC), state and local agencies, is investigating a multistate outbreak of Escherichia coli O157:H7 illnesses likely linked to romaine lettuce. The Public Health Agency of Canada (PHAC) and Canadian Food Inspection Agency are also coordinating with U.S. agencies as they investigate a similar outbreak in Canada.
Genetic analysis of the E. coli O157:H7 strains tested to date from patients in this current outbreak are similar to strains of E. coli O157:H7 associated with a previous outbreak from the Fall of 2017 that also affected consumers in both Canada and the U.S. The 2017 outbreak of E. coli O157:H7 was associated with leafy greens in the U.S. and romaine in Canada. This year, romaine lettuce is the suspected vehicle for both the U.S. and Canadian outbreaks. There is no genetic link between the current outbreak and the E.coli O157:H7 outbreak linked to romaine that occurred in the Spring of 2018.
The FDA is conducting a traceback investigation to determine the source of the romaine lettuce eaten by people who became sick. Additionally, FDA and states are conducting laboratory analysis of romaine lettuce samples potentially linked to the current outbreak.
The most recent illness onset in the U.S. in the current outbreak was October 31, 2018. For this outbreak investigation, the average interval between when a person becomes ill and when the illness is reported to CDC is 20 days.
Health officials are recommending that people not eat romaine lettuce until more is known about the source of the contaminated lettuce and the status of the outbreak.