Nov 23, 2018E. coli lettuce outbreak ‘likely from California’
The romaine lettuce responsible for an E. coli outbreak that sickened more than 30 people across multiple states likely originated in California, according to Food and Drug Administration commissioner Scott Gottlieb.
Gottlieb said Nov. 23 that the connection to California is based on observed “growing and harvesting patterns.”
“New romaine from different growing regions, including Florida and Arizona, will soon be harvested,” Gottlieb tweeted. “We’re working with growers and distributors on labeling produce for location and harvest date and possibly other ways of informing consumers that the product is ‘post-purge.'”
He also said the FDA is hoping to create a new labeling standard that would require companies to show where lettuce is from and when it is harvested.
The Centers for Disease Control and Prevention (CDC), public health and regulatory officials in several states, Canada, and the FDA said Nov. 20 they are investigating a multi-state outbreak of Shiga toxin-producing Escherichia coliO157:H7 (E. coli O157:H7) infections.
Public health investigators are using the PulseNet system to identify illnesses that may be part of this outbreak. PulseNet is the national subtyping network of public health and food regulatory agency laboratories coordinated by CDC. DNA fingerprinting is performed on E. coli bacteria isolated from ill people by using techniques called pulsed-field gel electrophoresis (PFGE) and whole genome sequencing (WGS). CDC PulseNet manages a national database of these DNA fingerprints to identify possible outbreaks. WGS gives a more detailed DNA fingerprint than PFGE. WGS performed on E. coli bacteria from ill people in this outbreak showed that the strains were closely related genetically. This means that the ill people were more likely to share a common source of infection.
As of Nov. 20, 2018, 32 people infected with the outbreak strain of E. coli O157:H7 have been reported from 11 states. A list of the states and the number of cases in each can be found on the Map of Reported Cases page.
Illnesses started on dates ranging from Oct. 8, 2018 to Oct. 31, 2018. Ill people range in age from 7 to 84 years, with a median age of 24. Sixty-six percent of ill people are female. Of 26 people with information available, 13 (50%) were hospitalized, including one person who developed hemolytic uremic syndrome, a type of kidney failure. No deaths have been reported.
Illnesses that occurred after October 30, 2018, might not yet be reported due to the time it takes between when a person becomes ill with E. coli infection and when the illness is reported. This takes an average of two to three weeks.
Investigation of the outbreak
Epidemiologic evidence indicates that romaine lettuce is a likely source of this outbreak.
In interviews, ill people answered questions about the foods they ate and other exposures in the week before they became ill. Eleven (79 percent) of 14 people interviewed reported eating romaine lettuce. This percentage is significantly higher than results from a survey of healthy people in which 47% reported eating romaine lettuce in the week before they were interviewed. Ill people reported eating different types of romaine lettuce in several restaurants and at home.
Whole genome sequencing (WGS) results showed that the E. coli O157:H7 strain isolated from ill people in this outbreak is closely related genetically to the E. coli strain isolated from ill people in a 2017 outbreak linked to leafy greens in the United States and to romaine lettuce in Canada. The current outbreak is not related to a recent multistate outbreak of E. coli O157:H7 infections linked to romaine lettuce. People in the spring outbreak were infected with E. coliO157:H7 bacteria with a different DNA fingerprint.
FDA and states are working to trace back romaine lettuce that ill people ate in the current outbreak. At this time, no common grower, supplier, distributor, or brand of romaine lettuce has been identified. CDC is advising that consumers not eat any romaine lettuce, and restaurants and retailers not sell any, until we learn more about this outbreak and the source of the contaminated lettuce.
This investigation is ongoing, and CDC will provide more information as it becomes available.