2018 E. coli Outbreak Linked to Romaine Lettuce B – Investigation Updates
Final Update
Posted January 9, 2019 at 4:30 PM ET
This outbreak appears to be over. E. coli is an important cause of illness in the United States. More information about E. coli, and steps people can take to reduce their risk of infection, can be found on the E. coli and Food Safety web page.
December 13, 2018
CDC, public health and regulatory officials in several states, Canada, and the FDA are investigating a multistate outbreak of Shiga toxin-producing Escherichia coli O157:H7 (E. coli O157:H7) infections.
As of December 13, 2018, 59 people infected with the outbreak strain of E. coli O157:H7 have been reported from 15 states and the District of Columbia. 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 October 5, 2018 to November 16, 2018. Ill people range in age from 1 to 84 years, with a median age of 26. Sixty-five percent of ill people are female. Of 50 people with information available, 23 (46%) have been hospitalized, including two people who developed hemolytic uremic syndrome, a type of kidney failure. No deaths have been reported.
Illnesses that occurred after November 21, 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, laboratory, and traceback evidence indicates that romaine lettuce from the Central Coastal growing regions of northern and central California 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. Twenty-seven (84%) of 32 people interviewed reported eating romaine lettuce. This percentage is significantly higher than results from a survey [PDF – 787 KB] 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.
Preliminary traceback information from the FDA indicates that ill people in this outbreak ate romaine lettuce harvested from the Central Coastal growing regions of northern and central California. Further information narrowed the number of counties identified in traceback. Based on the evidence available, people should not buy, serve, sell, or eat romaine lettuce from the following California counties: Monterey, San Benito, and Santa Barbara.
The FDA, along with CDC and state partners, is investigating farms and cooling facilities in California that were identified in traceback. CDC analyzed water and sediment samples from Adam Bros. Farming, Inc. farm in Santa Barbara County, California, which was one of the 8 farms identified in traceback. The outbreak strain of E. coli O157:H7 was found in sediment within an agricultural water reservoir located on the farm. Whole genome sequencing results showed that the E. coli O157:H7 found in the agricultural water reservoir was closely related genetically to the E. coli O157:H7 isolated from ill people. FDA is continuing to investigate to learn more about how the E. coli bacteria could have entered the agricultural water reservoir and ways romaine lettuce from the farm could have been contaminated. Romaine lettuce from Adam Bros. Farming, Inc. farm is no longer available for sale.
FDA’s traceback work suggests that additional romaine shipped from other farms could also be implicated in the outbreak. FDA is continuing its investigation.
This investigation is ongoing, and CDC will provide more information as it becomes available.
December 6, 2018
CDC, public health and regulatory officials in several states, Canada, and the FDA are investigating a multistate outbreak of Shiga toxin-producing Escherichia coli O157:H7 (E. coli O157:H7) infections.
As of December 6, 2018, 52 people infected with the outbreak strain of E. coli O157:H7 have been reported from 15 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 October 5, 2018 to November 18, 2018. Ill people range in age from 1 to 84 years, with a median age of 30. Sixty-nine percent of ill people are female. Of 45 people with information available, 19 (42%) have been hospitalized, including two people who developed hemolytic uremic syndrome, a type of kidney failure. No deaths have been reported.
Illnesses that occurred after November 14, 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 and traceback evidence indicates that romaine lettuce from the Central Coastal growing regions of northern and central California 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. Twenty-four (83%) of 29 people interviewed reported eating romaine lettuce. This percentage is significantly higher than results from a survey [PDF – 787 KB] 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.
Preliminary traceback information from the FDA indicates that ill people in this outbreak ate romaine lettuce harvested from the Central Coastal growing regions of northern and central California. The specific California counties FDA identified in the traceback investigation are Monterey, San Benito, San Luis Obispo, Santa Barbara, Santa Cruz, and Ventura. At this time, no common grower, supplier, distributor, or brand of romaine lettuce has been identified.
The FDA, along with CDC and state partners, is investigating farms and cooling facilities in California that were identified in traceback. CDC collected samples of water to test for E. coli O157:H7; these test results are pending.
This investigation is ongoing, and CDC will provide more information as it becomes available.
November 26, 2018
CDC, public health and regulatory officials in several states, Canada, and the FDA are investigating a multistate outbreak of Shiga toxin-producing Escherichia coli O157:H7 (E. coli O157:H7) infections.
As of November 26, 2018, 43 people infected with the outbreak strain of E. coli O157:H7 have been reported from 12 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 October 8, 2018 to October 31, 2018. Ill people range in age from 1 to 84 years, with a median age of 25. Sixty-nine percent of ill people are female. Of 38 people with information available, 16 (42%) have been hospitalized, including one person who developed hemolytic uremic syndrome, a type of kidney failure. No deaths have been reported.
Illnesses that occurred after October 31, 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 and traceback evidence indicates that romaine lettuce from the Central Coastal growing regions of northern and central California 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. Twenty-two (88%) of 25 people interviewed reported eating romaine lettuce. This percentage is significantly higher than results from a survey [PDF – 787 KB] 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.
Preliminary traceback information from the FDA indicates that ill people in this outbreak ate romaine lettuce harvested from the Central Coastal growing regions of northern and central California. At this time, no common grower, supplier, distributor, or brand of romaine lettuce has been identified. CDC is advising that consumers not eat and restaurants and retailers not sell any romaine lettuce from the Central Coastal growing regions of northern and central California.
This investigation is ongoing, and CDC will provide more information as it becomes available.
November 20, 2018
CDC, public health and regulatory officials in several states, Canada, and the FDA are investigating a multistate outbreak of Shiga toxin-producing Escherichia coli O157: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 November 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 October 8, 2018 to October 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%) of 14 people interviewed reported eating romaine lettuce. This percentage is significantly higher than results from a survey [PDF – 787 KB] 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. coli O157: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.
