CDC calls latest Romaine E. coli Outbreak over – Not so for the Victims

As of January 9, 2019, 62 people infected with the outbreak strain of E. coli O157:H7 were reported from 16 states and the District of Columbia.

Illnesses started on dates ranging from October 7, 2018, to December 4, 2018. Ill people ranged in age from 1 to 84 years, with a median age of 25. Sixty-six percent of ill people were female. Of 54 people with information available, 25 (46%) were hospitalized, including two people who developed hemolytic uremic syndrome, a type of kidney failure. No deaths were reported.

Epidemiologic, laboratory, and traceback evidence indicated that romaine lettuce from the Central Coastal growing regions of northern and central California was the likely source of this outbreak.Two illness clusters were identified at restaurants where ill people reported eating romaine lettuce. An illness cluster is defined as two or more people who do not live in the same household who report eating at the same restaurant location, attending a common event, or shopping at the same location of a grocery store in the week before becoming ill. In these two clusters, several ill people reported eating at the same restaurant or shopping at the same location of a grocery store. Investigating illness clusters provides critical clues about the source of an outbreak. If several unrelated ill people ate or shopped at the same location of a restaurant or store within several days of each other, it suggests that the contaminated food item was served or sold there.

Traceback information from the FDA indicated that ill people in this outbreak ate romaine lettuce harvested from specific counties in the Central Coastal growing regions of northern and central California. The FDA, along with CDC and state partners, investigated farms and cooling facilities in California that were identified in traceback. CDC analyzed water and sediment samples from an Adam Bros. Farming, Inc. farm in Santa Barbara County, which was one of the farms identified in the traceback investigation. The outbreak strain of E. coli O157:H7 was found in sediment within an agricultural water reservoir on the farm. WGS 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.

WGS results also 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 outbreak described here is not related to a spring 2018 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.

In Canada, as of December 24, 2018, there have been 29 confirmed cases of E. coli illness investigated in Ontario (5), Quebec (20), New Brunswick (1), and British Columbia (3). The illnesses in British Columbia were related to travel to Quebec, Ontario and the United States. Individuals became sick between mid-October and mid-November 2018. Ten individuals have been hospitalized, and two individuals suffered from hemolytic-uremic syndrome (HUS), which is a severe complication that can result from an E. coli infection. No deaths have been reported. Individuals who became ill are between 2 and 93 years of age. The majority of cases (52%) are female.

Republished with permission from Bill Marler and Marler Clark. Copyright (c) Marler Clark LLP, PS. All rights reserved.