An outbreak of E. coli O157:H7 was investigated by the Centers for Disease Control and Prevention (CDC), the US Food and Drug Administration (FDA), and several states from July to August 2022. This outbreak was assigned the CDC code 2208OHEXH-1. A case was defined as a E. coli O157:H7 infection with an isolate closely related to the outbreak strain by cgMLST, with illness onset date (or isolation date if illness onset date unknown) during 7/26/2022 to 8/24/2022.

A total of 109 cases, infected with the outbreak strain of E. coli O157:H7, were reported from 6 states, including Michigan, Ohio, Indiana, Pennsylvania, Kentucky, and New York. Ages ranged from 1 to 94 years (median age 22 years). Of cases with available information, 55% were male. Of 97 cases with information available, 52 were hospitalized and 13 developed hemolytic uremic syndrome (HUS), a serious condition that can cause kidney failure. No deaths were reported. Illnesses ranged from July 26 to August 17, 2022.

State and local public health officials interviewed people about the foods they ate in the week before they got sick. Among 82 people with detailed food histories, 68 (83%) reported eating at a Wendy’s restaurant in the week before their illness started. CDC noted the signal for dining at Wendy’s in this cluster was well above what was expected (around 10%) based on an unpublished analysis they had previously done evaluating exposure to multiple fast-food  restaurant chains. The Wendy’s restaurants where sick people ate were in Indiana, Kentucky, Michigan, New Jersey, Ohio, and Pennsylvania. Additionally, subclusters in other restaurants, grocery stores or other points of sale (POS) were not identified.

People reported eating a variety of menu items, including burgers and sandwiches. Of 68 people with detailed information about what they ate at Wendy’s, 46 (68%) reported eating romaine lettuce served on burgers and sandwiches. Petite romaine lettuce, a smaller head of romaine lettuce, was used on sandwiches and burgers while a chopped romaine product was used to assemble salads at the restaurant.

Most Michigan cases were from two neighboring counties, Kent and Ottawa. Of 22 people with specific restaurant location information, a total of 12 Wendy’s locations were identified. Illness sub-clusters were identified at 2 locations: one in Ottawa County with four ill people and one in Kent County with four ill people. In Ohio, several Wendy’s restaurant locations were reported by cases, and one subcluster was identified in Wood County, with seven people reporting the same location. Several food samples were collected from this Wendy’s. Local environmental health investigators reported this restaurant cycled through products every 3 days and product collected for sampling would not correspond to products served to cases.

Whole-genome sequencing (WGS) showed that bacteria from sick people’s samples were closely related, genetically, within 0 – 2 alleles by cgMLST, and within 0 – 2 SNPs (average: 1) in NCBI. The cluster isolates were closely related (4-7 alleles) to a 2021 multistate outbreak of E. coli O157 (2111MNEXH-1) linked to baby spinach. This suggests that people got sick from eating the same food. While several food items were tested during the outbreak investigation, the outbreak strain was not identified. FDA traced petite romaine lettuce supplied to eight Wendy’s locations in MI, OH, PA and KY where several growers, cooler facilities and distribution centers were identified; convergence was not identified. Given the inconclusive traceback and lack of laboratory evidence, romaine lettuce remains the suspect vehicle for this outbreak.

On August 19, 2022, Wendy’s removed the romaine lettuce being used in burgers and sandwiches at restaurants in states where sick people ate. During the week September 16, Wendy’s replenished the petite romaine lettuce for the restaurants in the region affected by the precautionary withdrawal. CDC closed this investigation on September 30, 2022, after the number of new uploads declined and the outbreak appeared over. This outbreak will be reported to NORS (ID: 2208OHEXH-1) as a multistate foodborne outbreak with petite romaine lettuce as the suspect vehicle.  [1] [2]

E. coli:  Marler Clark, The Food Safety Law Firm, is the nation’s leading law firm representing victims of E. coli outbreaks and hemolytic uremic syndrome (HUS). The E. coli lawyers of Marler Clark have represented thousands of victims of E. coli and other foodborne illness infections and have recovered over $850 million for clients. Marler Clark is the only law firm in the nation with a practice focused exclusively on foodborne illness litigation.  Our E. coli lawyers have litigated E. coli and HUS cases stemming from outbreaks traced to ground beef, raw milk, lettuce, spinach, sprouts, and other food products.  The law firm has brought E. coli lawsuits against such companies as Jack in the Box, Dole, ConAgra, Cargill, and Jimmy John’s.  We have proudly represented such victims as Brianne Kiner, Stephanie Smith and Linda Rivera.

If you or a family member became ill with an E. coli infection or HUS after consuming food and you’re interested in pursuing a legal claim, contact the Marler Clark E. coli attorneys for a free case evaluation.

Additional Resources:

[1]           E. coli Outbreak with Unknown Food Source | CDC

[2]           Investigations of Foodborne Illness Outbreaks | FDA