As of June 27, 2018, 210 people infected with the outbreak strain of E. coli O157:H7 were reported from 36 states. A list of the states and the number of cases in each can be found on the Case Count Map page. Illnesses started on dates ranging from March 13, 2018 to June 6, 2018. Ill people ranged in age from 1 to 88 years, with a median age of 28. Sixty-seven percent of ill people were female. Of 201 people with information available, 96 (48%) were hospitalized, including 27 people who developed hemolytic uremic syndrome, a type of kidney failure. Five deaths were reported from Arkansas, California, Minnesota (2), and New York.
WGS analysis of isolates from 184 ill people identified antibiotic resistance to chloramphenicol, streptomycin, sulfisoxazole, tetracycline, and trimethoprim-sulfamethoxazole. Standard antibiotic resistance testing of eight clinical isolates by CDC’s National Antimicrobial Resistance Monitoring System (NARMS) laboratory confirmed these findings. Isolates from four of those ill people also contained genes for resistance to ampicillin and ceftriaxone. These findings do not affect treatment guidance since antibiotics are not recommended for patients with E. coli O157 infections.
Epidemiologic, laboratory, and traceback evidence indicated that romaine lettuce from the Yuma growing region was the likely source of this outbreak.
The FDA and state and local regulatory officials traced the romaine lettuce to many farms in the Yuma growing region. The FDA, along with CDC and state partners, started an environmental assessment in the Yuma growing region and collected samples of water, soil, and manure. CDC laboratory testing identified the outbreak strain of E. coli O157:H7 in water samples taken from a canal in the Yuma growing region. WGS showed that the E. coli O157:H7 found in the canal water is closely related genetically to the E. coli O157:H7 from ill people. Laboratory testing for other environmental samples is continuing. FDA is continuing to investigate to learn more about how the E. coli bacteria could have entered the water and ways this water could have contaminated romaine lettuce in the region.