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Volume 31, Supplement—May 2025
SUPPLEMENT ISSUE
Supplement
Genomic Characterization of Escherichia coli O157:H7 Associated with Multiple Sources, United States
, Molly M. Leeper, Peyton A. Smith, Michael Vasser, Lee S. Katz, Eshaw Vidyaprakash, Heather A. Carleton, and Jessica C. Chen
Table 1
Outbreaks caused by reoccurring STEC O157:H7 strain REPEXH01 in a genomic characterization of Escherichia coli O157:H7 associated with multiple sources, United States*
| Outbreak | Timeframe | Source† | Origin‡ | No. reported illnesses | No. states | No. HUS cases | No. deaths | No. sequences | Allele differences(range)§ |
|---|---|---|---|---|---|---|---|---|---|
| A | Apr–May 2017 | Unknown | Unknown | 9 | 5 | 0 | 0 | 7 | 3 (0–8) |
| B | Jul–Sep 2017 | Recreational water¶ | California | 10 | 1 | 4 | 0 | 13 | 0 (0) |
| C | Mar–Jun 2018 | Romaine lettuce¶ | Arizona | 238 | 37 | 28 | 5 | 238 | 4 (0–12) |
| D | Aug–Oct 2018 | Ground beef# | Unknown | 12 | 4 | 1 | 0 | 4 | 7 (4–10) |
| E | Oct–Dec 2018 | Leafy greens# | Unknown | 25 | 10 | 4 | 0 | 8 | 7 (1–11) |
| F | May–Oct 2019 | Ground beef# | Unknown | 44 | 12 | 4 | 0 | 44 | 0 (0–5) |
| G | Nov 2019 | Unknown | Unknown | 8 | 1 | 0 | 0 | 8 | 0 (0–1) |
| H | Dec 2020–Mar 2021 | Unknown | Unknown | 22 | 7 | 3 | 1 | 22 | 0 (0–0) |
| I | Apr–May 2021 | Unknown | Unknown | 5 | 3 | 0 | 0 | 5 | 0 (0–1) |
*Outbreak dates are based on reported or estimated illness onset dates. HUS, hemolytic uremic syndrome; REPHEXHO1, recurring strain of STEC O157:H7; STEC, Shiga toxin–producing Escherichia coli. †Confirmed sources were implicated by epidemiologic plus traceback or laboratory data. Suspected sources were implicated by epidemiologic data only (https://www.cdc.gov/foodsafety/outbreaks/multistate-outbreaks/annual-summaries.html). ‡Geographic origin of a confirmed outbreak source might not always be known, which can happen when a food containing multiple ingredients (e.g., bagged salad blend) is confirmed as the source, but the evidence cannot implicate a specific ingredient, or when evidence confirms an outbreak source but traceback cannot pinpoint the exact geographic origin of the source. § Values indicate the median allele differences between the isolates of each respective outbreak. Values in parentheses indicate the range of minimum and maximum allele differences between the isolates of each respective outbreak. ¶Confirmed source. #Suspected source.